Merge pull request #90: Refactor compute architecture with workerized ONNX PDF/Whisper pipeline

- Monorepo Architecture: Separates processing into compute/core and compute/worker Fastify service.
- NATS JetStream: Migrates processing queues to NATS JetStream with lazy connection and 120s idle sleep for Railway.
- ONNX PDF Layout: Upgrades to PP-DocLayout-V3 with block overlay UI, force reparse, and block-level skip playback rules.
- ONNX Whisper Alignment: Replaces whisper.cpp with a pure JS ONNX alignment decoder.
- Onboarding Coordinator: Integrates OnboardingFlowContext to manage sequential modals (Privacy, Claim Guest Data, Dexie Cloud Migration).
- Database Schema: Adds documentSettings table and tracks parsing stages (parseState, parsedJsonKey) in the documents table.
- Error Contracts: Standardizes API endpoints on ServerAppError responses.

.env.example

@@ -1,4 +1,10 @@
 
+# Logging
+# pretty (default): human-readable logs
+# json: structured logs for log platforms
+# LOG_FORMAT=pretty
+# LOG_LEVEL=info
+
 # Local / OpenAI TTS API Configuration (default)
 # Suggest using https://github.com/remsky/Kokoro-FastAPI
 #
@@ -77,8 +83,39 @@ RUN_FS_MIGRATIONS=
 IMPORT_LIBRARY_DIR=
 IMPORT_LIBRARY_DIRS=
 
-# (Required without Docker) Path to your local whisper.cpp CLI binary for STT timestamp generation
-WHISPER_CPP_BIN=/whisper.cpp/build/bin/whisper-cli
+# Compute
+# Embedded/local (default): leave COMPUTE_WORKER_URL empty.
+# External worker: set COMPUTE_WORKER_URL + COMPUTE_WORKER_TOKEN.
+# External worker split:
+# - App side (this root `.env`): set only routing/auth + shared timeout/stale overrides.
+# - Worker side (`compute/worker/.env*` or worker platform env): set NATS_*, S3_*, model base URLs, and worker tuning.
+# Details: docs/deploy/compute-worker
+# COMPUTE_WORKER_URL=http://localhost:8081
+# COMPUTE_WORKER_TOKEN=local-compute-token
+# Optional embedded startup controls:
+# EMBEDDED_COMPUTE_WORKER_PORT=8081
+# EMBEDDED_NATS_PORT=4222
+# EMBEDDED_NATS_MONITOR_PORT=8222
+# EMBEDDED_NATS_STORE_DIR=docstore/nats/jetstream
+# `NATS_URL` here is for embedded startup only. In external worker mode, set `NATS_URL` on the worker service env.
+# NATS_URL=nats://127.0.0.1:4222
+# Optional worker log level:
+# COMPUTE_LOG_LEVEL=info
+# Optional shared compute tuning:
+# COMPUTE_JOB_CONCURRENCY=1
+# COMPUTE_WHISPER_TIMEOUT_MS=30000
+# COMPUTE_PDF_TIMEOUT_MS=300000
+# COMPUTE_OP_STALE_MS=1800000
+
+# Optional Whisper ONNX base URL override (must contain all expected files)
+# Default expected Whisper variant is q4:
+# - onnx/encoder_model_q4.onnx
+# - onnx/decoder_model_merged_q4.onnx
+# - onnx/decoder_with_past_model_q4.onnx
+# WHISPER_MODEL_BASE_URL=https://huggingface.co/onnx-community/whisper-base_timestamped/resolve/main
+
+# Optional PDF layout ONNX base URL override (must contain all expected files)
+# PDF_LAYOUT_MODEL_BASE_URL=https://huggingface.co/Bei0001/PP-DocLayoutV3-ONNX/resolve/main
 
 # (Optional) Override ffmpeg binary path used for audiobook processing
 FFMPEG_BIN=
@@ -86,13 +123,12 @@ FFMPEG_BIN=
 # (Optional) Client feature flags — seeded into the admin-managed runtime
 # config on first boot, then ignored. Edit values from Settings → Admin →
 # Site features instead of redeploying. SSR-injected so they take effect
-# without rebuilding (unlike the old NEXT_PUBLIC_* build-time pattern).
-# NEXT_PUBLIC_ENABLE_DOCX_CONVERSION=true
-# NEXT_PUBLIC_ENABLE_DESTRUCTIVE_DELETE_ACTIONS=true
-# NEXT_PUBLIC_ENABLE_TTS_PROVIDERS_TAB=true
-# NEXT_PUBLIC_ENABLE_USER_SIGNUPS=true
-# NEXT_PUBLIC_RESTRICT_USER_API_KEYS=true
-# NEXT_PUBLIC_DEFAULT_TTS_PROVIDER=custom-openai
-# NEXT_PUBLIC_CHANGELOG_FEED_URL=https://docs.openreader.richardr.dev/changelog/manifest.json
-# NEXT_PUBLIC_ENABLE_AUDIOBOOK_EXPORT=true
-# NEXT_PUBLIC_ENABLE_WORD_HIGHLIGHT=true
+# without rebuilding (unlike the old build-time public-env pattern).
+# RUNTIME_SEED_ENABLE_DOCX_CONVERSION=true
+# RUNTIME_SEED_ENABLE_DESTRUCTIVE_DELETE_ACTIONS=true
+# RUNTIME_SEED_ENABLE_TTS_PROVIDERS_TAB=true
+# RUNTIME_SEED_ENABLE_USER_SIGNUPS=true
+# RUNTIME_SEED_RESTRICT_USER_API_KEYS=true
+# RUNTIME_SEED_DEFAULT_TTS_PROVIDER=custom-openai
+# RUNTIME_SEED_CHANGELOG_FEED_URL=https://docs.openreader.richardr.dev/changelog/manifest.json
+# RUNTIME_SEED_ENABLE_AUDIOBOOK_EXPORT=true

.github/workflows/docker-publish.yml

@@ -22,30 +22,17 @@ jobs:
   prepare:
     runs-on: ubuntu-24.04
     outputs:
-      image_name: ${{ steps.image-name.outputs.image_name }}
-      legacy_image_name: ${{ steps.image-name.outputs.legacy_image_name }}
-      tags: ${{ steps.meta.outputs.tags }}
-      labels: ${{ steps.meta.outputs.labels }}
+      web_image_name: ${{ steps.image-name.outputs.web_image_name }}
+      web_legacy_image_name: ${{ steps.image-name.outputs.web_legacy_image_name }}
+      compute_worker_image_name: ${{ steps.image-name.outputs.compute_worker_image_name }}
     steps:
       - name: Compute Docker image names
         id: image-name
         run: |
           owner="${GITHUB_REPOSITORY_OWNER,,}"
-          echo "image_name=${owner}/openreader" >> "$GITHUB_OUTPUT"
-          echo "legacy_image_name=${owner}/openreader-webui" >> "$GITHUB_OUTPUT"
-
-      - name: Extract metadata (tags, labels) for Docker
-        id: meta
-        uses: docker/metadata-action@v6
-        with:
-          images: |
-            ${{ env.REGISTRY }}/${{ steps.image-name.outputs.image_name }}
-            ${{ env.REGISTRY }}/${{ steps.image-name.outputs.legacy_image_name }}
-          tags: |
-            type=raw,value=latest,enable=${{ (github.event_name == 'push' && !contains(github.ref, '-pre')) || (github.event_name == 'workflow_dispatch' && inputs.use_latest_tag == true) }},priority=1000
-            type=semver,pattern={{version}}
-            type=ref,event=tag
-            type=ref,event=branch,enable=${{ github.event_name == 'workflow_dispatch' && inputs.use_latest_tag != true }}
+          echo "web_image_name=${owner}/openreader" >> "$GITHUB_OUTPUT"
+          echo "web_legacy_image_name=${owner}/openreader-webui" >> "$GITHUB_OUTPUT"
+          echo "compute_worker_image_name=${owner}/openreader-compute-worker" >> "$GITHUB_OUTPUT"
 
   build:
     needs: prepare
@@ -58,12 +45,30 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - arch: amd64
+          - image_target: web
+            arch: amd64
             platform: linux/amd64
             runner: ubuntu-24.04
-          - arch: arm64
+            context: .
+            dockerfile: ./Dockerfile
+          - image_target: web
+            arch: arm64
             platform: linux/arm64
             runner: ubuntu-24.04-arm
+            context: .
+            dockerfile: ./Dockerfile
+          - image_target: compute-worker
+            arch: amd64
+            platform: linux/amd64
+            runner: ubuntu-24.04
+            context: .
+            dockerfile: ./compute/worker/Dockerfile
+          - image_target: compute-worker
+            arch: arm64
+            platform: linux/arm64
+            runner: ubuntu-24.04-arm
+            context: .
+            dockerfile: ./compute/worker/Dockerfile
 
     steps:
       - name: Checkout repository
@@ -82,46 +87,63 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
-      - name: Build and push Docker image (${{ matrix.arch }})
+      - name: Select image name
+        id: image
+        run: |
+          if [ "${{ matrix.image_target }}" = "web" ]; then
+            echo "image_name=${{ needs.prepare.outputs.web_image_name }}" >> "$GITHUB_OUTPUT"
+          else
+            echo "image_name=${{ needs.prepare.outputs.compute_worker_image_name }}" >> "$GITHUB_OUTPUT"
+          fi
+
+      - name: Build and push Docker image (${{ matrix.image_target }} / ${{ matrix.arch }})
         id: build
         uses: docker/build-push-action@v7
         with:
-          context: .
+          context: ${{ matrix.context }}
+          file: ${{ matrix.dockerfile }}
           platforms: ${{ matrix.platform }}
-          labels: ${{ needs.prepare.outputs.labels }}
-          cache-from: type=gha,scope=${{ matrix.arch }}
-          cache-to: type=gha,mode=max,scope=${{ matrix.arch }}
+          cache-from: type=gha,scope=${{ matrix.image_target }}-${{ matrix.arch }}
+          cache-to: type=gha,mode=max,scope=${{ matrix.image_target }}-${{ matrix.arch }}
           provenance: false
-          outputs: type=image,name=${{ env.REGISTRY }}/${{ needs.prepare.outputs.image_name }},push-by-digest=true,name-canonical=true,push=true
+          outputs: type=image,name=${{ env.REGISTRY }}/${{ steps.image.outputs.image_name }},push-by-digest=true,name-canonical=true,push=true
 
       - name: Export digest
         run: |
-          mkdir -p /tmp/digests
+          mkdir -p /tmp/digests/${{ matrix.image_target }}
           digest="${{ steps.build.outputs.digest }}"
-          touch "/tmp/digests/${digest#sha256:}"
+          touch "/tmp/digests/${{ matrix.image_target }}/${digest#sha256:}"
 
       - name: Upload digest
         uses: actions/upload-artifact@v7
         with:
-          name: digests-${{ matrix.arch }}
-          path: /tmp/digests
+          name: digests-${{ matrix.image_target }}-${{ matrix.arch }}
+          path: /tmp/digests/${{ matrix.image_target }}
           if-no-files-found: error
           retention-days: 1
 
   merge:
     needs: [prepare, build]
-    runs-on: ubuntu-24.04
+    runs-on: ${{ matrix.runner }}
     permissions:
       actions: read
       contents: read
       packages: write
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - image_target: web
+            runner: ubuntu-24.04
+          - image_target: compute-worker
+            runner: ubuntu-24.04
 
     steps:
       - name: Download digests
         uses: actions/download-artifact@v8
         with:
-          path: /tmp/digests
-          pattern: digests-*
+          path: /tmp/digests/${{ matrix.image_target }}
+          pattern: digests-${{ matrix.image_target }}-*
           merge-multiple: true
 
       - name: Set up Docker Buildx
@@ -134,20 +156,46 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
+      - name: Select image names
+        id: image
+        run: |
+          if [ "${{ matrix.image_target }}" = "web" ]; then
+            echo "image_name=${{ needs.prepare.outputs.web_image_name }}" >> "$GITHUB_OUTPUT"
+            echo "metadata_images<<EOF" >> "$GITHUB_OUTPUT"
+            echo "${{ env.REGISTRY }}/${{ needs.prepare.outputs.web_image_name }}" >> "$GITHUB_OUTPUT"
+            echo "${{ env.REGISTRY }}/${{ needs.prepare.outputs.web_legacy_image_name }}" >> "$GITHUB_OUTPUT"
+            echo "EOF" >> "$GITHUB_OUTPUT"
+          else
+            echo "image_name=${{ needs.prepare.outputs.compute_worker_image_name }}" >> "$GITHUB_OUTPUT"
+            echo "metadata_images=${{ env.REGISTRY }}/${{ needs.prepare.outputs.compute_worker_image_name }}" >> "$GITHUB_OUTPUT"
+          fi
+
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@v6
+        with:
+          images: ${{ steps.image.outputs.metadata_images }}
+          tags: |
+            type=raw,value=latest,enable=${{ (github.event_name == 'push' && !contains(github.ref, '-pre')) || (github.event_name == 'workflow_dispatch' && inputs.use_latest_tag == true) }},priority=1000
+            type=semver,pattern={{version}}
+            type=ref,event=tag
+            type=ref,event=branch,enable=${{ github.event_name == 'workflow_dispatch' && inputs.use_latest_tag != true }}
+
       - name: Create manifest list and push
-        working-directory: /tmp/digests
+        working-directory: /tmp/digests/${{ matrix.image_target }}
         run: |
           docker buildx imagetools create \
             $(echo "$TAGS" | xargs -I {} echo -t {}) \
-            $(printf '${{ env.REGISTRY }}/${{ needs.prepare.outputs.image_name }}@sha256:%s ' *)
+            $(printf '${{ env.REGISTRY }}/${{ steps.image.outputs.image_name }}@sha256:%s ' *)
         env:
-          TAGS: ${{ needs.prepare.outputs.tags }}
+          TAGS: ${{ steps.meta.outputs.tags }}
 
       - name: Output build information
         run: |
-          echo "✅ Docker images built and pushed successfully!"
+          echo "✅ Docker image built and pushed successfully!"
+          echo "🐋 Target: ${{ matrix.image_target }}"
           echo "🐋 Images:"
-          echo '${{ needs.prepare.outputs.tags }}' | sed 's/^/  - /'
+          echo '${{ steps.meta.outputs.tags }}' | sed 's/^/  - /'
           echo "📝 Event: ${{ github.event_name }}"
           if [ "${{ github.event_name }}" == "workflow_dispatch" ]; then
             echo "📝 Triggered by manual workflow dispatch on branch: ${{ github.ref_name }}"

.github/workflows/playwright.yml

@@ -34,8 +34,19 @@ jobs:
         sudo install -m 0755 ./weed /usr/local/bin/weed
         rm -f ./weed
         weed version
+    - name: Install NATS server binary
+      run: |
+        curl -fsSL -o /tmp/nats-server.tar.gz \
+          https://github.com/nats-io/nats-server/releases/download/v2.12.1/nats-server-v2.12.1-linux-amd64.tar.gz
+        tar -xzf /tmp/nats-server.tar.gz -C /tmp
+        sudo install -m 0755 /tmp/nats-server-v2.12.1-linux-amd64/nats-server /usr/local/bin/nats-server
+        nats-server -v
     - name: Install dependencies
       run: pnpm install --frozen-lockfile
+    - name: Build app and enforce bundle guard
+      run: |
+        pnpm build
+        pnpm build:bundle-guard
     - name: Verify ffprobe
       run: ffprobe -version
     - name: Install Playwright Browsers

.gitignore

@@ -33,7 +33,9 @@ yarn-error.log*
 
 # env files (can opt-in for committing if needed)
 .env
+.env.prod
 .dockerignore
+*.creds
 
 # vercel
 .vercel

Dockerfile

@@ -1,24 +1,14 @@
-# Stage 1: build whisper.cpp (no model download – the app handles that)
-FROM alpine:3.23 AS whisper-builder
-
-RUN apk add --no-cache git cmake build-base
-
-WORKDIR /opt
-
-ARG TARGETARCH
-
-RUN git clone --depth 1 https://github.com/ggml-org/whisper.cpp.git && \
-    cd whisper.cpp && \
-    cmake -S . -B build -DCMAKE_BUILD_TYPE=Release -DGGML_NATIVE=OFF $( [ "$TARGETARCH" = "arm64" ] && echo "-DGGML_CPU_ARM_ARCH=armv8-a" || true ) && \
-    cmake --build build -j
-
-# Stage 1b: extract seaweedfs weed binary (for optional embedded weed mini)
+# Stage 1: extract seaweedfs weed binary (for optional embedded weed mini)
 # Pin to 4.18 because CI observed upload regressions on 4.19.
 FROM chrislusf/seaweedfs:4.18 AS seaweedfs-builder
 RUN cp "$(command -v weed)" /tmp/weed && \
     (wget -qO /tmp/SeaweedFS-LICENSE.txt "https://raw.githubusercontent.com/seaweedfs/seaweedfs/master/LICENSE" || \
      wget -qO /tmp/SeaweedFS-LICENSE.txt "https://raw.githubusercontent.com/seaweedfs/seaweedfs/main/LICENSE")
 
+# Stage 1b: extract nats-server binary for embedded single-container worker mode.
+FROM nats:2.11-alpine AS nats-builder
+RUN cp "$(command -v nats-server)" /tmp/nats-server
+
 
 # Stage 2: build the Next.js app
 FROM node:lts-alpine AS app-builder
@@ -29,8 +19,10 @@ RUN npm install -g pnpm@11.1.2
 # Create app directory
 WORKDIR /app
 
-# Copy package files
+# Copy workspace manifests needed for dependency installation
 COPY package.json pnpm-lock.yaml pnpm-workspace.yaml ./
+COPY compute/core/package.json ./compute/core/package.json
+COPY compute/worker/package.json ./compute/worker/package.json
 
 # Install dependencies
 RUN pnpm install --frozen-lockfile
@@ -59,29 +51,30 @@ FROM node:lts-alpine AS runner
 # ffmpeg is provided by ffmpeg-static from node_modules.
 RUN apk add --no-cache ca-certificates libreoffice-writer
 
-# Install pnpm globally for running the app
-RUN npm install -g pnpm@11.1.2
+# Install pnpm for runtime process commands.
+RUN npm install -g pnpm@10.33.4
 
 # App runtime directory
 WORKDIR /app
 
-# Copy built app and dependencies from the builder stage
+# Copy built app and runtime files from the builder stage (non-standalone runtime).
 COPY --from=app-builder /app ./
 # Include third-party license report and copied license texts at a stable path in the image.
 COPY --from=app-builder /app/THIRD_PARTY_LICENSES /licenses
 # Include SeaweedFS license text for the copied weed binary.
 COPY --from=seaweedfs-builder /tmp/SeaweedFS-LICENSE.txt /licenses/SeaweedFS-LICENSE.txt
+# Include static model notices for runtime-downloaded assets.
+COPY --from=app-builder /app/compute/core/src/pdf/assets/LICENSE.txt /licenses/pp-doclayoutv3-LICENSE.txt
 
-# Copy the compiled whisper.cpp build output into the runtime image
-# (includes whisper-cli and its shared libraries, e.g. libwhisper.so, libggml.so)
-COPY --from=whisper-builder /opt/whisper.cpp/build /opt/whisper.cpp/build
 # Copy seaweedfs weed binary for optional embedded local S3.
 COPY --from=seaweedfs-builder /tmp/weed /usr/local/bin/weed
 RUN chmod +x /usr/local/bin/weed
+# Copy nats-server binary for embedded local JetStream.
+COPY --from=nats-builder /tmp/nats-server /usr/local/bin/nats-server
+RUN chmod +x /usr/local/bin/nats-server
 
-# Point the app at the compiled whisper-cli binary and ensure its libs are discoverable
-ENV WHISPER_CPP_BIN=/opt/whisper.cpp/build/bin/whisper-cli
-ENV LD_LIBRARY_PATH=/opt/whisper.cpp/build
+# Include OpenAI Whisper license text for runtime-downloaded ONNX artifacts.
+COPY --from=app-builder /app/compute/core/src/whisper/assets/LICENSE.txt /licenses/openai-whisper-LICENSE.txt
 
 # Expose the port the app runs on
 EXPOSE 3003

README.md

@@ -18,13 +18,13 @@ OpenReader is an open source, self-host-friendly text-to-speech document reader
 
 ## ✨ Highlights
 
-- 🎯 **Multi-provider TTS** with OpenAI-compatible endpoints and cloud providers (Kokoro-FastAPI, KittenTTS-FastAPI, Orpheus-FastAPI or OpenAI, Replicate, DeepInfra).
-- 📖 **Read-along playback** for PDF/EPUB with sentence-aware narration.
-- ⏱️ **Word-by-word highlighting** via optional `whisper.cpp` timestamps.
-- 🛜 **Sync + library import** to bring docs across devices and from server-mounted folders.
-- 🗂️ **Flexible storage** with embedded SeaweedFS or external S3-compatible backends.
+- 🧱 **Layout-aware PDF parsing** with PP-DocLayoutV3 (ONNX) — structured block detection, cross-page stitching, and geometry-based highlighting for precise read-along sync.
+- ⏱️ **Word-by-word highlighting** via ONNX Whisper alignment through the compute worker control plane (NATS JetStream-backed).
+- ⚡ **Segment-based read-along** for EPUB, PDF, TXT, MD, and DOCX — sentence-aware TTS with cached audio segments, background preloading, and resumable playback.
+- 🎯 **Multi-provider TTS** — self-hosted OpenAI-compatible servers (Kokoro-FastAPI, KittenTTS-FastAPI, Orpheus-FastAPI) or cloud APIs (OpenAI, Replicate, DeepInfra).
 - 🎧 **Audiobook export** in `m4b`/`mp3` with resumable chapter processing.
-- 🐳 **Self-host friendly** with Docker, optional auth, and automatic startup migrations.
+- 🗂️ **Flexible backend** — embedded SeaweedFS or S3-compatible storage, SQLite or Postgres, server library import, and device sync.
+- 🐳 **Self-host friendly** — Docker (amd64/arm64), optional auth, and automatic startup migrations.
 
 ## 🚀 Start Here
 
@@ -32,6 +32,7 @@ OpenReader is an open source, self-host-friendly text-to-speech document reader
 | --- | --- |
 | Run with Docker | [Docker Quick Start](https://docs.openreader.richardr.dev/docker-quick-start) |
 | Deploy on Vercel | [Vercel Deployment](https://docs.openreader.richardr.dev/deploy/vercel-deployment) |
+| Deploy external compute worker | [Compute Worker (NATS JetStream)](https://docs.openreader.richardr.dev/deploy/compute-worker) |
 | Develop locally | [Local Development](https://docs.openreader.richardr.dev/deploy/local-development) |
 | Configure auth | [Auth](https://docs.openreader.richardr.dev/configure/auth) |
 | Configure SQL database | [Database and Migrations](https://docs.openreader.richardr.dev/configure/database) |

compute/core/package.json

@@ -0,0 +1,21 @@
+{
+  "name": "@openreader/compute-core",
+  "version": "0.0.0",
+  "private": true,
+  "type": "module",
+  "dependencies": {
+    "@huggingface/tokenizers": "^0.1.3",
+    "@napi-rs/canvas": "^0.1.100",
+    "ffmpeg-static": "^5.3.0",
+    "jszip": "^3.10.1",
+    "onnxruntime-node": "^1.26.0",
+    "pdfjs-dist": "4.8.69"
+  },
+  "exports": {
+    ".": "./src/index.ts",
+    "./local-runtime": "./src/local-runtime.ts",
+    "./api-contracts": "./src/api-contracts/index.ts",
+    "./control-plane": "./src/control-plane/index.ts",
+    "./types": "./src/types/index.ts"
+  }
+}

compute/core/src/api-contracts/index.ts

@@ -0,0 +1,120 @@
+import type { TTSSentenceAlignment } from '../types/tts';
+import type { ParsedPdfDocument } from '../types/parsed-pdf';
+
+export type {
+  TTSAudioBuffer,
+  TTSAudioBytes,
+  TTSSentenceAlignment,
+  TTSSentenceWord,
+} from '../types/tts';
+export type {
+  ParsedPdfBlockKind,
+  ParsedPdfBlockFragment,
+  ParsedPdfBlock,
+  ParsedPdfPage,
+  ParsedPdfDocument,
+} from '../types/parsed-pdf';
+
+export const ALIGN_QUEUE_NAME = 'whisper-align';
+export const PDF_LAYOUT_QUEUE_NAME = 'pdf-layout';
+
+export interface WhisperAlignJobBase {
+  text: string;
+  lang?: string;
+  cacheKey?: string;
+}
+
+export interface WhisperAlignJobRequest extends WhisperAlignJobBase {
+  audioObjectKey: string;
+}
+
+export interface WhisperAlignJobResult {
+  alignments: TTSSentenceAlignment[];
+  timing?: WorkerJobTiming;
+}
+
+export interface PdfLayoutJobBase {
+  documentId: string;
+  namespace: string | null;
+}
+
+export interface PdfLayoutJobRequest extends PdfLayoutJobBase {
+  documentObjectKey: string;
+}
+
+export type PdfLayoutJobResult =
+  | {
+    parsed: ParsedPdfDocument;
+    parsedObjectKey?: never;
+    timing?: WorkerJobTiming;
+  }
+  | {
+    parsed?: never;
+    parsedObjectKey: string;
+    timing?: WorkerJobTiming;
+  };
+
+export type WorkerJobState = 'queued' | 'running' | 'succeeded' | 'failed';
+
+export interface WorkerJobErrorShape {
+  message: string;
+  code?: string;
+}
+
+export interface WorkerJobTiming {
+  queueWaitMs?: number;
+  s3FetchMs?: number;
+  computeMs?: number;
+}
+
+export type PdfLayoutProgressPhase = 'infer' | 'merge';
+
+export interface PdfLayoutProgress {
+  totalPages: number;
+  pagesParsed: number;
+  currentPage?: number;
+  phase: PdfLayoutProgressPhase;
+}
+
+export interface WorkerJobStatusResponse<Result> {
+  status: WorkerJobState;
+  result?: Result;
+  error?: WorkerJobErrorShape;
+  timing?: WorkerJobTiming;
+}
+
+export type WorkerOperationKind = 'whisper_align' | 'pdf_layout';
+
+export interface WhisperAlignOperationRequest {
+  kind: 'whisper_align';
+  opKey: string;
+  payload: WhisperAlignJobRequest;
+}
+
+export interface PdfLayoutOperationRequest {
+  kind: 'pdf_layout';
+  opKey: string;
+  payload: PdfLayoutJobRequest;
+}
+
+export type WorkerOperationRequest = WhisperAlignOperationRequest | PdfLayoutOperationRequest;
+
+export interface WorkerOperationState<Result = unknown> {
+  opId: string;
+  opKey: string;
+  kind: WorkerOperationKind;
+  jobId: string;
+  status: WorkerJobState;
+  queuedAt: number;
+  updatedAt: number;
+  startedAt?: number;
+  result?: Result;
+  error?: WorkerJobErrorShape;
+  timing?: WorkerJobTiming;
+  progress?: PdfLayoutProgress;
+}
+
+export interface WorkerOperationEvent<Result = unknown> {
+  eventId: number;
+  snapshot: WorkerOperationState<Result>;
+}

compute/core/src/config/cpu-budget.ts

@@ -0,0 +1,28 @@
+import os from 'node:os';
+
+function readPositiveInt(name: string, fallback: number): number {
+  const raw = process.env[name]?.trim();
+  if (!raw) return fallback;
+  const parsed = Number(raw);
+  if (!Number.isFinite(parsed) || parsed <= 0) return fallback;
+  return Math.floor(parsed);
+}
+
+export function getComputeJobConcurrency(): number {
+  return readPositiveInt('COMPUTE_JOB_CONCURRENCY', 1);
+}
+
+export function getAvailableCpuCores(): number {
+  if (typeof os.availableParallelism === 'function') {
+    const value = os.availableParallelism();
+    if (Number.isFinite(value) && value >= 1) return Math.floor(value);
+  }
+  const fallback = os.cpus().length;
+  return Number.isFinite(fallback) && fallback >= 1 ? Math.floor(fallback) : 1;
+}
+
+export function getOnnxThreadsPerJob(): number {
+  const concurrency = getComputeJobConcurrency();
+  const usableCores = Math.max(1, getAvailableCpuCores() - 1);
+  return Math.max(1, Math.floor(usableCores / concurrency));
+}

compute/core/src/config/timeout.ts

@@ -0,0 +1,119 @@
+const DEFAULT_COMPUTE_WHISPER_TIMEOUT_MS = 30_000;
+const DEFAULT_COMPUTE_PDF_TIMEOUT_MS = 300_000;
+const DEFAULT_COMPUTE_PDF_HARD_CAP_MS = 24 * 60 * 60 * 1000;
+const DEFAULT_COMPUTE_OP_STALE_MIN_MS = 30 * 60_000;
+const DEFAULT_WORKER_WAIT_BUFFER_MS = 15_000;
+const DEFAULT_WORKER_WAIT_MIN_MS = 60_000;
+
+export type ComputeTimeoutConfig = {
+  whisperTimeoutMs: number;
+  pdfTimeoutMs: number;
+  pdfHardCapMs: number;
+};
+
+export type ComputeOperationKind = 'whisper_align' | 'pdf_layout';
+export type IdleTimeoutAndHardCapInput<T> = {
+  run: (touchProgress: () => void) => Promise<T>;
+  idleTimeoutMs: number;
+  hardCapMs: number;
+  label: string;
+};
+
+function readPositiveIntEnv(name: string, fallback: number): number {
+  const raw = process.env[name]?.trim();
+  if (!raw) return fallback;
+  const parsed = Number(raw);
+  if (!Number.isFinite(parsed) || parsed <= 0) return fallback;
+  return Math.floor(parsed);
+}
+
+let timeoutConfigCache: ComputeTimeoutConfig | null = null;
+let opStaleMsCache: number | null = null;
+
+export function getComputeTimeoutConfig(): ComputeTimeoutConfig {
+  if (timeoutConfigCache) return timeoutConfigCache;
+  timeoutConfigCache = {
+    whisperTimeoutMs: readPositiveIntEnv('COMPUTE_WHISPER_TIMEOUT_MS', DEFAULT_COMPUTE_WHISPER_TIMEOUT_MS),
+    pdfTimeoutMs: readPositiveIntEnv('COMPUTE_PDF_TIMEOUT_MS', DEFAULT_COMPUTE_PDF_TIMEOUT_MS),
+    pdfHardCapMs: DEFAULT_COMPUTE_PDF_HARD_CAP_MS,
+  };
+  return timeoutConfigCache;
+}
+
+export function getComputeOpStaleMs(): number {
+  if (typeof opStaleMsCache === 'number') return opStaleMsCache;
+  const config = getComputeTimeoutConfig();
+  opStaleMsCache = readPositiveIntEnv(
+    'COMPUTE_OP_STALE_MS',
+    Math.max(DEFAULT_COMPUTE_OP_STALE_MIN_MS, Math.max(config.whisperTimeoutMs, config.pdfTimeoutMs) * 4),
+  );
+  return opStaleMsCache;
+}
+
+export function getWorkerClientWaitTimeoutMs(kind: ComputeOperationKind): number {
+  const config = getComputeTimeoutConfig();
+  const timeoutMs = kind === 'pdf_layout' ? config.pdfTimeoutMs : config.whisperTimeoutMs;
+  return Math.max(DEFAULT_WORKER_WAIT_MIN_MS, timeoutMs + DEFAULT_WORKER_WAIT_BUFFER_MS);
+}
+
+export async function withTimeout<T>(promise: Promise<T>, timeoutMs: number, label: string): Promise<T> {
+  let timer: NodeJS.Timeout | null = null;
+  try {
+    return await Promise.race([
+      promise,
+      new Promise<T>((_, reject) => {
+        timer = setTimeout(() => reject(new Error(`${label} timed out after ${timeoutMs}ms`)), timeoutMs);
+      }),
+    ]);
+  } finally {
+    if (timer) clearTimeout(timer);
+  }
+}
+
+export async function withIdleTimeoutAndHardCap<T>(input: IdleTimeoutAndHardCapInput<T>): Promise<T> {
+  let idleTimer: NodeJS.Timeout | null = null;
+  let hardCapTimer: NodeJS.Timeout | null = null;
+  let settled = false;
+  let rejectTimeout!: (reason: unknown) => void;
+
+  const clearTimers = () => {
+    if (idleTimer) {
+      clearTimeout(idleTimer);
+      idleTimer = null;
+    }
+    if (hardCapTimer) {
+      clearTimeout(hardCapTimer);
+      hardCapTimer = null;
+    }
+  };
+
+  const failTimeout = (kind: 'idle' | 'hard cap', timeoutMs: number) => {
+    if (settled) return;
+    settled = true;
+    clearTimers();
+    rejectTimeout(new Error(`${input.label} ${kind} timed out after ${timeoutMs}ms`));
+  };
+
+  const touchProgress = () => {
+    if (settled) return;
+    if (idleTimer) clearTimeout(idleTimer);
+    idleTimer = setTimeout(() => failTimeout('idle', input.idleTimeoutMs), input.idleTimeoutMs);
+  };
+
+  const timeoutPromise = new Promise<never>((_, reject) => {
+    rejectTimeout = reject;
+    hardCapTimer = setTimeout(() => failTimeout('hard cap', input.hardCapMs), input.hardCapMs);
+    touchProgress();
+  });
+
+  try {
+    const result = await Promise.race([input.run(touchProgress), timeoutPromise]);
+    settled = true;
+    clearTimers();
+    return result as T;
+  } catch (error) {
+    settled = true;
+    clearTimers();
+    throw error;
+  }
+}

compute/core/src/control-plane/in-memory.ts

@@ -0,0 +1,139 @@
+import { EventEmitter } from 'node:events';
+import type {
+  OperationEvent,
+  OperationEventStream,
+  OperationIndexEntry,
+  OperationQueue,
+  OperationState,
+  OperationStateStore,
+  QueuedOperation,
+} from './types';
+import type { WorkerOperationKind } from '../api-contracts';
+
+function topicFor(opId: string): string {
+  return `op.${opId}`;
+}
+
+function normalizeSinceEventId(value: number | undefined): number {
+  if (!Number.isFinite(value ?? 0)) return 0;
+  return Math.max(0, Math.floor(value ?? 0));
+}
+
+export class InMemoryOperationQueue implements OperationQueue {
+  private readonly byKind = new Map<WorkerOperationKind, QueuedOperation[]>();
+
+  constructor() {
+    this.byKind.set('whisper_align', []);
+    this.byKind.set('pdf_layout', []);
+  }
+
+  async enqueue(job: QueuedOperation): Promise<void> {
+    const list = this.byKind.get(job.kind);
+    if (!list) throw new Error(`Unsupported operation kind: ${job.kind}`);
+    list.push(job);
+  }
+
+  async claimNext(kind: WorkerOperationKind): Promise<QueuedOperation | null> {
+    const list = this.byKind.get(kind);
+    if (!list || list.length === 0) return null;
+    return list.shift() ?? null;
+  }
+
+  size(kind?: WorkerOperationKind): number {
+    if (kind) return this.byKind.get(kind)?.length ?? 0;
+    let total = 0;
+    for (const list of this.byKind.values()) total += list.length;
+    return total;
+  }
+}
+
+export class InMemoryOperationStateStore implements OperationStateStore {
+  private readonly stateByOpId = new Map<string, OperationState>();
+  private readonly opIndexByKey = new Map<string, string>();
+
+  async getOpState(opId: string): Promise<OperationState | null> {
+    return this.stateByOpId.get(opId) ?? null;
+  }
+
+  async putOpState(state: OperationState): Promise<void> {
+    this.stateByOpId.set(state.opId, state);
+  }
+
+  async getOpIndex(opKey: string): Promise<OperationIndexEntry | null> {
+    const opId = this.opIndexByKey.get(opKey);
+    return opId ? { opId } : null;
+  }
+
+  async compareAndSetOpIndex(input: {
+    opKey: string;
+    newOpId: string;
+    expectedOpId: string | null;
+  }): Promise<boolean> {
+    const current = this.opIndexByKey.get(input.opKey) ?? null;
+    if (current !== input.expectedOpId) return false;
+    this.opIndexByKey.set(input.opKey, input.newOpId);
+    return true;
+  }
+}
+
+export class InMemoryOperationEventStream implements OperationEventStream {
+  private readonly emitter = new EventEmitter();
+  private readonly lastIdByOpId = new Map<string, number>();
+  private readonly eventsByOpId = new Map<string, OperationEvent[]>();
+
+  constructor() {
+    this.emitter.setMaxListeners(0);
+  }
+
+  async append(opId: string, snapshot: OperationState): Promise<OperationEvent> {
+    const nextEventId = (this.lastIdByOpId.get(opId) ?? 0) + 1;
+    this.lastIdByOpId.set(opId, nextEventId);
+
+    const event: OperationEvent = {
+      eventId: nextEventId,
+      snapshot,
+    };
+
+    const list = this.eventsByOpId.get(opId) ?? [];
+    list.push(event);
+    this.eventsByOpId.set(opId, list);
+    this.emitter.emit(topicFor(opId), event);
+    return event;
+  }
+
+  async listSince(opId: string, sinceEventId: number, limit?: number): Promise<OperationEvent[]> {
+    const list = this.eventsByOpId.get(opId) ?? [];
+    const normalizedSince = normalizeSinceEventId(sinceEventId);
+    const filtered = list.filter((event) => event.eventId > normalizedSince);
+    if (!Number.isFinite(limit ?? 0) || !limit || limit <= 0) return filtered;
+    return filtered.slice(0, Math.floor(limit));
+  }
+
+  async subscribe(input: {
+    opId: string;
+    sinceEventId?: number;
+    onEvent: (event: OperationEvent) => void | Promise<void>;
+    onError?: (error: unknown) => void;
+  }): Promise<() => void> {
+    const replay = await this.listSince(input.opId, normalizeSinceEventId(input.sinceEventId));
+    for (const event of replay) {
+      try {
+        await input.onEvent(event);
+      } catch (error) {
+        input.onError?.(error);
+      }
+    }
+
+    const listener = (event: OperationEvent): void => {
+      Promise.resolve(input.onEvent(event)).catch((error) => {
+        input.onError?.(error);
+      });
+    };
+
+    const topic = topicFor(input.opId);
+    this.emitter.on(topic, listener);
+    return () => {
+      this.emitter.off(topic, listener);
+    };
+  }
+}

compute/core/src/control-plane/index.ts

@@ -0,0 +1,5 @@
+export * from './types';
+export * from './state-machine';
+export * from './orchestrator';
+export * from './in-memory';
+export * from './sse';

compute/core/src/control-plane/orchestrator.ts

@@ -0,0 +1,288 @@
+import { randomUUID } from 'node:crypto';
+import type {
+  WorkerJobErrorShape,
+  WorkerJobTiming,
+  WorkerOperationKind,
+  WorkerOperationRequest,
+  WorkerOperationState,
+} from '../api-contracts';
+import {
+  buildQueuedState,
+  createErrorShape,
+  explainReplacementReason,
+  isTerminalStatus,
+  shouldReuseExistingOperation,
+} from './state-machine';
+import type {
+  OperationClock,
+  OperationEventStream,
+  OperationIdFactory,
+  OperationLifecycleConfig,
+  OperationQueue,
+  OperationStateStore,
+  QueuedOperation,
+} from './types';
+
+const RETRY_DELAY_MS = 25;
+
+function sleep(ms: number): Promise<void> {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+export interface OperationOrchestratorDeps {
+  queue: OperationQueue;
+  stateStore: OperationStateStore;
+  eventStream: OperationEventStream;
+  config: OperationLifecycleConfig;
+  clock?: OperationClock;
+  idFactory?: OperationIdFactory;
+}
+
+export class OperationOrchestrator {
+  private readonly queue: OperationQueue;
+  private readonly stateStore: OperationStateStore;
+  private readonly eventStream: OperationEventStream;
+  private readonly opStaleMs: number;
+  private readonly maxCasRetries: number;
+  private readonly clock: OperationClock;
+  private readonly ids: OperationIdFactory;
+
+  constructor(deps: OperationOrchestratorDeps) {
+    this.queue = deps.queue;
+    this.stateStore = deps.stateStore;
+    this.eventStream = deps.eventStream;
+    this.opStaleMs = deps.config.opStaleMs;
+    this.maxCasRetries = Math.max(1, Math.floor(deps.config.maxCasRetries ?? 10));
+    this.clock = deps.clock ?? { now: () => Date.now() };
+    this.ids = deps.idFactory ?? {
+      opId: () => randomUUID(),
+      jobId: () => randomUUID(),
+    };
+  }
+
+  private async persistState(state: WorkerOperationState): Promise<void> {
+    await this.stateStore.putOpState(state);
+    await this.eventStream.append(state.opId, state);
+  }
+
+  private buildQueuedJob(state: WorkerOperationState, request: WorkerOperationRequest): QueuedOperation {
+    return {
+      jobId: state.jobId,
+      opId: state.opId,
+      opKey: state.opKey,
+      kind: state.kind,
+      queuedAt: state.queuedAt,
+      payload: request.payload,
+    };
+  }
+
+  async enqueueOrReuse(request: WorkerOperationRequest): Promise<WorkerOperationState> {
+    const opKey = request.opKey.trim();
+
+    for (let attempt = 0; attempt < this.maxCasRetries; attempt += 1) {
+      const indexEntry = await this.stateStore.getOpIndex(opKey);
+      if (indexEntry?.opId) {
+        const current = await this.stateStore.getOpState(indexEntry.opId);
+        if (!current) {
+          await sleep(RETRY_DELAY_MS);
+          continue;
+        }
+
+        const now = this.clock.now();
+        if (shouldReuseExistingOperation({
+          current,
+          requestKind: request.kind,
+          now,
+          opStaleMs: this.opStaleMs,
+        })) {
+          return current;
+        }
+
+        const replacement = buildQueuedState({
+          request,
+          opId: this.ids.opId(),
+          jobId: this.ids.jobId(),
+          queuedAt: now,
+        });
+
+        const replaced = await this.stateStore.compareAndSetOpIndex({
+          opKey,
+          newOpId: replacement.opId,
+          expectedOpId: indexEntry.opId,
+        });
+        if (!replaced) {
+          await sleep(RETRY_DELAY_MS);
+          continue;
+        }
+
+        await this.persistState(replacement);
+
+        try {
+          await this.queue.enqueue(this.buildQueuedJob(replacement, request));
+          return replacement;
+        } catch (error) {
+          const failed: WorkerOperationState = {
+            ...replacement,
+            status: 'failed',
+            updatedAt: this.clock.now(),
+            error: createErrorShape(error),
+          };
+          await this.persistState(failed);
+          return failed;
+        }
+      }
+
+      const now = this.clock.now();
+      const created = buildQueuedState({
+        request,
+        opId: this.ids.opId(),
+        jobId: this.ids.jobId(),
+        queuedAt: now,
+      });
+
+      const createdIndex = await this.stateStore.compareAndSetOpIndex({
+        opKey,
+        newOpId: created.opId,
+        expectedOpId: null,
+      });
+      if (!createdIndex) {
+        await sleep(RETRY_DELAY_MS);
+        continue;
+      }
+
+      await this.persistState(created);
+
+      try {
+        await this.queue.enqueue(this.buildQueuedJob(created, request));
+        return created;
+      } catch (error) {
+        const failed: WorkerOperationState = {
+          ...created,
+          status: 'failed',
+          updatedAt: this.clock.now(),
+          error: createErrorShape(error),
+        };
+        await this.persistState(failed);
+        return failed;
+      }
+    }
+
+    throw new Error('Unable to reserve operation after repeated CAS conflicts');
+  }
+
+  async getState(opId: string): Promise<WorkerOperationState | null> {
+    return this.stateStore.getOpState(opId);
+  }
+
+  async markRunning(input: {
+    opId: string;
+    startedAt?: number;
+    updatedAt?: number;
+    timing?: WorkerJobTiming;
+  }): Promise<WorkerOperationState> {
+    const current = await this.requireState(input.opId);
+    const now = input.updatedAt ?? this.clock.now();
+
+    const next: WorkerOperationState = {
+      ...current,
+      status: 'running',
+      startedAt: input.startedAt ?? current.startedAt ?? now,
+      updatedAt: now,
+      ...(input.timing ? { timing: input.timing } : {}),
+    };
+
+    await this.persistState(next);
+    return next;
+  }
+
+  async markProgress(input: {
+    opId: string;
+    progress: WorkerOperationState['progress'];
+    updatedAt?: number;
+    timing?: WorkerJobTiming;
+  }): Promise<WorkerOperationState> {
+    const current = await this.requireState(input.opId);
+    const now = input.updatedAt ?? this.clock.now();
+
+    const next: WorkerOperationState = {
+      ...current,
+      status: 'running',
+      startedAt: current.startedAt ?? now,
+      updatedAt: now,
+      progress: input.progress,
+      ...(input.timing ? { timing: input.timing } : {}),
+    };
+
+    await this.persistState(next);
+    return next;
+  }
+
+  async markSucceeded(input: {
+    opId: string;
+    result: unknown;
+    updatedAt?: number;
+    timing?: WorkerJobTiming;
+  }): Promise<WorkerOperationState> {
+    const current = await this.requireState(input.opId);
+    const now = input.updatedAt ?? this.clock.now();
+
+    const next: WorkerOperationState = {
+      ...current,
+      status: 'succeeded',
+      startedAt: current.startedAt ?? now,
+      updatedAt: now,
+      result: input.result,
+      ...(input.timing ? { timing: input.timing } : {}),
+    };
+
+    await this.persistState(next);
+    return next;
+  }
+
+  async markFailed(input: {
+    opId: string;
+    error: WorkerJobErrorShape | string;
+    updatedAt?: number;
+    timing?: WorkerJobTiming;
+  }): Promise<WorkerOperationState> {
+    const current = await this.requireState(input.opId);
+    const now = input.updatedAt ?? this.clock.now();
+
+    const shape = typeof input.error === 'string' ? { message: input.error } : input.error;
+
+    const next: WorkerOperationState = {
+      ...current,
+      status: 'failed',
+      startedAt: current.startedAt ?? now,
+      updatedAt: now,
+      error: shape,
+      ...(input.timing ? { timing: input.timing } : {}),
+    };
+
+    await this.persistState(next);
+    return next;
+  }
+
+  async explainReuseDecision(input: {
+    current: WorkerOperationState;
+    requestKind: WorkerOperationKind;
+  }): Promise<string> {
+    return explainReplacementReason({
+      current: input.current,
+      requestKind: input.requestKind,
+      now: this.clock.now(),
+      opStaleMs: this.opStaleMs,
+    });
+  }
+
+  private async requireState(opId: string): Promise<WorkerOperationState> {
+    const current = await this.stateStore.getOpState(opId);
+    if (!current) {
+      throw new Error(`Operation not found: ${opId}`);
+    }
+    if (isTerminalStatus(current.status)) {
+      return current;
+    }
+    return current;
+  }
+}

compute/core/src/control-plane/sse.ts

@@ -0,0 +1,49 @@
+export interface SseFrameInput<T = unknown> {
+  event?: string;
+  id?: string | number;
+  data?: T;
+  comment?: string;
+}
+
+export function encodeSseFrame<T = unknown>(input: SseFrameInput<T>): string {
+  const lines: string[] = [];
+  if (typeof input.comment === 'string') {
+    lines.push(`: ${input.comment}`);
+  }
+  if (typeof input.id !== 'undefined') {
+    lines.push(`id: ${String(input.id)}`);
+  }
+  if (typeof input.event === 'string' && input.event.trim()) {
+    lines.push(`event: ${input.event}`);
+  }
+  if (typeof input.data !== 'undefined') {
+    const serialized = typeof input.data === 'string' ? input.data : JSON.stringify(input.data);
+    for (const line of serialized.replace(/\r\n/g, '\n').split('\n')) {
+      lines.push(`data: ${line}`);
+    }
+  }
+  return `${lines.join('\n')}\n\n`;
+}
+
+export function parseSsePayload(frame: string): string | null {
+  const lines = frame.replace(/\r\n/g, '\n').split('\n');
+  const dataLines: string[] = [];
+  for (const line of lines) {
+    if (!line.startsWith('data:')) continue;
+    dataLines.push(line.slice('data:'.length).trimStart());
+  }
+  return dataLines.length > 0 ? dataLines.join('\n') : null;
+}
+
+export function parseSseEventId(frame: string): number | null {
+  const lines = frame.replace(/\r\n/g, '\n').split('\n');
+  for (const line of lines) {
+    if (!line.startsWith('id:')) continue;
+    const value = Number(line.slice('id:'.length).trim());
+    if (Number.isFinite(value) && value > 0) {
+      return Math.floor(value);
+    }
+  }
+  return null;
+}
+

compute/core/src/control-plane/state-machine.ts

@@ -0,0 +1,65 @@
+import type {
+  WorkerJobErrorShape,
+  WorkerJobState,
+  WorkerOperationKind,
+  WorkerOperationRequest,
+  WorkerOperationState,
+} from '../api-contracts';
+
+export function isTerminalStatus(status: WorkerJobState): boolean {
+  return status === 'succeeded' || status === 'failed';
+}
+
+export function isInflightStatus(status: WorkerJobState): boolean {
+  return status === 'queued' || status === 'running';
+}
+
+export function createErrorShape(error: unknown): WorkerJobErrorShape {
+  if (error && typeof error === 'object' && 'message' in error && typeof (error as { message: unknown }).message === 'string') {
+    return { message: (error as { message: string }).message };
+  }
+  return { message: String(error) };
+}
+
+export function buildQueuedState(input: {
+  request: WorkerOperationRequest;
+  opId: string;
+  jobId: string;
+  queuedAt: number;
+}): WorkerOperationState {
+  return {
+    opId: input.opId,
+    opKey: input.request.opKey,
+    kind: input.request.kind,
+    jobId: input.jobId,
+    status: 'queued',
+    queuedAt: input.queuedAt,
+    updatedAt: input.queuedAt,
+  };
+}
+
+export function explainReplacementReason(input: {
+  current: WorkerOperationState;
+  requestKind: WorkerOperationKind;
+  now: number;
+  opStaleMs: number;
+}): string {
+  if (input.current.kind !== input.requestKind) return 'kind_mismatch';
+  const ageMs = input.now - input.current.updatedAt;
+  if (isInflightStatus(input.current.status) && ageMs > input.opStaleMs) return 'stale_running';
+  if (input.current.status === 'failed') return 'failed_prior';
+  return `status_${input.current.status}`;
+}
+
+export function shouldReuseExistingOperation(input: {
+  current: WorkerOperationState;
+  requestKind: WorkerOperationKind;
+  now: number;
+  opStaleMs: number;
+}): boolean {
+  if (input.current.kind !== input.requestKind) return false;
+  if (input.current.status === 'succeeded') return true;
+  if (!isInflightStatus(input.current.status)) return false;
+  const ageMs = input.now - input.current.updatedAt;
+  return ageMs <= input.opStaleMs;
+}

compute/core/src/control-plane/types.ts

@@ -0,0 +1,63 @@
+import type {
+  WorkerOperationEvent,
+  WorkerOperationKind,
+  WorkerOperationState,
+} from '../api-contracts';
+
+export type OperationState<Result = unknown> = WorkerOperationState<Result>;
+export type OperationEvent<Result = unknown> = WorkerOperationEvent<Result>;
+
+export interface QueuedOperation<TPayload = unknown> {
+  jobId: string;
+  opId: string;
+  opKey: string;
+  kind: WorkerOperationKind;
+  queuedAt: number;
+  payload: TPayload;
+}
+
+export interface OperationQueue<TPayload = unknown> {
+  enqueue(job: QueuedOperation<TPayload>): Promise<void>;
+  claimNext(kind: WorkerOperationKind): Promise<QueuedOperation<TPayload> | null>;
+  size(kind?: WorkerOperationKind): number;
+}
+
+export interface OperationIndexEntry {
+  opId: string;
+}
+
+export interface OperationStateStore<Result = unknown> {
+  getOpState(opId: string): Promise<OperationState<Result> | null>;
+  putOpState(state: OperationState<Result>): Promise<void>;
+  getOpIndex(opKey: string): Promise<OperationIndexEntry | null>;
+  compareAndSetOpIndex(input: {
+    opKey: string;
+    newOpId: string;
+    expectedOpId: string | null;
+  }): Promise<boolean>;
+}
+
+export interface OperationEventStream<Result = unknown> {
+  append(opId: string, snapshot: OperationState<Result>): Promise<OperationEvent<Result>>;
+  listSince(opId: string, sinceEventId: number, limit?: number): Promise<OperationEvent<Result>[]>;
+  subscribe(input: {
+    opId: string;
+    sinceEventId?: number;
+    onEvent: (event: OperationEvent<Result>) => void | Promise<void>;
+    onError?: (error: unknown) => void;
+  }): Promise<() => void>;
+}
+
+export interface OperationClock {
+  now(): number;
+}
+
+export interface OperationIdFactory {
+  opId(): string;
+  jobId(): string;
+}
+
+export interface OperationLifecycleConfig {
+  opStaleMs: number;
+  maxCasRetries?: number;
+}

compute/core/src/index.ts

@@ -0,0 +1,24 @@
+export * from './api-contracts';
+export {
+  getComputeJobConcurrency,
+  getAvailableCpuCores,
+  getOnnxThreadsPerJob,
+} from './config/cpu-budget';
+export {
+  getComputeTimeoutConfig,
+  getComputeOpStaleMs,
+  getWorkerClientWaitTimeoutMs,
+  withTimeout,
+  withIdleTimeoutAndHardCap,
+  type ComputeTimeoutConfig,
+  type ComputeOperationKind,
+  type IdleTimeoutAndHardCapInput,
+} from './config/timeout';
+export { renderPage } from './pdf/render';
+export { mergeTextWithRegions } from './pdf/merge';
+export { stitchCrossPageBlocks } from './pdf/stitch';
+export { normalizeTextItemsForLayout } from './pdf/normalize-text';
+export { mapWordsToSentenceOffsets, type WhisperWord } from './whisper/alignment-map';
+export { buildGoertzelCoefficients, goertzelPower } from './whisper/spectral';
+export { buildWordsFromTimestampedTokens, extractTokenStartTimestamps } from './whisper/token-timestamps';
+export * from './control-plane';

compute/core/src/local-runtime.ts

@@ -0,0 +1,40 @@
+import { ensureWhisperModel } from './whisper/model';
+import { alignAudioWithText } from './whisper/align';
+import { ensureModel as ensurePdfLayoutModel } from './pdf/model';
+import { parsePdf } from './pdf/parse';
+
+export async function ensureComputeModels(): Promise<void> {
+  await Promise.all([ensureWhisperModel(), ensurePdfLayoutModel()]);
+}
+
+export async function runWhisperAlignmentFromAudioBuffer(input: {
+  audioBuffer: ArrayBuffer;
+  text: string;
+  cacheKey?: string;
+  lang?: string;
+}) {
+  const alignments = await alignAudioWithText(
+    input.audioBuffer,
+    input.text,
+    input.cacheKey,
+    { lang: input.lang },
+  );
+  return { alignments };
+}
+
+export async function runPdfLayoutFromPdfBuffer(input: {
+  documentId: string;
+  pdfBytes: ArrayBuffer;
+  onPageParsed?: (input: {
+    pageNumber: number;
+    totalPages: number;
+    pageMs: number;
+  }) => void | Promise<void>;
+}) {
+  const parsed = await parsePdf({
+    documentId: input.documentId,
+    pdfBytes: input.pdfBytes,
+    onPageParsed: input.onPageParsed,
+  });
+  return { parsed };
+}

compute/core/src/pdf/assets/LICENSE.txt

@@ -0,0 +1,3 @@
+PP-DocLayoutV3 ONNX model assets are distributed by the model publisher under Apache-2.0.
+See upstream for the authoritative license and terms:
+https://huggingface.co/Bei0001/PP-DocLayoutV3-ONNX

compute/core/src/pdf/assets/manifest.json

@@ -0,0 +1,31 @@
+{
+  "name": "pp-doclayoutv3",
+  "version": "Bei0001/PP-DocLayoutV3-ONNX@main",
+  "files": [
+    {
+      "path": "model.onnx",
+      "sha256": "c0721928ff08741bb208ebed539c77170db5234a68cb7e546e6cc9bc172a695b",
+      "size": 5088167
+    },
+    {
+      "path": "model.onnx.data",
+      "sha256": "34df3e4b79d7bbbf82abce1b4f3cde3d540fa57ad42ec8905c352b97c408d437",
+      "size": 136774480
+    },
+    {
+      "path": "config.json",
+      "sha256": "3cf834b91d23a756b1519bce4db42c09e852f3e35c35092dd5a3e253a50c071a",
+      "size": 2460
+    },
+    {
+      "path": "preprocessor_config.json",
+      "sha256": "519fe0187a43a1ca429e3ad8317bab8700f0d5e8fb3a6e3a0a413ffac078ba42",
+      "size": 575
+    },
+    {
+      "path": "LICENSE.txt",
+      "sha256": "578a6ba6f86b0692a8f719843f575a3eebf4705768ac5c37d149f441208f601f",
+      "size": 195
+    }
+  ]
+}

compute/core/src/pdf/merge.ts

@@ -0,0 +1,153 @@
+import type { LayoutRegion, PdfTextItem } from './types';
+
+const NON_TEXT_REGION_LABELS = new Set<LayoutRegion['label']>(['chart', 'image', 'table', 'seal']);
+const TEXT_ASSIGNABLE_LABELS = new Set<LayoutRegion['label']>([
+  'abstract',
+  'algorithm',
+  'aside_text',
+  'content',
+  'doc_title',
+  'figure_title',
+  'footer',
+  'footnote',
+  'formula_number',
+  'header',
+  'number',
+  'paragraph_title',
+  'reference',
+  'reference_content',
+  'text',
+  'vision_footnote',
+  'formula',
+]);
+
+function centroid(item: PdfTextItem): { x: number; y: number } {
+  return {
+    x: item.x + item.width / 2,
+    y: item.y + item.height / 2,
+  };
+}
+
+function contains(region: LayoutRegion, item: PdfTextItem): boolean {
+  const c = centroid(item);
+  return c.x >= region.bbox[0] && c.x <= region.bbox[2] && c.y >= region.bbox[1] && c.y <= region.bbox[3];
+}
+
+function sortReadingOrder(items: PdfTextItem[]): PdfTextItem[] {
+  const tolerance = 2;
+  return [...items].sort((a, b) => {
+    if (Math.abs(a.y - b.y) <= tolerance) return a.x - b.x;
+    return a.y - b.y;
+  });
+}
+
+function joinText(items: PdfTextItem[]): string {
+  let out = '';
+  let prev: PdfTextItem | null = null;
+  for (const item of items) {
+    if (!prev) {
+      out += item.text;
+      prev = item;
+      continue;
+    }
+    const prevEndX = prev.x + prev.width;
+    const gap = item.x - prevEndX;
+    const lineJump = item.y - prev.y;
+    const lineBreak = lineJump > Math.max(2, Math.min(prev.height, item.height) * 0.6);
+    const avgCharWidth = item.width / Math.max(1, item.text.length);
+    const needsSpace = lineBreak || gap > Math.max(avgCharWidth * 0.3, 2);
+    out += needsSpace ? ` ${item.text}` : item.text;
+    prev = item;
+  }
+  return out.replace(/\s+/g, ' ').trim();
+}
+
+function regionArea(region: LayoutRegion): number {
+  return Math.max(1, (region.bbox[2] - region.bbox[0]) * (region.bbox[3] - region.bbox[1]));
+}
+
+function regionScore(region: LayoutRegion): number {
+  return Number.isFinite(region.confidence) ? Number(region.confidence) : 0;
+}
+
+export interface RegionTextBlock {
+  region: LayoutRegion;
+  text: string;
+  items: PdfTextItem[];
+  sourceOrder: number;
+}
+
+export function mergeTextWithRegions(regions: LayoutRegion[], textItems: PdfTextItem[]): RegionTextBlock[] {
+  const sourceIndex = new Map<PdfTextItem, number>();
+  for (let i = 0; i < textItems.length; i += 1) {
+    sourceIndex.set(textItems[i]!, i);
+  }
+
+  const chunkSourceOrder = (items: PdfTextItem[]): number => {
+    let min = Number.POSITIVE_INFINITY;
+    for (const item of items) {
+      const index = sourceIndex.get(item);
+      if (typeof index === 'number' && index < min) min = index;
+    }
+    return Number.isFinite(min) ? min : Number.MAX_SAFE_INTEGER;
+  };
+
+  const assignableRegions = regions
+    .map((region, index) => ({ region, index }))
+    .filter(({ region }) => TEXT_ASSIGNABLE_LABELS.has(region.label));
+  const assignedByRegion = new Map<number, PdfTextItem[]>();
+
+  for (const item of textItems) {
+    const candidates = assignableRegions.filter(({ region }) => contains(region, item));
+    if (candidates.length === 0) continue;
+
+    candidates.sort((a, b) => {
+      const scoreDelta = regionScore(b.region) - regionScore(a.region);
+      if (Math.abs(scoreDelta) > 1e-6) return scoreDelta;
+      return regionArea(a.region) - regionArea(b.region);
+    });
+
+    const winner = candidates[0];
+    const list = assignedByRegion.get(winner.index) ?? [];
+    list.push(item);
+    assignedByRegion.set(winner.index, list);
+  }
+
+  const out: RegionTextBlock[] = [];
+
+  for (const [regionIndex, assignedItems] of assignedByRegion.entries()) {
+    const region = regions[regionIndex];
+    if (!region) continue;
+    if (assignedItems.length === 0) continue;
+    const ordered = sortReadingOrder(assignedItems);
+    const text = joinText(ordered);
+    if (!text) continue;
+
+    out.push({
+      region,
+      text,
+      items: ordered,
+      sourceOrder: chunkSourceOrder(ordered),
+    });
+  }
+
+  for (const region of regions) {
+    if (!NON_TEXT_REGION_LABELS.has(region.label)) continue;
+    out.push({
+      region,
+      text: '',
+      items: [],
+      sourceOrder: Number.MAX_SAFE_INTEGER,
+    });
+  }
+
+  out.sort((a, b) => {
+    if (a.sourceOrder !== b.sourceOrder) return a.sourceOrder - b.sourceOrder;
+    const ay = a.region.bbox[1];
+    const by = b.region.bbox[1];
+    if (Math.abs(ay - by) <= 2) return a.region.bbox[0] - b.region.bbox[0];
+    return ay - by;
+  });
+
+  return out;
+}

compute/core/src/pdf/model.ts

@@ -0,0 +1,147 @@
+import path from 'path';
+import { fileURLToPath } from 'url';
+import { createHash } from 'crypto';
+import { readFileSync } from 'fs';
+import { access, mkdir, rename, writeFile, readFile, unlink, copyFile } from 'fs/promises';
+import { DOCSTORE_DIR } from '../platform/docstore';
+
+const DEFAULT_MODEL_BASE_URL = 'https://huggingface.co/Bei0001/PP-DocLayoutV3-ONNX/resolve/main';
+const PDF_LAYOUT_MODEL_BASE_URL_ENV = 'PDF_LAYOUT_MODEL_BASE_URL';
+const MODULE_DIR = path.dirname(fileURLToPath(import.meta.url));
+const MODEL_DIR = path.join(DOCSTORE_DIR, 'model');
+const MANIFEST_PATH = path.join(MODULE_DIR, 'assets', 'manifest.json');
+export const MODEL_PATH = path.join(MODEL_DIR, 'PP-DocLayoutV3.onnx');
+export const MODEL_DATA_PATH = path.join(MODEL_DIR, 'PP-DocLayoutV3.onnx.data');
+export const MODEL_CONFIG_PATH = path.join(MODEL_DIR, 'pp-doclayoutv3.config.json');
+export const MODEL_PREPROCESSOR_PATH = path.join(MODEL_DIR, 'pp-doclayoutv3.preprocessor_config.json');
+const LICENSE_PATH = path.join(MODEL_DIR, 'pp-doclayoutv3.LICENSE.txt');
+const STATIC_LICENSE_PATH = path.join(MODULE_DIR, 'assets', 'LICENSE.txt');
+
+type ManifestEntry = {
+  path: string;
+  sha256?: string;
+  size?: number;
+};
+
+function loadManifest(): { files: ManifestEntry[] } {
+  const manifestText = readFileSync(MANIFEST_PATH, 'utf8');
+  const parsed = JSON.parse(manifestText) as { files?: ManifestEntry[] };
+  return { files: Array.isArray(parsed.files) ? parsed.files : [] };
+}
+
+const manifest = loadManifest();
+
+let inflight: Promise<string> | null = null;
+
+async function sha256Hex(filePath: string): Promise<string> {
+  const bytes = await readFile(filePath);
+  return createHash('sha256').update(bytes).digest('hex');
+}
+
+async function downloadToFile(url: string, outPath: string): Promise<void> {
+  const res = await fetch(url);
+  if (!res.ok) {
+    throw new Error(`Download failed for ${url}: ${res.status} ${res.statusText}`);
+  }
+  const bytes = new Uint8Array(await res.arrayBuffer());
+  await writeFile(outPath, bytes);
+}
+
+function joinModelUrl(baseUrl: string, relativePath: string): string {
+  return `${baseUrl.replace(/\/+$/, '')}/${relativePath}`;
+}
+
+function manifestEntry(filePath: string): { sha256: string; size: number } | null {
+  const found = manifest.files.find((entry) => entry.path === filePath);
+  if (!found || !found.sha256) return null;
+  return {
+    sha256: found.sha256.toLowerCase(),
+    size: Number(found.size),
+  };
+}
+
+async function verifyFile(pathToFile: string, manifestPath: string): Promise<boolean> {
+  const expected = manifestEntry(manifestPath);
+  if (!expected) return true;
+  const bytes = await readFile(pathToFile);
+  if (Number.isFinite(expected.size) && expected.size > 0 && bytes.byteLength !== expected.size) {
+    return false;
+  }
+  const actual = await sha256Hex(pathToFile);
+  return actual === expected.sha256;
+}
+
+async function ensureLicense(): Promise<void> {
+  await copyFile(STATIC_LICENSE_PATH, LICENSE_PATH);
+  if (!(await verifyFile(LICENSE_PATH, 'LICENSE.txt'))) {
+    throw new Error('PDF layout model license checksum verification failed');
+  }
+}
+
+async function ensureModelInternal(): Promise<string> {
+  try {
+    await access(MODEL_PATH);
+    await access(MODEL_DATA_PATH);
+    await access(MODEL_CONFIG_PATH);
+    await access(MODEL_PREPROCESSOR_PATH);
+    if (
+      await verifyFile(MODEL_PATH, 'model.onnx')
+      && await verifyFile(MODEL_DATA_PATH, 'model.onnx.data')
+      && await verifyFile(MODEL_CONFIG_PATH, 'config.json')
+      && await verifyFile(MODEL_PREPROCESSOR_PATH, 'preprocessor_config.json')
+    ) {
+      await ensureLicense();
+      return MODEL_PATH;
+    }
+  } catch {
+    // continue
+  }
+
+  await mkdir(MODEL_DIR, { recursive: true });
+  const modelTmpPath = `${MODEL_PATH}.tmp`;
+  const modelDataTmpPath = `${MODEL_DATA_PATH}.tmp`;
+  const configTmpPath = `${MODEL_CONFIG_PATH}.tmp`;
+  const preprocessorTmpPath = `${MODEL_PREPROCESSOR_PATH}.tmp`;
+  const modelBaseUrl = process.env[PDF_LAYOUT_MODEL_BASE_URL_ENV]?.trim()
+    || DEFAULT_MODEL_BASE_URL;
+  const modelUrl = joinModelUrl(modelBaseUrl, 'PP-DocLayoutV3.onnx');
+  const modelDataUrl = joinModelUrl(modelBaseUrl, 'PP-DocLayoutV3.onnx.data');
+  const configUrl = joinModelUrl(modelBaseUrl, 'config.json');
+  const preprocessorUrl = joinModelUrl(modelBaseUrl, 'preprocessor_config.json');
+
+  await downloadToFile(modelUrl, modelTmpPath);
+  if (!(await verifyFile(modelTmpPath, 'model.onnx'))) {
+    await unlink(modelTmpPath).catch(() => undefined);
+    throw new Error('PDF layout model checksum verification failed');
+  }
+  await downloadToFile(modelDataUrl, modelDataTmpPath);
+  if (!(await verifyFile(modelDataTmpPath, 'model.onnx.data'))) {
+    await unlink(modelDataTmpPath).catch(() => undefined);
+    throw new Error('PDF layout model external data checksum verification failed');
+  }
+  await downloadToFile(configUrl, configTmpPath);
+  if (!(await verifyFile(configTmpPath, 'config.json'))) {
+    await unlink(configTmpPath).catch(() => undefined);
+    throw new Error('PDF layout model config checksum verification failed');
+  }
+  await downloadToFile(preprocessorUrl, preprocessorTmpPath);
+  if (!(await verifyFile(preprocessorTmpPath, 'preprocessor_config.json'))) {
+    await unlink(preprocessorTmpPath).catch(() => undefined);
+    throw new Error('PDF layout model preprocessor checksum verification failed');
+  }
+
+  await rename(modelTmpPath, MODEL_PATH);
+  await rename(modelDataTmpPath, MODEL_DATA_PATH);
+  await rename(configTmpPath, MODEL_CONFIG_PATH);
+  await rename(preprocessorTmpPath, MODEL_PREPROCESSOR_PATH);
+  await ensureLicense();
+  return MODEL_PATH;
+}
+
+export async function ensureModel(): Promise<string> {
+  if (inflight) return inflight;
+  inflight = ensureModelInternal().finally(() => {
+    inflight = null;
+  });
+  return inflight;
+}

compute/core/src/pdf/normalize-text.ts

@@ -0,0 +1,35 @@
+import type { TextItem } from 'pdfjs-dist/types/src/display/api';
+import type { PdfTextItem } from './types';
+
+export function normalizeTextItemsForLayout(items: TextItem[], pageHeight: number): PdfTextItem[] {
+  return items
+    .filter((item) => {
+      if (!(typeof item.str === 'string' && item.str.trim().length > 0)) return false;
+      const transform = item.transform;
+      if (!Array.isArray(transform) || transform.length < 6) return false;
+
+      // Reject heavily skewed/rotated text runs (e.g. vertical margin labels
+      // such as arXiv metadata) so they do not get merged into body blocks.
+      const skewX = Number(transform[1] ?? 0);
+      const skewY = Number(transform[2] ?? 0);
+      if (Math.abs(skewX) > 0.5 || Math.abs(skewY) > 0.5) return false;
+
+      return true;
+    })
+    .map((item) => {
+      const x = Number(item.transform[4] ?? 0);
+      const width = Math.max(0, Number(item.width ?? 0));
+      const height = Math.max(1, Math.abs(Number(item.transform[3] ?? 1)));
+      const baselineY = Number(item.transform[5] ?? 0);
+      // pdf.js text transforms are in PDF user-space (origin bottom-left).
+      // Normalize into top-left page coordinates to match rendered image/model boxes.
+      const y = Math.max(0, pageHeight - baselineY - height);
+      return {
+        text: item.str,
+        x,
+        y,
+        width,
+        height,
+      };
+    });
+}

compute/core/src/pdf/parse.ts

@@ -0,0 +1,150 @@
+import path from 'path';
+import type { TextItem } from 'pdfjs-dist/types/src/display/api';
+import type { ParsedPdfDocument, ParsedPdfPage } from '../types/parsed-pdf';
+import { ensureModel } from './model';
+import { runLayoutModel } from './runLayoutModel';
+import { mergeTextWithRegions } from './merge';
+import { stitchCrossPageBlocks } from './stitch';
+import { renderPage } from './render';
+import { normalizeTextItemsForLayout } from './normalize-text';
+
+interface ParsePdfInput {
+  documentId: string;
+  pdfBytes: ArrayBuffer;
+  onPageParsed?: (input: {
+    pageNumber: number;
+    totalPages: number;
+    pageMs: number;
+  }) => void | Promise<void>;
+}
+
+const LAYOUT_RENDER_SCALE = 1.5;
+
+function resolvePdfjsStandardFontDataUrl(): string {
+  const standardFontDir = path.join(process.cwd(), 'node_modules', 'pdfjs-dist', 'standard_fonts');
+  return `${standardFontDir.replace(/\/?$/, '/')}`;
+}
+
+export async function parsePdf(input: ParsePdfInput): Promise<ParsedPdfDocument> {
+  await ensureModel();
+
+  // Keep independent byte copies for text extraction and page rendering. pdf.js
+  // can detach buffers passed to getDocument().
+  const pdfBytesForText = new Uint8Array(input.pdfBytes).slice();
+  const pdfBytesForRender = new Uint8Array(input.pdfBytes).slice();
+
+  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+  // @ts-ignore
+  const pdfjs = await import('pdfjs-dist/legacy/build/pdf.mjs');
+  if (pdfjs.GlobalWorkerOptions) {
+    pdfjs.GlobalWorkerOptions.workerSrc = 'pdfjs-dist/legacy/build/pdf.worker.mjs';
+    pdfjs.GlobalWorkerOptions.workerPort = null;
+  }
+  const standardFontDataUrl = resolvePdfjsStandardFontDataUrl();
+
+  const loadingTask = pdfjs.getDocument({
+    data: pdfBytesForText,
+    useWorkerFetch: false,
+    standardFontDataUrl,
+    isEvalSupported: false,
+  });
+  const pdf = await loadingTask.promise;
+
+  try {
+    const pages: ParsedPdfPage[] = [];
+    let nextBlockId = 1;
+    let sawText = false;
+
+    for (let pageNumber = 1; pageNumber <= pdf.numPages; pageNumber += 1) {
+      const pageStartedAt = Date.now();
+      const page = await pdf.getPage(pageNumber);
+      const viewport = page.getViewport({ scale: 1.0 });
+      const textContent = await page.getTextContent();
+      const textItems = normalizeTextItemsForLayout(
+        textContent.items.filter((item): item is TextItem => 'str' in item && 'transform' in item),
+        viewport.height,
+      );
+
+      if (textItems.length > 0) sawText = true;
+
+      const rendered = await renderPage({
+        pdfBytes: pdfBytesForRender.buffer.slice(
+          pdfBytesForRender.byteOffset,
+          pdfBytesForRender.byteOffset + pdfBytesForRender.byteLength,
+        ),
+        pageNumber,
+        scale: LAYOUT_RENDER_SCALE,
+      });
+      const scaleX = rendered.width / Math.max(1, viewport.width);
+      const scaleY = rendered.height / Math.max(1, viewport.height);
+      const layoutTextItems = textItems.map((item) => ({
+        ...item,
+        x: item.x * scaleX,
+        y: item.y * scaleY,
+        width: item.width * scaleX,
+        height: item.height * scaleY,
+      }));
+      const regions = await runLayoutModel({
+        pageWidth: rendered.width,
+        pageHeight: rendered.height,
+        textItems: layoutTextItems,
+        pageImage: rendered.image,
+      });
+      const merged = mergeTextWithRegions(regions, layoutTextItems);
+      if (textItems.length > 0 && merged.length === 0) {
+        throw new Error(`layout-merge-empty: page=${pageNumber} regions=${regions.length}`);
+      }
+
+      const blocks = merged
+        .map((entry, readingOrder) => ({
+          id: `b${String(nextBlockId++).padStart(4, '0')}`,
+          kind: entry.region.label,
+          fragments: [{
+            page: pageNumber,
+            bbox: [
+              entry.region.bbox[0] / scaleX,
+              entry.region.bbox[1] / scaleY,
+              entry.region.bbox[2] / scaleX,
+              entry.region.bbox[3] / scaleY,
+            ] as [number, number, number, number],
+            text: entry.text,
+            readingOrder,
+            ...(typeof entry.region.confidence === 'number' ? { modelConfidence: entry.region.confidence } : {}),
+          }],
+          text: entry.text,
+        }));
+
+      pages.push({
+        pageNumber,
+        width: viewport.width,
+        height: viewport.height,
+        blocks,
+      });
+
+      if (input.onPageParsed) {
+        await input.onPageParsed({
+          pageNumber,
+          totalPages: pdf.numPages,
+          pageMs: Date.now() - pageStartedAt,
+        });
+      }
+    }
+
+    if (!sawText) {
+      throw new Error('no-text-layer');
+    }
+
+    const doc: ParsedPdfDocument = {
+      schemaVersion: 1,
+      documentId: input.documentId,
+      parserVersion: 'pp-doclayoutv3-onnx@800+pdfjs@4.8.69',
+      parsedAt: Date.now(),
+      pages,
+    };
+
+    return stitchCrossPageBlocks(doc);
+  } finally {
+    await pdf.destroy().catch(() => undefined);
+    await loadingTask.destroy().catch(() => undefined);
+  }
+}

compute/core/src/pdf/render.ts

@@ -0,0 +1,166 @@
+import path from 'path';
+import type { Canvas } from '@napi-rs/canvas';
+
+type CanvasRuntime = {
+  DOMMatrixCtor: unknown;
+  Path2DCtor: unknown;
+  createCanvasFn: (width: number, height: number) => Canvas;
+};
+
+let canvasRuntimePromise: Promise<CanvasRuntime> | null = null;
+
+function resolvePdfjsStandardFontDataUrl(): string {
+  const standardFontDir = path.join(process.cwd(), 'node_modules', 'pdfjs-dist', 'standard_fonts');
+  return `${standardFontDir.replace(/\/?$/, '/')}`;
+}
+
+async function loadCanvasRuntime(): Promise<CanvasRuntime> {
+  if (!canvasRuntimePromise) {
+    canvasRuntimePromise = (async () => {
+      const mod = await import('@napi-rs/canvas');
+      const namespace = mod as Record<string, unknown>;
+      const fallback = (namespace.default ?? {}) as Record<string, unknown>;
+
+      const createCanvasFn = (namespace.createCanvas ?? fallback.createCanvas) as
+        | ((width: number, height: number) => Canvas)
+        | undefined;
+      const DOMMatrixCtor = namespace.DOMMatrix ?? fallback.DOMMatrix;
+      const Path2DCtor = namespace.Path2D ?? fallback.Path2D;
+
+      if (typeof createCanvasFn !== 'function') {
+        throw new Error(
+          `Canvas runtime missing createCanvas export (keys=${Object.keys(namespace).join(',')}; defaultKeys=${Object.keys(fallback).join(',')})`,
+        );
+      }
+      if (!DOMMatrixCtor || !Path2DCtor) {
+        throw new Error(
+          `Canvas runtime missing DOMMatrix/Path2D exports (keys=${Object.keys(namespace).join(',')}; defaultKeys=${Object.keys(fallback).join(',')})`,
+        );
+      }
+
+      return {
+        DOMMatrixCtor,
+        Path2DCtor,
+        createCanvasFn,
+      };
+    })();
+  }
+  return canvasRuntimePromise;
+}
+
+function ensureNodeCanvasGlobals(runtime: CanvasRuntime): void {
+  const g = globalThis as Record<string, unknown>;
+  if (typeof g.DOMMatrix === 'undefined') g.DOMMatrix = runtime.DOMMatrixCtor;
+  if (typeof g.Path2D === 'undefined') g.Path2D = runtime.Path2DCtor;
+}
+
+interface RenderInput {
+  pdfBytes: ArrayBuffer;
+  pageNumber: number;
+  scale?: number;
+  targetWidth?: number;
+  format?: 'png' | 'jpeg';
+  jpegQuality?: number;
+}
+
+function createPdfjsCanvasFactory(runtime: CanvasRuntime) {
+  return class OpenReaderCanvasFactory {
+    create(width: number, height: number) {
+      const canvas = runtime.createCanvasFn(Math.max(1, Math.floor(width)), Math.max(1, Math.floor(height)));
+      return {
+        canvas,
+        context: canvas.getContext('2d') as unknown as CanvasRenderingContext2D,
+      };
+    }
+
+    reset(target: { canvas: Canvas; context: CanvasRenderingContext2D }, width: number, height: number): void {
+      target.canvas.width = Math.max(1, Math.floor(width));
+      target.canvas.height = Math.max(1, Math.floor(height));
+    }
+
+    destroy(target: { canvas: Canvas; context: CanvasRenderingContext2D }): void {
+      target.canvas.width = 0;
+      target.canvas.height = 0;
+      // @ts-expect-error pdf.js expects these nulled on destroy
+      target.canvas = null;
+      // @ts-expect-error pdf.js expects these nulled on destroy
+      target.context = null;
+    }
+  };
+}
+
+export async function renderPage({
+  pdfBytes,
+  pageNumber,
+  scale = 1.5,
+  targetWidth,
+  format = 'png',
+  jpegQuality = 82,
+}: RenderInput): Promise<{
+  width: number;
+  height: number;
+  image: Buffer;
+  contentType: 'image/png' | 'image/jpeg';
+}> {
+  // pdf.js may detach the provided ArrayBuffer. Work with an isolated copy so
+  // callers can safely reuse their original bytes across pages/calls.
+  const isolatedBytes = new Uint8Array(pdfBytes).slice();
+
+  const canvasRuntime = await loadCanvasRuntime();
+  ensureNodeCanvasGlobals(canvasRuntime);
+  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+  // @ts-ignore
+  const pdfjs = await import('pdfjs-dist/legacy/build/pdf.mjs');
+
+  if (pdfjs.GlobalWorkerOptions) {
+    pdfjs.GlobalWorkerOptions.workerSrc = 'pdfjs-dist/legacy/build/pdf.worker.mjs';
+    pdfjs.GlobalWorkerOptions.workerPort = null;
+  }
+
+  const standardFontDataUrl = resolvePdfjsStandardFontDataUrl();
+
+  const loadingTask = pdfjs.getDocument({
+    data: isolatedBytes,
+    useWorkerFetch: false,
+    standardFontDataUrl,
+    isEvalSupported: false,
+    // Ensure pdf.js transport uses our canvas backend in Node/Next runtime.
+    CanvasFactory: createPdfjsCanvasFactory(canvasRuntime),
+  });
+
+  const pdf = await loadingTask.promise;
+  try {
+    const page = await pdf.getPage(pageNumber);
+    const baseViewport = page.getViewport({ scale: 1.0 });
+    const effectiveScale = typeof targetWidth === 'number' && Number.isFinite(targetWidth) && targetWidth > 0
+      ? (Math.max(1, Math.round(targetWidth)) / Math.max(1, baseViewport.width))
+      : scale;
+    const viewport = page.getViewport({ scale: effectiveScale });
+    const width = Math.max(1, Math.floor(viewport.width));
+    const height = Math.max(1, Math.floor(viewport.height));
+    const canvas = canvasRuntime.createCanvasFn(width, height);
+    const ctx = canvas.getContext('2d');
+    ctx.fillStyle = '#ffffff';
+    ctx.fillRect(0, 0, width, height);
+
+    const renderTask = page.render({
+      canvasContext: ctx as unknown as CanvasRenderingContext2D,
+      viewport,
+      intent: 'display',
+    });
+    await renderTask.promise;
+    const contentType = format === 'jpeg' ? 'image/jpeg' : 'image/png';
+    const image = format === 'jpeg'
+      ? canvas.toBuffer('image/jpeg', jpegQuality)
+      : canvas.toBuffer('image/png');
+    return {
+      width,
+      height,
+      image,
+      contentType,
+    };
+  } finally {
+    await pdf.destroy().catch(() => undefined);
+    await loadingTask.destroy().catch(() => undefined);
+  }
+}

compute/core/src/pdf/runLayoutModel.ts

@@ -0,0 +1,339 @@
+import * as ort from 'onnxruntime-node';
+import { readFile } from 'fs/promises';
+import type { LayoutRegion, PdfTextItem } from './types';
+import { ensureModel, MODEL_CONFIG_PATH, MODEL_PREPROCESSOR_PATH } from './model';
+import { getOnnxThreadsPerJob } from '../config/cpu-budget';
+
+interface RunLayoutInput {
+  pageWidth: number;
+  pageHeight: number;
+  textItems: PdfTextItem[];
+  pageImage: Buffer;
+}
+
+const DEFAULT_INPUT_SIZE = 800;
+const MIN_SCORE = 0.5;
+const CLASS_MIN_SCORE: Partial<Record<LayoutRegion['label'], number>> = {
+  header: 0.4,
+  footer: 0.4,
+  figure_title: 0.45,
+  footnote: 0.45,
+  vision_footnote: 0.45,
+};
+
+const LABEL_MAP: Record<string, LayoutRegion['label'] | null> = {
+  // PP-DocLayoutV3 labels
+  abstract: 'abstract',
+  algorithm: 'algorithm',
+  aside_text: 'aside_text',
+  chart: 'chart',
+  content: 'content',
+  display_formula: 'formula',
+  doc_title: 'doc_title',
+  figure_title: 'figure_title',
+  footer: 'footer',
+  footer_image: 'footer',
+  footnote: 'footnote',
+  formula_number: 'formula_number',
+  header: 'header',
+  header_image: 'header',
+  image: 'image',
+  inline_formula: 'formula',
+  number: 'number',
+  paragraph_title: 'paragraph_title',
+  reference: 'reference',
+  reference_content: 'reference_content',
+  seal: 'seal',
+  table: 'table',
+  text: 'text',
+  vertical_text: 'text',
+  vision_footnote: 'vision_footnote',
+};
+
+const MIN_REGION_SIZE: Partial<Record<LayoutRegion['label'], { minWidth: number; minHeight: number }>> = {
+  abstract: { minWidth: 24, minHeight: 14 },
+  algorithm: { minWidth: 24, minHeight: 14 },
+  aside_text: { minWidth: 24, minHeight: 14 },
+  content: { minWidth: 24, minHeight: 14 },
+  text: { minWidth: 24, minHeight: 14 },
+  reference: { minWidth: 24, minHeight: 14 },
+  reference_content: { minWidth: 24, minHeight: 14 },
+  paragraph_title: { minWidth: 24, minHeight: 14 },
+  doc_title: { minWidth: 24, minHeight: 14 },
+  number: { minWidth: 18, minHeight: 12 },
+  figure_title: { minWidth: 18, minHeight: 10 },
+  footnote: { minWidth: 18, minHeight: 10 },
+  vision_footnote: { minWidth: 18, minHeight: 10 },
+  header: { minWidth: 18, minHeight: 10 },
+  footer: { minWidth: 18, minHeight: 10 },
+};
+
+interface ModelPreprocessor {
+  inputWidth: number;
+  inputHeight: number;
+  rescaleFactor: number;
+  mean: [number, number, number];
+  std: [number, number, number];
+}
+
+let sessionPromise: Promise<ort.InferenceSession> | null = null;
+let idToLabelPromise: Promise<Record<number, string>> | null = null;
+let preprocessorPromise: Promise<ModelPreprocessor> | null = null;
+let canvasFnsPromise: Promise<{
+  createCanvasFn: (width: number, height: number) => { getContext: (kind: '2d') => CanvasRenderingContext2D };
+  loadImageFn: (src: Buffer) => Promise<{ width: number; height: number } & CanvasImageSource>;
+}> | null = null;
+
+async function getCanvasFns(): Promise<{
+  createCanvasFn: (width: number, height: number) => { getContext: (kind: '2d') => CanvasRenderingContext2D };
+  loadImageFn: (src: Buffer) => Promise<{ width: number; height: number } & CanvasImageSource>;
+}> {
+  if (!canvasFnsPromise) {
+    canvasFnsPromise = (async () => {
+      const mod = await import('@napi-rs/canvas');
+      const namespace = mod as Record<string, unknown>;
+      const fallback = (namespace.default ?? {}) as Record<string, unknown>;
+      const createCanvasFn = (namespace.createCanvas ?? fallback.createCanvas) as
+        | ((width: number, height: number) => { getContext: (kind: '2d') => CanvasRenderingContext2D })
+        | undefined;
+      const loadImageFn = (namespace.loadImage ?? fallback.loadImage) as
+        | ((src: Buffer) => Promise<{ width: number; height: number } & CanvasImageSource>)
+        | undefined;
+
+      if (typeof createCanvasFn !== 'function' || typeof loadImageFn !== 'function') {
+        throw new Error(
+          `Canvas runtime missing createCanvas/loadImage exports (keys=${Object.keys(namespace).join(',')}; defaultKeys=${Object.keys(fallback).join(',')})`,
+        );
+      }
+
+      return { createCanvasFn, loadImageFn };
+    })();
+  }
+  return canvasFnsPromise;
+}
+
+async function getSession(): Promise<ort.InferenceSession> {
+  if (!sessionPromise) {
+    sessionPromise = (async () => {
+      const modelPath = await ensureModel();
+      const onnxThreadsPerJob = getOnnxThreadsPerJob();
+      const stableSessionOptions: ort.InferenceSession.SessionOptions = {
+        executionProviders: ['cpu'],
+        graphOptimizationLevel: 'all',
+        intraOpNumThreads: onnxThreadsPerJob,
+        interOpNumThreads: 1,
+        executionMode: 'sequential',
+      };
+      return ort.InferenceSession.create(modelPath, {
+        ...stableSessionOptions,
+      });
+    })();
+  }
+  return sessionPromise;
+}
+
+async function getIdToLabel(): Promise<Record<number, string>> {
+  if (!idToLabelPromise) {
+    idToLabelPromise = (async () => {
+      await ensureModel();
+      const raw = await readFile(MODEL_CONFIG_PATH, 'utf8');
+      const parsed = JSON.parse(raw) as { id2label?: Record<string, string> };
+      const out: Record<number, string> = {};
+      for (const [key, value] of Object.entries(parsed.id2label ?? {})) {
+        const n = Number(key);
+        if (Number.isFinite(n)) out[n] = String(value ?? '').trim();
+      }
+      return out;
+    })();
+  }
+  return idToLabelPromise;
+}
+
+async function getPreprocessor(): Promise<ModelPreprocessor> {
+  if (!preprocessorPromise) {
+    preprocessorPromise = (async () => {
+      await ensureModel();
+      const raw = await readFile(MODEL_PREPROCESSOR_PATH, 'utf8');
+      const parsed = JSON.parse(raw) as {
+        size?: { width?: number; height?: number };
+        rescale_factor?: number;
+        image_mean?: number[];
+        image_std?: number[];
+      };
+
+      const inputWidth = Math.max(1, Number(parsed.size?.width ?? DEFAULT_INPUT_SIZE));
+      const inputHeight = Math.max(1, Number(parsed.size?.height ?? DEFAULT_INPUT_SIZE));
+      const rescaleFactor = Number.isFinite(parsed.rescale_factor) ? Number(parsed.rescale_factor) : (1 / 255);
+      const mean = [
+        Number(parsed.image_mean?.[0] ?? 0),
+        Number(parsed.image_mean?.[1] ?? 0),
+        Number(parsed.image_mean?.[2] ?? 0),
+      ] as [number, number, number];
+      const std = [
+        Number(parsed.image_std?.[0] ?? 1),
+        Number(parsed.image_std?.[1] ?? 1),
+        Number(parsed.image_std?.[2] ?? 1),
+      ] as [number, number, number];
+
+      return {
+        inputWidth,
+        inputHeight,
+        rescaleFactor,
+        mean,
+        std,
+      };
+    })();
+  }
+  return preprocessorPromise;
+}
+
+function preprocessResized(
+  image: CanvasImageSource,
+  preprocessor: ModelPreprocessor,
+  createCanvasFn: (width: number, height: number) => { getContext: (kind: '2d') => CanvasRenderingContext2D },
+): ort.Tensor {
+  const canvas = createCanvasFn(preprocessor.inputWidth, preprocessor.inputHeight);
+  const ctx = canvas.getContext('2d');
+  ctx.fillStyle = '#ffffff';
+  ctx.fillRect(0, 0, preprocessor.inputWidth, preprocessor.inputHeight);
+  ctx.imageSmoothingEnabled = true;
+  ctx.imageSmoothingQuality = 'high';
+  ctx.drawImage(image, 0, 0, preprocessor.inputWidth, preprocessor.inputHeight);
+
+  const imageData = ctx.getImageData(0, 0, preprocessor.inputWidth, preprocessor.inputHeight);
+  const chw = new Float32Array(1 * 3 * preprocessor.inputWidth * preprocessor.inputHeight);
+  const channelSize = preprocessor.inputWidth * preprocessor.inputHeight;
+  for (let y = 0; y < preprocessor.inputHeight; y += 1) {
+    for (let x = 0; x < preprocessor.inputWidth; x += 1) {
+      const pixelIndex = (y * preprocessor.inputWidth + x) * 4;
+      const idx = y * preprocessor.inputWidth + x;
+      const r = imageData.data[pixelIndex] * preprocessor.rescaleFactor;
+      const g = imageData.data[pixelIndex + 1] * preprocessor.rescaleFactor;
+      const b = imageData.data[pixelIndex + 2] * preprocessor.rescaleFactor;
+
+      chw[idx] = (r - preprocessor.mean[0]) / Math.max(1e-8, preprocessor.std[0]);
+      chw[channelSize + idx] = (g - preprocessor.mean[1]) / Math.max(1e-8, preprocessor.std[1]);
+      chw[channelSize * 2 + idx] = (b - preprocessor.mean[2]) / Math.max(1e-8, preprocessor.std[2]);
+    }
+  }
+  return new ort.Tensor('float32', chw, [1, 3, preprocessor.inputHeight, preprocessor.inputWidth]);
+}
+
+function clampBox(
+  bbox: [number, number, number, number],
+  pageWidth: number,
+  pageHeight: number,
+): [number, number, number, number] | null {
+  const x0 = Math.max(0, Math.min(pageWidth, bbox[0]));
+  const y0 = Math.max(0, Math.min(pageHeight, bbox[1]));
+  const x1 = Math.max(0, Math.min(pageWidth, bbox[2]));
+  const y1 = Math.max(0, Math.min(pageHeight, bbox[3]));
+  if (x1 <= x0 || y1 <= y0) return null;
+  return [x0, y0, x1, y1];
+}
+
+function softmaxMax(logits: Float32Array, offset: number, count: number): { index: number; score: number } {
+  let maxLogit = Number.NEGATIVE_INFINITY;
+  let maxIndex = 0;
+  for (let i = 0; i < count; i += 1) {
+    const value = logits[offset + i];
+    if (value > maxLogit) {
+      maxLogit = value;
+      maxIndex = i;
+    }
+  }
+
+  let sum = 0;
+  for (let i = 0; i < count; i += 1) {
+    sum += Math.exp(logits[offset + i] - maxLogit);
+  }
+
+  const score = sum > 0 ? (1 / sum) : 0;
+  return { index: maxIndex, score };
+}
+
+function normalizeModelLabel(rawLabel: string): string {
+  const normalized = rawLabel.trim().toLowerCase().replace(/[\s-]+/g, '_');
+  if (normalized.endsWith('_image')) {
+    const base = normalized.slice(0, -'_image'.length);
+    if (base === 'header' || base === 'footer') return normalized;
+  }
+  // Some exports suffix duplicate classes (e.g. header_1, footer_1, text_1).
+  return normalized.replace(/_\d+$/g, '');
+}
+
+export async function runLayoutModel(input: RunLayoutInput): Promise<LayoutRegion[]> {
+  const { pageWidth, pageHeight, textItems, pageImage } = input;
+  if (!textItems.length) return [];
+  if (!pageImage || pageImage.byteLength === 0) {
+    throw new Error('layout-render-missing-page-image');
+  }
+
+  try {
+    const [session, idToLabel, preprocessor, canvasFns] = await Promise.all([
+      getSession(),
+      getIdToLabel(),
+      getPreprocessor(),
+      getCanvasFns(),
+    ]);
+
+    const decodedPageImage = await canvasFns.loadImageFn(pageImage);
+    const pixelValues = preprocessResized(decodedPageImage, preprocessor, canvasFns.createCanvasFn);
+    const output = await session.run({ pixel_values: pixelValues });
+
+    const logits = output.logits?.data as Float32Array | undefined;
+    const predBoxes = output.pred_boxes?.data as Float32Array | undefined;
+    if (!logits || !predBoxes) return [];
+
+    const numQueries = Math.floor(predBoxes.length / 4);
+    if (numQueries <= 0) return [];
+    const classCount = Math.floor(logits.length / numQueries);
+    if (classCount <= 0) return [];
+
+    const regions: LayoutRegion[] = [];
+
+    for (let queryIdx = 0; queryIdx < numQueries; queryIdx += 1) {
+      const cls = softmaxMax(logits, queryIdx * classCount, classCount);
+      const rawLabel = idToLabel[cls.index];
+      if (!rawLabel) continue;
+      const mapped = LABEL_MAP[normalizeModelLabel(rawLabel)];
+      if (!mapped) continue;
+
+      const minScore = CLASS_MIN_SCORE[mapped] ?? MIN_SCORE;
+      if (!Number.isFinite(cls.score) || cls.score < minScore) continue;
+
+      const cx = predBoxes[queryIdx * 4 + 0] * pageWidth;
+      const cy = predBoxes[queryIdx * 4 + 1] * pageHeight;
+      const w = predBoxes[queryIdx * 4 + 2] * pageWidth;
+      const h = predBoxes[queryIdx * 4 + 3] * pageHeight;
+      const rawBox: [number, number, number, number] = [
+        cx - w / 2,
+        cy - h / 2,
+        cx + w / 2,
+        cy + h / 2,
+      ];
+
+      const clamped = clampBox(rawBox, pageWidth, pageHeight);
+      if (!clamped) continue;
+
+      const sizeRule = MIN_REGION_SIZE[mapped];
+      if (sizeRule) {
+        const width = clamped[2] - clamped[0];
+        const height = clamped[3] - clamped[1];
+        if (width < sizeRule.minWidth || height < sizeRule.minHeight) continue;
+      }
+
+      regions.push({
+        bbox: clamped,
+        label: mapped,
+        confidence: cls.score,
+      });
+    }
+
+    return regions.sort((a, b) => (b.confidence ?? 0) - (a.confidence ?? 0));
+  } catch (error) {
+    throw new Error(
+      `layout-model-inference-failed: ${error instanceof Error ? error.message : String(error)}`,
+    );
+  }
+}

compute/core/src/pdf/stitch.ts

@@ -0,0 +1,144 @@
+import type { ParsedPdfDocument, ParsedPdfBlock } from '../types/parsed-pdf';
+
+const STITCHABLE_KINDS = new Set<ParsedPdfBlock['kind']>([
+  'text',
+  'content',
+  'reference_content',
+  'aside_text',
+  'abstract',
+  'algorithm',
+  'reference',
+]);
+
+function stripTrailingClosers(text: string): string {
+  return text.trim().replace(/[\"'”’\]\)]+$/g, '');
+}
+
+function isSentenceTerminal(text: string): boolean {
+  return /[.!?]$/.test(stripTrailingClosers(text));
+}
+
+function canStitch(a: ParsedPdfBlock, b: ParsedPdfBlock): boolean {
+  if (!STITCHABLE_KINDS.has(a.kind)) return false;
+  if (a.kind !== b.kind) return false;
+  if (isSentenceTerminal(a.text)) return false;
+  const next = b.text.trim();
+  if (!next) return false;
+  if (/^[A-Z]/.test(next)) return false;
+  return true;
+}
+
+function splitHeadContinuation(text: string): { continuation: string; remainder: string } {
+  const normalized = text.replace(/\s+/g, ' ').trim();
+  if (!normalized) return { continuation: '', remainder: '' };
+
+  const CLOSERS = new Set(['"', "'", '”', '’', ')', ']', '}']);
+  const isTerminal = (ch: string): boolean => ch === '.' || ch === '!' || ch === '?';
+
+  for (let i = 0; i < normalized.length; i += 1) {
+    const ch = normalized[i];
+    if (!isTerminal(ch)) continue;
+
+    const prev = i > 0 ? normalized[i - 1] : '';
+    const next = i + 1 < normalized.length ? normalized[i + 1] : '';
+    if (ch === '.' && /\d/.test(prev) && /\d/.test(next)) continue;
+
+    let cut = i + 1;
+    while (cut < normalized.length && CLOSERS.has(normalized[cut])) cut += 1;
+
+    const after = cut < normalized.length ? normalized[cut] : '';
+    if (!after || /\s/.test(after) || /[A-Z]/.test(after)) {
+      return {
+        continuation: normalized.slice(0, cut).trim(),
+        remainder: normalized.slice(cut).trim(),
+      };
+    }
+  }
+
+  return {
+    continuation: normalized,
+    remainder: '',
+  };
+}
+
+const HARD_BOUNDARY_KINDS = new Set<ParsedPdfBlock['kind']>([
+  'paragraph_title',
+  'doc_title',
+]);
+
+function findTailCandidateIndex(blocks: ParsedPdfBlock[]): number {
+  for (let i = blocks.length - 1; i >= 0; i -= 1) {
+    const block = blocks[i];
+    if (!block || !block.text.trim()) continue;
+    if (STITCHABLE_KINDS.has(block.kind)) return i;
+  }
+  return -1;
+}
+
+function findHeadCandidateIndex(blocks: ParsedPdfBlock[]): number {
+  for (let i = 0; i < blocks.length; i += 1) {
+    const block = blocks[i];
+    if (!block || !block.text.trim()) continue;
+    if (STITCHABLE_KINDS.has(block.kind)) return i;
+  }
+  return -1;
+}
+
+function hasHardBoundaryBetween(
+  pageBlocks: ParsedPdfBlock[],
+  startInclusive: number,
+  endExclusive: number,
+): boolean {
+  for (let i = startInclusive; i < endExclusive; i += 1) {
+    const block = pageBlocks[i];
+    if (block && HARD_BOUNDARY_KINDS.has(block.kind)) return true;
+  }
+  return false;
+}
+
+export function stitchCrossPageBlocks(doc: ParsedPdfDocument): ParsedPdfDocument {
+  const pages = doc.pages.map((page) => ({ ...page, blocks: page.blocks.map((b) => ({ ...b, fragments: b.fragments.map((f) => ({ ...f })) })) }));
+
+  for (let i = 0; i < pages.length - 1; i += 1) {
+    const page = pages[i];
+    const next = pages[i + 1];
+    const tailIndex = findTailCandidateIndex(page.blocks);
+    const headIndex = findHeadCandidateIndex(next.blocks);
+    if (tailIndex < 0 || headIndex < 0) continue;
+
+    if (hasHardBoundaryBetween(page.blocks, tailIndex + 1, page.blocks.length)) continue;
+    if (hasHardBoundaryBetween(next.blocks, 0, headIndex)) continue;
+
+    const tail = page.blocks[tailIndex];
+    const head = next.blocks[headIndex];
+    if (!tail || !head) continue;
+    if (!canStitch(tail, head)) continue;
+
+    const { continuation, remainder } = splitHeadContinuation(head.text);
+    if (!continuation) continue;
+
+    const continuationFragment = head.fragments[0]
+      ? { ...head.fragments[0], text: continuation }
+      : null;
+
+    if (continuationFragment) {
+      tail.fragments.push(continuationFragment);
+    }
+    tail.text = `${tail.text} ${continuation}`.replace(/\s+/g, ' ').trim();
+
+    if (!remainder) {
+      next.blocks.splice(headIndex, 1);
+      continue;
+    }
+
+    head.text = remainder;
+    if (head.fragments[0]) {
+      head.fragments[0].text = remainder;
+    }
+  }
+
+  return {
+    ...doc,
+    pages,
+  };
+}

compute/core/src/pdf/types.ts

@@ -0,0 +1,15 @@
+import type { ParsedPdfBlockKind } from '../types/parsed-pdf';
+
+export interface PdfTextItem {
+  text: string;
+  x: number;
+  y: number;
+  width: number;
+  height: number;
+}
+
+export interface LayoutRegion {
+  bbox: [number, number, number, number];
+  label: ParsedPdfBlockKind;
+  confidence?: number;
+}

compute/core/src/platform/docstore.ts

@@ -0,0 +1,21 @@
+import fs from 'fs';
+import path from 'path';
+
+function findMonorepoRoot(startDir: string): string | null {
+  let current = path.resolve(startDir);
+  for (;;) {
+    const marker = path.join(current, 'pnpm-workspace.yaml');
+    if (fs.existsSync(marker)) return current;
+    const parent = path.dirname(current);
+    if (parent === current) return null;
+    current = parent;
+  }
+}
+
+function resolveDocstoreDir(): string {
+  const repoRoot = findMonorepoRoot(process.cwd());
+  if (repoRoot) return path.join(repoRoot, 'docstore');
+  return path.join(process.cwd(), 'docstore');
+}
+
+export const DOCSTORE_DIR = resolveDocstoreDir();

compute/core/src/platform/ffmpeg.ts

@@ -0,0 +1,36 @@
+import { existsSync } from 'fs';
+import ffmpegStatic from 'ffmpeg-static';
+
+function normalizePath(value: unknown): string | null {
+  if (typeof value !== 'string') return null;
+  const trimmed = value.trim();
+  return trimmed.length > 0 ? trimmed : null;
+}
+
+function resolveBinary(envValue: string | null, bundledValue: string | null, envVarName: string, packageName: string): string {
+  if (envValue) {
+    if ((envValue.includes('/') || envValue.includes('\\')) && !existsSync(envValue)) {
+      throw new Error(`${envVarName} points to a missing binary: ${envValue}`);
+    }
+    return envValue;
+  }
+
+  if (!bundledValue) {
+    throw new Error(`${packageName} binary is unavailable on this platform. Set ${envVarName} to an installed binary path.`);
+  }
+
+  if ((bundledValue.includes('/') || bundledValue.includes('\\')) && !existsSync(bundledValue)) {
+    throw new Error(`${packageName} resolved to a missing binary path: ${bundledValue}`);
+  }
+
+  return bundledValue;
+}
+
+export function getFFmpegPath(): string {
+  return resolveBinary(
+    normalizePath(process.env.FFMPEG_BIN),
+    normalizePath(ffmpegStatic),
+    'FFMPEG_BIN',
+    'ffmpeg-static',
+  );
+}

compute/core/src/types/index.ts

@@ -0,0 +1,17 @@
+export type {
+  TTSAudioBuffer,
+  TTSAudioBytes,
+  TTSSentenceAlignment,
+  TTSSentenceWord,
+} from './tts';
+
+export type {
+  ParsedPdfBlock,
+  ParsedPdfBlockFragment,
+  ParsedPdfBlockKind,
+  ParsedPdfDocument,
+  ParsedPdfPage,
+  PdfParsePhase,
+  PdfParseProgress,
+  PdfParseStatus,
+} from './parsed-pdf';

compute/core/src/types/parsed-pdf.ts

@@ -0,0 +1,63 @@
+export type ParsedPdfBlockKind =
+  | 'abstract'
+  | 'algorithm'
+  | 'aside_text'
+  | 'chart'
+  | 'content'
+  | 'formula'
+  | 'doc_title'
+  | 'figure_title'
+  | 'footer'
+  | 'footnote'
+  | 'formula_number'
+  | 'header'
+  | 'image'
+  | 'number'
+  | 'paragraph_title'
+  | 'reference'
+  | 'reference_content'
+  | 'seal'
+  | 'table'
+  | 'text'
+  | 'vision_footnote';
+
+export interface ParsedPdfBlockFragment {
+  page: number;
+  bbox: [number, number, number, number];
+  text: string;
+  readingOrder: number;
+  modelConfidence?: number;
+}
+
+export interface ParsedPdfBlock {
+  id: string;
+  kind: ParsedPdfBlockKind;
+  fragments: ParsedPdfBlockFragment[];
+  text: string;
+  parentSectionId?: string;
+}
+
+export interface ParsedPdfPage {
+  pageNumber: number;
+  width: number;
+  height: number;
+  blocks: ParsedPdfBlock[];
+}
+
+export interface ParsedPdfDocument {
+  schemaVersion: 1;
+  documentId: string;
+  parserVersion: string;
+  parsedAt: number;
+  pages: ParsedPdfPage[];
+}
+
+export type PdfParseStatus = 'pending' | 'running' | 'ready' | 'failed';
+export type PdfParsePhase = 'infer' | 'merge';
+
+export interface PdfParseProgress {
+  totalPages: number;
+  pagesParsed: number;
+  currentPage?: number;
+  phase: PdfParsePhase;
+}

compute/core/src/types/tts.ts

@@ -0,0 +1,16 @@
+export type TTSAudioBuffer = ArrayBuffer;
+export type TTSAudioBytes = number[];
+
+export interface TTSSentenceWord {
+  text: string;
+  startSec: number;
+  endSec: number;
+  charStart: number;
+  charEnd: number;
+}
+
+export interface TTSSentenceAlignment {
+  sentence: string;
+  sentenceIndex: number;
+  words: TTSSentenceWord[];
+}

compute/core/src/whisper/alignment-map.ts

@@ -0,0 +1,54 @@
+import type { TTSSentenceAlignment, TTSSentenceWord } from '../types/tts';
+
+function preprocessSentenceForAudio(text: string): string {
+  return text
+    .replace(/\S*(?:https?:\/\/|www\.)([^\/\s]+)(?:\/\S*)?/gi, '- (link to $1) -')
+    .replace(/(\w+)-\s+(\w+)/g, '$1$2')
+    .replace(/\*/g, '')
+    .replace(/\s+/g, ' ')
+    .trim();
+}
+
+export interface WhisperWord {
+  start: number;
+  end: number;
+  word: string;
+}
+
+export function mapWordsToSentenceOffsets(sentence: string, words: WhisperWord[]): TTSSentenceAlignment {
+  const normalizedSentence = preprocessSentenceForAudio(sentence);
+  const lowerSentence = normalizedSentence.toLowerCase();
+  let cursor = 0;
+
+  const alignedWords: TTSSentenceWord[] = words.map((w) => {
+    const token = w.word.trim();
+    if (!token) {
+      return {
+        text: '',
+        startSec: w.start,
+        endSec: w.end,
+        charStart: cursor,
+        charEnd: cursor,
+      };
+    }
+
+    const idx = lowerSentence.indexOf(token.toLowerCase(), cursor);
+    const start = idx >= 0 ? idx : cursor;
+    const end = Math.min(normalizedSentence.length, start + token.length);
+    cursor = Math.max(cursor, end);
+
+    return {
+      text: token,
+      startSec: w.start,
+      endSec: w.end,
+      charStart: start,
+      charEnd: end,
+    };
+  }).filter((word) => word.text.length > 0);
+
+  return {
+    sentence,
+    sentenceIndex: 0,
+    words: alignedWords,
+  };
+}

compute/core/src/whisper/assets/LICENSE.txt

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2022 OpenAI
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

compute/core/src/whisper/assets/manifest.json

@@ -0,0 +1,76 @@
+{
+  "name": "whisper-base_timestamped-q4",
+  "version": "onnx-community/whisper-base_timestamped@608c49e61301901684bc36cac8f74b95ff6b5a8e",
+  "files": [
+    {
+      "path": "config.json",
+      "sha256": "f4d0608f7d918166da7edb3e188de5ef1bfe70d9802e785d271fd88111e9cf4b",
+      "size": 2243
+    },
+    {
+      "path": "generation_config.json",
+      "sha256": "61070cf8de25b1e9256e8e102ded49d8d24a8369ed36ef84fdf21549e68125a0",
+      "size": 3832
+    },
+    {
+      "path": "tokenizer.json",
+      "sha256": "27fc476bfe7f17299480be2273fc0608e4d5a99aba2ab5dec5374b4482d1a566",
+      "size": 2480466
+    },
+    {
+      "path": "tokenizer_config.json",
+      "sha256": "2e036e4dbacfdeb7242c7d4ec4149f4a16e86026048f94d1637e3a8ee9c6a573",
+      "size": 282682
+    },
+    {
+      "path": "merges.txt",
+      "sha256": "2df2990a395e35e8dfbc7511e08c12d56018d8d04691e0133e5d63b21e154dc6",
+      "size": 493869
+    },
+    {
+      "path": "vocab.json",
+      "sha256": "50d6a919f0a0601d56a04eb583c780d18553aa388254ba3158eb6a00f13e2c1a",
+      "size": 1036584
+    },
+    {
+      "path": "normalizer.json",
+      "sha256": "bf1c507dc8724ca9cf9903640dacfb69dae2f00edee4f21ceba106a7392f26dd",
+      "size": 52666
+    },
+    {
+      "path": "added_tokens.json",
+      "sha256": "9715fd2243b6f06a5858b5e32950d2853f73dd5bc201aafcf76f5082a2d8acd1",
+      "size": 34604
+    },
+    {
+      "path": "preprocessor_config.json",
+      "sha256": "a6a76d28c93edb273669eb9e0b0636a2bddbb1272c3261e47b7ca6dfdbac1b8d",
+      "size": 339
+    },
+    {
+      "path": "special_tokens_map.json",
+      "sha256": "e67ae3a0aaa99abcd9f187138e12db1f65c16a14761c50ef10eef2c174a7a691",
+      "size": 2194
+    },
+    {
+      "path": "onnx/encoder_model_q4.onnx",
+      "sha256": "0df94e35822653ba16e23c3f19f05b9b7fe7aae97884d1b277e02044f33c4880",
+      "size": 18771046
+    },
+    {
+      "path": "onnx/decoder_model_merged_q4.onnx",
+      "sha256": "fc1902ce2e42c69b2346d8e2a98898c60c01da1e6a64ae90f41d22350ac7db13",
+      "size": 123738327
+    },
+    {
+      "path": "onnx/decoder_with_past_model_q4.onnx",
+      "sha256": "d864ca26509968b00d92e6823c4db7ac460c106f9228a21bc5199e9893fe4126",
+      "size": 121378741
+    },
+    {
+      "path": "LICENSE.txt",
+      "sha256": "b5d65a59060e68c4ff940e1eddfa6f94b2d68fdf58ed7f4dd57721c997e35e9d",
+      "size": 1063
+    }
+  ]
+}

compute/core/src/whisper/model.ts

@@ -0,0 +1,249 @@
+import path from 'path';
+import { fileURLToPath } from 'url';
+import { createHash } from 'crypto';
+import { readFileSync } from 'fs';
+import { access, copyFile, mkdir, readFile, rename, unlink, writeFile } from 'fs/promises';
+import { DOCSTORE_DIR } from '../platform/docstore';
+
+const MODULE_DIR = path.dirname(fileURLToPath(import.meta.url));
+const MODEL_DIR = path.join(DOCSTORE_DIR, 'model', 'whisper-base_timestamped');
+const STATIC_LICENSE_PATH = path.join(MODULE_DIR, 'assets', 'LICENSE.txt');
+const MANIFEST_PATH = path.join(MODULE_DIR, 'assets', 'manifest.json');
+
+export const WHISPER_CONFIG_PATH = path.join(MODEL_DIR, 'config.json');
+export const WHISPER_GENERATION_CONFIG_PATH = path.join(MODEL_DIR, 'generation_config.json');
+export const WHISPER_TOKENIZER_PATH = path.join(MODEL_DIR, 'tokenizer.json');
+export const WHISPER_TOKENIZER_CONFIG_PATH = path.join(MODEL_DIR, 'tokenizer_config.json');
+export const WHISPER_ENCODER_MODEL_PATH = path.join(MODEL_DIR, 'onnx', 'encoder_model_q4.onnx');
+export const WHISPER_DECODER_MERGED_MODEL_PATH = path.join(MODEL_DIR, 'onnx', 'decoder_model_merged_q4.onnx');
+export const WHISPER_DECODER_WITH_PAST_MODEL_PATH = path.join(MODEL_DIR, 'onnx', 'decoder_with_past_model_q4.onnx');
+
+const BASE_MODEL_URL = 'https://huggingface.co/onnx-community/whisper-base_timestamped/resolve/main';
+const WHISPER_MODEL_BASE_URL_ENV = 'WHISPER_MODEL_BASE_URL';
+
+const MODEL_RELATIVE_PATHS: string[] = [
+  'config.json',
+  'generation_config.json',
+  'tokenizer.json',
+  'tokenizer_config.json',
+  'merges.txt',
+  'vocab.json',
+  'normalizer.json',
+  'added_tokens.json',
+  'preprocessor_config.json',
+  'special_tokens_map.json',
+  'onnx/encoder_model_q4.onnx',
+  'onnx/decoder_model_merged_q4.onnx',
+  'onnx/decoder_with_past_model_q4.onnx',
+];
+
+const DEFAULT_URLS: Record<string, string> = {
+  'config.json': `${BASE_MODEL_URL}/config.json`,
+  'generation_config.json': `${BASE_MODEL_URL}/generation_config.json`,
+  'tokenizer.json': `${BASE_MODEL_URL}/tokenizer.json`,
+  'tokenizer_config.json': `${BASE_MODEL_URL}/tokenizer_config.json`,
+  'merges.txt': `${BASE_MODEL_URL}/merges.txt`,
+  'vocab.json': `${BASE_MODEL_URL}/vocab.json`,
+  'normalizer.json': `${BASE_MODEL_URL}/normalizer.json`,
+  'added_tokens.json': `${BASE_MODEL_URL}/added_tokens.json`,
+  'preprocessor_config.json': `${BASE_MODEL_URL}/preprocessor_config.json`,
+  'special_tokens_map.json': `${BASE_MODEL_URL}/special_tokens_map.json`,
+  'onnx/encoder_model_q4.onnx': `${BASE_MODEL_URL}/onnx/encoder_model_q4.onnx`,
+  'onnx/decoder_model_merged_q4.onnx': `${BASE_MODEL_URL}/onnx/decoder_model_merged_q4.onnx`,
+  'onnx/decoder_with_past_model_q4.onnx': `${BASE_MODEL_URL}/onnx/decoder_with_past_model_q4.onnx`,
+};
+
+type ManifestEntry = { path: string; sha256?: string; size?: number };
+
+export interface WhisperArtifactSpec {
+  path: string;
+  sha256?: string;
+  size?: number;
+  url: string;
+}
+
+export interface WhisperStaticArtifactSpec {
+  path: string;
+  sha256?: string;
+  size?: number;
+  sourcePath: string;
+}
+
+export type WhisperFetch = (input: RequestInfo | URL, init?: RequestInit) => Promise<Response>;
+
+function loadManifestFiles(): ManifestEntry[] {
+  const manifestText = readFileSync(MANIFEST_PATH, 'utf8');
+  const parsed = JSON.parse(manifestText) as { files?: ManifestEntry[] };
+  return Array.isArray(parsed.files) ? parsed.files : [];
+}
+
+const MANIFEST_FILES = loadManifestFiles();
+const MODEL_FILES = MANIFEST_FILES.filter((entry) => entry.path !== 'LICENSE.txt');
+const LICENSE_FILE = MANIFEST_FILES.find((entry) => entry.path === 'LICENSE.txt');
+
+function normalizeExpected(entry: { sha256?: string; size?: number }): { sha256: string | null; size: number } {
+  return {
+    sha256: typeof entry.sha256 === 'string' ? entry.sha256.toLowerCase() : null,
+    size: Number(entry.size ?? 0),
+  };
+}
+
+function resolvePath(relativePath: string, modelDir: string): string {
+  return path.join(modelDir, relativePath);
+}
+
+function joinModelUrl(baseUrl: string, relativePath: string): string {
+  return `${baseUrl.replace(/\/+$/, '')}/${relativePath}`;
+}
+
+function resolveUrl(relativePath: string): string {
+  const overrideBase = process.env[WHISPER_MODEL_BASE_URL_ENV]?.trim();
+  if (overrideBase) {
+    return joinModelUrl(overrideBase, relativePath);
+  }
+  const fallback = DEFAULT_URLS[relativePath];
+  if (!fallback) {
+    throw new Error(`No default URL configured for Whisper model artifact: ${relativePath}`);
+  }
+  return fallback;
+}
+
+function sha256OfBytes(bytes: Uint8Array): string {
+  return createHash('sha256').update(bytes).digest('hex');
+}
+
+function verifyBytes(bytes: Uint8Array, expected: { sha256?: string; size?: number }): boolean {
+  const normalized = normalizeExpected(expected);
+  if (Number.isFinite(normalized.size) && normalized.size > 0 && bytes.byteLength !== normalized.size) {
+    return false;
+  }
+  if (!normalized.sha256) return true;
+  return sha256OfBytes(bytes) === normalized.sha256;
+}
+
+async function verifyFile(filePath: string, expected: { sha256?: string; size?: number }): Promise<boolean> {
+  const bytes = await readFile(filePath);
+  return verifyBytes(bytes, expected);
+}
+
+async function downloadToFile(fetchImpl: WhisperFetch, url: string, outPath: string): Promise<void> {
+  const res = await fetchImpl(url);
+  if (!res.ok) {
+    throw new Error(`Download failed for ${url}: ${res.status} ${res.statusText}`);
+  }
+  const bytes = new Uint8Array(await res.arrayBuffer());
+  await writeFile(outPath, bytes);
+}
+
+export async function ensureWhisperArtifacts(options: {
+  modelDir: string;
+  artifacts: WhisperArtifactSpec[];
+  staticArtifacts?: WhisperStaticArtifactSpec[];
+  fetchImpl?: WhisperFetch;
+}): Promise<void> {
+  const {
+    modelDir,
+    artifacts,
+    staticArtifacts = [],
+    fetchImpl = fetch,
+  } = options;
+
+  try {
+    await Promise.all(artifacts.map(async (artifact) => {
+      const target = resolvePath(artifact.path, modelDir);
+      await access(target);
+      const valid = await verifyFile(target, artifact);
+      if (!valid) {
+        throw new Error(`Checksum mismatch for existing Whisper artifact: ${artifact.path}`);
+      }
+    }));
+
+    await Promise.all(staticArtifacts.map(async (artifact) => {
+      const target = resolvePath(artifact.path, modelDir);
+      await access(target);
+      const valid = await verifyFile(target, artifact);
+      if (!valid) {
+        throw new Error(`Checksum mismatch for existing Whisper static artifact: ${artifact.path}`);
+      }
+    }));
+
+    return;
+  } catch {
+    // Continue to repair/download.
+  }
+
+  for (const artifact of artifacts) {
+    const target = resolvePath(artifact.path, modelDir);
+    const targetDir = path.dirname(target);
+    const tmp = `${target}.tmp`;
+
+    await mkdir(targetDir, { recursive: true });
+    await downloadToFile(fetchImpl, artifact.url, tmp);
+    if (!(await verifyFile(tmp, artifact))) {
+      await unlink(tmp).catch(() => undefined);
+      throw new Error(`Whisper artifact checksum verification failed: ${artifact.path}`);
+    }
+    await rename(tmp, target);
+  }
+
+  for (const artifact of staticArtifacts) {
+    const target = resolvePath(artifact.path, modelDir);
+    const targetDir = path.dirname(target);
+    await mkdir(targetDir, { recursive: true });
+    await copyFile(artifact.sourcePath, target);
+    if (!(await verifyFile(target, artifact))) {
+      throw new Error(`Whisper static artifact checksum verification failed: ${artifact.path}`);
+    }
+  }
+}
+
+export function createSingleflightRunner<T>(work: () => Promise<T>): () => Promise<T> {
+  let inflight: Promise<T> | null = null;
+  return async () => {
+    if (inflight) return inflight;
+    inflight = work().finally(() => {
+      inflight = null;
+    });
+    return inflight;
+  };
+}
+
+async function ensureModelInternal(): Promise<string> {
+  if (process.env[WHISPER_MODEL_BASE_URL_ENV]?.trim()) {
+    for (const relativePath of MODEL_RELATIVE_PATHS) {
+      if (!(relativePath in DEFAULT_URLS)) {
+        throw new Error(`Missing default URL path mapping for Whisper artifact: ${relativePath}`);
+      }
+    }
+  }
+
+  const artifacts: WhisperArtifactSpec[] = MODEL_FILES.map((entry) => ({
+    path: entry.path,
+    sha256: entry.sha256,
+    size: entry.size,
+    url: resolveUrl(entry.path),
+  }));
+
+  const staticArtifacts: WhisperStaticArtifactSpec[] = LICENSE_FILE
+    ? [{
+        path: LICENSE_FILE.path,
+        sha256: LICENSE_FILE.sha256,
+        size: LICENSE_FILE.size,
+        sourcePath: STATIC_LICENSE_PATH,
+      }]
+    : [];
+
+  await ensureWhisperArtifacts({
+    modelDir: MODEL_DIR,
+    artifacts,
+    staticArtifacts,
+  });
+
+  return WHISPER_ENCODER_MODEL_PATH;
+}
+
+const ensureWhisperModelSingleflight = createSingleflightRunner(ensureModelInternal);
+
+export async function ensureWhisperModel(): Promise<string> {
+  return ensureWhisperModelSingleflight();
+}

compute/core/src/whisper/spectral.ts

@@ -0,0 +1,21 @@
+export function buildGoertzelCoefficients(freqBins: number, fftSize: number): Float64Array {
+  const coeffs = new Float64Array(freqBins);
+  for (let k = 0; k < freqBins; k += 1) {
+    coeffs[k] = 2 * Math.cos((2 * Math.PI * k) / fftSize);
+  }
+  return coeffs;
+}
+
+export function goertzelPower(samples: Float32Array, coeff: number): number {
+  let s1 = 0;
+  let s2 = 0;
+  for (let i = 0; i < samples.length; i += 1) {
+    const s0 = samples[i] + (coeff * s1) - s2;
+    s2 = s1;
+    s1 = s0;
+  }
+
+  const power = (s1 * s1) + (s2 * s2) - (coeff * s1 * s2);
+  if (!Number.isFinite(power) || power < 0) return 0;
+  return power;
+}

compute/core/src/whisper/token-timestamps.ts

@@ -0,0 +1,449 @@
+import type { Tokenizer } from '@huggingface/tokenizers';
+import type * as ort from 'onnxruntime-node';
+
+const PUNCTUATION_REGEX = '\\p{P}\\u0021-\\u002F\\u003A-\\u0040\\u005B-\\u0060\\u007B-\\u007E';
+const PUNCTUATION_ONLY_REGEX = new RegExp(`^[${PUNCTUATION_REGEX}]+$`, 'gu');
+
+type TokenTimestamp = [start: number, end: number];
+
+export interface WhisperWordTiming {
+  word: string;
+  startSec: number;
+  endSec: number;
+}
+
+function medianFilter(data: Float32Array, windowSize: number): Float32Array {
+  if (windowSize % 2 === 0 || windowSize <= 0) {
+    throw new Error('Window size must be a positive odd number');
+  }
+
+  const output = new Float32Array(data.length);
+  const buffer = new Float32Array(windowSize);
+  const halfWindow = Math.floor(windowSize / 2);
+
+  for (let i = 0; i < data.length; i += 1) {
+    let valuesIndex = 0;
+    for (let j = -halfWindow; j <= halfWindow; j += 1) {
+      let index = i + j;
+      if (index < 0) {
+        index = Math.abs(index);
+      } else if (index >= data.length) {
+        index = (2 * (data.length - 1)) - index;
+      }
+      buffer[valuesIndex] = data[index];
+      valuesIndex += 1;
+    }
+
+    const sortable = Array.from(buffer);
+    sortable.sort((a, b) => a - b);
+    output[i] = sortable[halfWindow] ?? 0;
+  }
+
+  return output;
+}
+
+function dynamicTimeWarping(matrix: Float32Array[], rows: number, cols: number): [number[], number[]] {
+  const cost: number[][] = Array.from({ length: rows + 1 }, () => Array(cols + 1).fill(Number.POSITIVE_INFINITY));
+  const trace: number[][] = Array.from({ length: rows + 1 }, () => Array(cols + 1).fill(-1));
+  cost[0][0] = 0;
+
+  for (let j = 1; j <= cols; j += 1) {
+    for (let i = 1; i <= rows; i += 1) {
+      const c0 = cost[i - 1][j - 1];
+      const c1 = cost[i - 1][j];
+      const c2 = cost[i][j - 1];
+      let c: number;
+      let t: number;
+      if (c0 < c1 && c0 < c2) {
+        c = c0;
+        t = 0;
+      } else if (c1 < c0 && c1 < c2) {
+        c = c1;
+        t = 1;
+      } else {
+        c = c2;
+        t = 2;
+      }
+      cost[i][j] = matrix[i - 1][j - 1] + c;
+      trace[i][j] = t;
+    }
+  }
+
+  for (let i = 0; i <= cols; i += 1) trace[0][i] = 2;
+  for (let i = 0; i <= rows; i += 1) trace[i][0] = 1;
+
+  let i = rows;
+  let j = cols;
+  const textIndices: number[] = [];
+  const timeIndices: number[] = [];
+  while (i > 0 || j > 0) {
+    textIndices.push(i - 1);
+    timeIndices.push(j - 1);
+    const step = trace[i][j];
+    if (step === 0) {
+      i -= 1;
+      j -= 1;
+    } else if (step === 1) {
+      i -= 1;
+    } else if (step === 2) {
+      j -= 1;
+    } else {
+      throw new Error(`Unexpected DTW trace state at [${i}, ${j}]`);
+    }
+  }
+
+  textIndices.reverse();
+  timeIndices.reverse();
+  return [textIndices, timeIndices];
+}
+
+function round2(value: number): number {
+  return Math.round(value * 100) / 100;
+}
+
+function decodeTokens(tokenizer: Pick<Tokenizer, 'decode'>, tokens: number[]): string {
+  return tokenizer.decode(tokens, { skip_special_tokens: false });
+}
+
+function splitTokensOnUnicode(
+  tokenizer: Pick<Tokenizer, 'decode'>,
+  tokens: number[],
+): [string[], number[][], number[][]] {
+  const decodedFull = decodeTokens(tokenizer, tokens);
+  const replacementChar = '\uFFFD';
+  const words: string[] = [];
+  const wordTokens: number[][] = [];
+  const tokenIndices: number[][] = [];
+  let currentTokens: number[] = [];
+  let currentIndices: number[] = [];
+  let unicodeOffset = 0;
+
+  for (let i = 0; i < tokens.length; i += 1) {
+    currentTokens.push(tokens[i]);
+    currentIndices.push(i);
+
+    const decoded = decodeTokens(tokenizer, currentTokens);
+    if (
+      !decoded.includes(replacementChar)
+      || decodedFull[unicodeOffset + decoded.indexOf(replacementChar)] === replacementChar
+    ) {
+      words.push(decoded);
+      wordTokens.push(currentTokens);
+      tokenIndices.push(currentIndices);
+      currentTokens = [];
+      currentIndices = [];
+      unicodeOffset += decoded.length;
+    }
+  }
+
+  return [words, wordTokens, tokenIndices];
+}
+
+function splitTokensOnSpaces(
+  tokenizer: Pick<Tokenizer, 'decode'>,
+  tokens: number[],
+  eosTokenId: number,
+): [string[], number[][], number[][]] {
+  const [subwords, subwordTokens, subwordIndices] = splitTokensOnUnicode(tokenizer, tokens);
+  const words: string[] = [];
+  const wordTokens: number[][] = [];
+  const tokenIndices: number[][] = [];
+
+  for (let i = 0; i < subwords.length; i += 1) {
+    const subword = subwords[i];
+    const tokenList = subwordTokens[i];
+    const indices = subwordIndices[i];
+    const special = tokenList[0] >= eosTokenId;
+    const withSpace = subword.startsWith(' ');
+    const trimmed = subword.trim();
+    const punctuation = PUNCTUATION_ONLY_REGEX.test(trimmed);
+
+    if (special || withSpace || punctuation || words.length === 0) {
+      words.push(subword);
+      wordTokens.push([...tokenList]);
+      tokenIndices.push([...indices]);
+    } else {
+      const ix = words.length - 1;
+      words[ix] += subword;
+      wordTokens[ix].push(...tokenList);
+      tokenIndices[ix].push(...indices);
+    }
+  }
+
+  return [words, wordTokens, tokenIndices];
+}
+
+function mergePunctuations(
+  words: string[],
+  tokens: number[][],
+  indices: number[][],
+  prependPunctuations = '"\'“¡¿([{-',
+  appendPunctuations = '"\'.。,，!！?？:：”)]}、',
+): [string[], number[][], number[][]] {
+  const newWords = words.map((w) => `${w}`);
+  const newTokens = tokens.map((t) => [...t]);
+  const newIndices = indices.map((idx) => [...idx]);
+
+  let i = newWords.length - 2;
+  let j = newWords.length - 1;
+  while (i >= 0) {
+    if (newWords[i].startsWith(' ') && prependPunctuations.includes(newWords[i].trim())) {
+      newWords[j] = newWords[i] + newWords[j];
+      newTokens[j] = [...newTokens[i], ...newTokens[j]];
+      newIndices[j] = [...newIndices[i], ...newIndices[j]];
+      newWords[i] = '';
+      newTokens[i] = [];
+      newIndices[i] = [];
+    } else {
+      j = i;
+    }
+    i -= 1;
+  }
+
+  i = 0;
+  j = 1;
+  while (j < newWords.length) {
+    if (!newWords[i].endsWith(' ') && appendPunctuations.includes(newWords[j])) {
+      newWords[i] += newWords[j];
+      newTokens[i] = [...newTokens[i], ...newTokens[j]];
+      newIndices[i] = [...newIndices[i], ...newIndices[j]];
+      newWords[j] = '';
+      newTokens[j] = [];
+      newIndices[j] = [];
+    } else {
+      i = j;
+    }
+    j += 1;
+  }
+
+  return [
+    newWords.filter((w) => w.length > 0),
+    newTokens.filter((t) => t.length > 0),
+    newIndices.filter((t) => t.length > 0),
+  ];
+}
+
+function combineTokensIntoWords(
+  tokenizer: Pick<Tokenizer, 'decode'>,
+  tokens: number[],
+  eosTokenId: number,
+  language = 'english',
+): [string[], number[][], number[][]] {
+  let words: string[];
+  let wordTokens: number[][];
+  let tokenIndices: number[][];
+
+  if (['chinese', 'japanese', 'thai', 'lao', 'myanmar', 'zh', 'ja', 'th', 'lo', 'my'].includes(language)) {
+    [words, wordTokens, tokenIndices] = splitTokensOnUnicode(tokenizer, tokens);
+  } else {
+    [words, wordTokens, tokenIndices] = splitTokensOnSpaces(tokenizer, tokens, eosTokenId);
+  }
+
+  return mergePunctuations(words, wordTokens, tokenIndices);
+}
+
+export function extractTokenStartTimestamps(input: {
+  crossAttentions: Record<string, ort.Tensor>;
+  decoderLayers: number;
+  alignmentHeads: Array<[number, number]>;
+  numFrames: number;
+  numInputIds: number;
+  timePrecision?: number;
+  sequenceLength: number;
+}): number[] {
+  const {
+    crossAttentions,
+    decoderLayers,
+    alignmentHeads,
+    numFrames,
+    numInputIds,
+    timePrecision = 0.02,
+    sequenceLength,
+  } = input;
+
+  const frameCount = Math.max(1, numFrames);
+  const perLayer: Float32Array[] = [];
+  for (let layer = 0; layer < decoderLayers; layer += 1) {
+    const key = `cross_attentions.${layer}`;
+    const tensor = crossAttentions[key];
+    if (!tensor) continue;
+    perLayer[layer] = tensor.data as Float32Array;
+  }
+
+  const selected: Float32Array[] = [];
+  let seqLen = 0;
+  let attnFrames = 0;
+  for (const [layer, head] of alignmentHeads) {
+    const flat = perLayer[layer];
+    if (!flat) continue;
+    const layerTensor = crossAttentions[`cross_attentions.${layer}`];
+    if (!layerTensor || layerTensor.dims.length < 4) continue;
+    const [, numHeads, currentSeqLen, currentFrames] = layerTensor.dims;
+    if (head >= numHeads) continue;
+    seqLen = currentSeqLen;
+    attnFrames = Math.min(currentFrames, frameCount);
+    const headSlice = new Float32Array(seqLen * attnFrames);
+    for (let s = 0; s < seqLen; s += 1) {
+      for (let f = 0; f < attnFrames; f += 1) {
+        const flatIndex = (((head * currentSeqLen) + s) * currentFrames) + f;
+        headSlice[(s * attnFrames) + f] = flat[flatIndex] ?? 0;
+      }
+    }
+    selected.push(headSlice);
+  }
+
+  if (!selected.length || seqLen === 0 || attnFrames === 0) {
+    return new Array(sequenceLength).fill(0);
+  }
+
+  const normalizedHeads = selected.map((headData) => {
+    const means = new Float32Array(attnFrames);
+    const stds = new Float32Array(attnFrames);
+
+    for (let f = 0; f < attnFrames; f += 1) {
+      let sum = 0;
+      for (let s = 0; s < seqLen; s += 1) sum += headData[(s * attnFrames) + f];
+      const mean = sum / seqLen;
+      means[f] = mean;
+      let varSum = 0;
+      for (let s = 0; s < seqLen; s += 1) {
+        const d = headData[(s * attnFrames) + f] - mean;
+        varSum += d * d;
+      }
+      stds[f] = Math.sqrt(varSum / seqLen) || 1;
+    }
+
+    const out = new Float32Array(headData.length);
+    for (let s = 0; s < seqLen; s += 1) {
+      const row = new Float32Array(attnFrames);
+      for (let f = 0; f < attnFrames; f += 1) {
+        row[f] = (headData[(s * attnFrames) + f] - means[f]) / stds[f];
+      }
+      const filtered = medianFilter(row, 7);
+      out.set(filtered, s * attnFrames);
+    }
+    return out;
+  });
+
+  const croppedRows = Math.max(0, seqLen - numInputIds);
+  if (croppedRows === 0) return new Array(sequenceLength).fill(0);
+
+  const matrix: Float32Array[] = Array.from({ length: croppedRows }, () => new Float32Array(attnFrames));
+  for (const headData of normalizedHeads) {
+    for (let r = 0; r < croppedRows; r += 1) {
+      const srcRow = r + numInputIds;
+      for (let f = 0; f < attnFrames; f += 1) {
+        matrix[r][f] += headData[(srcRow * attnFrames) + f];
+      }
+    }
+  }
+
+  const scale = 1 / normalizedHeads.length;
+  for (let r = 0; r < croppedRows; r += 1) {
+    for (let f = 0; f < attnFrames; f += 1) {
+      matrix[r][f] = -matrix[r][f] * scale;
+    }
+  }
+
+  const [textIndices, timeIndices] = dynamicTimeWarping(matrix, croppedRows, attnFrames);
+  const jumps = new Array(textIndices.length).fill(false);
+  for (let i = 0; i < textIndices.length; i += 1) {
+    jumps[i] = i === 0 ? true : textIndices[i] !== textIndices[i - 1];
+  }
+
+  const jumpTimes: number[] = [];
+  for (let i = 0; i < jumps.length; i += 1) {
+    if (jumps[i]) jumpTimes.push(timeIndices[i] * timePrecision);
+  }
+
+  const timestamps = new Array(sequenceLength).fill(0);
+  for (let i = 0; i < numInputIds && i < timestamps.length; i += 1) timestamps[i] = 0;
+  for (let i = 0; i < jumpTimes.length && (numInputIds + i) < timestamps.length; i += 1) {
+    timestamps[numInputIds + i] = jumpTimes[i];
+  }
+  if (timestamps.length > 0 && jumpTimes.length > 0) {
+    timestamps[timestamps.length - 1] = jumpTimes[jumpTimes.length - 1];
+  }
+  return timestamps;
+}
+
+export function buildWordsFromTimestampedTokens(input: {
+  tokens: number[];
+  tokenStartTimestamps: number[];
+  tokenizer: Pick<Tokenizer, 'decode'>;
+  eosTokenId: number;
+  promptLength: number;
+  timestampBeginTokenId: number;
+  timePrecision?: number;
+  language?: string;
+}): WhisperWordTiming[] {
+  const {
+    tokens,
+    tokenStartTimestamps,
+    tokenizer,
+    eosTokenId,
+    promptLength,
+    timestampBeginTokenId,
+    timePrecision = 0.02,
+    language = 'english',
+  } = input;
+
+  const limit = Math.min(tokens.length, tokenStartTimestamps.length);
+  const tokenRanges: TokenTimestamp[] = [];
+  for (let i = 0; i < limit; i += 1) {
+    const start = tokenStartTimestamps[i] ?? 0;
+    const end = i + 1 < limit ? (tokenStartTimestamps[i + 1] ?? (start + timePrecision)) : (start + timePrecision);
+    tokenRanges.push([start, Math.max(start, end)]);
+  }
+
+  const words: WhisperWordTiming[] = [];
+  let segmentStart: number | null = null;
+  let textTokens: number[] = [];
+  let textRanges: TokenTimestamp[] = [];
+
+  const flushSegment = (segmentEnd: number | null) => {
+    if (!textTokens.length) return;
+    const [wordTexts, , tokenIndices] = combineTokensIntoWords(tokenizer, textTokens, eosTokenId, language);
+    for (let i = 0; i < wordTexts.length; i += 1) {
+      const indices = tokenIndices[i];
+      if (!indices.length) continue;
+      const start = textRanges[indices[0]]?.[0] ?? segmentStart ?? 0;
+      const end = textRanges[indices[indices.length - 1]]?.[1] ?? segmentEnd ?? start;
+      const clampedStart = segmentStart == null ? start : Math.max(segmentStart, start);
+      const clampedEndBase = segmentEnd == null ? end : Math.min(segmentEnd, end);
+      const clampedEnd = Math.max(
+        clampedStart + (clampedEndBase <= clampedStart ? timePrecision : 0),
+        clampedEndBase,
+      );
+      words.push({
+        word: wordTexts[i].trim(),
+        startSec: round2(clampedStart),
+        endSec: round2(clampedEnd),
+      });
+    }
+    textTokens = [];
+    textRanges = [];
+  };
+
+  for (let i = promptLength; i < limit; i += 1) {
+    const token = tokens[i];
+    if (token === eosTokenId) break;
+
+    if (token >= timestampBeginTokenId) {
+      const ts = (token - timestampBeginTokenId) * timePrecision;
+      if (segmentStart == null) {
+        segmentStart = ts;
+      } else {
+        flushSegment(ts);
+        segmentStart = ts;
+      }
+      continue;
+    }
+
+    textTokens.push(token);
+    textRanges.push(tokenRanges[i]);
+  }
+
+  flushSegment(null);
+  return words.filter((w) => w.word.length > 0);
+}

compute/core/tsconfig.json

@@ -0,0 +1,7 @@
+{
+  "extends": "../../tsconfig.json",
+  "compilerOptions": {
+    "noEmit": true
+  },
+  "include": ["src/**/*.ts"]
+}

compute/worker/.env.example

@@ -0,0 +1,58 @@
+# External compute-worker service env only.
+# Keep COMPUTE_WORKER_TOKEN and S3_* aligned with app env.
+# In external worker mode, worker runtime vars live here (or worker platform env),
+# not in the app/root `.env`.
+# App/root `.env` should only set:
+# - COMPUTE_WORKER_URL
+# - COMPUTE_WORKER_TOKEN
+# - optional shared timeout/stale overrides
+# Details: docs/deploy/compute-worker
+
+# Compute worker bind
+# Platform note:
+# - Local/manual: keep PORT=8081
+# - Railway/Render/Fly/etc: platform injects PORT
+# COMPUTE_WORKER_HOST=0.0.0.0
+# PORT=8081
+# LOG_FORMAT=pretty
+# COMPUTE_LOG_LEVEL=info
+
+# Must match app env when app uses COMPUTE_WORKER_URL
+COMPUTE_WORKER_TOKEN=local-compute-token
+
+# NATS/JetStream
+NATS_URL=nats://nats:4222
+# Optional: NATS authentication credentials (e.g. for Synadia Cloud / NGS)
+# You can specify the file path:
+# NATS_CREDS_FILE=/path/to/NGS-Default-compute-worker.creds
+# Or specify the raw credentials string content (excellent for container/cloud platforms):
+# NATS_CREDS="-----BEGIN NATS USER JWT-----\n...\n-----BEGIN USER NKEY SEED-----\n..."
+
+# Shared object storage (must be reachable from worker)
+S3_BUCKET=openreader-documents
+S3_REGION=us-east-1
+S3_ACCESS_KEY_ID=devkey
+S3_SECRET_ACCESS_KEY=devsecret
+# S3_PREFIX=openreader
+# Optional for non-AWS S3-compatible endpoints:
+S3_ENDPOINT=http://host.docker.internal:8333
+S3_FORCE_PATH_STYLE=true
+
+# Optional tuning
+# COMPUTE_PREWARM_MODELS=true
+# COMPUTE_JOB_CONCURRENCY=1
+# COMPUTE_WHISPER_TIMEOUT_MS=30000
+# COMPUTE_PDF_TIMEOUT_MS=300000
+# COMPUTE_PDF_JOB_ATTEMPTS=1
+# COMPUTE_JOBS_STREAM_MAX_BYTES=268435456
+# COMPUTE_EVENTS_STREAM_MAX_BYTES=134217728
+# COMPUTE_JOB_STATES_MAX_BYTES=67108864
+# COMPUTE_NATS_REPLICAS=1
+# COMPUTE_OP_STALE_MS=1800000
+# Optional model mirrors
+# Default expected Whisper variant is q4:
+# - onnx/encoder_model_q4.onnx
+# - onnx/decoder_model_merged_q4.onnx
+# - onnx/decoder_with_past_model_q4.onnx
+# WHISPER_MODEL_BASE_URL=https://huggingface.co/onnx-community/whisper-base_timestamped/resolve/main
+# PDF_LAYOUT_MODEL_BASE_URL=https://huggingface.co/Bei0001/PP-DocLayoutV3-ONNX/resolve/main

compute/worker/Dockerfile

@@ -0,0 +1,29 @@
+FROM node:lts AS deploy-stage
+
+RUN npm install -g pnpm@11.1.2
+
+WORKDIR /workspace
+
+COPY package.json pnpm-lock.yaml pnpm-workspace.yaml ./
+COPY compute/worker/package.json compute/worker/package.json
+COPY compute/core/package.json compute/core/package.json
+
+COPY compute/worker compute/worker
+COPY compute/core compute/core
+
+RUN pnpm --config.inject-workspace-packages=true --filter @openreader/compute-worker deploy /opt/compute-worker
+
+FROM node:lts
+
+RUN npm install -g pnpm@11.1.2
+
+WORKDIR /workspace
+
+COPY --from=deploy-stage /opt/compute-worker ./
+
+ENV COMPUTE_WORKER_HOST=0.0.0.0
+ENV PORT=8081
+
+EXPOSE 8081
+
+CMD ["node", "--import", "tsx", "src/server.ts"]

compute/worker/docker-compose.yml

@@ -0,0 +1,47 @@
+services:
+  nats:
+    image: nats:2.14-alpine
+    container_name: openreader-compute-nats
+    command: ["-js", "-sd", "/data"]
+    ports:
+      - "4222:4222"
+      - "8222:8222"
+    volumes:
+      - nats-data:/data
+
+  compute-worker:
+    build:
+      context: ../..
+      dockerfile: compute/worker/Dockerfile
+    container_name: openreader-compute-worker
+    depends_on:
+      - nats
+    env_file:
+      - ./.env
+    environment:
+      NATS_URL: ${NATS_URL:-nats://nats:4222}
+      COMPUTE_WORKER_HOST: ${COMPUTE_WORKER_HOST:-0.0.0.0}
+      PORT: ${PORT:-8081}
+      COMPUTE_WORKER_TOKEN: ${COMPUTE_WORKER_TOKEN:-local-compute-token}
+      S3_PREFIX: ${S3_PREFIX:-openreader}
+      COMPUTE_PREWARM_MODELS: ${COMPUTE_PREWARM_MODELS:-true}
+    ports:
+      - "8081:8081"
+    develop:
+      watch:
+        - action: sync+restart
+          path: .
+          target: /workspace
+        - action: rebuild
+          path: ../../compute/core
+        - action: rebuild
+          path: ./package.json
+        - action: rebuild
+          path: ../../compute/core/package.json
+        - action: rebuild
+          path: ../../pnpm-lock.yaml
+        - action: rebuild
+          path: ../../pnpm-workspace.yaml
+
+volumes:
+  nats-data:

compute/worker/package.json

@@ -0,0 +1,22 @@
+{
+  "name": "@openreader/compute-worker",
+  "version": "0.0.0",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "dev": "tsx watch src/server.ts",
+    "start": "tsx src/server.ts"
+  },
+  "dependencies": {
+    "@aws-sdk/client-s3": "^3.1050.0",
+    "@nats-io/jetstream": "^3.4.0",
+    "@nats-io/kv": "^3.4.0",
+    "@nats-io/transport-node": "^3.4.0",
+    "@openreader/compute-core": "workspace:*",
+    "fastify": "^5.6.2",
+    "pino": "^10.3.1",
+    "pino-pretty": "^13.1.2",
+    "tsx": "^4.22.3",
+    "zod": "^4.1.12"
+  }
+}

compute/worker/src/control-plane/jetstream.ts

@@ -0,0 +1,315 @@
+import { createHash } from 'node:crypto';
+import { AckPolicy, DeliverPolicy, ReplayPolicy, type JetStreamClient, type JetStreamManager } from '@nats-io/jetstream';
+import { nanos } from '@nats-io/transport-node';
+import type {
+  OperationEvent,
+  OperationEventStream,
+  OperationQueue,
+  OperationState,
+  OperationStateStore,
+  QueuedOperation,
+} from '@openreader/compute-core/control-plane';
+import type {
+  PdfLayoutJobRequest,
+  WhisperAlignJobRequest,
+  WorkerOperationKind,
+} from '@openreader/compute-core/api-contracts';
+import { createJsonCodec } from './json-codec';
+
+export interface KvEntryLike {
+  operation?: string;
+  value: Uint8Array;
+  revision: number;
+}
+
+export interface KvStoreLike {
+  get(key: string): Promise<KvEntryLike | null>;
+  put(key: string, data: Uint8Array): Promise<unknown>;
+  create(key: string, data: Uint8Array): Promise<unknown>;
+  update(key: string, data: Uint8Array, version: number): Promise<unknown>;
+}
+
+function toErrorMessage(error: unknown): string {
+  if (error instanceof Error && error.message) return error.message;
+  return String(error);
+}
+
+function isCasConflictError(error: unknown): boolean {
+  const message = toErrorMessage(error).toLowerCase();
+  return message.includes('wrong last sequence') || message.includes('key exists') || message.includes('wrong last');
+}
+
+function isPut(entry: KvEntryLike | null): entry is KvEntryLike {
+  return Boolean(entry && entry.operation === 'PUT');
+}
+
+interface OpIndexEntry {
+  opId: string;
+}
+
+export const OP_EVENTS_SUBJECT_PREFIX = 'ops.events';
+export const OP_EVENTS_SUBJECT_WILDCARD = `${OP_EVENTS_SUBJECT_PREFIX}.*`;
+
+export function hashOpKey(opKey: string): string {
+  return createHash('sha256').update(opKey).digest('hex');
+}
+
+export function opIndexKvKey(opKey: string): string {
+  return `op_index.${hashOpKey(opKey)}`;
+}
+
+export function opStateKvKey(opId: string): string {
+  return `op_state.${opId}`;
+}
+
+export function opEventsSubject(opId: string): string {
+  return `${OP_EVENTS_SUBJECT_PREFIX}.${opId}`;
+}
+
+export interface JetStreamOperationStateStoreDeps {
+  getKv: () => Promise<KvStoreLike>;
+}
+
+export class JetStreamOperationStateStore<Result = unknown> implements OperationStateStore<Result> {
+  private readonly getKv: () => Promise<KvStoreLike>;
+  private readonly opStateCodec = createJsonCodec<OperationState<Result>>();
+  private readonly opIndexCodec = createJsonCodec<OpIndexEntry>();
+
+  constructor(deps: JetStreamOperationStateStoreDeps) {
+    this.getKv = deps.getKv;
+  }
+
+  async getOpState(opId: string): Promise<OperationState<Result> | null> {
+    const kv = await this.getKv();
+    const entry = await kv.get(opStateKvKey(opId));
+    if (!isPut(entry)) return null;
+    return this.opStateCodec.decode(entry.value);
+  }
+
+  async putOpState(state: OperationState<Result>): Promise<void> {
+    const kv = await this.getKv();
+    await kv.put(opStateKvKey(state.opId), this.opStateCodec.encode(state));
+  }
+
+  async getOpIndex(opKey: string): Promise<{ opId: string } | null> {
+    const kv = await this.getKv();
+    const entry = await kv.get(opIndexKvKey(opKey));
+    if (!isPut(entry)) return null;
+    return this.opIndexCodec.decode(entry.value);
+  }
+
+  async compareAndSetOpIndex(input: {
+    opKey: string;
+    newOpId: string;
+    expectedOpId: string | null;
+  }): Promise<boolean> {
+    const kv = await this.getKv();
+    const key = opIndexKvKey(input.opKey);
+    const value = this.opIndexCodec.encode({ opId: input.newOpId });
+
+    if (input.expectedOpId === null) {
+      try {
+        await kv.create(key, value);
+        return true;
+      } catch (error) {
+        if (isCasConflictError(error)) return false;
+        throw error;
+      }
+    }
+
+    const current = await kv.get(key);
+    if (!isPut(current)) return false;
+    const decoded = this.opIndexCodec.decode(current.value);
+    if (decoded.opId !== input.expectedOpId) return false;
+
+    try {
+      await kv.update(key, value, current.revision);
+      return true;
+    } catch (error) {
+      if (isCasConflictError(error)) return false;
+      throw error;
+    }
+  }
+}
+
+export interface JetStreamOperationEventStreamDeps {
+  getJs: () => Promise<Pick<JetStreamClient, 'publish' | 'consumers'>>;
+  getJsm: () => Promise<Pick<JetStreamManager, 'consumers'>>;
+  eventsStreamName: string;
+  inactiveThresholdMs?: number;
+}
+
+export class JetStreamOperationEventStream<Result = unknown> implements OperationEventStream<Result> {
+  private readonly getJs: () => Promise<Pick<JetStreamClient, 'publish' | 'consumers'>>;
+  private readonly getJsm: () => Promise<Pick<JetStreamManager, 'consumers'>>;
+  private readonly eventsStreamName: string;
+  private readonly inactiveThresholdNanos: number;
+  private readonly opStateCodec = createJsonCodec<OperationState<Result>>();
+
+  constructor(deps: JetStreamOperationEventStreamDeps) {
+    this.getJs = deps.getJs;
+    this.getJsm = deps.getJsm;
+    this.eventsStreamName = deps.eventsStreamName;
+    this.inactiveThresholdNanos = nanos((deps.inactiveThresholdMs ?? 60_000));
+  }
+
+  async append(opId: string, snapshot: OperationState<Result>): Promise<OperationEvent<Result>> {
+    const js = await this.getJs();
+    const encoder = new TextEncoder();
+    const ack = await js.publish(opEventsSubject(opId), encoder.encode(JSON.stringify(snapshot)));
+    return {
+      eventId: ack.seq,
+      snapshot,
+    };
+  }
+
+  private async createConsumer(input: {
+    opId: string;
+    sinceEventId?: number;
+    replayOnly: boolean;
+  }): Promise<{ name: string; js: Pick<JetStreamClient, 'publish' | 'consumers'> }> {
+    const js = await this.getJs();
+    const jsm = await this.getJsm();
+    const subject = opEventsSubject(input.opId);
+    const since = Math.max(0, Math.floor(input.sinceEventId ?? 0));
+    const name = `op_events_${input.opId.slice(0, 12)}_${crypto.randomUUID().replaceAll('-', '').slice(0, 12)}`;
+    const config = {
+      name,
+      ack_policy: AckPolicy.None,
+      deliver_policy: since > 0 ? DeliverPolicy.StartSequence : (input.replayOnly ? DeliverPolicy.All : DeliverPolicy.New),
+      replay_policy: ReplayPolicy.Instant,
+      filter_subject: subject,
+      max_deliver: 1,
+      inactive_threshold: this.inactiveThresholdNanos,
+      ...(since > 0 ? { opt_start_seq: since + 1 } : {}),
+    };
+    await jsm.consumers.add(this.eventsStreamName, config);
+    return { name, js };
+  }
+
+  private async deleteConsumer(name: string): Promise<void> {
+    const jsm = await this.getJsm();
+    await jsm.consumers.delete(this.eventsStreamName, name).catch(() => undefined);
+  }
+
+  async listSince(opId: string, sinceEventId: number, limit = 200): Promise<OperationEvent<Result>[]> {
+    const boundedLimit = Number.isFinite(limit) && limit > 0 ? Math.floor(limit) : 200;
+    const { name, js } = await this.createConsumer({
+      opId,
+      sinceEventId,
+      replayOnly: true,
+    });
+    try {
+      const consumer = await js.consumers.get(this.eventsStreamName, name);
+      const output: OperationEvent<Result>[] = [];
+      while (output.length < boundedLimit) {
+        const msg = await consumer.next({ expires: 250 });
+        if (!msg) break;
+        output.push({
+          eventId: msg.seq,
+          snapshot: this.opStateCodec.decode(msg.data),
+        });
+      }
+      return output;
+    } finally {
+      await this.deleteConsumer(name);
+    }
+  }
+
+  async subscribe(input: {
+    opId: string;
+    sinceEventId?: number;
+    onEvent: (event: OperationEvent<Result>) => void | Promise<void>;
+    onError?: (error: unknown) => void;
+  }): Promise<() => void> {
+    const { name, js } = await this.createConsumer({
+      opId: input.opId,
+      sinceEventId: input.sinceEventId,
+      replayOnly: false,
+    });
+    const consumer = await js.consumers.get(this.eventsStreamName, name);
+    const messages = await consumer.consume();
+    let closed = false;
+
+    void (async () => {
+      try {
+        for await (const msg of messages) {
+          if (closed) break;
+          try {
+            await input.onEvent({
+              eventId: msg.seq,
+              snapshot: this.opStateCodec.decode(msg.data),
+            });
+          } catch (error) {
+            input.onError?.(error);
+          }
+        }
+      } catch (error) {
+        if (!closed) input.onError?.(error);
+      } finally {
+        if (!closed) {
+          closed = true;
+          await this.deleteConsumer(name);
+        }
+      }
+    })();
+
+    return () => {
+      if (closed) return;
+      closed = true;
+      void messages.close().catch(() => undefined);
+      void this.deleteConsumer(name);
+    };
+  }
+}
+
+export interface JetStreamOperationQueueDeps<TPayload> {
+  getJs: () => Promise<Pick<JetStreamClient, 'publish'>>;
+  whisperSubject: string;
+  layoutSubject: string;
+  onEnqueued?: (job: QueuedOperation<TPayload>) => Promise<void> | void;
+}
+
+export class JetStreamOperationQueue implements OperationQueue<WhisperAlignJobRequest | PdfLayoutJobRequest> {
+  private readonly getJs: () => Promise<Pick<JetStreamClient, 'publish'>>;
+  private readonly whisperSubject: string;
+  private readonly layoutSubject: string;
+  private readonly onEnqueued?: (job: QueuedOperation<WhisperAlignJobRequest | PdfLayoutJobRequest>) => Promise<void> | void;
+  private readonly whisperCodec = createJsonCodec<QueuedOperation<WhisperAlignJobRequest>>();
+  private readonly layoutCodec = createJsonCodec<QueuedOperation<PdfLayoutJobRequest>>();
+
+  constructor(deps: JetStreamOperationQueueDeps<WhisperAlignJobRequest | PdfLayoutJobRequest>) {
+    this.getJs = deps.getJs;
+    this.whisperSubject = deps.whisperSubject;
+    this.layoutSubject = deps.layoutSubject;
+    this.onEnqueued = deps.onEnqueued;
+  }
+
+  async enqueue(job: QueuedOperation<WhisperAlignJobRequest | PdfLayoutJobRequest>): Promise<void> {
+    const js = await this.getJs();
+    if (job.kind === 'whisper_align') {
+      await js.publish(
+        this.whisperSubject,
+        this.whisperCodec.encode(job as QueuedOperation<WhisperAlignJobRequest>),
+      );
+    } else if (job.kind === 'pdf_layout') {
+      await js.publish(
+        this.layoutSubject,
+        this.layoutCodec.encode(job as QueuedOperation<PdfLayoutJobRequest>),
+      );
+    } else {
+      const exhaustive: never = job.kind;
+      throw new Error(`Unsupported operation kind: ${String(exhaustive)}`);
+    }
+
+    await this.onEnqueued?.(job);
+  }
+
+  async claimNext(_kind: WorkerOperationKind): Promise<QueuedOperation<WhisperAlignJobRequest | PdfLayoutJobRequest> | null> {
+    throw new Error('JetStreamOperationQueue.claimNext is not used by the worker runtime');
+  }
+
+  size(): number {
+    return 0;
+  }
+}

compute/worker/src/control-plane/json-codec.ts

@@ -0,0 +1,17 @@
+export type JsonCodec<T> = {
+  encode(value: T): Uint8Array;
+  decode(data: Uint8Array): T;
+};
+
+export function createJsonCodec<T>(): JsonCodec<T> {
+  const encoder = new TextEncoder();
+  const decoder = new TextDecoder();
+  return {
+    encode(value: T): Uint8Array {
+      return encoder.encode(JSON.stringify(value));
+    },
+    decode(data: Uint8Array): T {
+      return JSON.parse(decoder.decode(data)) as T;
+    },
+  };
+}

compute/worker/tsconfig.json

@@ -0,0 +1,8 @@
+{
+  "extends": "../../tsconfig.json",
+  "compilerOptions": {
+    "noEmit": true
+  },
+  "include": ["src/**/*.ts"],
+  "exclude": []
+}

docs-site/docs/about/acknowledgements.md

@@ -10,7 +10,7 @@ This project is built with support from the following open-source projects and t
 - [SQLite](https://www.sqlite.org/)
 - [PostgreSQL](https://www.postgresql.org/)
 - [SeaweedFS](https://github.com/seaweedfs/seaweedfs)
-- [whisper.cpp](https://github.com/ggerganov/whisper.cpp)
+- [OpenAI Whisper](https://github.com/openai/whisper)
 - [ffmpeg](https://ffmpeg.org)
 - [react-pdf](https://github.com/wojtekmaj/react-pdf)
 - [react-reader](https://github.com/happyr/react-reader)

docs-site/docs/configure/admin-panel.md

@@ -21,7 +21,7 @@ On every session resolution the server compares the user's email against this li
 When the logged-in user is an admin, an **Admin** tab appears in **Settings → sidebar** with two sub-tabs:
 
 - **Shared providers** — server-side TTS provider instances visible to all users.
-- **Site features** — runtime-editable replacements for what were previously `NEXT_PUBLIC_*` build-time flags.
+- **Site features** — runtime-editable replacements for what were previously build-time public env flags.
 
 ## Shared TTS providers
 
@@ -74,14 +74,15 @@ Runtime-editable settings, one row per key:
 | `restrictUserApiKeys` | Restrict user-supplied API keys/base URLs; when `true`, only admin shared providers are allowed. |
 | `enableTtsProvidersTab` | Whether the user-facing TTS Provider tab in Settings is shown. |
 | `showAllProviderModels` | When `false`, users are restricted to each provider's default model (shared provider `defaultModel` or built-in provider default). |
-| `enableWordHighlight` | Enable whisper.cpp word-by-word highlighting during TTS playback. |
 | `enableAudiobookExport` | Show the audiobook export entry points on PDF/EPUB pages. |
 | `enableDocxConversion` | Accept .docx uploads (converted to PDF server-side). |
 | `enableDestructiveDeleteActions` | Show "Delete all data" buttons in the Documents tab (auth-disabled mode). |
 
+Word-by-word highlighting and PDF layout parsing capability are controlled by compute-worker server env configuration, not an admin runtime flag.
+
 Each row shows a source badge:
 
-- **from env** — the value was migrated from the corresponding `NEXT_PUBLIC_*` env var on first boot. Editing it in the UI flips the source to **admin**.
+- **from env** — the value was migrated from the corresponding `RUNTIME_SEED_*` env var on first boot. Editing it in the UI flips the source to **admin**.
 - **admin** — explicit admin override. Use **Reset** on the row to clear it back to the env-default state.
 - **default** — neither env nor admin set; uses the built-in default.
 
@@ -91,11 +92,11 @@ Turning `restrictUserApiKeys` off allows user-supplied API keys to flow through
 
 ## Migrating off env vars
 
-The future-direction goal is to remove `NEXT_PUBLIC_*` / `API_KEY` / `API_BASE` from your `.env` entirely. To do that safely:
+The future-direction goal is to remove `RUNTIME_SEED_*` / `API_KEY` / `API_BASE` from your `.env` entirely. To do that safely:
 
 1. Deploy this version with your existing env values in place.
 2. Boot the app once. Open Settings → Admin and verify:
-   - Each `NEXT_PUBLIC_*` setting appears as **from env**.
+   - Each `RUNTIME_SEED_*` setting appears as **from env**.
    - A `default-openai` row exists in **Shared providers** (if you had `API_KEY` set).
 3. Remove the env vars from your `.env`.
 4. Redeploy. Behavior is unchanged — the DB is now the source of truth.

docs-site/docs/configure/auth.md

@@ -31,7 +31,7 @@ ADMIN_EMAILS=alice@example.com,bob@example.com
 Admins see a new **Admin** tab in **Settings** with two sub-tabs:
 
 - **Shared TTS providers** — server-managed TTS provider instances with encrypted keys, visible to all users.
-- **Site features** — runtime overrides for what were previously `NEXT_PUBLIC_*` build-time flags (including account signup availability, default TTS provider/model, word highlighting, audiobook export, etc.).
+- **Site features** — runtime overrides for what were previously build-time public env flags (including account signup availability, default TTS provider, audiobook export, etc.).
 
 Admin assignment is reconciled on every session resolution, so removing an email from `ADMIN_EMAILS` demotes the user on next login without a restart. See [Admin Panel](./admin-panel) for the full reference.
 

docs-site/docs/configure/tts-providers.md

@@ -11,7 +11,7 @@ OpenReader routes all TTS requests through the Next.js server to an OpenAI-compa
 **Environment variables**: `API_KEY` and `API_BASE` exist as a one-shot first-boot seed that auto-creates a `default-openai` admin shared provider. After the first boot they are no longer read by the running app.
 
 :::tip
-If you're running a private/self-hosted instance and want per-user BYOK behavior, turn off **Settings → Admin → Site features → Restrict user API keys**. Legacy first-boot seed via `NEXT_PUBLIC_RESTRICT_USER_API_KEYS=false` is still supported for no-admin bootstrap flows.
+If you're running a private/self-hosted instance and want per-user BYOK behavior, turn off **Settings → Admin → Site features → Restrict user API keys**. Legacy first-boot seed via `RUNTIME_SEED_RESTRICT_USER_API_KEYS=false` is still supported for no-admin bootstrap flows.
 :::
 
 ## Providers

docs-site/docs/deploy/compute-worker.md

@@ -0,0 +1,221 @@
+title: Compute Worker (NATS JetStream)
+---
+
+Use this guide when compute-worker runs as a standalone service outside the Next.js app server.
+For embedded/local startup (`pnpm dev` / `pnpm start` without `COMPUTE_WORKER_URL`), use root `.env` instead.
+
+## Overview
+
+The compute worker handles:
+
+- Whisper word alignment operations
+- PDF layout parsing operations
+
+The app server submits operations to `POST /ops`, reuses in-flight work via required `opKey`, and consumes status updates via `GET /ops/:opId/events` (SSE). Queue durability and retries are backed by NATS JetStream WorkQueue consumers and NATS KV.
+
+## Published image
+
+- App server image: `ghcr.io/richardr1126/openreader`
+- Compute worker image: `ghcr.io/richardr1126/openreader-compute-worker`
+- Compute worker image (example pinned tag): `ghcr.io/richardr1126/openreader-compute-worker:refactor-ppdoclayoutv3-onnx-layout-parsing`
+
+## Worker environment variables
+
+Required:
+
+- `COMPUTE_WORKER_TOKEN`: bearer token expected by worker routes
+- `NATS_URL`: NATS server connection string (JetStream enabled)
+- `S3_BUCKET`
+- `S3_REGION`
+- `S3_ACCESS_KEY_ID`
+- `S3_SECRET_ACCESS_KEY`
+
+> [!IMPORTANT]
+> This file (`compute/worker/.env*`) is only for standalone worker deployments.
+> In embedded/local startup, app entrypoint spawns worker with the already-resolved root `.env` values.
+> In standalone external worker mode:
+> - App server env (root `.env` or platform env): `COMPUTE_WORKER_URL`, `COMPUTE_WORKER_TOKEN`, optional shared timeout/stale overrides.
+> - Worker service env (`compute/worker/.env*` or platform env): worker runtime values (`NATS_*`, `S3_*`, model base URLs, worker tuning).
+> For standalone worker deployments, keep shared app/worker values aligned:
+> - `COMPUTE_WORKER_TOKEN`
+> - shared object storage settings (`S3_*`)
+> - shared timeout/stale settings (`COMPUTE_WHISPER_TIMEOUT_MS`, `COMPUTE_PDF_TIMEOUT_MS`, `COMPUTE_OP_STALE_MS`)
+
+Common optional:
+
+- `NATS_CREDS`: raw user credentials file content (JWT + private key), ideal for cloud container environments where mounting files is difficult.
+- `NATS_CREDS_FILE`: path to a `.creds` file on the server.
+- `S3_ENDPOINT` (for non-AWS S3-compatible storage)
+- `S3_FORCE_PATH_STYLE=true` (for many S3-compatible providers)
+- `S3_PREFIX=openreader`
+- `COMPUTE_WORKER_HOST=0.0.0.0`
+- `PORT=8081` (local/manual; on Railway platform injects this)
+- `LOG_FORMAT=pretty` (default) or `json`
+
+Advanced tuning (usually leave unset unless you need overrides):
+
+- `COMPUTE_PREWARM_MODELS=true`
+- `COMPUTE_JOB_CONCURRENCY=1` (shared total compute jobs across whisper + PDF)
+- `COMPUTE_WHISPER_TIMEOUT_MS=30000`
+- `COMPUTE_PDF_TIMEOUT_MS=300000`
+- `WHISPER_MODEL_BASE_URL=https://huggingface.co/onnx-community/whisper-base_timestamped/resolve/main` (optional override, q4 defaults)
+- `PDF_LAYOUT_MODEL_BASE_URL=https://huggingface.co/Bei0001/PP-DocLayoutV3-ONNX/resolve/main` (optional override)
+- `COMPUTE_PDF_JOB_ATTEMPTS=1` (PDF layout retry attempts)
+- `COMPUTE_JOBS_STREAM_MAX_BYTES=268435456` (256MB JetStream jobs stream cap)
+- `COMPUTE_JOB_STATES_MAX_BYTES=67108864` (64MB JetStream KV bucket cap)
+- `COMPUTE_NATS_REPLICAS=1` (JetStream stream + KV replicas; valid: `1`, `3`, `5`)
+- `COMPUTE_OP_STALE_MS=1800000` (stale op replacement window)
+
+## App server environment variables
+
+Set on the Next.js app server:
+
+```env
+# Local worker example:
+# COMPUTE_WORKER_URL=http://localhost:8081
+# Cloud worker example (Railway):
+COMPUTE_WORKER_URL=https://<railway-worker-domain>
+COMPUTE_WORKER_TOKEN=<same-token-as-worker>
+# Optional shared timeout overrides (keep equal to worker service values):
+# COMPUTE_WHISPER_TIMEOUT_MS=30000
+# COMPUTE_PDF_TIMEOUT_MS=300000
+# COMPUTE_OP_STALE_MS=1800000
+```
+
+Model artifact overrides (`WHISPER_MODEL_BASE_URL`, `PDF_LAYOUT_MODEL_BASE_URL`) are worker runtime variables and should be set on the compute worker service environment. Current Whisper defaults expect q4 artifacts (`encoder_model_q4.onnx`, `decoder_model_merged_q4.onnx`, `decoder_with_past_model_q4.onnx`) under that base URL.
+
+`COMPUTE_OP_STALE_MS` is shared by both services in worker mode:
+
+- Worker: opKey stale replacement window in compute op state.
+- App server: stale PDF parse-state healing window (`/api/documents/[id]/parsed*`).
+
+Set the same value on app + worker envs.
+
+There is no app-local compute fallback. If worker is unavailable, affected requests fail.
+
+## Config ownership summary
+
+- Embedded/local startup (`pnpm dev` / `pnpm start`, no `COMPUTE_WORKER_URL`):
+  - Configure root `.env` only.
+  - `compute/worker/.env*` is ignored.
+- Standalone external worker service:
+  - Configure app root `.env` with `COMPUTE_WORKER_URL` + `COMPUTE_WORKER_TOKEN`.
+  - Configure worker service env (`compute/worker/.env*` or platform env).
+  - Keep shared values aligned (`COMPUTE_WORKER_TOKEN`, `S3_*`, timeout/stale values).
+
+## Production notes
+
+- Worker mode assumes shared object storage is reachable by both app server and worker.
+- Non-exposed embedded `weed mini` is not supported with external worker mode.
+- Protect `COMPUTE_WORKER_TOKEN` and avoid exposing worker routes publicly without auth.
+
+## Railway sleep & idle behavior
+
+The worker connects to NATS lazily (on the first request needing the queue/KV) and
+disconnects after **120s** of full idle — no in-flight request, SSE stream, job, or
+queued work. This stops outbound pull polling and keepalive PINGs so Railway can sleep
+it; the next inbound request transparently reconnects, re-ensures the stream/consumers
+and KV (idempotent), and drains anything pending. No separate mode, no extra env vars,
+and the `/ops*` contract is unchanged.
+
+Caveats: inbound HTTP is the wake signal (in OpenReader the app server only enqueues via
+`POST /ops`, so this is always satisfied); a continuous external `/health/*` probe keeps
+it awake and prevents sleep; and the first request after a cold start re-runs model
+prewarm, so it's slower.
+
+## Health endpoints
+
+- `GET /health/live` — liveness; always returns `{ ok: true }`.
+- `GET /health/ready` — returns `{ ok: true, natsConnected }`. It does not probe NATS (that
+  would reconnect and prevent idle sleep); `natsConnected` just reflects the current session.
+
+## Synadia Cloud + Railway Setup (Complete Guide)
+
+Use this end-to-end guide when your queue backend is Synadia Cloud (NGS) and your worker runs on Railway.
+
+### 1. Create Synadia account and credentials
+
+1. Create a Synadia Cloud account and create/select your NGS environment.
+2. Create a user or service account for OpenReader compute worker access.
+3. Download the generated credentials file (usually `<name>.creds`) and keep it secure.
+
+You will use:
+
+- `NATS_URL=tls://connect.ngs.global:4222`
+- The full `.creds` file content
+
+### 2. Deploy compute worker on Railway
+
+Create a Railway service from:
+
+```text
+ghcr.io/richardr1126/openreader-compute-worker:refactor-ppdoclayoutv3-onnx-layout-parsing
+```
+
+Railway injects a dynamic `PORT` env var and routes traffic there.
+Do not hardcode Railway ingress to `8081`; keep service networking enabled and use the public Railway URL.
+
+### 3. Configure Railway worker environment variables
+
+Set these in the Railway worker service:
+
+```env
+COMPUTE_WORKER_HOST=0.0.0.0
+# Local/manual only:
+# PORT=8081
+# Railway: rely on injected PORT
+COMPUTE_WORKER_TOKEN=<long-random-shared-token>
+# Optional advanced tuning overrides (defaults shown):
+# COMPUTE_PREWARM_MODELS=true
+# COMPUTE_JOB_CONCURRENCY=1
+# COMPUTE_WHISPER_TIMEOUT_MS=30000
+# COMPUTE_PDF_TIMEOUT_MS=300000
+# WHISPER_MODEL_BASE_URL=https://huggingface.co/onnx-community/whisper-base_timestamped/resolve/main
+# # Expects q4 files at that base:
+# # - onnx/encoder_model_q4.onnx
+# # - onnx/decoder_model_merged_q4.onnx
+# # - onnx/decoder_with_past_model_q4.onnx
+# PDF_LAYOUT_MODEL_BASE_URL=https://huggingface.co/Bei0001/PP-DocLayoutV3-ONNX/resolve/main
+# COMPUTE_PDF_JOB_ATTEMPTS=1
+# COMPUTE_JOBS_STREAM_MAX_BYTES=268435456
+# COMPUTE_JOB_STATES_MAX_BYTES=67108864
+# COMPUTE_NATS_REPLICAS=1
+
+NATS_URL=tls://connect.ngs.global:4222
+NATS_CREDS="-----BEGIN NATS USER JWT-----
+...
+------END USER NKEY SEED------"
+
+S3_BUCKET=<bucket>
+S3_REGION=<region>
+S3_ACCESS_KEY_ID=<key>
+S3_SECRET_ACCESS_KEY=<secret>
+S3_ENDPOINT=<optional-for-s3-compatible-providers>
+S3_FORCE_PATH_STYLE=true
+S3_PREFIX=openreader
+```
+
+Notes:
+
+- `NATS_CREDS` should be the full Synadia `.creds` file content, including begin/end markers.
+- Keep `COMPUTE_WORKER_TOKEN` identical between app server and worker.
+- On Railway, leave `PORT` managed by the platform.
+- If your platform supports mounted files, you can use `NATS_CREDS_FILE` instead of `NATS_CREDS`.
+- `COMPUTE_JOBS_STREAM_MAX_BYTES` and `COMPUTE_JOB_STATES_MAX_BYTES` are optional; defaults are `268435456` (256MiB) and `67108864` (64MiB).
+- `COMPUTE_NATS_REPLICAS` is optional; default is `1`. Valid values are `1`, `3`, `5`.
+
+### 4. Configure the OpenReader app server
+
+Set these env vars on the app server:
+
+```env
+COMPUTE_WORKER_URL=https://<railway-worker-domain>
+COMPUTE_WORKER_TOKEN=<same-token-as-worker>
+```
+
+### 5. Verify health
+
+After deploy, check:
+
+- `GET https://<railway-worker-domain>/health/live`
+- `GET https://<railway-worker-domain>/health/ready`

docs-site/docs/deploy/local-development.md

@@ -89,6 +89,41 @@ OpenReader currently pins `4.18` in CI and Docker builds while `4.19` compatibil
 
 </details>
 
+<details>
+<summary><strong>NATS Server <code>nats-server</code> (required for embedded compute mode)</strong></summary>
+
+If `COMPUTE_WORKER_URL` is unset, startup launches embedded compute worker + NATS, so `nats-server` must be available on host PATH.
+
+If you always use an external worker (`COMPUTE_WORKER_URL` set), this is not required.
+
+<Tabs groupId="local-dev-nats-os">
+<TabItem value="macos" label="macOS" default>
+
+```bash
+brew install nats-server
+nats-server -v
+```
+
+</TabItem>
+<TabItem value="linux" label="Linux">
+
+```bash
+# Linux amd64 example
+mkdir -p "$HOME/.local/bin"
+curl -fsSL -o /tmp/nats-server.zip \
+  https://github.com/nats-io/nats-server/releases/latest/download/nats-server-v2.12.1-linux-amd64.zip
+unzip -j /tmp/nats-server.zip '*/nats-server' -d /tmp
+install -m 0755 /tmp/nats-server "$HOME/.local/bin/nats-server"
+echo 'export PATH="$HOME/.local/bin:$PATH"' >> ~/.bashrc
+export PATH="$HOME/.local/bin:$PATH"
+nats-server -v
+```
+
+</TabItem>
+</Tabs>
+
+</details>
+
 <details>
 <summary><strong>LibreOffice (optional, for DOCX conversion)</strong></summary>
 
@@ -114,50 +149,51 @@ sudo apt install -y libreoffice
 </details>
 
 <details>
-<summary><strong>whisper.cpp (optional, for word-by-word highlighting)</strong></summary>
+<summary><strong>Word-by-word highlighting (optional)</strong></summary>
 
-Install build dependencies:
+No extra native Whisper CLI build step is required.
 
-<Tabs groupId="local-dev-whisper-deps-os">
-<TabItem value="macos" label="macOS" default>
+Word-by-word highlighting and PDF layout parsing are worker-backed in current releases.
+
+If you need mirrors or pinned artifact locations, set `WHISPER_MODEL_BASE_URL` in `.env` (current defaults expect q4 Whisper files at that base URL).
+
+</details>
+
+<details>
+<summary><strong>External compute worker dev stack (optional)</strong></summary>
+
+Use this only when you intentionally run compute-worker as a separate service.
+Default local flow does not need `compute/worker/.env`; embedded worker startup reads root `.env`.
+Full worker deployment details are in [Compute Worker (NATS JetStream)](./compute-worker).
+
+Start only NATS + compute-worker via compose watch:
 
 ```bash
-brew install cmake
+docker compose --env-file compute/worker/.env -f compute/worker/docker-compose.yml up --watch
+# or: pnpm compute:dev:watch
 ```
 
-</TabItem>
-<TabItem value="linux" label="Linux">
+`compute/worker/.env.example` contains a starter config for standalone worker service deployments.
+
+Run the main app separately on the host:
 
 ```bash
-# Debian/Ubuntu example
-sudo apt update
-sudo apt install -y git build-essential cmake
+pnpm dev
 ```
 
-</TabItem>
-</Tabs>
+For app -> external worker routing, set in root `.env`:
 
-Build whisper.cpp:
-
-```bash
-# clone and build whisper.cpp (no model download needed – OpenReader handles that)
-git clone https://github.com/ggml-org/whisper.cpp.git
-cd whisper.cpp
-cmake -B build
-cmake --build build -j --config Release
-
-# point OpenReader to the compiled whisper-cli binary
-echo WHISPER_CPP_BIN="$(pwd)/build/bin/whisper-cli"
+```env
+COMPUTE_WORKER_URL=http://localhost:8081
+COMPUTE_WORKER_TOKEN=<same-token-used-by-worker>
 ```
 
-If you are not on Debian/Ubuntu, install equivalent packages with your distro package manager:
+Ownership in external worker mode:
+- root `.env`: app routing/auth (`COMPUTE_WORKER_URL`, `COMPUTE_WORKER_TOKEN`) plus optional shared timeout/stale overrides
+- `compute/worker/.env*` (or worker platform env): worker runtime variables (`NATS_*`, `S3_*`, model base URLs, worker tuning)
 
-- Fedora/RHEL: use `dnf` (`gcc gcc-c++ make cmake curl git tar xz`)
-- Arch: use `pacman` (`base-devel cmake curl git tar xz`)
-
-:::tip
-Set `WHISPER_CPP_BIN` in your `.env` to enable word-by-word highlighting.
-:::
+Worker mode requires worker-reachable shared object storage (S3-compatible endpoint).
+For external worker mode, object storage must be shared/reachable by both app and worker services.
 
 </details>
 
@@ -186,6 +222,24 @@ cp .env.example .env
 
 Then edit `.env`.
 
+Default embedded worker flow (no external worker URL):
+
+```env
+# Leave COMPUTE_WORKER_URL unset.
+# Entry point auto-starts embedded worker+NATS when available.
+```
+
+External worker flow:
+
+```env
+COMPUTE_WORKER_URL=http://localhost:8081
+COMPUTE_WORKER_TOKEN=<same-token-used-by-worker>
+```
+
+Use the same ownership split:
+- root `.env`: app routing/auth (`COMPUTE_WORKER_URL`, `COMPUTE_WORKER_TOKEN`) plus optional shared timeout/stale overrides
+- `compute/worker/.env*` (or worker platform env): worker runtime variables (`NATS_*`, `S3_*`, model base URLs, worker tuning)
+
 Use one of these `.env` mode templates:
 
 <Tabs groupId="local-env-modes">
@@ -239,17 +293,35 @@ S3_SECRET_ACCESS_KEY=your-secret-key
 # Optional for non-AWS providers:
 # S3_ENDPOINT=https://your-s3-compatible-endpoint
 # S3_FORCE_PATH_STYLE=true
+```
+
+  </TabItem>
+  <TabItem value="worker-mode" label="External Worker Service">
+
+```env
+API_BASE=http://host.docker.internal:8880/v1
+API_KEY=none
+COMPUTE_WORKER_URL=http://localhost:8081
+COMPUTE_WORKER_TOKEN=<same-token-used-by-worker>
+USE_EMBEDDED_WEED_MINI=false
+S3_BUCKET=your-bucket
+S3_REGION=us-east-1
+S3_ACCESS_KEY_ID=your-access-key
+S3_SECRET_ACCESS_KEY=your-secret-key
+# Optional for non-AWS providers:
+# S3_ENDPOINT=https://your-s3-compatible-endpoint
+# S3_FORCE_PATH_STYLE=true
 ```
 
   </TabItem>
 </Tabs>
 
 :::note Env vars vs. admin panel
-On first boot, `API_KEY` / `API_BASE` and any `NEXT_PUBLIC_*` flags you've set get auto-seeded into the admin-managed runtime config (DB-backed, keys encrypted at rest). After that, the admin UI is authoritative and editing those env vars no longer changes app behavior. See [Admin Panel](../configure/admin-panel).
+On first boot, `API_KEY` / `API_BASE` and any `RUNTIME_SEED_*` flags you've set get auto-seeded into the admin-managed runtime config (DB-backed, keys encrypted at rest). After that, the admin UI is authoritative and editing those env vars no longer changes app behavior. See [Admin Panel](../configure/admin-panel).
 :::
 
 :::note User BYOK restriction default
-If you want each user to enter personal provider credentials, set `restrictUserApiKeys=false` (from **Settings → Admin** when auth/admin is enabled, or via legacy first-boot seed `NEXT_PUBLIC_RESTRICT_USER_API_KEYS=false` for no-admin bootstrap flows).
+If you want each user to enter personal provider credentials, set `restrictUserApiKeys=false` (from **Settings → Admin** when auth/admin is enabled, or via legacy first-boot seed `RUNTIME_SEED_RESTRICT_USER_API_KEYS=false` for no-admin bootstrap flows).
 :::
 
 :::info
@@ -271,6 +343,9 @@ Learn about migration behavior and commands in [Migrations](../configure/migrati
 pnpm dev
 ```
 
+If you use embedded worker startup (no `COMPUTE_WORKER_URL`) and the host is missing `nats-server`,
+install `nats-server` locally or switch to external worker mode.
+
   </TabItem>
   <TabItem value="prod" label="Build + Start">
 

docs-site/docs/deploy/vercel-deployment.md

@@ -8,6 +8,8 @@ This guide covers deploying OpenReader to Vercel with external Postgres and S3-c
 
 - Documents (PDF/EPUB/TXT/MD) work with `POSTGRES_URL` + external S3 storage.
 - Audiobook routes work on Node.js serverless functions using `ffmpeg-static`.
+- Heavy compute features (Whisper alignment + PDF layout parsing) run through an external compute worker service.
+- For worker setup details and worker-specific env vars, see [Compute Worker (NATS JetStream)](./compute-worker).
 
 :::warning DOCX Conversion Limitation
 `docx` conversion requires `soffice` (LibreOffice), which is not available in a standard Vercel runtime.
@@ -35,15 +37,40 @@ BASE_URL=https://your-app.vercel.app
 AUTH_SECRET=...
 ADMIN_EMAILS=you@example.com  # comma-separated; admins manage TTS + features in-app
 
+# Heavy compute (required on Vercel in current releases)
+COMPUTE_WORKER_URL=https://<railway-worker-domain>
+COMPUTE_WORKER_TOKEN=...
+
+# Logging (recommended for Vercel log ingestion)
+LOG_FORMAT=json
+LOG_LEVEL=info
+
 # First-boot seed for the TTS shared provider (optional; manage in-app afterwards)
-API_KEY=your_replicate_key
+# API_KEY=your_replicate_key
 # API_BASE only needed for OpenAI-compatible self-hosted providers
 ```
 
+If you also run an external worker service (for example Railway), set these there too:
+
+- `LOG_FORMAT=json`
+- `COMPUTE_LOG_LEVEL=info`
+
 :::note Env vars vs. admin panel (important for Vercel)
 `API_KEY` / `API_BASE` are one-shot bootstrap seeds on first deploy. After boot, manage providers and site features in **Settings → Admin**. Changes there apply on refresh without a redeploy. See [Admin Panel](../configure/admin-panel).
 :::
 
+## 1a. Railway + Synadia quick start (worker mode)
+
+If your Vercel app uses an external compute worker on Railway with Synadia Cloud (NGS):
+
+1. Deploy a Railway service from:
+   - `ghcr.io/richardr1126/openreader-compute-worker:refactor-ppdoclayoutv3-onnx-layout-parsing`
+2. Enable public networking on that Railway service and set:
+   - `COMPUTE_WORKER_URL=https://<railway-worker-domain>` (in Vercel)
+3. Use the same `COMPUTE_WORKER_TOKEN` value in both Vercel and Railway worker env vars.
+
+For complete Railway worker env vars (`NATS_*`, `S3_*`, health checks, and Synadia `.creds` guidance), see [Compute Worker (NATS JetStream)](./compute-worker).
+
 ## 2. First-run admin configuration (recommended)
 
 After the first successful deploy and admin login, open **Settings → Admin** and configure:
@@ -58,11 +85,10 @@ After the first successful deploy and admin login, open **Settings → Admin** a
   - `defaultTtsProvider=replicate` (or your preferred shared slug).
   - `showAllProviderModels=false` if you want users locked to each provider's default model.
   - `enableAudiobookExport=true`.
-  - `enableWordHighlight=false` unless your timestamp stack is configured.
 
 ## 3. Legacy first-boot seed (optional)
 
-If you must pre-seed site features via environment variables, the legacy `NEXT_PUBLIC_*` seeds are still supported on first boot only. Prefer the admin panel for ongoing management.
+If you must pre-seed site features via environment variables, the legacy `RUNTIME_SEED_*` seeds are still supported on first boot only. Prefer the admin panel for ongoing management.
 
 See [Environment Variables](../reference/environment-variables#legacy-first-boot-runtime-seeds-optional) for the complete legacy seed list.
 
@@ -91,8 +117,7 @@ Vercel deployments do not run `scripts/openreader-entrypoint.mjs`, so automatic
 
 - `/api/audiobook`
 - `/api/audiobook/chapter`
-- `/api/audiobook/status`
-- `/api/whisper`
+- `/api/tts/segments/ensure`
 
 :::info
 `serverExternalPackages` should include `ffmpeg-static` so package paths resolve at runtime instead of being bundled into route output.
@@ -109,7 +134,7 @@ FFmpeg workloads benefit from more memory/CPU. This repo includes:
   "$schema": "https://openapi.vercel.sh/vercel.json",
   "functions": {
     "app/api/audiobook/route.ts": { "memory": 3009 },
-    "app/api/whisper/route.ts": { "memory": 3009 }
+    "app/api/tts/segments/ensure/route.ts": { "memory": 3009 }
   }
 }
 ```
@@ -126,4 +151,4 @@ Adjust memory per route if your files are larger or your plan differs.
 1. Upload and read a PDF/EPUB document.
 2. Confirm sync/blob fetch works across refreshes/devices.
 3. Generate at least one audiobook chapter and play/download it.
-4. If using word highlighting, verify timestamps are produced and rendered.
+4. Verify worker-backed word highlighting and PDF parsing.

docs-site/docs/docker-quick-start.md

@@ -22,6 +22,12 @@ OpenReader currently pins embedded SeaweedFS to `4.18` in CI and Docker builds.
 `4.19` introduced intermittent `InternalError` responses on S3 `PutObject` in our upload flow.
 :::
 
+## Published images
+
+- App server: `ghcr.io/richardr1126/openreader:latest`
+- Compute worker (Optional): `ghcr.io/richardr1126/openreader-compute-worker:latest`
+- Legacy app alias: `ghcr.io/richardr1126/openreader-webui:latest`
+
 ## 1. Start the Docker container
 
 <Tabs groupId="docker-start-mode">
@@ -113,7 +119,7 @@ What this command enables:
 - Set `API_BASE` on first boot to a TTS endpoint the container can reach (`host.docker.internal` works for host-local services). After first boot, manage providers in **Settings → Admin → Shared providers**.
 - Auth is enabled only when both `BASE_URL` and `AUTH_SECRET` are set. The admin panel requires auth.
 - Set `ADMIN_EMAILS` to your email if you want the **Admin** tab in Settings.
-- `restrictUserApiKeys` controls shared-provider-only mode. For per-user BYOK in auth-enabled setups, toggle it off in **Settings → Admin → Site features**. Legacy first-boot seed via `NEXT_PUBLIC_RESTRICT_USER_API_KEYS=false` is still supported.
+- `restrictUserApiKeys` controls shared-provider-only mode. For per-user BYOK in auth-enabled setups, toggle it off in **Settings → Admin → Site features**. Legacy first-boot seed via `RUNTIME_SEED_RESTRICT_USER_API_KEYS=false` is still supported.
 - Use a `/app/docstore` mount if you want data to survive container/image replacement.
 - Startup automatically runs DB/storage migrations via the shared entrypoint.
 :::
@@ -135,6 +141,7 @@ Visit [http://localhost:3003](http://localhost:3003) after startup.
 ## 3. Update Docker image
 
 Legacy image compatibility: `ghcr.io/richardr1126/openreader-webui:latest` remains available as an alias.
+For external compute mode image details, see [Compute Worker (NATS JetStream)](./deploy/compute-worker).
 
 ```bash
 docker stop openreader || true && \

docs-site/docs/introduction.md

@@ -12,28 +12,19 @@ It supports multiple TTS providers including OpenAI, Replicate, DeepInfra, and c
 
 ## ✨ Highlights
 
+- 🧱 **Layout-aware PDF Parsing**
+  - PP-DocLayoutV3 (ONNX) detects structured blocks with cross-page stitching and geometry-based highlighting for precise read-along sync and clean TTS segmentation
+- ⏱️ **Word-by-word Highlighting** via ONNX Whisper alignment
+  - Powered by the external compute worker control plane (NATS JetStream-backed)
+- ⚡ **Segment-based TTS Playback**
+  - Sentence-aware generation with cached audio segments, background preloading, and resumable playback across EPUB, PDF, TXT, MD, and DOCX
 - 🎯 **Multi-Provider TTS Support**
-  - [**Kokoro-FastAPI**](https://github.com/remsky/Kokoro-FastAPI): supports multi-voice combinations (for example `af_heart+af_bella`)
-  - [**KittenTTS-FastAPI**](https://github.com/richardr1126/KittenTTS-FastAPI): lightweight, CPU-friendly self-hosted TTS
-  - [**Orpheus-FastAPI**](https://github.com/Lex-au/Orpheus-FastAPI)
-  - **Custom OpenAI-compatible**: any TTS API with `/v1/audio/voices` and `/v1/audio/speech` endpoints
-  - **Cloud TTS providers**:
-    - [**Replicate**](https://replicate.com/explore): includes a built-in catalog and supports any Replicate model ID via `Other`
-    - [**DeepInfra**](https://deepinfra.com/models/text-to-speech): Kokoro-82M and other hosted models
-    - [**OpenAI API**](https://platform.openai.com/docs/pricing#transcription-and-speech): `tts-1`, `tts-1-hd`, and `gpt-4o-mini-tts`
-- 📖 **Read Along Experience**
-  - Real-time highlighting for PDF/EPUB, with optional word-level [whisper.cpp](https://github.com/ggml-org/whisper.cpp) timestamps
-- 🛜 **Document Storage**
-  - Documents are persisted in server blob/object storage for consistent access
-- ⚡ **Segment-based TTS Playback** for reusable generation + preloading
-  - Stores segment audio in object storage for fast replay/resume
+  - Self-hosted: [**Kokoro-FastAPI**](https://github.com/remsky/Kokoro-FastAPI) (multi-voice combinations), [**KittenTTS-FastAPI**](https://github.com/richardr1126/KittenTTS-FastAPI), [**Orpheus-FastAPI**](https://github.com/Lex-au/Orpheus-FastAPI), or any custom OpenAI-compatible endpoint
+  - Cloud: [**OpenAI**](https://platform.openai.com/docs/pricing#transcription-and-speech) (`tts-1`, `tts-1-hd`, `gpt-4o-mini-tts`), [**Replicate**](https://replicate.com/explore) (built-in catalog + any model ID), [**DeepInfra**](https://deepinfra.com/models/text-to-speech) (Kokoro-82M and others)
 - 🎧 **Audiobook Export** in `m4b`/`mp3` with resumable chapter generation
-- 🔐 **Auth Optional by Design**
-  - Run no-auth for local use, or enable auth with user isolation and claim flow
-- 🗂️ **Flexible Storage and Database Modes** with embedded defaults or external S3/Postgres
-- 🚀 **Production-ready Server Behavior** with TTS caching/retries/rate limits and startup migrations
-- 🎨 **Customizable Experience**
-  - 13 built-in themes (light and dark palettes), TTS, and document handling controls
+- 🗂️ **Flexible Backend** — embedded SeaweedFS or S3-compatible storage, SQLite or Postgres, server library import, and device sync
+- 🔐 **Auth Optional** — run no-auth for local use, or enable full user isolation with a claim flow for multi-user deployments
+- 🎨 **Customizable** — 13 built-in themes (light and dark palettes), per-user TTS settings, and document handling controls
 
 ## 🧭 Key Docs
 

docs-site/docs/reference/environment-variables.md

@@ -6,19 +6,17 @@ toc_max_heading_level: 3
 This is the single reference page for OpenReader environment variables.
 
 :::note Recommended configuration path
-For auth-enabled deployments, use **Settings → Admin** as the primary source of truth for shared TTS providers and site features. Legacy env vars (`API_KEY`, `API_BASE`, and `NEXT_PUBLIC_*`) are optional first-boot seeds only.
+For auth-enabled deployments, use **Settings → Admin** as the primary source of truth for shared TTS providers and site features. Legacy env vars (`API_KEY`, `API_BASE`, and `RUNTIME_SEED_*`) are optional first-boot seeds only.
 :::
 
 ## Quick Reference Table
 
 | Variable | Area | Default | When to set |
 | --- | --- | --- | --- |
-| `ADMIN_EMAILS` | Auth/Admin | empty | Comma-separated emails auto-promoted to admin (requires auth enabled) |
+| `LOG_FORMAT` | Runtime logging | `pretty` | Set `json` for structured logs; shared by app server + compute worker |
+| `LOG_LEVEL` | Runtime logging | `info` | Set app server log level |
 | `API_BASE` | Legacy bootstrap seed | none | Optional first-boot seed into `default-openai`; then manage in Settings → Admin → Shared providers |
 | `API_KEY` | Legacy bootstrap seed | none | Optional first-boot seed into `default-openai`; then manage in Settings → Admin → Shared providers |
-| `NEXT_PUBLIC_*` runtime seeds | Legacy bootstrap seed | varies | Optional first-boot seeds for site features; then manage in Settings → Admin → Site features |
-| `NEXT_PUBLIC_CHANGELOG_FEED_URL` | Legacy bootstrap seed | `https://docs.openreader.richardr.dev/changelog/manifest.json` | Optional first-boot seed for changelog feed URL; then manage in Settings → Admin → Site features |
-| `NEXT_PUBLIC_ENABLE_USER_SIGNUPS` | Legacy bootstrap seed | `true` | Optional first-boot seed for whether new accounts can be created; then manage in Settings → Admin → Site features |
 | `TTS_CACHE_MAX_SIZE_BYTES` | TTS caching | `268435456` (256 MB) | Tune in-memory TTS cache size |
 | `TTS_CACHE_TTL_MS` | TTS caching | `1800000` (30 min) | Tune in-memory TTS cache TTL |
 | `TTS_MAX_RETRIES` | TTS retry | `2` | Tune retry attempts for upstream 429/5xx |
@@ -38,6 +36,7 @@ For auth-enabled deployments, use **Settings → Admin** as the primary source o
 | `GITHUB_CLIENT_ID` | Auth/OAuth | unset | Set with `GITHUB_CLIENT_SECRET` to enable GitHub sign-in |
 | `GITHUB_CLIENT_SECRET` | Auth/OAuth | unset | Set with `GITHUB_CLIENT_ID` to enable GitHub sign-in |
 | `DISABLE_AUTH_RATE_LIMIT` | Rate limiting | `false` | Set `true` to disable auth-layer rate limiting |
+| `ADMIN_EMAILS` | Auth/Admin | empty | Comma-separated emails auto-promoted to admin (requires auth enabled) |
 | `POSTGRES_URL` | Database | unset (SQLite mode) | Set to switch metadata/auth DB to Postgres |
 | `USE_EMBEDDED_WEED_MINI` | Storage | `true` when unset | Set `false` to use external S3-compatible storage only |
 | `WEED_MINI_DIR` | Storage | `docstore/seaweedfs` | Override embedded SeaweedFS data directory |
@@ -53,11 +52,50 @@ For auth-enabled deployments, use **Settings → Admin** as the primary source o
 | `RUN_FS_MIGRATIONS` | Storage migrations | `true` | Set `false` to skip startup filesystem -> S3/DB migration pass |
 | `IMPORT_LIBRARY_DIR` | Library import | `docstore/library` fallback | Set a single server library root |
 | `IMPORT_LIBRARY_DIRS` | Library import | unset | Set multiple roots (comma/colon/semicolon separated) |
-| `WHISPER_CPP_BIN` | Word timing | unset | Set to enable `whisper.cpp` timestamps |
+| `COMPUTE_WORKER_URL` | Heavy compute backend | unset | Set only for standalone external compute worker; leave unset for embedded worker startup |
+| `COMPUTE_WORKER_TOKEN` | Heavy compute backend | unset (auto-generated in embedded startup) | Required for standalone external compute worker auth; must match worker |
+| `EMBEDDED_COMPUTE_WORKER_PORT` | Heavy compute backend | `8081` | Override embedded worker bind port |
+| `EMBEDDED_NATS_PORT` | Heavy compute backend | `4222` | Override embedded NATS client port |
+| `EMBEDDED_NATS_MONITOR_PORT` | Heavy compute backend | `8222` | Override embedded NATS monitor port |
+| `EMBEDDED_NATS_STORE_DIR` | Heavy compute backend | `docstore/nats/jetstream` | Override embedded JetStream storage directory |
+| `NATS_URL` | Heavy compute backend | `nats://127.0.0.1:4222` in embedded startup | Optional override for embedded startup or required on standalone worker service |
+| `COMPUTE_LOG_LEVEL` | Heavy compute backend | `info` | Compute worker log level |
+| `COMPUTE_JOB_CONCURRENCY` | Heavy compute backend | `1` | Worker-side shared compute concurrency cap |
+| `COMPUTE_WHISPER_TIMEOUT_MS` | Heavy compute backend | `30000` | Shared whisper alignment timeout budget (worker + worker client wait budget) |
+| `COMPUTE_PDF_TIMEOUT_MS` | Heavy compute backend | `300000` | Shared PDF idle-timeout budget (worker + worker client wait budget) |
+| `COMPUTE_OP_STALE_MS` | Heavy compute backend | `max(30m, 4x max compute timeout)` | Shared stale window for worker op replacement and app-side stale PDF parse-state healing |
+| `PDF_LAYOUT_MODEL_BASE_URL` | PDF layout model | PP-DocLayoutV3 ONNX base URL | Optional base URL override for `ensureModel()` |
+| `WHISPER_MODEL_BASE_URL` | Whisper ONNX model | onnx-community defaults | Optional base URL override for ONNX whisper-base_timestamped q4 downloads |
 | `FFMPEG_BIN` | Audio runtime | auto-detected (`ffmpeg-static`) | Override ffmpeg binary path |
+| `RUNTIME_SEED_*` runtime seeds | Legacy bootstrap seed | varies | Optional first-boot seeds for site features; then manage in Settings → Admin → Site features |
+| `RUNTIME_SEED_ENABLE_DOCX_CONVERSION` | Legacy bootstrap seed | `true` | Optional first-boot seed to enable/disable DOCX conversion UI |
+| `RUNTIME_SEED_ENABLE_DESTRUCTIVE_DELETE_ACTIONS` | Legacy bootstrap seed | `true` | Optional first-boot seed to show/hide destructive delete actions |
+| `RUNTIME_SEED_ENABLE_TTS_PROVIDERS_TAB` | Legacy bootstrap seed | `true` | Optional first-boot seed to show/hide user TTS providers tab |
+| `RUNTIME_SEED_CHANGELOG_FEED_URL` | Legacy bootstrap seed | `https://docs.openreader.richardr.dev/changelog/manifest.json` | Optional first-boot seed for changelog feed URL; then manage in Settings → Admin → Site features |
+| `RUNTIME_SEED_ENABLE_USER_SIGNUPS` | Legacy bootstrap seed | `true` | Optional first-boot seed for whether new accounts can be created; then manage in Settings → Admin → Site features |
+| `RUNTIME_SEED_RESTRICT_USER_API_KEYS` | Legacy bootstrap seed | runtime-dependent | Optional first-boot seed to restrict per-user BYOK |
+| `RUNTIME_SEED_DEFAULT_TTS_PROVIDER` | Legacy bootstrap seed | `custom-openai` | Optional first-boot seed for default TTS provider slug |
+| `RUNTIME_SEED_ENABLE_AUDIOBOOK_EXPORT` | Legacy bootstrap seed | `true` | Optional first-boot seed to enable audiobook export UI |
 
 
 
+## Runtime Logging
+
+### LOG_FORMAT
+
+Controls log output format for server-side Pino loggers.
+
+- Default: `pretty`
+- Allowed values: `pretty`, `json`
+- Applies to app server and compute worker
+- Recommended in production (Vercel + external worker): `json`
+
+### LOG_LEVEL
+
+App server log level.
+
+- Default: `info`
+
 ## TTS Provider and Request Behavior
 
 ### API_BASE
@@ -230,6 +268,8 @@ Switches metadata/auth storage from SQLite to Postgres.
 - Set: Postgres mode
 - Related docs: [Database](../configure/database)
 
+### Embedded SeaweedFS weed mini config
+
 ### USE_EMBEDDED_WEED_MINI
 
 Controls embedded SeaweedFS startup.
@@ -252,6 +292,8 @@ Maximum seconds to wait for embedded SeaweedFS startup.
 - Default: `20`
 - Related docs: [Object / Blob Storage](../configure/object-blob-storage)
 
+### S3 storage config
+
 ### S3_ACCESS_KEY_ID
 
 Access key for S3-compatible storage.
@@ -346,12 +388,121 @@ Multiple library roots for server library import.
 
 ## Audio Tooling and Alignment
 
-### WHISPER_CPP_BIN
+### COMPUTE_WORKER_URL
 
-Absolute path to compiled `whisper.cpp` binary for word-level timestamps.
+Base URL for standalone external compute worker mode.
 
-- Example: `/whisper.cpp/build/bin/whisper-cli`
-- Required only for optional word-by-word highlighting
+- Leave unset for embedded/local startup (`pnpm dev` / `pnpm start`) so entrypoint can start embedded worker+NATS.
+- Embedded startup requires `nats-server` available on host PATH.
+- Required only when using a standalone external worker service.
+- App-side only: set on app server/root `.env` (routing target), not worker-only env files.
+- Example: `http://localhost:8081`
+
+### COMPUTE_WORKER_TOKEN
+
+Bearer token for compute-worker auth.
+
+- Required for standalone external worker service mode.
+- Must match worker service `COMPUTE_WORKER_TOKEN`.
+- In embedded startup, entrypoint auto-generates one if unset.
+- In external worker mode, set this on both app server/root `.env` and worker service env (`compute/worker/.env*` or platform env).
+
+### EMBEDDED_COMPUTE_WORKER_PORT
+
+Embedded compute-worker HTTP port.
+
+- Default: `8081`
+
+### EMBEDDED_NATS_PORT
+
+Embedded NATS client port.
+
+- Default: `4222`
+
+### EMBEDDED_NATS_MONITOR_PORT
+
+Embedded NATS monitor (`/healthz`) port.
+
+- Default: `8222`
+
+### EMBEDDED_NATS_STORE_DIR
+
+Embedded JetStream storage directory.
+
+- Default: `docstore/nats/jetstream`
+
+### NATS_URL
+
+NATS connection URL used by compute worker runtime.
+
+- Embedded startup default: `nats://127.0.0.1:4222`
+- Standalone worker service: set in worker service env (`compute/worker/.env*` or platform env)
+- For embedded startup, this is optional; startup supplies the default value.
+- Worker-side only in external mode: set on worker service env, not app/root `.env`.
+
+### COMPUTE_LOG_LEVEL
+
+Compute worker log level.
+
+- Default: `info`
+- In standalone mode, set this on the worker service env.
+
+### COMPUTE_JOB_CONCURRENCY
+
+Worker-side shared compute concurrency cap.
+
+- Default: `1`
+- Set on the compute-worker service environment
+
+### COMPUTE_WHISPER_TIMEOUT_MS
+
+Shared whisper alignment timeout budget in milliseconds.
+
+- Default: `30000`
+- Used by:
+  - Worker compute whisper runtime
+  - App server worker-client wait budget (SSE wait timeout)
+
+### COMPUTE_PDF_TIMEOUT_MS
+
+Shared PDF idle-timeout budget in milliseconds.
+
+- Default: `300000` (5 minutes)
+- Used by:
+  - Worker compute PDF runtime (idle timeout)
+  - App server worker-client wait budget (SSE wait timeout)
+
+### COMPUTE_OP_STALE_MS
+
+Shared stale window in milliseconds.
+
+- Default: `max(30m, 4x max(COMPUTE_WHISPER_TIMEOUT_MS, COMPUTE_PDF_TIMEOUT_MS))`
+- Used by:
+  - Worker op reuse/replacement guard (`/ops` opKey stale detection)
+  - App-server PDF parse-state stale healing in `/api/documents/[id]/parsed*`
+- If a parse row is stuck in `pending`/`running` past this window, app routes mark it failed so retries/reparse can proceed.
+- Keep this value aligned on both app-server and worker service envs.
+
+### PDF_LAYOUT_MODEL_BASE_URL
+
+Optional base URL override for PP-DocLayoutV3 artifacts downloaded by `ensureModel()`.
+
+- Default: `https://huggingface.co/Bei0001/PP-DocLayoutV3-ONNX/resolve/main`
+- Required files at that base:
+  - `PP-DocLayoutV3.onnx`
+  - `PP-DocLayoutV3.onnx.data`
+  - `config.json`
+  - `preprocessor_config.json`
+- Configure this on the worker service env (not only the app server env)
+
+### WHISPER_MODEL_BASE_URL
+
+Optional base URL override for the built-in ONNX Whisper alignment model downloader.
+
+- Default: `https://huggingface.co/onnx-community/whisper-base_timestamped/resolve/main`
+- Default model variant: q4 (`encoder_model_q4.onnx`, `decoder_model_merged_q4.onnx`, `decoder_with_past_model_q4.onnx`)
+- The base URL must host all expected manifest files under the same relative paths.
+- Configure this on the worker service env (not only the app server env)
 
 ### FFMPEG_BIN
 
@@ -364,23 +515,23 @@ Absolute path or executable name for the ffmpeg binary used by audiobook/process
 
 These variables exist only as **first-boot seeds** for the admin-managed runtime config. Prefer changing site features from **Settings → Admin → Site features**. Keep these only when you need bootstrap defaults before the first admin login. See [Admin Panel](../configure/admin-panel) for migration behavior.
 
-The values are SSR-injected via `window.__OPENREADER_RUNTIME_CONFIG__`, so admin edits take effect for all users on the next page load — no rebuild required (unlike the old `NEXT_PUBLIC_*` build-time pattern).
+The values are SSR-injected via `window.__RUNTIME_CONFIG__`, so admin edits take effect for all users on the next page load — no rebuild required (unlike the old build-time public env pattern).
 
-### NEXT_PUBLIC_ENABLE_DOCX_CONVERSION
+### RUNTIME_SEED_ENABLE_DOCX_CONVERSION
 
 Controls whether the experimental DOCX-to-PDF conversion and upload feature is enabled.
 
 - Default: `true` (enabled)
 - Runtime key: `enableDocxConversion`
 
-### NEXT_PUBLIC_ENABLE_DESTRUCTIVE_DELETE_ACTIONS
+### RUNTIME_SEED_ENABLE_DESTRUCTIVE_DELETE_ACTIONS
 
 Controls whether the "Delete all user docs" and other bulk-delete buttons are shown in Settings.
 
 - Default: `true` (enabled)
 - Runtime key: `enableDestructiveDeleteActions`
 
-### NEXT_PUBLIC_ENABLE_TTS_PROVIDERS_TAB
+### RUNTIME_SEED_ENABLE_TTS_PROVIDERS_TAB
 
 Controls whether the **TTS Provider** section appears in the user-facing Settings modal.
 
@@ -388,7 +539,7 @@ Controls whether the **TTS Provider** section appears in the user-facing Setting
 - Set `false` to hide provider/model/API controls in the per-user Settings modal (the admin panel is unaffected).
 - Runtime key: `enableTtsProvidersTab`
 
-### NEXT_PUBLIC_ENABLE_USER_SIGNUPS
+### RUNTIME_SEED_ENABLE_USER_SIGNUPS
 
 Controls whether new user accounts can be created.
 
@@ -397,7 +548,7 @@ Controls whether new user accounts can be created.
 - Existing users can still sign in.
 - Runtime key: `enableUserSignups`
 
-### NEXT_PUBLIC_RESTRICT_USER_API_KEYS
+### RUNTIME_SEED_RESTRICT_USER_API_KEYS
 
 Controls whether users can supply personal API keys/base URLs for built-in providers.
 
@@ -406,7 +557,7 @@ Controls whether users can supply personal API keys/base URLs for built-in provi
 - When `false`, users can use per-user BYOK credentials for built-in providers.
 - Runtime key: `restrictUserApiKeys`
 
-### NEXT_PUBLIC_DEFAULT_TTS_PROVIDER
+### RUNTIME_SEED_DEFAULT_TTS_PROVIDER
 
 Sets the default TTS provider for new users.
 
@@ -416,7 +567,7 @@ Sets the default TTS provider for new users.
 
 `showAllProviderModels` is a runtime-only admin setting (no env seed). Configure it in **Settings → Admin → Site features**.
 
-### NEXT_PUBLIC_CHANGELOG_FEED_URL
+### RUNTIME_SEED_CHANGELOG_FEED_URL
 
 Sets the changelog manifest URL used by the Settings modal changelog viewer.
 
@@ -425,21 +576,10 @@ Sets the changelog manifest URL used by the Settings modal changelog viewer.
 - Runtime key: `changelogFeedUrl`
 
 
-### NEXT_PUBLIC_ENABLE_AUDIOBOOK_EXPORT
+### RUNTIME_SEED_ENABLE_AUDIOBOOK_EXPORT
 
 Controls whether audiobook export UI/actions are shown in the client.
 
 - Default: `true` (enabled)
 - Affects export entry points in PDF/EPUB pages and document settings UI
 - Runtime key: `enableAudiobookExport`
-
-### NEXT_PUBLIC_ENABLE_WORD_HIGHLIGHT
-
-Controls word-by-word highlighting UI and timestamp-alignment behavior.
-
-- Default: `true` (enabled)
-- Requires working timestamp generation (for example `WHISPER_CPP_BIN`)
-- Affects:
-  - Word-highlight toggles in document settings
-  - Alignment requests during TTS playback
-- Runtime key: `enableWordHighlight`

docs-site/docs/reference/stack.md

@@ -4,9 +4,10 @@ title: Stack
 
 ## Framework
 
-- [Next.js](https://nextjs.org/) 15 (App Router)
+- [Next.js](https://nextjs.org/) 15 (App Router, Turbopack in dev)
 - [React](https://react.dev/) 19
 - [TypeScript](https://www.typescriptlang.org/)
+- [pnpm](https://pnpm.io/) workspaces monorepo
 
 ## Containerization and runtime
 
@@ -17,24 +18,48 @@ title: Stack
 
 - UI: [Tailwind CSS](https://tailwindcss.com), [Headless UI](https://headlessui.com), [@tailwindcss/typography](https://tailwindcss.com/docs/typography-plugin)
 - Interactions: `react-dnd`, `react-dropzone`
+- Server state: [TanStack Query](https://tanstack.com/query) (React Query v5)
 - Authentication: [Better Auth](https://www.better-auth.com/) client SDK
 - Local storage/cache: [Dexie.js](https://dexie.org/) (IndexedDB)
+- Audio playback: [Howler.js](https://howlerjs.com/)
+- Notifications: `react-hot-toast`
 - Document rendering:
   - PDF: [react-pdf](https://github.com/wojtekmaj/react-pdf), [pdf.js](https://mozilla.github.io/pdf.js/)
   - EPUB: [react-reader](https://github.com/gerhardsletten/react-reader), [epubjs](https://github.com/futurepress/epub.js/)
   - Markdown/Text: [react-markdown](https://github.com/remarkjs/react-markdown), [remark-gfm](https://github.com/remarkjs/remark-gfm)
 - Text preprocessing/matching: [compromise](https://github.com/spencermountain/compromise), [cmpstr](https://github.com/remsky/cmpstr)
+- Analytics: [Vercel Analytics](https://vercel.com/analytics)
 
 ## Next.js server
 
 - APIs: Route Handlers for sync, blob/content access, migrations, audiobook export, TTS/Whisper proxying
 - State sync: request-based today (not realtime push updates)
-- Authentication: [Better Auth](https://www.better-auth.com/) server handlers/adapters
+- Authentication: [Better Auth](https://www.better-auth.com/) server handlers/adapters with anonymous session support
 - Metadata DB: [Drizzle ORM](https://orm.drizzle.team/) with SQLite (`better-sqlite3`) by default and optional Postgres (`pg`)
   - App tables are manually maintained in Drizzle schema files
   - Auth tables are auto-generated by the [Better Auth](https://www.better-auth.com/) CLI and migrated alongside app tables via Drizzle
 - Blob storage: embedded [SeaweedFS](https://github.com/seaweedfs/seaweedfs) (`weed mini`) by default, or external S3-compatible storage via AWS SDK v3
-- Audio/processing pipeline: OpenAI-compatible TTS providers, [ffmpeg](https://ffmpeg.org/) for audiobook assembly, optional [whisper.cpp](https://github.com/ggerganov/whisper.cpp) for word timestamps
+- TTS providers: OpenAI-compatible API (`openai` SDK), [Replicate](https://replicate.com/) (`replicate` client), DeepInfra, and custom OpenAI-compatible endpoints — credentials are encrypted at rest
+- Audio pipeline: [ffmpeg](https://ffmpeg.org/) (`ffmpeg-static`) for audiobook assembly, `archiver` for export packaging
+- Utilities: `lru-cache` for in-process caching, `fast-xml-parser` for EPUB/XML parsing, `uuid` for identifier generation, `zod` for schema validation
+
+## External compute worker (optional)
+
+Monorepo packages under `compute/`:
+
+- **`@openreader/compute-core`** — ONNX runtime lifecycle, model management, and inference logic shared by compute worker runtime + app/worker contracts
+  - ONNX runtime: `onnxruntime-node` with `@huggingface/tokenizers`
+  - Whisper alignment: `onnx-community/whisper-base_timestamped` (q4) for word-level timestamps
+  - PDF layout: `Bei0001/PP-DocLayoutV3-ONNX` for document block detection and layout parsing
+  - PDF rendering: `pdfjs-dist`, `@napi-rs/canvas` for server-side page rasterization
+  - Utilities: `jszip`, `ffmpeg-static`
+- **`@openreader/compute-worker`** — standalone Node.js worker service
+  - HTTP server: [Fastify](https://fastify.dev/) v5
+  - Job queue + state: [NATS](https://nats.io/) JetStream WorkQueue pull consumers + NATS KV (`jobs.whisper`, `jobs.layout`)
+  - Storage: AWS SDK v3 S3 client for reading/writing blobs
+  - Logging: [Pino](https://getpino.io/)
+  - Validation: [Zod](https://zod.dev/)
+- Heavy compute is worker-backed via `COMPUTE_WORKER_URL` + `COMPUTE_WORKER_TOKEN` (remote queue via HTTP + NATS)
 
 ## Tooling and testing
 
@@ -42,3 +67,4 @@ title: Stack
 - TypeScript
 - [Playwright](https://playwright.dev/) end-to-end tests
 - Drizzle migration/generation scripts
+- [Docusaurus](https://docusaurus.io/) documentation site (`docs-site/`)

docs-site/sidebars.ts

@@ -53,7 +53,7 @@ const sidebars: SidebarsConfig = {
     {
       type: 'category',
       label: '🚀 Deploy',
-      items: ['deploy/local-development', 'deploy/vercel-deployment'],
+      items: ['deploy/local-development', 'deploy/compute-worker', 'deploy/vercel-deployment'],
     },
     {
       type: 'category',

docs-site/versioned_docs/version-v3.0.0/reference/environment-variables.md

@@ -364,7 +364,7 @@ Absolute path or executable name for the ffmpeg binary used by audiobook/process
 
 These variables exist only as **first-boot seeds** for the admin-managed runtime config. Prefer changing site features from **Settings → Admin → Site features**. Keep these only when you need bootstrap defaults before the first admin login. See [Admin Panel](../configure/admin-panel) for migration behavior.
 
-The values are SSR-injected via `window.__OPENREADER_RUNTIME_CONFIG__`, so admin edits take effect for all users on the next page load — no rebuild required (unlike the old `NEXT_PUBLIC_*` build-time pattern).
+The values are SSR-injected via `window.__RUNTIME_CONFIG__`, so admin edits take effect for all users on the next page load — no rebuild required (unlike the old `NEXT_PUBLIC_*` build-time pattern).
 
 ### NEXT_PUBLIC_ENABLE_DOCX_CONVERSION
 

drizzle/postgres/0005_pdf_layout_and_compute.sql

@@ -0,0 +1,14 @@
+CREATE TABLE "document_settings" (
+	"document_id" text NOT NULL,
+	"user_id" text NOT NULL,
+	"data_json" jsonb DEFAULT '{}'::jsonb NOT NULL,
+	"client_updated_at_ms" bigint DEFAULT 0 NOT NULL,
+	"created_at" bigint DEFAULT (extract(epoch from now()) * 1000)::bigint,
+	"updated_at" bigint DEFAULT (extract(epoch from now()) * 1000)::bigint,
+	CONSTRAINT "document_settings_document_id_user_id_pk" PRIMARY KEY("document_id","user_id")
+);
+--> statement-breakpoint
+ALTER TABLE "documents" ADD COLUMN "parse_status" text;--> statement-breakpoint
+ALTER TABLE "documents" ADD COLUMN "parsed_json_key" text;--> statement-breakpoint
+ALTER TABLE "document_settings" ADD CONSTRAINT "document_settings_user_id_user_id_fk" FOREIGN KEY ("user_id") REFERENCES "public"."user"("id") ON DELETE cascade ON UPDATE no action;--> statement-breakpoint
+CREATE INDEX "idx_document_settings_user_id" ON "document_settings" USING btree ("user_id");

drizzle/postgres/0006_preview-defaults-cleanup.sql

@@ -0,0 +1,2 @@
+ALTER TABLE "document_previews" ALTER COLUMN "variant" DROP DEFAULT;--> statement-breakpoint
+ALTER TABLE "document_previews" ALTER COLUMN "width" DROP DEFAULT;

drizzle/postgres/0007_pdf_parse_progress.sql

@@ -0,0 +1,2 @@
+ALTER TABLE "documents" ADD COLUMN "parse_state" text;--> statement-breakpoint
+ALTER TABLE "documents" DROP COLUMN "parse_status";

drizzle/postgres/meta/_journal.json

@@ -36,6 +36,27 @@
       "when": 1778644075378,
       "tag": "0004_admin_panel",
       "breakpoints": true
+    },
+    {
+      "idx": 5,
+      "version": "7",
+      "when": 1779041718214,
+      "tag": "0005_pdf_layout_and_compute",
+      "breakpoints": true
+    },
+    {
+      "idx": 6,
+      "version": "7",
+      "when": 1779102950715,
+      "tag": "0006_preview-defaults-cleanup",
+      "breakpoints": true
+    },
+    {
+      "idx": 7,
+      "version": "7",
+      "when": 1779378127846,
+      "tag": "0007_pdf_parse_progress",
+      "breakpoints": true
     }
   ]
 }

drizzle/sqlite/0005_pdf_layout_and_compute.sql

@@ -0,0 +1,14 @@
+CREATE TABLE `document_settings` (
+	`document_id` text NOT NULL,
+	`user_id` text NOT NULL,
+	`data_json` text DEFAULT '{}' NOT NULL,
+	`client_updated_at_ms` integer DEFAULT 0 NOT NULL,
+	`created_at` integer DEFAULT (cast(unixepoch('subsecond') * 1000 as integer)),
+	`updated_at` integer DEFAULT (cast(unixepoch('subsecond') * 1000 as integer)),
+	PRIMARY KEY(`document_id`, `user_id`),
+	FOREIGN KEY (`user_id`) REFERENCES `user`(`id`) ON UPDATE no action ON DELETE cascade
+);
+--> statement-breakpoint
+CREATE INDEX `idx_document_settings_user_id` ON `document_settings` (`user_id`);--> statement-breakpoint
+ALTER TABLE `documents` ADD `parse_status` text;--> statement-breakpoint
+ALTER TABLE `documents` ADD `parsed_json_key` text;

drizzle/sqlite/0006_preview-defaults-cleanup.sql

@@ -0,0 +1,27 @@
+PRAGMA foreign_keys=OFF;--> statement-breakpoint
+CREATE TABLE `__new_document_previews` (
+	`document_id` text NOT NULL,
+	`namespace` text DEFAULT '' NOT NULL,
+	`variant` text NOT NULL,
+	`status` text DEFAULT 'queued' NOT NULL,
+	`source_last_modified_ms` integer NOT NULL,
+	`object_key` text NOT NULL,
+	`content_type` text DEFAULT 'image/jpeg' NOT NULL,
+	`width` integer NOT NULL,
+	`height` integer,
+	`byte_size` integer,
+	`etag` text,
+	`lease_owner` text,
+	`lease_until_ms` integer DEFAULT 0 NOT NULL,
+	`attempt_count` integer DEFAULT 0 NOT NULL,
+	`last_error` text,
+	`created_at_ms` integer DEFAULT 0 NOT NULL,
+	`updated_at_ms` integer DEFAULT 0 NOT NULL,
+	PRIMARY KEY(`document_id`, `namespace`, `variant`)
+);
+--> statement-breakpoint
+INSERT INTO `__new_document_previews`("document_id", "namespace", "variant", "status", "source_last_modified_ms", "object_key", "content_type", "width", "height", "byte_size", "etag", "lease_owner", "lease_until_ms", "attempt_count", "last_error", "created_at_ms", "updated_at_ms") SELECT "document_id", "namespace", "variant", "status", "source_last_modified_ms", "object_key", "content_type", "width", "height", "byte_size", "etag", "lease_owner", "lease_until_ms", "attempt_count", "last_error", "created_at_ms", "updated_at_ms" FROM `document_previews`;--> statement-breakpoint
+DROP TABLE `document_previews`;--> statement-breakpoint
+ALTER TABLE `__new_document_previews` RENAME TO `document_previews`;--> statement-breakpoint
+PRAGMA foreign_keys=ON;--> statement-breakpoint
+CREATE INDEX `idx_document_previews_status_lease` ON `document_previews` (`status`,`lease_until_ms`);

drizzle/sqlite/0007_pdf_parse_progress.sql

@@ -0,0 +1,2 @@
+ALTER TABLE `documents` ADD `parse_state` text;--> statement-breakpoint
+ALTER TABLE `documents` DROP COLUMN `parse_status`;

drizzle/sqlite/meta/_journal.json

@@ -36,6 +36,27 @@
       "when": 1778644075081,
       "tag": "0004_admin_panel",
       "breakpoints": true
+    },
+    {
+      "idx": 5,
+      "version": "6",
+      "when": 1779041717890,
+      "tag": "0005_pdf_layout_and_compute",
+      "breakpoints": true
+    },
+    {
+      "idx": 6,
+      "version": "6",
+      "when": 1779102950385,
+      "tag": "0006_preview-defaults-cleanup",
+      "breakpoints": true
+    },
+    {
+      "idx": 7,
+      "version": "6",
+      "when": 1779378125905,
+      "tag": "0007_pdf_parse_progress",
+      "breakpoints": true
     }
   ]
 }

empty-module.ts

@@ -1 +1,3 @@
-export default {};
+const emptyModule = {};
+
+export default emptyModule;

eslint.config.mjs

@@ -9,8 +9,114 @@ const compat = new FlatCompat({
   baseDirectory: __dirname,
 });
 
+const LOGGER_LEVEL_METHOD = "trace|debug|info|warn|error|fatal";
+const STATIC_LOGGER_CALL_SELECTOR =
+  `CallExpression[callee.type='MemberExpression'][callee.computed=false][callee.property.name=/^(${LOGGER_LEVEL_METHOD})$/]`;
+const DYNAMIC_LOGGER_CALL_SELECTOR =
+  "CallExpression[callee.type='MemberExpression'][callee.computed=true]";
+const LOGGER_RECEIVER_SELECTOR =
+  ":matches([callee.object.name=/^(logger|serverLogger)$/],[callee.object.property.name='logger'])";
+const SERVER_LOGGER_CALL_SELECTOR = `:matches(${STATIC_LOGGER_CALL_SELECTOR}${LOGGER_RECEIVER_SELECTOR},${DYNAMIC_LOGGER_CALL_SELECTOR}${LOGGER_RECEIVER_SELECTOR})`;
+const NEXT_RESPONSE_ERROR_JSON_SELECTOR =
+  "CallExpression[callee.type='MemberExpression'][callee.object.name='NextResponse'][callee.property.name='json'][arguments.0.type='ObjectExpression']:has(Property[key.name='error'])";
+
 const eslintConfig = [
   ...compat.extends("next/core-web-vitals", "next/typescript"),
+  {
+    rules: {
+      "no-restricted-imports": [
+        "error",
+        {
+          patterns: [
+            {
+              group: [
+                "@openreader/compute-core/*",
+                "!@openreader/compute-core/local-runtime",
+                "!@openreader/compute-core/types",
+                "!@openreader/compute-core/api-contracts",
+              ],
+              message:
+                "Use '@openreader/compute-core' root imports for light APIs. Allowed subpaths are '@openreader/compute-core/local-runtime', '@openreader/compute-core/types', and '@openreader/compute-core/api-contracts'.",
+            },
+          ],
+        },
+      ],
+    },
+  },
+  {
+    files: ["src/app/api/**/*.ts", "src/lib/server/**/*.ts"],
+    rules: {
+      "no-console": "error",
+      "no-restricted-syntax": [
+        "error",
+        {
+          selector: `${SERVER_LOGGER_CALL_SELECTOR}[arguments.length<2]`,
+          message:
+            "Server logger calls must pass context + message: logger.<level>({ event, ...ctx }, 'message').",
+        },
+        {
+          selector: `${SERVER_LOGGER_CALL_SELECTOR}[arguments.0.type!='ObjectExpression']`,
+          message:
+            "Server logger first argument must be an object with an event field.",
+        },
+        {
+          selector: `${SERVER_LOGGER_CALL_SELECTOR}[arguments.0.type='Literal']`,
+          message:
+            "Server logger first argument must be an object with an event field, not a string literal.",
+        },
+        {
+          selector: `${SERVER_LOGGER_CALL_SELECTOR}[arguments.0.type='TemplateLiteral']`,
+          message:
+            "Server logger first argument must be an object with an event field, not a template string.",
+        },
+        {
+          selector: `${SERVER_LOGGER_CALL_SELECTOR}[arguments.0.type='ObjectExpression']:not(:has(Property[key.name='event']))`,
+          message:
+            "Server logger context object must include an event field.",
+        },
+        {
+          selector: `${SERVER_LOGGER_CALL_SELECTOR}[arguments.1.type!='Literal'][arguments.1.type!='TemplateLiteral']`,
+          message:
+            "Server logger second argument must be a message string (literal or template literal).",
+        },
+        {
+          selector: `${STATIC_LOGGER_CALL_SELECTOR}[callee.property.name='error']${LOGGER_RECEIVER_SELECTOR}[arguments.0.type='ObjectExpression']:not(:has(ObjectExpression > Property[key.name='error'])):not(:has(ObjectExpression > SpreadElement))`,
+          message:
+            "Error-level server logger calls must include nested `error` payload (prefer `error: errorToLog(...)`).",
+        },
+        {
+          selector: `${SERVER_LOGGER_CALL_SELECTOR} > ObjectExpression:first-child > Property[key.name='detail']`,
+          message:
+            "Do not use top-level `detail` in server logger context; keep throwable text under `error.message`.",
+        },
+        {
+          selector: `${SERVER_LOGGER_CALL_SELECTOR} > ObjectExpression:first-child > Property[key.name='errorCode']`,
+          message:
+            "Do not use top-level `errorCode` in server logger context; classify failures under nested `error.code`.",
+        },
+        {
+          selector: `${SERVER_LOGGER_CALL_SELECTOR} > ObjectExpression:first-child > Property[key.name='err']`,
+          message:
+            "Use `error` (typically from errorToLog(...)) instead of `err` in server logs.",
+        },
+        {
+          selector: `${SERVER_LOGGER_CALL_SELECTOR} > ObjectExpression:first-child > Property[key.name='error'][value.type='Literal']`,
+          message:
+            "Server logger `error` must be a structured object (prefer `errorToLog(...)`), not a literal.",
+        },
+        {
+          selector: `${SERVER_LOGGER_CALL_SELECTOR} > ObjectExpression:first-child > Property[key.name='error'][value.type='TemplateLiteral']`,
+          message:
+            "Server logger `error` must be a structured object (prefer `errorToLog(...)`), not template text.",
+        },
+        {
+          selector: `CatchClause ReturnStatement > ${NEXT_RESPONSE_ERROR_JSON_SELECTOR}[arguments.1.type='ObjectExpression']:has(Property[key.name='status'][value.value=500])`,
+          message:
+            "Use shared error response helpers (e.g. errorResponse(...)) for terminal 500 route failures instead of direct NextResponse.json({ error }).",
+        },
+      ],
+    },
+  },
 ];
 
 export default eslintConfig;

next.config.ts

@@ -15,6 +15,14 @@ const securityHeaders = [
   },
 ];
 
+const bundleWorkerCompute = true;
+const serverExternalPackages = [
+  '@napi-rs/canvas',
+  'better-sqlite3',
+  'ffmpeg-static',
+  ...(!bundleWorkerCompute ? ['onnxruntime-node', '@huggingface/tokenizers'] : []),
+];
+
 const nextConfig: NextConfig = {
   async headers() {
     return [
@@ -30,7 +38,8 @@ const nextConfig: NextConfig = {
       canvas: '@napi-rs/canvas',
     },
   },
-  serverExternalPackages: ["@napi-rs/canvas", "ffmpeg-static", "better-sqlite3"],
+  transpilePackages: [],
+  serverExternalPackages,
   outputFileTracingIncludes: {
     '/api/audiobook': [
       './node_modules/ffmpeg-static/ffmpeg',
@@ -38,7 +47,7 @@ const nextConfig: NextConfig = {
     '/api/audiobook/chapter': [
       './node_modules/ffmpeg-static/ffmpeg',
     ],
-    '/api/whisper': [
+    '/api/tts/segments/ensure': [
       './node_modules/ffmpeg-static/ffmpeg',
     ],
     '/api/documents/blob/preview/ensure': [
@@ -51,6 +60,24 @@ const nextConfig: NextConfig = {
       './node_modules/pdfjs-dist/legacy/build/pdf.worker.mjs',
     ],
   },
+  outputFileTracingExcludes: {
+    '/*': [
+      './docstore/**/*',
+      './node_modules/onnxruntime-node/**/*',
+      './node_modules/@huggingface/tokenizers/**/*',
+    ],
+  },
+  webpack: (config, { isServer }) => {
+    if (isServer && bundleWorkerCompute) {
+      config.resolve.alias = {
+        ...(config.resolve.alias || {}),
+        '@openreader/compute-core/local-runtime$': false,
+        'onnxruntime-node$': false,
+        '@huggingface/tokenizers$': false,
+      };
+    }
+    return config;
+  },
 };
 
 export default nextConfig;

package.json

@@ -7,6 +7,7 @@
     "dev": "node scripts/openreader-entrypoint.mjs -- pnpm dev:raw",
     "dev:raw": "next dev --turbopack -p 3003",
     "build": "next build",
+    "build:bundle-guard": "node scripts/check-next-server-bundle.mjs",
     "start": "node scripts/openreader-entrypoint.mjs -- pnpm start:raw",
     "start:raw": "next start -p 3003",
     "lint": "next lint",
@@ -20,12 +21,18 @@
     "docs:build": "pnpm --dir docs-site build",
     "docs:serve": "pnpm --dir docs-site serve",
     "docs:version": "pnpm --dir docs-site docusaurus docs:version",
-    "docs:clear": "pnpm --dir docs-site clear"
+    "docs:clear": "pnpm --dir docs-site clear",
+    "compute:worker:dev": "pnpm --filter @openreader/compute-worker dev",
+    "compute:worker:start": "pnpm --filter @openreader/compute-worker start",
+    "compute:dev:compose": "docker compose --env-file compute/worker/.env -f compute/worker/docker-compose.yml up --build",
+    "compute:dev:watch": "docker compose --env-file compute/worker/.env -f compute/worker/docker-compose.yml up --watch",
+    "lint:route-errors": "node scripts/check-route-error-responses.mjs"
   },
   "dependencies": {
     "@aws-sdk/client-s3": "^3.1045.0",
     "@aws-sdk/s3-request-presigner": "^3.1045.0",
     "@headlessui/react": "^2.2.10",
+    "@huggingface/tokenizers": "^0.1.3",
     "@napi-rs/canvas": "^0.1.100",
     "@tanstack/react-query": "^5.100.10",
     "@types/archiver": "^7.0.0",
@@ -48,9 +55,12 @@
     "jszip": "^3.10.1",
     "lru-cache": "^11.3.6",
     "next": "^15.5.18",
+    "onnxruntime-node": "^1.26.0",
     "openai": "^6.37.0",
     "pdfjs-dist": "4.8.69",
     "pg": "^8.20.0",
+    "pino": "^10.3.1",
+    "pino-pretty": "^13.1.3",
     "react": "^19.2.6",
     "react-dnd": "^16.0.1",
     "react-dnd-html5-backend": "^16.0.1",

playwright.config.ts

@@ -6,6 +6,7 @@ import 'dotenv/config';
  */
 export default defineConfig({
   testDir: './tests',
+  tsconfig: './tsconfig.json',
   timeout: 30 * 1000,
   outputDir: './tests/results',
   globalTeardown: './tests/global-teardown.ts',
@@ -29,7 +30,7 @@ export default defineConfig({
   /* Run your local dev server before starting the tests */
   webServer: {
     // Disable auth rate limiting for tests to support parallel workers creating sessions
-    command: `npm run build && DISABLE_AUTH_RATE_LIMIT=true npm run start`,
+    command: `pnpm build && DISABLE_AUTH_RATE_LIMIT=true pnpm start`,
     url: 'http://localhost:3003',
     reuseExistingServer: !process.env.CI,
     timeout: 120 * 1000,

pnpm-workspace.yaml

@@ -1,7 +1,6 @@
 packages:
   - .
-
-strictDepBuilds: false
+  - compute/*
 
 allowBuilds:
   '@napi-rs/canvas': true
@@ -11,10 +10,13 @@ allowBuilds:
   es5-ext: false
   esbuild: false
   ffmpeg-static: true
+  onnxruntime-node: true
   sharp: false
   unrs-resolver: false
 
 overrides:
-  lodash: ^4.17.23
-  '@xmldom/xmldom': ^0.9.8
   '@types/localforage': npm:empty-module@0.0.2
+  '@xmldom/xmldom': ^0.9.8
+  lodash: ^4.17.23
+
+strictDepBuilds: false

scripts/check-next-server-bundle.mjs

@@ -0,0 +1,50 @@
+import fs from 'node:fs';
+import path from 'node:path';
+
+const root = process.cwd();
+const serverDir = path.join(root, '.next', 'server');
+
+if (!fs.existsSync(serverDir)) {
+  console.error('[bundle-guard] Missing .next/server. Run `pnpm build` first.');
+  process.exit(1);
+}
+
+const forbidden = [
+  'onnxruntime-node',
+  '@huggingface/tokenizers',
+  '@openreader/compute-core/local-runtime',
+];
+
+const includeExt = new Set(['.js', '.mjs', '.cjs']);
+const failures = [];
+
+function walk(dir) {
+  for (const entry of fs.readdirSync(dir, { withFileTypes: true })) {
+    const fullPath = path.join(dir, entry.name);
+    if (entry.isDirectory()) {
+      walk(fullPath);
+      continue;
+    }
+    if (!entry.isFile()) continue;
+    const ext = path.extname(entry.name).toLowerCase();
+    if (!includeExt.has(ext)) continue;
+    const text = fs.readFileSync(fullPath, 'utf8');
+    for (const pattern of forbidden) {
+      if (text.includes(pattern)) {
+        failures.push({ file: fullPath, pattern });
+      }
+    }
+  }
+}
+
+walk(serverDir);
+
+if (failures.length > 0) {
+  console.error('[bundle-guard] Forbidden compute deps detected in Next server bundle:');
+  for (const failure of failures) {
+    console.error(`- ${failure.pattern} in ${path.relative(root, failure.file)}`);
+  }
+  process.exit(1);
+}
+
+console.info('[bundle-guard] OK: no forbidden compute deps in .next/server');

scripts/check-route-error-responses.mjs

@@ -0,0 +1,54 @@
+#!/usr/bin/env node
+import fs from 'node:fs/promises';
+import path from 'node:path';
+
+const ROOT = process.cwd();
+const API_DIR = path.join(ROOT, 'src', 'app', 'api');
+
+async function walk(dir) {
+  const entries = await fs.readdir(dir, { withFileTypes: true });
+  const files = [];
+  for (const entry of entries) {
+    const full = path.join(dir, entry.name);
+    if (entry.isDirectory()) {
+      files.push(...await walk(full));
+      continue;
+    }
+    if (entry.isFile() && full.endsWith('.ts')) files.push(full);
+  }
+  return files;
+}
+
+function findViolations(source) {
+  const violations = [];
+  const catchWithDirectJson500 =
+    /catch\s*\(\s*error\s*\)\s*\{[\s\S]{0,1200}?NextResponse\.json\s*\(\s*\{\s*error:[\s\S]{0,240}status:\s*500/g;
+  let match;
+  while ((match = catchWithDirectJson500.exec(source)) !== null) {
+    const index = match.index;
+    const line = source.slice(0, index).split('\n').length;
+    violations.push(line);
+  }
+  return violations;
+}
+
+const files = await walk(API_DIR);
+const failures = [];
+for (const file of files) {
+  const source = await fs.readFile(file, 'utf8');
+  const lines = findViolations(source);
+  if (lines.length > 0) {
+    failures.push({ file, lines });
+  }
+}
+
+if (failures.length > 0) {
+  for (const failure of failures) {
+    for (const line of failure.lines) {
+      console.error(`${path.relative(ROOT, failure.file)}:${line} direct NextResponse.json({ error }) in catch`);
+    }
+  }
+  process.exit(1);
+}
+
+console.log('Route error response check passed.');

scripts/openreader-entrypoint.mjs

@@ -137,6 +137,12 @@ function hasWeedBinary() {
   return true;
 }
 
+function hasNatsBinary() {
+  const probe = spawnSync('nats-server', ['-v'], { stdio: 'ignore' });
+  if (probe.error) return false;
+  return true;
+}
+
 async function waitForEndpoint(url, timeoutSeconds) {
   const waitMs = Math.max(1, timeoutSeconds) * 1000;
   const deadline = Date.now() + waitMs;
@@ -181,19 +187,20 @@ function spawnMainCommand(command, env) {
   const exitPromise = new Promise((resolve) => {
     child.on('error', (error) => {
       console.error('Failed to launch command:', error);
-      resolve(1);
+      resolve({ code: 1, signal: null, launchError: true });
     });
 
     child.on('exit', (code, signal) => {
+      console.error(`Main command exit event: code=${code ?? 'null'} signal=${signal ?? 'null'}.`);
       if (typeof code === 'number') {
-        resolve(code);
+        resolve({ code, signal: null, launchError: false });
         return;
       }
       if (signal) {
-        resolve(1);
+        resolve({ code: 1, signal, launchError: false });
         return;
       }
-      resolve(0);
+      resolve({ code: 0, signal: null, launchError: false });
     });
   });
 
@@ -311,12 +318,23 @@ async function main() {
   }
 
   const runtimeEnv = { ...process.env };
+  runtimeEnv.LOG_FORMAT = withDefault(runtimeEnv.LOG_FORMAT, 'pretty');
   let weedProc = null;
   let weedExitPromise = Promise.resolve();
+  let natsProc = null;
+  let natsExitPromise = Promise.resolve();
+  let workerProc = null;
+  let workerExitPromise = Promise.resolve();
   let appProc = null;
   let shutdownPromise = null;
+  let isShuttingDown = false;
+  let fatalExitScheduled = false;
   let stopWeedStdoutForward = () => { };
   let stopWeedStderrForward = () => { };
+  let stopNatsStdoutForward = () => { };
+  let stopNatsStderrForward = () => { };
+  let stopWorkerStdoutForward = () => { };
+  let stopWorkerStderrForward = () => { };
   let didExit = false;
 
   const exitOnce = (code) => {
@@ -325,16 +343,38 @@ async function main() {
     process.exit(code);
   };
 
+  const scheduleFatalShutdown = (serviceName, code, signal, detail) => {
+    if (fatalExitScheduled || isShuttingDown || didExit) return;
+    fatalExitScheduled = true;
+    const codeLabel = typeof code === 'number' ? String(code) : 'null';
+    const signalLabel = signal ?? 'null';
+    const suffix = detail ? ` (${detail})` : '';
+    console.error(
+      `Critical service "${serviceName}" exited unexpectedly: code=${codeLabel} signal=${signalLabel}${suffix}. `
+      + 'Shutting down all services.',
+    );
+    void shutdown('SIGTERM').finally(() => exitOnce(typeof code === 'number' && code !== 0 ? code : 1));
+  };
+
   const shutdown = async (signal = 'SIGTERM') => {
     if (shutdownPromise) return shutdownPromise;
+    isShuttingDown = true;
     shutdownPromise = (async () => {
       await Promise.all([
         terminateChild(appProc, signal, 4000),
+        terminateChild(workerProc, 'SIGTERM', 4000),
+        terminateChild(natsProc, 'SIGTERM', 4000),
         terminateChild(weedProc, 'SIGTERM', 4000),
       ]);
       await weedExitPromise;
+      await natsExitPromise;
+      await workerExitPromise;
       stopWeedStdoutForward();
       stopWeedStderrForward();
+      stopNatsStdoutForward();
+      stopNatsStderrForward();
+      stopWorkerStdoutForward();
+      stopWorkerStderrForward();
     })();
     return shutdownPromise;
   };
@@ -374,7 +414,12 @@ async function main() {
       const waitTimeout = Number.isFinite(waitSec) ? waitSec : 20;
       const launchWeed = (endpointUrl) => {
         const parsedEndpoint = parseS3Endpoint(endpointUrl);
-        const weedArgs = ['mini', `-dir=${runtimeEnv.WEED_MINI_DIR}`];
+        const weedArgs = [
+          '-alsologtostderr=false',
+          '-stderrthreshold=WARNING',
+          'mini',
+          `-dir=${runtimeEnv.WEED_MINI_DIR}`,
+        ];
         weedArgs.push(`-s3.port=${parsedEndpoint.port}`);
         if (runningInDocker) {
           weedArgs.push('-ip.bind=0.0.0.0');
@@ -389,13 +434,13 @@ async function main() {
         weedExitPromise = once(weedProc, 'exit').then(() => undefined).catch(() => undefined);
 
         weedProc.on('exit', (code, signal) => {
+          if (isShuttingDown) return;
           if (typeof code === 'number' && code !== 0) {
             console.error(`Embedded weed mini exited with code ${code}.`);
-            return;
-          }
-          if (signal) {
+          } else if (signal) {
             console.error(`Embedded weed mini exited due to signal ${signal}.`);
           }
+          scheduleFatalShutdown('weed mini', code, signal, 'embedded storage service');
         });
       };
 
@@ -419,9 +464,108 @@ async function main() {
       }
     }
 
+    const embeddedWorkerPort = Number.parseInt(withDefault(runtimeEnv.EMBEDDED_COMPUTE_WORKER_PORT, '8081'), 10);
+    const embeddedNatsPort = Number.parseInt(withDefault(runtimeEnv.EMBEDDED_NATS_PORT, '4222'), 10);
+    const embeddedNatsMonitorPort = Number.parseInt(withDefault(runtimeEnv.EMBEDDED_NATS_MONITOR_PORT, '8222'), 10);
+    const shouldStartEmbeddedWorker = !Boolean(runtimeEnv.COMPUTE_WORKER_URL?.trim());
+
+    if (shouldStartEmbeddedWorker && !hasNatsBinary()) {
+      throw new Error(
+        '`nats-server` binary is required when COMPUTE_WORKER_URL is unset. '
+        + 'Install nats-server or set COMPUTE_WORKER_URL and COMPUTE_WORKER_TOKEN for an external worker.',
+      );
+    }
+
+    if (shouldStartEmbeddedWorker) {
+      runtimeEnv.NATS_URL = withDefault(runtimeEnv.NATS_URL, `nats://127.0.0.1:${embeddedNatsPort}`);
+      runtimeEnv.COMPUTE_WORKER_URL = withDefault(runtimeEnv.COMPUTE_WORKER_URL, `http://127.0.0.1:${embeddedWorkerPort}`);
+      runtimeEnv.COMPUTE_WORKER_TOKEN = withDefault(
+        runtimeEnv.COMPUTE_WORKER_TOKEN,
+        randomBytes(24).toString('base64url'),
+      );
+      runtimeEnv.COMPUTE_WORKER_HOST = withDefault(runtimeEnv.COMPUTE_WORKER_HOST, '127.0.0.1');
+      runtimeEnv.COMPUTE_NATS_REPLICAS = withDefault(runtimeEnv.COMPUTE_NATS_REPLICAS, '1');
+
+      const natsStoreDir = withDefault(runtimeEnv.EMBEDDED_NATS_STORE_DIR, 'docstore/nats/jetstream');
+      fs.mkdirSync(natsStoreDir, { recursive: true });
+
+      console.log(`Starting embedded nats-server on 127.0.0.1:${embeddedNatsPort}...`);
+      natsProc = spawn(
+        'nats-server',
+        [
+          '-js',
+          '-sd', natsStoreDir,
+          '-a', '127.0.0.1',
+          '-p', String(embeddedNatsPort),
+          '-m', String(embeddedNatsMonitorPort),
+        ],
+        {
+          env: runtimeEnv,
+          stdio: ['ignore', 'pipe', 'pipe'],
+        },
+      );
+      stopNatsStdoutForward = forwardChildStream(natsProc.stdout, process.stdout);
+      stopNatsStderrForward = forwardChildStream(natsProc.stderr, process.stderr);
+      natsExitPromise = once(natsProc, 'exit').then(() => undefined).catch(() => undefined);
+      natsProc.on('exit', (code, signal) => {
+        if (isShuttingDown) return;
+        if (typeof code === 'number' && code !== 0) {
+          console.error(`Embedded nats-server exited with code ${code}.`);
+        } else if (signal) {
+          console.error(`Embedded nats-server exited due to signal ${signal}.`);
+        }
+        scheduleFatalShutdown('nats-server', code, signal, 'embedded queue service');
+      });
+      natsProc.on('error', (error) => {
+        console.error(`Embedded nats-server failed to start: ${error instanceof Error ? error.message : String(error)}`);
+        scheduleFatalShutdown('nats-server', null, null, 'failed to start');
+      });
+      await waitForEndpoint(`http://127.0.0.1:${embeddedNatsMonitorPort}/healthz`, 20);
+      console.log(`Embedded nats-server is ready at nats://127.0.0.1:${embeddedNatsPort}`);
+
+      console.log(`Starting embedded compute-worker on 127.0.0.1:${embeddedWorkerPort}...`);
+      const workerEnv = {
+        ...runtimeEnv,
+        PORT: String(embeddedWorkerPort),
+      };
+      workerProc = spawn(
+        'pnpm',
+        ['--filter', '@openreader/compute-worker', 'start'],
+        {
+          env: workerEnv,
+          stdio: ['ignore', 'pipe', 'pipe'],
+          shell: process.platform === 'win32',
+        },
+      );
+      stopWorkerStdoutForward = forwardChildStream(workerProc.stdout, process.stdout);
+      stopWorkerStderrForward = forwardChildStream(workerProc.stderr, process.stderr);
+      workerExitPromise = once(workerProc, 'exit').then(() => undefined).catch(() => undefined);
+      workerProc.on('exit', (code, signal) => {
+        if (isShuttingDown) return;
+        if (typeof code === 'number' && code !== 0) {
+          console.error(`Embedded compute-worker exited with code ${code}.`);
+        } else if (signal) {
+          console.error(`Embedded compute-worker exited due to signal ${signal}.`);
+        }
+        scheduleFatalShutdown('compute-worker', code, signal, 'embedded compute service');
+      });
+      workerProc.on('error', (error) => {
+        console.error(`Embedded compute-worker failed to start: ${error instanceof Error ? error.message : String(error)}`);
+        scheduleFatalShutdown('compute-worker', null, null, 'failed to start');
+      });
+      await waitForEndpoint(`http://127.0.0.1:${embeddedWorkerPort}/health/ready`, 30);
+      console.log(`Embedded compute-worker is ready at http://127.0.0.1:${embeddedWorkerPort}`);
+    } else if (!runtimeEnv.COMPUTE_WORKER_URL?.trim() || !runtimeEnv.COMPUTE_WORKER_TOKEN?.trim()) {
+      throw new Error('COMPUTE_WORKER_URL and COMPUTE_WORKER_TOKEN are required when embedded compute worker startup is disabled.');
+    }
+
     const { child, exitPromise } = spawnMainCommand(command, runtimeEnv);
     appProc = child;
-    const exitCode = await exitPromise;
+    const exitInfo = await exitPromise;
+    const exitCode = typeof exitInfo?.code === 'number' ? exitInfo.code : 1;
+    console.error(
+      `Main command finished with code=${exitInfo?.code ?? 'null'} signal=${exitInfo?.signal ?? 'null'} launchError=${Boolean(exitInfo?.launchError)}.`,
+    );
 
     await shutdown('SIGTERM');
     exitOnce(exitCode);

src/app/(app)/app/layout.tsx

@@ -4,16 +4,13 @@ import type { ReactNode } from 'react';
 
 import { ConfigProvider } from '@/contexts/ConfigContext';
 import { DocumentProvider } from '@/contexts/DocumentContext';
-import { DexieMigrationModal } from '@/components/documents/DexieMigrationModal';
+import { OnboardingFlowProvider } from '@/contexts/OnboardingFlowContext';
 
 export default function AppHomeLayout({ children }: { children: ReactNode }) {
   return (
     <ConfigProvider>
       <DocumentProvider>
-        <>
-          {children}
-          <DexieMigrationModal />
-        </>
+        <OnboardingFlowProvider>{children}</OnboardingFlowProvider>
       </DocumentProvider>
     </ConfigProvider>
   );

src/app/(app)/epub/[id]/page.tsx

@@ -19,6 +19,7 @@ import { resolveDocumentId } from '@/lib/client/dexie';
 import { RateLimitBanner } from '@/components/auth/RateLimitBanner';
 import { useAuthRateLimit } from '@/contexts/AuthRateLimitContext';
 import { useFeatureFlag } from '@/contexts/RuntimeConfigContext';
+import { useUnmountCleanupRef } from '@/hooks/useUnmountCleanupRef';
 import { useEpubDocument } from './useEpubDocument';
 
 export default function EPUBPage() {
@@ -102,6 +103,8 @@ export default function EPUBPage() {
     loadDocument();
   }, [loadDocument, isLoading]);
 
+  useUnmountCleanupRef(clearCurrDoc);
+
   // Compute available height = viewport - (header height + tts bar height)
   useEffect(() => {
     const compute = () => {
@@ -111,7 +114,9 @@ export default function EPUBPage() {
       const ttsH = ttsbar ? ttsbar.getBoundingClientRect().height : 0;
       const vh = window.innerHeight;
       const h = Math.max(0, vh - headerH - ttsH);
-      setContainerHeight(`${h}px`);
+      if (h > 0) {
+        setContainerHeight(`${h}px`);
+      }
 
       // compute max horizontal padding while preserving a minimum readable width,
       // but still allow some padding on small screens
@@ -122,9 +127,15 @@ export default function EPUBPage() {
       setMaxPadPx(maxPad);
     };
     compute();
+    const settleT1 = window.setTimeout(compute, 0);
+    const settleT2 = window.setTimeout(compute, 120);
     window.addEventListener('resize', compute);
-    return () => window.removeEventListener('resize', compute);
-  }, []);
+    return () => {
+      window.removeEventListener('resize', compute);
+      window.clearTimeout(settleT1);
+      window.clearTimeout(settleT2);
+    };
+  }, [isLoading, activeSidebar]);
 
   // Nudge EPUB renderer to reflow on horizontal padding changes
   useEffect(() => {
@@ -162,7 +173,6 @@ export default function EPUBPage() {
         <p className="text-red-500 mb-4">{error}</p>
         <Link
           href="/app"
-          onClick={() => clearCurrDoc()}
           className="inline-flex items-center px-3 py-1 bg-base text-foreground rounded-lg hover:bg-offbase transition-all duration-200 ease-in-out hover:scale-[1.04] hover:text-accent"
         >
           <svg className="w-4 h-4 mr-2 text-muted" fill="none" stroke="currentColor" viewBox="0 0 24 24">
@@ -180,7 +190,6 @@ export default function EPUBPage() {
         left={
           <Link
             href="/app"
-            onClick={() => clearCurrDoc()}
             className="inline-flex items-center py-1 px-2 rounded-md border border-offbase bg-base text-foreground text-xs hover:bg-offbase transition-all duration-200 ease-in-out hover:scale-[1.04] hover:text-accent"
             aria-label="Back to documents"
           >

src/app/(app)/epub/[id]/useEpubDocument.ts

@@ -101,7 +101,6 @@ export function useEpubDocument(documentId?: string): EpubDocumentState {
     baseUrl,
     providerRef,
     ttsSegmentMaxBlockLength,
-    smartSentenceSplitting,
     epubTheme,
     epubHighlightEnabled,
   } = useConfig();
@@ -239,22 +238,13 @@ export function useEpubDocument(documentId?: string): EpubDocumentState {
       const leadingPreview = collectLeadingContextFromRange(range);
       const continuationPreview = collectContinuationFromRange(range);
 
-      if (smartSentenceSplitting) {
-        setTTSText(textContent, {
-          shouldPause,
-          location: start.cfi,
-          previousText: leadingPreview,
-          nextLocation: end.cfi,
-          nextText: continuationPreview
-        });
-      } else {
-        // When smart splitting is disabled, behave like the original implementation:
-        // send only the current page/location text without any continuation preview.
-        setTTSText(textContent, {
-          shouldPause,
-          location: start.cfi,
-        });
-      }
+      setTTSText(textContent, {
+        shouldPause,
+        location: start.cfi,
+        previousText: leadingPreview,
+        nextLocation: end.cfi,
+        nextText: continuationPreview
+      });
       setCurrDocText(textContent);
 
       return textContent;
@@ -262,7 +252,7 @@ export function useEpubDocument(documentId?: string): EpubDocumentState {
       console.error('Error extracting EPUB text:', error);
       return '';
     }
-  }, [setRenderedTextMaps, setTTSText, smartSentenceSplitting]);
+  }, [setRenderedTextMaps, setTTSText]);
 
   /**
    * Resolves a draft EPUB locator (typically `{ readerType: 'epub', location:

src/app/(app)/html/[id]/page.tsx

@@ -17,6 +17,7 @@ import { RateLimitBanner } from '@/components/auth/RateLimitBanner';
 import { AudiobookExportModal } from '@/components/AudiobookExportModal';
 import { useAuthRateLimit } from '@/contexts/AuthRateLimitContext';
 import { useFeatureFlag } from '@/contexts/RuntimeConfigContext';
+import { useUnmountCleanupRef } from '@/hooks/useUnmountCleanupRef';
 import type { TTSAudiobookChapter } from '@/types/tts';
 import type { AudiobookGenerationSettings } from '@/types/client';
 import { useHtmlDocument } from './useHtmlDocument';
@@ -102,6 +103,8 @@ export default function HTMLPage() {
     loadDocument();
   }, [loadDocument, isLoading]);
 
+  useUnmountCleanupRef(clearCurrDoc);
+
   // Compute available height = viewport - (header height + tts bar height)
   useEffect(() => {
     const compute = () => {
@@ -111,7 +114,9 @@ export default function HTMLPage() {
       const ttsH = ttsbar ? ttsbar.getBoundingClientRect().height : 0;
       const vh = window.innerHeight;
       const h = Math.max(0, vh - headerH - ttsH);
-      setContainerHeight(`${h}px`);
+      if (h > 0) {
+        setContainerHeight(`${h}px`);
+      }
 
       // Adaptive minimum content width: allow some padding on narrow screens
       const vw = window.innerWidth;
@@ -121,9 +126,15 @@ export default function HTMLPage() {
       setMaxPadPx(maxPad);
     };
     compute();
+    const settleT1 = window.setTimeout(compute, 0);
+    const settleT2 = window.setTimeout(compute, 120);
     window.addEventListener('resize', compute);
-    return () => window.removeEventListener('resize', compute);
-  }, []);
+    return () => {
+      window.removeEventListener('resize', compute);
+      window.clearTimeout(settleT1);
+      window.clearTimeout(settleT2);
+    };
+  }, [isLoading, activeSidebar]);
 
   const handleGenerateAudiobook = useCallback(async (
     onProgress: (progress: number) => void,
@@ -149,7 +160,6 @@ export default function HTMLPage() {
         <p className="text-red-500 mb-4">{error}</p>
         <Link
           href="/app"
-          onClick={() => { clearCurrDoc(); }}
           className="inline-flex items-center px-3 py-1 bg-base text-foreground rounded-lg hover:bg-offbase transition-all duration-200 ease-in-out hover:scale-[1.04] hover:text-accent"
         >
           <svg className="w-4 h-4 mr-2" fill="none" stroke="currentColor" viewBox="0 0 24 24">
@@ -167,7 +177,6 @@ export default function HTMLPage() {
         left={
           <Link
             href="/app"
-            onClick={() => clearCurrDoc()}
             className="inline-flex items-center py-1 px-2 rounded-md border border-offbase bg-base text-foreground text-xs hover:bg-offbase transition-all duration-200 ease-in-out hover:scale-[1.04] hover:text-accent"
             aria-label="Back to documents"
           >

src/app/(app)/html/[id]/useHtmlDocument.ts

@@ -68,7 +68,6 @@ export function useHtmlDocument(): HtmlDocumentState {
     apiKey,
     baseUrl,
     providerRef,
-    smartSentenceSplitting,
     ttsSegmentMaxBlockLength,
   } = useConfig();
 
@@ -133,10 +132,9 @@ export function useHtmlDocument(): HtmlDocumentState {
       createHtmlAudiobookSourceAdapter({
         blocks,
         isTxt,
-        smartSentenceSplitting,
         maxBlockLength: ttsSegmentMaxBlockLength,
       }),
-    [blocks, isTxt, smartSentenceSplitting, ttsSegmentMaxBlockLength],
+    [blocks, isTxt, ttsSegmentMaxBlockLength],
   );
 
   const createFullAudioBook = useCallback(

src/app/(app)/layout.tsx

@@ -3,7 +3,6 @@ import type { ReactNode } from 'react';
 import { Toaster } from 'react-hot-toast';
 
 import { Providers } from '@/app/providers';
-import ClaimDataPopup from '@/components/auth/ClaimDataModal';
 import { getAuthBaseUrl, isAnonymousAuthSessionsEnabled, isAuthEnabled, isGithubAuthEnabled } from '@/lib/server/auth/config';
 
 export const dynamic = 'force-dynamic';
@@ -36,7 +35,6 @@ export default function AppLayout({ children }: { children: ReactNode }) {
       githubAuthEnabled={githubAuthEnabled}
     >
       <div className="app-shell min-h-screen flex flex-col bg-background">
-        {authEnabled && <ClaimDataPopup />}
         <main className="flex-1 flex flex-col">{children}</main>
       </div>
       <Toaster

src/app/(app)/pdf/[id]/page.tsx

@@ -3,14 +3,14 @@
 import dynamic from 'next/dynamic';
 import { useParams, useRouter } from 'next/navigation';
 import Link from 'next/link';
-import { useCallback, useEffect, useRef, useState } from 'react';
-import { DocumentSkeleton } from '@/components/documents/DocumentSkeleton';
+import { useCallback, useEffect, useRef, useState, type MouseEvent } from 'react';
 import { useTTS } from '@/contexts/TTSContext';
 import { DocumentSettings } from '@/components/documents/DocumentSettings';
 import { DocumentHeaderMenu } from '@/components/documents/DocumentHeaderMenu';
 import { SegmentsSidebar } from '@/components/reader/SegmentsSidebar';
 import { Header } from '@/components/Header';
 import { AudiobookExportModal } from '@/components/AudiobookExportModal';
+import { ConfirmDialog } from '@/components/ConfirmDialog';
 import type { TTSAudiobookChapter } from '@/types/tts';
 import type { AudiobookGenerationSettings } from '@/types/client';
 import TTSPlayer from '@/components/player/TTSPlayer';
@@ -19,6 +19,14 @@ import { resolveDocumentId } from '@/lib/client/dexie';
 import { RateLimitBanner } from '@/components/auth/RateLimitBanner';
 import { useAuthRateLimit } from '@/contexts/AuthRateLimitContext';
 import { useFeatureFlag } from '@/contexts/RuntimeConfigContext';
+import { LoadingSpinner } from '@/components/Spinner';
+import {
+  FORCE_REPARSE_CONFIRM_MESSAGE,
+  FORCE_REPARSE_CONFIRM_TEXT,
+  FORCE_REPARSE_CONFIRM_TITLE,
+  isForceReparseDisabled,
+} from '@/lib/client/pdf/force-reparse';
+import { useUnmountCleanupRef } from '@/hooks/useUnmountCleanupRef';
 import { usePdfDocument } from './usePdfDocument';
 
 // Dynamic import for client-side rendering only
@@ -26,10 +34,12 @@ const PDFViewer = dynamic(
   () => import('@/components/views/PDFViewer').then((module) => module.PDFViewer),
   {
     ssr: false,
-    loading: () => <DocumentSkeleton />
+    loading: () => null
   }
 );
 
+const PARSE_LOADER_EXPAND_DELAY_MS = 320;
+
 export default function PDFViewerPage() {
   const canExportAudiobook = useFeatureFlag('enableAudiobookExport');
   const { id } = useParams();
@@ -41,6 +51,13 @@ export default function PDFViewerPage() {
     clearCurrDoc,
     currDocPage,
     currDocPages,
+    parseStatus,
+    parseProgress,
+    documentSettings,
+    updateDocumentSettings,
+    parsedOverlayEnabled,
+    setParsedOverlayEnabled,
+    forceReparseParsedPdf,
     createFullAudioBook: createPDFAudioBook,
     regenerateChapter: regeneratePDFChapter,
   } = pdfState;
@@ -48,14 +65,29 @@ export default function PDFViewerPage() {
   const { isAtLimit } = useAuthRateLimit();
   const [error, setError] = useState<string | null>(null);
   const [isLoading, setIsLoading] = useState(true);
+  const [isPdfViewerReady, setIsPdfViewerReady] = useState(false);
   const [zoomLevel, setZoomLevel] = useState<number>(100);
   const [activeSidebar, setActiveSidebar] = useState<null | 'settings' | 'audiobook' | 'segments'>(null);
+  const [showForceReparseConfirm, setShowForceReparseConfirm] = useState(false);
+  const [showDetailedParseLoader, setShowDetailedParseLoader] = useState(false);
   const [containerHeight, setContainerHeight] = useState<string>('auto');
   const inFlightDocIdRef = useRef<string | null>(null);
   const loadedDocIdRef = useRef<string | null>(null);
+  const [isNavigatingBack, setIsNavigatingBack] = useState(false);
+  const parseUiState: NonNullable<typeof parseStatus> = parseStatus ?? 'pending';
+  const hasResolvedParseStatus = parseStatus !== null;
+  const isParseReady = parseUiState === 'ready';
+  const forceReparseDisabled = isForceReparseDisabled(parseStatus);
+  const hasRealParseProgress = !!parseProgress
+    && parseProgress.totalPages > 0
+    && parseProgress.pagesParsed >= 0;
+  const shouldShowExpandedParseLoader = !isLoading
+    && hasResolvedParseStatus
+    && (parseUiState === 'pending' || parseUiState === 'running' || parseUiState === 'failed' || hasRealParseProgress);
 
   useEffect(() => {
     setIsLoading(true);
+    setIsPdfViewerReady(false);
     setError(null);
     setActiveSidebar(null);
     inFlightDocIdRef.current = null;
@@ -67,6 +99,7 @@ export default function PDFViewerPage() {
     console.log('Loading new document (from page.tsx)');
     let didRedirect = false;
     let startedLoad = false;
+    let loadSucceeded = false;
     try {
       if (!id) {
         setError('Document not found');
@@ -89,8 +122,20 @@ export default function PDFViewerPage() {
       startedLoad = true;
       inFlightDocIdRef.current = resolved;
       stop(); // Reset TTS when loading new document
-      await setCurrentDocument(resolved);
-      loadedDocIdRef.current = resolved;
+      for (let attempt = 0; attempt < 2; attempt += 1) {
+        const loaded = await setCurrentDocument(resolved);
+        if (loaded) {
+          loadSucceeded = true;
+          loadedDocIdRef.current = resolved;
+          break;
+        }
+        if (attempt === 0) {
+          await new Promise((resolve) => setTimeout(resolve, 250));
+        }
+      }
+      if (!loadSucceeded) {
+        throw new Error(`Failed to load PDF document ${resolved}`);
+      }
     } catch (err) {
       console.error('Error loading document:', err);
       setError('Failed to load document');
@@ -98,7 +143,7 @@ export default function PDFViewerPage() {
       if (startedLoad) {
         inFlightDocIdRef.current = null;
       }
-      if (!didRedirect && startedLoad) {
+      if (!didRedirect && startedLoad && loadSucceeded) {
         setIsLoading(false);
       }
     }
@@ -108,6 +153,30 @@ export default function PDFViewerPage() {
     loadDocument();
   }, [loadDocument]);
 
+  useUnmountCleanupRef(clearCurrDoc);
+
+  useEffect(() => {
+    if (isLoading) return;
+    if (isParseReady) return;
+    stop();
+  }, [isLoading, isParseReady, stop]);
+
+  useEffect(() => {
+    if (!shouldShowExpandedParseLoader) {
+      // Keep the current loader variant stable during the final
+      // parse-ready -> first-frame handoff to avoid a visual flash.
+      if (!isLoading && isParseReady && !isPdfViewerReady) {
+        return;
+      }
+      setShowDetailedParseLoader(false);
+      return;
+    }
+    const timeout = window.setTimeout(() => {
+      setShowDetailedParseLoader(true);
+    }, PARSE_LOADER_EXPAND_DELAY_MS);
+    return () => window.clearTimeout(timeout);
+  }, [shouldShowExpandedParseLoader, id, isLoading, isParseReady, isPdfViewerReady]);
+
   // Compute available height = viewport - (header height + tts bar height)
   useEffect(() => {
     const compute = () => {
@@ -117,24 +186,55 @@ export default function PDFViewerPage() {
       const ttsH = ttsbar ? ttsbar.getBoundingClientRect().height : 0;
       const vh = window.innerHeight;
       const h = Math.max(0, vh - headerH - ttsH);
-      setContainerHeight(`${h}px`);
+      // Avoid locking the reader at 0px during transient startup layout states.
+      if (h > 0) {
+        setContainerHeight(`${h}px`);
+      }
     };
     compute();
+    const settleT1 = window.setTimeout(compute, 0);
+    const settleT2 = window.setTimeout(compute, 120);
     window.addEventListener('resize', compute);
-    return () => window.removeEventListener('resize', compute);
-  }, []);
+    return () => {
+      window.removeEventListener('resize', compute);
+      window.clearTimeout(settleT1);
+      window.clearTimeout(settleT2);
+    };
+  }, [isLoading, isParseReady, isAtLimit, activeSidebar]);
 
   const handleZoomIn = () => setZoomLevel(prev => Math.min(prev + 10, 300));
   const handleZoomOut = () => setZoomLevel(prev => Math.max(prev - 10, 50));
 
+  const handleBackToDocuments = useCallback((event?: MouseEvent) => {
+    event?.preventDefault();
+    if (isNavigatingBack) return;
+    setIsNavigatingBack(true);
+    stop();
+    setActiveSidebar(null);
+    router.push('/app');
+  }, [isNavigatingBack, stop, router]);
+
+  const requestForceReparse = useCallback(() => {
+    if (forceReparseDisabled) return;
+    setShowForceReparseConfirm(true);
+  }, [forceReparseDisabled]);
+
+  const confirmForceReparse = useCallback(() => {
+    setShowForceReparseConfirm(false);
+    void forceReparseParsedPdf();
+  }, [forceReparseParsedPdf]);
+
   const handleGenerateAudiobook = useCallback(async (
     onProgress: (progress: number) => void,
     signal: AbortSignal,
     onChapterComplete: (chapter: TTSAudiobookChapter) => void,
     settings: AudiobookGenerationSettings
   ) => {
+    if (!isParseReady) {
+      throw new Error('PDF parsing is not ready yet.');
+    }
     return createPDFAudioBook(onProgress, signal, onChapterComplete, id as string, settings.format, settings);
-  }, [createPDFAudioBook, id]);
+  }, [createPDFAudioBook, id, isParseReady]);
 
   const handleRegenerateChapter = useCallback(async (
     chapterIndex: number,
@@ -142,8 +242,11 @@ export default function PDFViewerPage() {
     settings: AudiobookGenerationSettings,
     signal: AbortSignal
   ) => {
+    if (!isParseReady) {
+      throw new Error('PDF parsing is not ready yet.');
+    }
     return regeneratePDFChapter(chapterIndex, bookId, settings.format, signal, settings);
-  }, [regeneratePDFChapter]);
+  }, [regeneratePDFChapter, isParseReady]);
 
   if (error) {
     return (
@@ -151,7 +254,7 @@ export default function PDFViewerPage() {
         <p className="text-red-500 mb-4">{error}</p>
         <Link
           href="/app"
-          onClick={() => { clearCurrDoc(); }}
+          onClick={handleBackToDocuments}
           className="inline-flex items-center px-3 py-1 bg-base text-foreground rounded-lg hover:bg-offbase transition-all duration-200 ease-in-out hover:scale-[1.04] hover:text-accent"
         >
           <svg className="w-4 h-4 mr-2 text-muted" fill="none" stroke="currentColor" viewBox="0 0 24 24">
@@ -163,13 +266,124 @@ export default function PDFViewerPage() {
     );
   }
 
+  const renderPdfStatusLoader = () => {
+    const compactLabel = isLoading
+      ? 'Opening PDF...'
+      : (parseUiState === 'ready' ? 'Rendering pages...' : 'Preparing PDF layout...');
+    const compactSubLabel = isLoading
+      ? 'Loading document data'
+      : (parseUiState === 'ready' ? 'Preparing first frame' : 'Queueing parser and preparing page extraction');
+
+    const totalPages = parseProgress?.totalPages ?? 0;
+    const pagesParsed = parseProgress?.pagesParsed ?? 0;
+    const progressPercent = totalPages > 0
+      ? Math.max(0, Math.min(100, (pagesParsed / totalPages) * 100))
+      : 0;
+    const hasMeasuredProgress = totalPages > 0;
+    const isMerging = parseProgress?.phase === 'merge';
+
+    let statusText = 'Loading PDF...';
+    let statusSubText = 'Initializing document renderer';
+    if (!isLoading) {
+      if (parseUiState === 'pending') {
+        statusText = 'Preparing PDF layout...';
+        statusSubText = parseProgress?.phase === 'merge'
+          ? 'Finalizing stitched block structure'
+          : 'Queueing parser and preparing page extraction';
+      } else if (parseUiState === 'running') {
+        statusText = 'Parsing PDF layout blocks...';
+        statusSubText = parseProgress?.phase === 'merge'
+          ? 'Merging cross-page sections'
+          : 'Inferring reading order and text regions';
+      } else if (parseUiState === 'failed') {
+        statusText = 'PDF parsing failed. Retry to continue.';
+        statusSubText = 'The parser could not build a usable layout map';
+      }
+    }
+
+    const stageLabel = parseUiState === 'failed'
+      ? 'Stage: blocked'
+      : (parseUiState === 'pending'
+        ? 'Stage: prepare'
+        : (isMerging ? 'Stage: merge' : 'Stage: infer'));
+
+    return (
+      <div className="h-full w-full bg-base">
+        <div className={`mx-auto flex h-full items-center px-4 py-6 transition-all duration-300 ease-out ${showDetailedParseLoader ? 'max-w-lg' : 'max-w-md'}`}>
+          {showDetailedParseLoader ? (
+            <div className="w-full rounded-xl border border-offbase bg-offbase/95 shadow-sm overflow-hidden">
+              <div className="h-1 bg-[linear-gradient(90deg,var(--accent),transparent_80%)]" />
+              <div className="p-3.5 sm:p-4">
+                <div className="space-y-1.5">
+                  <div className="inline-flex items-center gap-2 rounded-md border border-offbase bg-base/70 px-2.5 py-1">
+                    <LoadingSpinner className="h-3.5 w-3.5 text-accent" />
+                    <span className="text-[10px] font-semibold uppercase tracking-[0.08em] text-muted">PDF Layout Parse</span>
+                  </div>
+                  <p className="text-sm font-semibold text-foreground">{statusText}</p>
+                </div>
+
+                <div className="mt-3 rounded-lg border border-offbase bg-base/75 p-2.5">
+                  <div className="mb-1.5 flex items-end justify-between gap-2">
+                    <p className="text-[11px] font-semibold text-foreground">
+                      {hasMeasuredProgress ? `Page ${pagesParsed} / ${totalPages}` : 'Awaiting first page'}
+                    </p>
+                    <p className="text-[10px] text-muted">{stageLabel}</p>
+                  </div>
+                  <div className="h-2 w-full rounded-full bg-offbase overflow-hidden">
+                    <div
+                      className="h-full bg-accent transition-all duration-300 ease-out"
+                      style={{ width: `${hasMeasuredProgress ? progressPercent : 6}%` }}
+                    />
+                  </div>
+                  <p className="mt-1.5 text-[10px] text-muted">
+                    {hasMeasuredProgress ? `${Math.round(progressPercent)}% complete` : statusSubText}
+                  </p>
+                </div>
+
+                {!isLoading && parseUiState === 'failed' ? (
+                  <div className="mt-3 flex justify-start">
+                    <button
+                      type="button"
+                      onClick={requestForceReparse}
+                      className="inline-flex items-center rounded-md border border-offbase bg-base px-3 py-1.5 text-xs font-medium text-foreground hover:text-accent transition-colors"
+                    >
+                      Retry Parse
+                    </button>
+                  </div>
+                ) : null}
+              </div>
+            </div>
+          ) : (
+            <div className="w-full rounded-xl border border-offbase bg-offbase/95 p-4 shadow-sm transition-all duration-300 ease-out overflow-hidden">
+              <div className="h-0.5 -mx-4 -mt-4 mb-3 bg-[linear-gradient(90deg,var(--accent),transparent_75%)]" />
+              <div className="flex items-start justify-between gap-3">
+                <div className="min-w-0">
+                  <p className="text-sm font-semibold text-foreground">{compactLabel}</p>
+                  <p className="mt-1 text-xs text-muted">{compactSubLabel}</p>
+                </div>
+                <span className="inline-flex items-center justify-center rounded-md border border-offbase bg-base p-1.5">
+                  <LoadingSpinner className="h-3.5 w-3.5 text-accent" />
+                </span>
+              </div>
+              <div className="mt-3 grid grid-cols-3 gap-1.5">
+                <span className="h-1.5 rounded-full bg-accent/30 animate-pulse" />
+                <span className="h-1.5 rounded-full bg-accent/20 animate-pulse [animation-delay:120ms]" />
+                <span className="h-1.5 rounded-full bg-accent/15 animate-pulse [animation-delay:220ms]" />
+              </div>
+            </div>
+          )}
+        </div>
+      </div>
+    );
+  };
+
   return (
     <>
       <Header
         left={
           <Link
             href="/app"
-            onClick={() => clearCurrDoc()}
+            onClick={handleBackToDocuments}
             className="inline-flex items-center py-1 px-2 rounded-md border border-offbase bg-base text-foreground text-xs hover:bg-offbase transition-all duration-200 ease-in-out hover:scale-[1.04] hover:text-accent"
             aria-label="Back to documents"
           >
@@ -199,15 +413,21 @@ export default function PDFViewerPage() {
           </div>
         }
       />
-      <div className="overflow-hidden" style={{ height: containerHeight }}>
-
-        {isLoading ? (
-          <div className="p-4">
-            <DocumentSkeleton />
+      <div className="relative overflow-hidden" style={{ height: containerHeight }}>
+        {isParseReady ? (
+          <div className={isPdfViewerReady ? 'h-full' : 'h-full opacity-0 pointer-events-none'}>
+            <PDFViewer
+              zoomLevel={zoomLevel}
+              onDocumentReady={() => setIsPdfViewerReady(true)}
+              pdfState={pdfState}
+            />
           </div>
-        ) : (
-          <PDFViewer zoomLevel={zoomLevel} pdfState={pdfState} />
-        )}
+        ) : null}
+        {isLoading || !isParseReady || !isPdfViewerReady ? (
+          <div className="absolute inset-0 z-10" data-testid="pdf-status-loader">
+            {renderPdfStatusLoader()}
+          </div>
+        ) : null}
       </div>
       {canExportAudiobook && (
         <AudiobookExportModal
@@ -226,12 +446,41 @@ export default function PDFViewerPage() {
             <RateLimitBanner />
           </div>
         </div>
-      ) : (
+      ) : isParseReady ? (
         <TTSPlayer currentPage={currDocPage} numPages={currDocPages} />
-      )}
+      ) : null}
       <DocumentSettings
         isOpen={activeSidebar === 'settings'}
         setIsOpen={(isOpen) => setActiveSidebar((prev) => isOpen ? 'settings' : (prev === 'settings' ? null : prev))}
+        pdf={{
+          parseStatus,
+          parsedOverlayEnabled,
+          skipBlockKinds: documentSettings.pdf?.skipBlockKinds ?? [],
+          onToggleOverlay: (enabled) => setParsedOverlayEnabled(enabled),
+          onToggleSkipKind: (kind, enabled) => {
+            const current = new Set(documentSettings.pdf?.skipBlockKinds ?? []);
+            if (enabled) current.add(kind);
+            else current.delete(kind);
+            void updateDocumentSettings({
+              ...documentSettings,
+              schemaVersion: 1,
+              pdf: {
+                ...(documentSettings.pdf ?? {}),
+                skipBlockKinds: Array.from(current),
+              },
+            });
+          },
+          onForceReparse: requestForceReparse,
+        }}
+      />
+      <ConfirmDialog
+        isOpen={showForceReparseConfirm}
+        onClose={() => setShowForceReparseConfirm(false)}
+        onConfirm={confirmForceReparse}
+        title={FORCE_REPARSE_CONFIRM_TITLE}
+        message={FORCE_REPARSE_CONFIRM_MESSAGE}
+        confirmText={FORCE_REPARSE_CONFIRM_TEXT}
+        cancelText="Cancel"
       />
       <SegmentsSidebar
         isOpen={activeSidebar === 'segments'}

src/app/(app)/pdf/[id]/usePdfDocument.ts

@@ -18,26 +18,41 @@ import {
 
 import type { PDFDocumentProxy } from 'pdfjs-dist';
 
-import { getDocumentMetadata } from '@/lib/client/api/documents';
+import {
+  forceReparsePdfDocument,
+  getDocumentMetadata,
+  getDocumentSettings,
+  getParsedPdfDocument,
+  putDocumentSettings,
+  subscribeParsedPdfDocumentEvents,
+} from '@/lib/client/api/documents';
 import { createPdfAudiobookSourceAdapter } from '@/lib/client/audiobooks/adapters/pdf';
 import { regenerateAudiobookChapter, runAudiobookGeneration } from '@/lib/client/audiobooks/pipeline';
 import { ensureCachedDocument } from '@/lib/client/cache/documents';
 import { useTTS } from '@/contexts/TTSContext';
 import { useConfig } from '@/contexts/ConfigContext';
 import {
-  extractTextFromPDF,
   highlightPattern,
   clearHighlights,
   clearWordHighlights,
   highlightWordIndex,
 } from '@/lib/client/pdf';
+import { buildPageTextFromBlocks } from '@/lib/client/pdf-block-text';
+import { buildPdfPageSourceUnits, buildPdfPrefetchPayload } from '@/lib/client/pdf-tts-planning';
+import type { CanonicalTtsSourceUnit } from '@/lib/shared/tts-segment-plan';
+import {
+  DEFAULT_DOCUMENT_SETTINGS,
+  type DocumentSettings,
+} from '@/types/document-settings';
+import { mergeDocumentSettings } from '@/lib/shared/document-settings';
+import type { ParsedPdfDocument, ParsedPdfPage, PdfParseProgress, PdfParseStatus } from '@/types/parsed-pdf';
 
 import type {
   TTSSentenceAlignment,
   TTSAudiobookFormat,
   TTSAudiobookChapter,
 } from '@/types/tts';
-import type { AudiobookGenerationSettings } from '@/types/client';
+import type { AudiobookGenerationSettings, TTSSegmentLocator } from '@/types/client';
 import { clampSegmentPreloadDepth } from '@/types/config';
 
 /**
@@ -52,12 +67,29 @@ export interface PdfDocumentState {
   currDocPage: number;
   currDocText: string | undefined;
   pdfDocument: PDFDocumentProxy | undefined;
-  setCurrentDocument: (id: string) => Promise<void>;
+  parsedDocument: ParsedPdfDocument | null;
+  parseStatus: PdfParseStatus | null;
+  parseProgress: PdfParseProgress | null;
+  documentSettings: DocumentSettings;
+  updateDocumentSettings: (settings: DocumentSettings) => Promise<void>;
+  parsedOverlayEnabled: boolean;
+  setParsedOverlayEnabled: (enabled: boolean) => void;
+  forceReparseParsedPdf: () => Promise<void>;
+  setCurrentDocument: (id: string) => Promise<boolean>;
   clearCurrDoc: () => void;
 
   // PDF functionality
   onDocumentLoadSuccess: (pdf: PDFDocumentProxy) => void;
-  highlightPattern: (text: string, pattern: string, containerRef: RefObject<HTMLDivElement>) => void;
+  highlightPattern: (
+    text: string,
+    pattern: string,
+    containerRef: RefObject<HTMLDivElement>,
+    options?: {
+      parsedDocument?: ParsedPdfDocument | null;
+      locator?: TTSSegmentLocator | null;
+      useBlockGeometryOnly?: boolean;
+    },
+  ) => void;
   clearHighlights: () => void;
   clearWordHighlights: () => void;
   highlightWordIndex: (
@@ -84,9 +116,6 @@ export interface PdfDocumentState {
   isAudioCombining: boolean;
 }
 
-const EMPTY_TEXT_RETRY_DELAY_MS = 120;
-const EMPTY_TEXT_MAX_RETRIES = 6;
-
 /**
  * Main PDF route hook.
  */
@@ -101,14 +130,9 @@ export function usePdfDocument(): PdfDocumentState {
     registerVisualPageChangeHandler,
   } = useTTS();
   const {
-    headerMargin,
-    footerMargin,
-    leftMargin,
-    rightMargin,
     apiKey,
     baseUrl,
     providerRef,
-    smartSentenceSplitting,
     segmentPreloadDepthPages,
     ttsSegmentMaxBlockLength,
   } = useConfig();
@@ -119,18 +143,18 @@ export function usePdfDocument(): PdfDocumentState {
   const [currDocName, setCurrDocName] = useState<string>();
   const [currDocText, setCurrDocText] = useState<string>();
   const [pdfDocument, setPdfDocument] = useState<PDFDocumentProxy>();
+  const [parsedDocument, setParsedDocument] = useState<ParsedPdfDocument | null>(null);
+  const [parseStatus, setParseStatus] = useState<PdfParseStatus | null>(null);
+  const [parseProgress, setParseProgress] = useState<PdfParseProgress | null>(null);
+  const [, setActiveParseOpId] = useState<string | null>(null);
+  const [documentSettings, setDocumentSettings] = useState<DocumentSettings>(DEFAULT_DOCUMENT_SETTINGS);
+  const [parsedOverlayEnabled, setParsedOverlayEnabled] = useState(false);
   const [isAudioCombining] = useState(false);
   const audiobookAdapter = useMemo(() => createPdfAudiobookSourceAdapter({
-    pdfDocument,
-    margins: {
-      header: headerMargin,
-      footer: footerMargin,
-      left: leftMargin,
-      right: rightMargin,
-    },
-    smartSentenceSplitting,
+    parsed: parsedDocument ?? undefined,
+    settings: documentSettings,
     maxBlockLength: ttsSegmentMaxBlockLength,
-  }), [pdfDocument, headerMargin, footerMargin, leftMargin, rightMargin, smartSentenceSplitting, ttsSegmentMaxBlockLength]);
+  }), [parsedDocument, documentSettings, ttsSegmentMaxBlockLength]);
   const pageTextCacheRef = useRef<Map<number, string>>(new Map());
   const [currDocPage, setCurrDocPage] = useState<number>(currDocPageNumber);
 
@@ -139,11 +163,129 @@ export function usePdfDocument(): PdfDocumentState {
   const pdfDocGenerationRef = useRef(0);
   const pdfDocumentRef = useRef<PDFDocumentProxy | undefined>(undefined);
   const loadSeqRef = useRef(0);
-  const emptyRetryRef = useRef<{ page: number; attempt: number; timer: ReturnType<typeof setTimeout> | null } | null>(null);
 
   // Guards for setCurrentDocument to prevent stale loads from overwriting newer selections.
   const docLoadSeqRef = useRef(0);
   const docLoadAbortRef = useRef<AbortController | null>(null);
+  const parsePollAbortRef = useRef<AbortController | null>(null);
+  const parseSseCloseRef = useRef<(() => void) | null>(null);
+
+  const fetchParsedDocument = useCallback(async (
+    documentId: string,
+    initialStatus: PdfParseStatus | null,
+    signal: AbortSignal,
+    initialOpId?: string | null,
+  ): Promise<void> => {
+    // Legacy PDFs may have null parseStatus; treat as pending so opening the
+    // document backfills parse output via the parsed endpoint polling path.
+    const effectiveInitialStatus: PdfParseStatus = initialStatus ?? 'pending';
+    setParseStatus(effectiveInitialStatus);
+    setParseProgress(null);
+    const delayMs = 1200;
+    const retryFailed = effectiveInitialStatus === 'failed';
+    let attempt = 0;
+    let effectiveOpId = initialOpId?.trim() || null;
+    while (!signal.aborted) {
+      if (signal.aborted) return;
+      const result = await getParsedPdfDocument(documentId, {
+        signal,
+        retryFailed: retryFailed && attempt === 0,
+        ...(effectiveOpId ? { opId: effectiveOpId } : {}),
+      });
+      if (result.status === 'ready') {
+        setParsedDocument(result.parsed);
+        setParseStatus('ready');
+        setParseProgress(null);
+        setActiveParseOpId(null);
+        return;
+      }
+      if ('opId' in result && typeof result.opId === 'string' && result.opId.trim()) {
+        effectiveOpId = result.opId.trim();
+        setActiveParseOpId(effectiveOpId);
+      }
+      setParseStatus(result.status);
+      setParseProgress(result.parseProgress ?? null);
+      if (result.status === 'failed') {
+        setParsedDocument(null);
+        setActiveParseOpId(null);
+        return;
+      }
+      attempt += 1;
+      await new Promise((resolve) => setTimeout(resolve, delayMs));
+    }
+  }, []);
+
+  const fetchDocumentSettings = useCallback(async (documentId: string, signal: AbortSignal): Promise<void> => {
+    try {
+      const response = await getDocumentSettings(documentId, { signal });
+      setDocumentSettings(mergeDocumentSettings(DEFAULT_DOCUMENT_SETTINGS, response.settings));
+    } catch (error) {
+      if (error instanceof DOMException && error.name === 'AbortError') return;
+      console.warn('Failed to load document settings, using defaults:', error);
+      setDocumentSettings(DEFAULT_DOCUMENT_SETTINGS);
+    }
+  }, []);
+
+  const startParsedPolling = useCallback((documentId: string, initialOpId?: string | null) => {
+    parsePollAbortRef.current?.abort();
+    parseSseCloseRef.current?.();
+    parseSseCloseRef.current = null;
+    setParseProgress(null);
+    setActiveParseOpId(initialOpId?.trim() || null);
+    const controller = new AbortController();
+    parsePollAbortRef.current = controller;
+
+    const closeSse = subscribeParsedPdfDocumentEvents(documentId, {
+      opId: initialOpId?.trim() || null,
+    }, {
+      onSnapshot: (snapshot) => {
+        if (controller.signal.aborted) return;
+        if (typeof snapshot.opId === 'string' && snapshot.opId.trim()) {
+          setActiveParseOpId(snapshot.opId.trim());
+        }
+        setParseStatus(snapshot.parseStatus);
+        setParseProgress(snapshot.parseProgress);
+        if (snapshot.parseStatus === 'ready' || snapshot.parseStatus === 'failed') {
+          if (snapshot.parseStatus === 'failed') {
+            setParsedDocument(null);
+            setActiveParseOpId(null);
+          } else {
+            void fetchParsedDocument(
+              documentId,
+              'ready',
+              controller.signal,
+              typeof snapshot.opId === 'string' ? snapshot.opId : (initialOpId ?? null),
+            );
+          }
+          closeSse();
+          parseSseCloseRef.current = null;
+          if (parsePollAbortRef.current === controller) {
+            parsePollAbortRef.current = null;
+          }
+          return;
+        }
+      },
+      onError: () => {
+        // EventSource reconnects automatically. Keep stream open, but log so
+        // production debugging can correlate UI stalls with SSE churn.
+        if (controller.signal.aborted) return;
+        console.warn('[pdf] parsed/events stream error; waiting for auto-reconnect', {
+          documentId,
+        });
+      },
+    });
+    parseSseCloseRef.current = closeSse;
+
+    controller.signal.addEventListener('abort', () => {
+      closeSse();
+      if (parseSseCloseRef.current === closeSse) {
+        parseSseCloseRef.current = null;
+      }
+      if (parsePollAbortRef.current === controller) {
+        parsePollAbortRef.current = null;
+      }
+    }, { once: true });
+  }, [fetchParsedDocument, setActiveParseOpId]);
 
   useEffect(() => {
     pdfDocumentRef.current = pdfDocument;
@@ -167,7 +309,7 @@ export function usePdfDocument(): PdfDocumentState {
 
   /**
    * Loads and processes text from the current document page
-   * Extracts text from the PDF and updates both document text and TTS text states
+   * Uses parsed PDF blocks only and updates both document text and TTS text states.
    * 
    * @returns {Promise<void>}
    */
@@ -179,20 +321,18 @@ export function usePdfDocument(): PdfDocumentState {
       const seq = ++loadSeqRef.current;
       const pageNumber = currDocPageNumber;
 
-      const existingRetry = emptyRetryRef.current;
-      if (existingRetry?.timer) {
-        clearTimeout(existingRetry.timer);
-      }
-      emptyRetryRef.current =
-        existingRetry && existingRetry.page === pageNumber
-          ? { ...existingRetry, timer: null }
-          : null;
+      const pageFromParsed = (pageNum: number): ParsedPdfPage | undefined =>
+        parsedDocument?.pages.find((page) => page.pageNumber === pageNum);
 
-      const margins = {
-        header: headerMargin,
-        footer: footerMargin,
-        left: leftMargin,
-        right: rightMargin
+      if (parseStatus !== 'ready' || !parsedDocument) {
+        setCurrDocText(undefined);
+        setTTSText('', { location: currDocPageNumber });
+        return;
+      }
+
+      const sourceUnitsFromParsedPage = (pageNum: number): CanonicalTtsSourceUnit[] => {
+        const page = pageFromParsed(pageNum);
+        return buildPdfPageSourceUnits(page, pageNum, documentSettings.pdf?.skipBlockKinds ?? []);
       };
 
       const getPageText = async (pageNumber: number, shouldCache = false): Promise<string> => {
@@ -209,7 +349,10 @@ export function usePdfDocument(): PdfDocumentState {
           return cached;
         }
 
-        const extracted = await extractTextFromPDF(currentPdf, pageNumber, margins);
+        const parsedPage = pageFromParsed(pageNumber);
+        const extracted = parsedPage
+          ? buildPageTextFromBlocks(parsedPage, documentSettings.pdf?.skipBlockKinds ?? [])
+          : '';
 
         if (generation !== pdfDocGenerationRef.current || pdfDocumentRef.current !== currentPdf) {
           throw new DOMException('Stale PDF extraction', 'AbortError');
@@ -237,14 +380,15 @@ export function usePdfDocument(): PdfDocumentState {
         prevPageNumber ? getPageText(prevPageNumber) : Promise.resolve<string | undefined>(undefined),
         ...upcomingPageNumbers.map((pageNum) => getPageText(pageNum, true)),
       ]);
-      const nextText = upcomingTexts[0];
-      const additionalUpcoming = upcomingPageNumbers
-        .slice(1)
-        .map((pageNum, idx) => ({
-          location: pageNum,
-          text: upcomingTexts[idx + 1] || '',
-        }))
-        .filter((item) => item.text.trim().length > 0);
+      const {
+        nextText,
+        nextSourceUnits,
+        additionalUpcoming,
+      } = buildPdfPrefetchPayload(
+        upcomingPageNumbers,
+        upcomingTexts,
+        sourceUnitsFromParsedPage,
+      );
 
       if (generation !== pdfDocGenerationRef.current || pdfDocumentRef.current !== currentPdf) {
         return;
@@ -253,40 +397,17 @@ export function usePdfDocument(): PdfDocumentState {
         return;
       }
 
-      const trimmed = text.trim();
-      if (!trimmed) {
-        const prevAttempt = emptyRetryRef.current?.page === pageNumber ? emptyRetryRef.current.attempt : 0;
-        const attempt = prevAttempt + 1;
-
-        // Avoid pushing empty text into TTS immediately; transient empty extractions can happen
-        // during page turns or react-pdf worker churn. Retry a few times before treating it as
-        // a truly blank page.
-        if (attempt <= EMPTY_TEXT_MAX_RETRIES) {
-          const timer = setTimeout(() => {
-            if (generation !== pdfDocGenerationRef.current || pdfDocumentRef.current !== currentPdf) {
-              return;
-            }
-            if (pageNumber !== currDocPageNumber) {
-              return;
-            }
-            void loadCurrDocText();
-          }, EMPTY_TEXT_RETRY_DELAY_MS);
-
-          emptyRetryRef.current = { page: pageNumber, attempt, timer };
-          return;
-        }
-      } else {
-        emptyRetryRef.current = null;
-      }
-
       if (text !== currDocText || text === '') {
         setCurrDocText(text);
+        const sourceUnits = sourceUnitsFromParsedPage(currDocPageNumber);
         setTTSText(text, {
           location: currDocPageNumber,
           previousText: prevText,
           nextLocation: nextPageNumber,
           nextText: nextText,
+          nextSourceUnits,
           upcomingLocations: additionalUpcoming,
+          ...(sourceUnits.length > 0 ? { sourceUnits } : {}),
         });
       }
     } catch (error) {
@@ -300,11 +421,10 @@ export function usePdfDocument(): PdfDocumentState {
     currDocPages,
     setTTSText,
     currDocText,
-    headerMargin,
-    footerMargin,
-    leftMargin,
-    rightMargin,
     segmentPreloadDepthPages,
+    parsedDocument,
+    parseStatus,
+    documentSettings,
   ]);
 
   /**
@@ -324,7 +444,7 @@ export function usePdfDocument(): PdfDocumentState {
    * @param {string} id - The unique identifier of the document to set
    * @returns {Promise<void>}
    */
-  const setCurrentDocument = useCallback(async (id: string): Promise<void> => {
+  const setCurrentDocument = useCallback(async (id: string): Promise<boolean> => {
     // --- race-condition guard ---
     const seq = ++docLoadSeqRef.current;
     docLoadAbortRef.current?.abort();
@@ -337,10 +457,10 @@ export function usePdfDocument(): PdfDocumentState {
       // or fast refresh.
       pdfDocGenerationRef.current += 1;
       loadSeqRef.current += 1;
-      if (emptyRetryRef.current?.timer) {
-        clearTimeout(emptyRetryRef.current.timer);
-      }
-      emptyRetryRef.current = null;
+      parsePollAbortRef.current?.abort();
+      parsePollAbortRef.current = null;
+      parseSseCloseRef.current?.();
+      parseSseCloseRef.current = null;
       pageTextCacheRef.current.clear();
       setPdfDocument(undefined);
       setCurrDocPages(undefined);
@@ -348,35 +468,85 @@ export function usePdfDocument(): PdfDocumentState {
       setCurrDocId(id);
       setCurrDocName(undefined);
       setCurrDocData(undefined);
+      setParsedDocument(null);
+      setParseStatus(null);
+      setParseProgress(null);
+      setActiveParseOpId(null);
+      setDocumentSettings(DEFAULT_DOCUMENT_SETTINGS);
 
       const meta = await getDocumentMetadata(id, { signal: controller.signal });
-      if (seq !== docLoadSeqRef.current) return; // stale
+      if (seq !== docLoadSeqRef.current) return false; // stale
       if (!meta) {
         console.error('Document not found on server');
-        return;
+        return false;
+      }
+      if (meta.type === 'pdf') {
+        const initialParseStatus = (meta.parseStatus ?? null) as PdfParseStatus | null;
+        setParseStatus(initialParseStatus);
+        setParseProgress(null);
+        setActiveParseOpId(null);
+        startParsedPolling(id, null);
+        void fetchDocumentSettings(id, controller.signal);
       }
 
       const doc = await ensureCachedDocument(meta, { signal: controller.signal });
-      if (seq !== docLoadSeqRef.current) return; // stale
+      if (seq !== docLoadSeqRef.current) return false; // stale
       if (doc.type !== 'pdf') {
         console.error('Document is not a PDF');
-        return;
+        return false;
       }
 
       setCurrDocName(doc.name);
       // IMPORTANT: keep an immutable copy. pdf.js may transfer/detach the
       // buffer passed into the worker; we always pass clones to react-pdf.
       setCurrDocData(doc.data.slice(0));
+      return true;
     } catch (error) {
-      if (error instanceof DOMException && error.name === 'AbortError') return;
+      if (error instanceof DOMException && error.name === 'AbortError') return false;
       console.error('Failed to get document:', error);
+      return false;
     } finally {
       // Clean up the controller only if it's still ours (a newer call hasn't replaced it).
       if (docLoadAbortRef.current === controller) {
         docLoadAbortRef.current = null;
       }
     }
-  }, [setCurrDocId, setCurrDocName, setCurrDocData, setCurrDocPages, setCurrDocText, setPdfDocument]);
+    return false;
+  }, [
+    setCurrDocId,
+    setCurrDocName,
+    setCurrDocData,
+    setCurrDocPages,
+    setCurrDocText,
+    setPdfDocument,
+    fetchDocumentSettings,
+    startParsedPolling,
+  ]);
+
+  const updateDocumentSettings = useCallback(async (settings: DocumentSettings): Promise<void> => {
+    if (!currDocId) return;
+    setDocumentSettings(settings);
+    try {
+      const updated = await putDocumentSettings(currDocId, settings);
+      setDocumentSettings(mergeDocumentSettings(DEFAULT_DOCUMENT_SETTINGS, updated.settings));
+    } catch (error) {
+      console.warn('Failed to persist document settings:', error);
+    }
+  }, [currDocId]);
+
+  const forceReparseParsedPdf = useCallback(async (): Promise<void> => {
+    if (!currDocId) return;
+    try {
+      const forced = await forceReparsePdfDocument(currDocId);
+      setParsedDocument(null);
+      setParseStatus(forced.status);
+      setParseProgress(null);
+      setActiveParseOpId(forced.opId ?? null);
+      startParsedPolling(currDocId, forced.opId ?? null);
+    } catch (error) {
+      console.error('Failed to force PDF reparse:', error);
+    }
+  }, [currDocId, startParsedPolling]);
 
   /**
    * Clears the current document state
@@ -390,16 +560,21 @@ export function usePdfDocument(): PdfDocumentState {
     docLoadSeqRef.current += 1;
     docLoadAbortRef.current?.abort();
     docLoadAbortRef.current = null;
-    if (emptyRetryRef.current?.timer) {
-      clearTimeout(emptyRetryRef.current.timer);
-    }
-    emptyRetryRef.current = null;
+    parsePollAbortRef.current?.abort();
+    parsePollAbortRef.current = null;
+    parseSseCloseRef.current?.();
+    parseSseCloseRef.current = null;
     setCurrDocId(undefined);
     setCurrDocName(undefined);
     setCurrDocData(undefined);
     setCurrDocText(undefined);
     setCurrDocPages(undefined);
     setPdfDocument(undefined);
+    setParsedDocument(null);
+    setParseStatus(null);
+    setParseProgress(null);
+    setActiveParseOpId(null);
+    setDocumentSettings(DEFAULT_DOCUMENT_SETTINGS);
     pageTextCacheRef.current.clear();
     stop();
   }, [setCurrDocId, setCurrDocName, setCurrDocData, setCurrDocPages, setCurrDocText, setPdfDocument, stop]);
@@ -499,6 +674,14 @@ export function usePdfDocument(): PdfDocumentState {
       currDocPages,
       currDocPage,
       currDocText,
+      parsedDocument,
+      parseStatus,
+      parseProgress,
+      documentSettings,
+      updateDocumentSettings,
+      parsedOverlayEnabled,
+      setParsedOverlayEnabled,
+      forceReparseParsedPdf,
       clearCurrDoc,
       highlightPattern,
       clearHighlights,
@@ -518,6 +701,14 @@ export function usePdfDocument(): PdfDocumentState {
       currDocPages,
       currDocPage,
       currDocText,
+      parsedDocument,
+      parseStatus,
+      parseProgress,
+      documentSettings,
+      updateDocumentSettings,
+      parsedOverlayEnabled,
+      setParsedOverlayEnabled,
+      forceReparseParsedPdf,
       clearCurrDoc,
       pdfDocument,
       createFullAudioBook,

src/app/api/account/delete/route.ts

@@ -4,6 +4,8 @@ import { auth } from '@/lib/server/auth/auth';
 import { isAuthEnabled } from '@/lib/server/auth/config';
 import { getOpenReaderTestNamespace } from '@/lib/server/testing/test-namespace';
 import { deleteUserStorageData } from '@/lib/server/user/data-cleanup';
+import { errorToLog, hashForLog, serverLogger } from '@/lib/server/logger';
+import { errorResponse } from '@/lib/server/errors/next-response';
 
 export async function DELETE() {
   if (!isAuthEnabled() || !auth) {
@@ -28,7 +30,13 @@ export async function DELETE() {
       try {
         await deleteUserStorageData(session.user.id, testNamespace);
       } catch (error) {
-        console.error('[account-delete] Failed to clean up namespaced user storage before deletion:', error);
+        serverLogger.warn({
+          event: 'account.delete.storage_cleanup_failed',
+          degraded: true,
+          step: 'namespaced_storage_cleanup',
+          userIdHash: hashForLog(session.user.id),
+          error: errorToLog(error),
+        }, 'Failed to clean up namespaced user storage before deletion');
       }
     }
 
@@ -40,10 +48,13 @@ export async function DELETE() {
 
     return NextResponse.json({ success: true });
   } catch (error) {
-    console.error('Failed to delete account:', error);
-    return NextResponse.json(
-      { error: 'Failed to delete account' },
-      { status: 500 }
-    );
+    serverLogger.error({
+      event: 'account.delete.failed',
+      error: errorToLog(error),
+    }, 'Failed to delete account');
+    return errorResponse(error, {
+      apiErrorMessage: 'Failed to delete account',
+      normalize: { code: 'ACCOUNT_DELETE_FAILED', errorClass: 'db' },
+    });
   }
 }

src/app/api/admin/providers/[id]/route.ts

@@ -1,5 +1,7 @@
 import { NextRequest, NextResponse } from 'next/server';
 import { requireAdminContext } from '@/lib/server/auth/admin';
+import { errorToLog, serverLogger } from '@/lib/server/logger';
+import { errorResponse } from '@/lib/server/errors/next-response';
 import {
   AdminProviderError,
   deleteAdminProvider,
@@ -39,10 +41,25 @@ export async function PUT(
     return NextResponse.json({ provider: toMasked(updated) });
   } catch (error) {
     if (error instanceof AdminProviderError) {
-      return NextResponse.json({ error: error.message }, { status: error.status });
+      return errorResponse(error, {
+        apiErrorMessage: error.message,
+        normalize: {
+          code: 'ADMIN_PROVIDERS_UPDATE_REQUEST_FAILED',
+          errorClass: error.status >= 500 ? 'db' : 'validation',
+          httpStatus: error.status,
+          retryable: error.status >= 500,
+        },
+      });
     }
-    console.error('[admin/providers/:id] update failed:', error);
-    return NextResponse.json({ error: 'Internal error' }, { status: 500 });
+    serverLogger.error({
+      event: 'admin.providers.update.failed',
+      providerId: id,
+      error: errorToLog(error),
+    }, 'Admin provider update failed');
+    return errorResponse(error, {
+      apiErrorMessage: 'Internal error',
+      normalize: { code: 'ADMIN_PROVIDERS_UPDATE_FAILED', errorClass: 'db' },
+    });
   }
 }
 
@@ -59,9 +76,24 @@ export async function DELETE(
     return NextResponse.json({ ok: true });
   } catch (error) {
     if (error instanceof AdminProviderError) {
-      return NextResponse.json({ error: error.message }, { status: error.status });
+      return errorResponse(error, {
+        apiErrorMessage: error.message,
+        normalize: {
+          code: 'ADMIN_PROVIDERS_DELETE_REQUEST_FAILED',
+          errorClass: error.status >= 500 ? 'db' : 'validation',
+          httpStatus: error.status,
+          retryable: error.status >= 500,
+        },
+      });
     }
-    console.error('[admin/providers/:id] delete failed:', error);
-    return NextResponse.json({ error: 'Internal error' }, { status: 500 });
+    serverLogger.error({
+      event: 'admin.providers.delete.failed',
+      providerId: id,
+      error: errorToLog(error),
+    }, 'Admin provider delete failed');
+    return errorResponse(error, {
+      apiErrorMessage: 'Internal error',
+      normalize: { code: 'ADMIN_PROVIDERS_DELETE_FAILED', errorClass: 'db' },
+    });
   }
 }

src/app/api/admin/providers/route.ts

@@ -1,5 +1,7 @@
 import { NextRequest, NextResponse } from 'next/server';
 import { requireAdminContext } from '@/lib/server/auth/admin';
+import { errorToLog, serverLogger } from '@/lib/server/logger';
+import { errorResponse } from '@/lib/server/errors/next-response';
 import {
   AdminProviderError,
   createAdminProvider,
@@ -44,9 +46,23 @@ export async function POST(req: NextRequest) {
     return NextResponse.json({ provider: toMasked(record) }, { status: 201 });
   } catch (error) {
     if (error instanceof AdminProviderError) {
-      return NextResponse.json({ error: error.message }, { status: error.status });
+      return errorResponse(error, {
+        apiErrorMessage: error.message,
+        normalize: {
+          code: 'ADMIN_PROVIDERS_CREATE_REQUEST_FAILED',
+          errorClass: error.status >= 500 ? 'db' : 'validation',
+          httpStatus: error.status,
+          retryable: error.status >= 500,
+        },
+      });
     }
-    console.error('[admin/providers] create failed:', error);
-    return NextResponse.json({ error: 'Internal error' }, { status: 500 });
+    serverLogger.error({
+      event: 'admin.providers.create.failed',
+      error: errorToLog(error),
+    }, 'Admin provider create failed');
+    return errorResponse(error, {
+      apiErrorMessage: 'Internal error',
+      normalize: { code: 'ADMIN_PROVIDERS_CREATE_FAILED', errorClass: 'db' },
+    });
   }
 }

src/app/api/audiobook/chapter/route.ts

@@ -11,6 +11,7 @@ import { requireAuthContext } from '@/lib/server/auth/auth';
 import { rateLimiter, RATE_LIMITS, isTtsRateLimitEnabled } from '@/lib/server/rate-limit/rate-limiter';
 import { getClientIp } from '@/lib/server/rate-limit/request-ip';
 import { getOrCreateDeviceId, setDeviceIdCookie } from '@/lib/server/rate-limit/device-id';
+import { errorToLog, serverLogger } from '@/lib/server/logger';
 import {
   deleteAudiobookObject,
   getAudiobookObjectBuffer,
@@ -43,6 +44,7 @@ import {
   coerceAudiobookGenerationSettings,
   type SharedProviderPolicyEntry,
 } from '@/lib/server/audiobooks/settings';
+import { errorResponse } from '@/lib/server/errors/next-response';
 
 export const dynamic = 'force-dynamic';
 
@@ -185,7 +187,12 @@ async function runFFmpeg(args: string[], signal?: AbortSignal): Promise<void> {
     }
 
     ffmpeg.stderr.on('data', (data) => {
-      console.error(`ffmpeg stderr: ${data}`);
+      serverLogger.warn({
+        event: 'audiobook.chapter.ffmpeg.stderr',
+        degraded: true,
+        step: 'ffmpeg',
+        stderr: String(data),
+      }, 'ffmpeg stderr');
     });
 
     ffmpeg.on('close', (code) => {
@@ -325,8 +332,19 @@ export async function POST(request: NextRequest) {
         fallbackProviderRef: runtimeConfig.defaultTtsProvider,
       });
       if (!existingResult.settings) {
-        console.error('Invalid audiobook.meta.json settings payload', { bookId, storageUserId });
-        return NextResponse.json({ error: 'Invalid audiobook metadata settings' }, { status: 500 });
+        serverLogger.error({
+          event: 'audiobook.chapter.meta_settings.invalid',
+          bookId,
+          storageUserId,
+          error: {
+            name: 'AudiobookMetaSettingsInvalid',
+            message: 'Invalid audiobook.meta.json settings payload',
+          },
+        }, 'Invalid audiobook.meta.json settings payload');
+        return errorResponse(new Error('Invalid audiobook metadata settings payload'), {
+          apiErrorMessage: 'Invalid audiobook metadata settings',
+          normalize: { code: 'AUDIOBOOK_CHAPTER_META_SETTINGS_INVALID', errorClass: 'validation', httpStatus: 500 },
+        });
       }
       normalizedExistingSettings = normalizeNativeSpeedForSettings(existingResult.settings);
       existingSettingsNeedsMigration = existingResult.migrated;
@@ -399,11 +417,14 @@ export async function POST(request: NextRequest) {
           testNamespace,
         );
       } catch (error) {
-        console.warn('Failed to persist migrated audiobook metadata settings', {
+        serverLogger.warn({
+          event: 'audiobook.chapter.meta_settings.persist_migration_failed',
+          degraded: true,
+          step: 'persist_migrated_settings',
           bookId,
           storageUserId,
-          error: error instanceof Error ? error.message : String(error),
-        });
+          error: errorToLog(error),
+        }, 'Failed to persist migrated audiobook metadata settings');
       }
     }
 
@@ -486,7 +507,10 @@ export async function POST(request: NextRequest) {
     }
     const provider = credResolved.provider;
     if (!isBuiltInTtsProviderId(provider)) {
-      return NextResponse.json({ error: `Unsupported TTS provider type: ${provider}` }, { status: 500 });
+      return errorResponse(new Error(`Unsupported TTS provider type: ${provider}`), {
+        apiErrorMessage: `Unsupported TTS provider type: ${provider}`,
+        normalize: { code: 'AUDIOBOOK_CHAPTER_UNSUPPORTED_PROVIDER', errorClass: 'validation', httpStatus: 500 },
+      });
     }
     const openApiKey = credResolved.apiKey || 'none';
     const openApiBaseUrl = credResolved.baseUrl;
@@ -608,7 +632,12 @@ export async function POST(request: NextRequest) {
           request.signal,
         );
       } catch (copyError) {
-        console.warn('Chapter remux failed; falling back to mp3 re-encode:', copyError);
+        serverLogger.warn({
+          event: 'audiobook.chapter.remux.failed',
+          degraded: true,
+          fallbackPath: 'mp3_reencode',
+          error: errorToLog(copyError),
+        }, 'Chapter remux failed; falling back to mp3 re-encode');
         await runFFmpeg(
           chapterEncodeArgs(inputPath, chapterOutputTempPath, format, postSpeed, titleTag),
           request.signal,
@@ -728,8 +757,14 @@ export async function POST(request: NextRequest) {
       return response;
     }
 
-    console.error('Error processing audio chapter:', error);
-    const response = NextResponse.json({ error: 'Failed to process audio chapter' }, { status: 500 });
+    serverLogger.error({
+      event: 'audiobook.chapter.process.failed',
+      error: errorToLog(error),
+    }, 'Failed to process audio chapter');
+    const response = errorResponse(error, {
+      apiErrorMessage: 'Failed to process audio chapter',
+      normalize: { code: 'AUDIOBOOK_CHAPTER_PROCESS_FAILED', errorClass: 'upstream' },
+    });
     attachDeviceIdCookie(response, deviceIdToSet, didCreateDeviceIdCookie);
     return response;
   } finally {
@@ -823,8 +858,14 @@ export async function GET(request: NextRequest) {
       },
     });
   } catch (error) {
-    console.error('Error downloading chapter:', error);
-    return NextResponse.json({ error: 'Failed to download chapter' }, { status: 500 });
+    serverLogger.error({
+      event: 'audiobook.chapter.download.failed',
+      error: errorToLog(error),
+    }, 'Failed to download chapter');
+    return errorResponse(error, {
+      apiErrorMessage: 'Failed to download chapter',
+      normalize: { code: 'AUDIOBOOK_CHAPTER_DOWNLOAD_FAILED', errorClass: 'storage' },
+    });
   }
 }
 
@@ -891,7 +932,13 @@ export async function DELETE(request: NextRequest) {
 
     return NextResponse.json({ success: true });
   } catch (error) {
-    console.error('Error deleting chapter:', error);
-    return NextResponse.json({ error: 'Failed to delete chapter' }, { status: 500 });
+    serverLogger.error({
+      event: 'audiobook.chapter.delete.failed',
+      error: errorToLog(error),
+    }, 'Failed to delete chapter');
+    return errorResponse(error, {
+      apiErrorMessage: 'Failed to delete chapter',
+      normalize: { code: 'AUDIOBOOK_CHAPTER_DELETE_FAILED', errorClass: 'db' },
+    });
   }
 }

src/app/api/audiobook/route.ts

@@ -7,6 +7,8 @@ import { and, eq, inArray } from 'drizzle-orm';
 import { db } from '@/db';
 import { audiobooks, audiobookChapters } from '@/db/schema';
 import { requireAuthContext } from '@/lib/server/auth/auth';
+import { errorToLog, serverLogger } from '@/lib/server/logger';
+import { errorResponse } from '@/lib/server/errors/next-response';
 import {
   audiobookPrefix,
   deleteAudiobookObject,
@@ -115,7 +117,12 @@ async function runFFmpeg(args: string[], signal?: AbortSignal): Promise<void> {
     }
 
     ffmpeg.stderr.on('data', (data) => {
-      console.error(`ffmpeg stderr: ${data}`);
+      serverLogger.warn({
+        event: 'audiobook.ffmpeg.stderr',
+        degraded: true,
+        step: 'ffmpeg',
+        stderr: String(data),
+      }, 'ffmpeg stderr');
     });
 
     ffmpeg.on('close', (code) => {
@@ -282,7 +289,12 @@ export async function GET(request: NextRequest) {
           request.signal,
         );
       } catch (copyError) {
-        console.warn('MP3 concat copy failed; falling back to re-encode:', copyError);
+        serverLogger.warn({
+          event: 'audiobook.concat_copy.mp3.failed',
+          degraded: true,
+          fallbackPath: 'reencode',
+          error: errorToLog(copyError),
+        }, 'MP3 concat copy failed; falling back to re-encode');
         await runFFmpeg(
           ['-f', 'concat', '-safe', '0', '-i', listPath, '-c:a', 'libmp3lame', '-b:a', '64k', outputPath],
           request.signal,
@@ -311,7 +323,12 @@ export async function GET(request: NextRequest) {
           request.signal,
         );
       } catch (copyError) {
-        console.warn('M4B concat copy failed; falling back to re-encode:', copyError);
+        serverLogger.warn({
+          event: 'audiobook.concat_copy.m4b.failed',
+          degraded: true,
+          fallbackPath: 'reencode',
+          error: errorToLog(copyError),
+        }, 'M4B concat copy failed; falling back to re-encode');
         await runFFmpeg(
           [
             '-f',
@@ -360,8 +377,14 @@ export async function GET(request: NextRequest) {
     if ((error as Error)?.message === 'ABORTED' || request.signal.aborted) {
       return NextResponse.json({ error: 'cancelled' }, { status: 499 });
     }
-    console.error('Error creating full audiobook:', error);
-    return NextResponse.json({ error: 'Failed to create full audiobook file' }, { status: 500 });
+    serverLogger.error({
+      event: 'audiobook.create.failed',
+      error: errorToLog(error),
+    }, 'Failed to create full audiobook');
+    return errorResponse(error, {
+      apiErrorMessage: 'Failed to create full audiobook file',
+      normalize: { code: 'AUDIOBOOK_CREATE_FAILED', errorClass: 'upstream' },
+    });
   } finally {
     if (workDir) await rm(workDir, { recursive: true, force: true }).catch(() => {});
   }
@@ -408,7 +431,13 @@ export async function DELETE(request: NextRequest) {
     const deleted = await deleteAudiobookPrefix(audiobookPrefix(bookId, storageUserId, testNamespace)).catch(() => 0);
     return NextResponse.json({ success: true, existed: deleted > 0 });
   } catch (error) {
-    console.error('Error resetting audiobook:', error);
-    return NextResponse.json({ error: 'Failed to reset audiobook' }, { status: 500 });
+    serverLogger.error({
+      event: 'audiobook.reset.failed',
+      error: errorToLog(error),
+    }, 'Failed to reset audiobook');
+    return errorResponse(error, {
+      apiErrorMessage: 'Failed to reset audiobook',
+      normalize: { code: 'AUDIOBOOK_RESET_FAILED', errorClass: 'db' },
+    });
   }
 }