refactor(compute-worker): migrate compute logic to modular architecture

- Remove legacy compute-worker monolith under `src/compute/`, including PDF and Whisper inference, control-plane, and runtime orchestration
- Move PDF and Whisper inference logic to new `src/inference/` module
- Move control-plane, orchestrator, and state machine logic to `src/operations/`
- Move NATS/JetStream adapters to `src/infrastructure/`
- Move job orchestration, progress, and artifact persistence to `src/jobs/`
- Update imports throughout tests and main app to reference new module structure
- Update Dockerfile and scripts to use new asset paths
- Add new entrypoints: `src/api/app.ts` and `src/api/contracts.ts`
- Remove obsolete files and update `.gitignore` for new dev artifacts

This refactor modularizes the compute-worker, improving maintainability and separation of concerns. No functional changes to inference or orchestration logic.

BREAKING CHANGE: compute-worker internal APIs, directory structure, and imports have changed; downstream code must update imports and integration points.

.gitignore

@@ -56,5 +56,7 @@ node_modules/
 # vscode
 .vscode
 
-# .agents
+# Agents
 .agents
+.codex
+.claude

Dockerfile

@@ -87,7 +87,7 @@ 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-worker/src/compute/pdf/assets/LICENSE.txt /licenses/pp-doclayoutv3-LICENSE.txt
+COPY --from=app-builder /app/compute-worker/src/inference/pdf/assets/LICENSE.txt /licenses/pp-doclayoutv3-LICENSE.txt
 
 # Copy seaweedfs weed binary for optional embedded local S3.
 COPY --from=seaweedfs-builder /tmp/weed /usr/local/bin/weed
@@ -97,7 +97,7 @@ COPY --from=nats-builder /tmp/nats-server /usr/local/bin/nats-server
 RUN chmod +x /usr/local/bin/nats-server
 
 # Include OpenAI Whisper license text for runtime-downloaded ONNX artifacts.
-COPY --from=app-builder /app/compute-worker/src/compute/whisper/assets/LICENSE.txt /licenses/openai-whisper-LICENSE.txt
+COPY --from=app-builder /app/compute-worker/src/inference/whisper/assets/LICENSE.txt /licenses/openai-whisper-LICENSE.txt
 
 # Match the app's historical container port now that standalone server.js
 # is started directly instead of `next start -p 3003`.

compute-worker/scripts/generate-openapi.ts

@@ -1,6 +1,6 @@
 import { mkdir, writeFile } from 'node:fs/promises';
 import { dirname, resolve } from 'node:path';
-import { createComputeWorkerApp } from '../src/runtime';
+import { createComputeWorkerApp } from '../src/api/app';
 
 process.env.COMPUTE_WORKER_TOKEN ||= 'openapi-generation-token';
 process.env.NATS_URL ||= 'nats://127.0.0.1:4222';

compute-worker/src/api/contracts.ts

@@ -1,24 +1,24 @@
-import type { TTSSentenceAlignment } from '../types/tts';
-import type { ParsedPdfDocument } from '../types/parsed-pdf';
+import type { TTSSentenceAlignment } from '../inference/types/tts';
+import type { ParsedPdfDocument } from '../inference/types/parsed-pdf';
 
 export type {
   TTSAudioBuffer,
   TTSAudioBytes,
   TTSSentenceAlignment,
   TTSSentenceWord,
-} from '../types/tts';
+} from '../inference/types/tts';
 export type {
   ParsedPdfBlockKind,
   ParsedPdfBlockFragment,
   ParsedPdfBlock,
   ParsedPdfPage,
   ParsedPdfDocument,
-} from '../types/parsed-pdf';
+} from '../inference/types/parsed-pdf';
 
 export const ALIGN_QUEUE_NAME = 'whisper-align';
 export const PDF_LAYOUT_QUEUE_NAME = 'pdf-layout';
-export { PDF_PARSER_VERSION } from '../pdf/parser-version';
-export { encodeParserVersion } from '../pdf/parser-version-key';
+export { PDF_PARSER_VERSION } from '../inference/pdf/parser-version';
+export { encodeParserVersion } from '../inference/pdf/parser-version-key';
 
 export interface WhisperAlignJobBase {
   text: string;

compute-worker/src/api/operation-keys.ts

@@ -1,5 +1,5 @@
 import { createHash } from 'node:crypto';
-import { PDF_PARSER_VERSION } from '../compute/pdf/parser-version';
+import { PDF_PARSER_VERSION } from '../inference/pdf/parser-version';
 
 function sha256Hex(input: string): string {
   return createHash('sha256').update(input).digest('hex');

compute-worker/src/api/public-operation.ts

@@ -1,4 +1,4 @@
-import type { WorkerOperationState } from '../compute/api-contracts';
+import type { WorkerOperationState } from '../api/contracts';
 import { pdfSubjectFromOperationKey } from './operation-keys';
 
 export type PublicOperationSubject =

compute-worker/src/inference/index.ts

@@ -1,4 +1,4 @@
-export * from './api-contracts';
+export * from '../api/contracts';
 export {
   getComputeJobConcurrency,
   getAvailableCpuCores,
@@ -23,4 +23,4 @@ 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';
+export * from '../operations';

compute-worker/src/infrastructure/nats-adapters.ts

@@ -8,12 +8,12 @@ import type {
   OperationState,
   OperationStateStore,
   QueuedOperation,
-} from '../compute/control-plane';
+} from '../operations';
 import type {
   PdfLayoutJobRequest,
   WhisperAlignJobRequest,
   WorkerOperationKind,
-} from '../compute/api-contracts';
+} from '../api/contracts';
 import { createJsonCodec } from './json-codec';
 
 export interface KvEntryLike {

compute-worker/src/infrastructure/nats.ts

@@ -0,0 +1,104 @@
+import {
+  AckPolicy,
+  DeliverPolicy,
+  ReplayPolicy,
+  RetentionPolicy,
+  StorageType,
+  type JetStreamManager,
+} from '@nats-io/jetstream';
+import { nanos } from '@nats-io/transport-node';
+import { OP_EVENTS_SUBJECT_WILDCARD } from './nats-adapters';
+
+export const JOBS_STREAM_NAME = 'compute_jobs';
+export const WHISPER_JOBS_SUBJECT = 'jobs.whisper';
+export const LAYOUT_JOBS_SUBJECT = 'jobs.layout';
+export const WHISPER_CONSUMER_NAME = 'compute_whisper';
+export const LAYOUT_CONSUMER_NAME = 'compute_layout';
+export const EVENTS_STREAM_NAME = 'compute_events';
+export const COMPUTE_STATE_BUCKET = 'compute_state';
+export const COMPUTE_STATE_TTL_MS = 24 * 60 * 60 * 1000;
+export const NATS_API_TIMEOUT_MS = 60_000;
+
+const WHISPER_MAX_DELIVER = 1;
+
+function isAlreadyExistsError(error: unknown): boolean {
+  const message = (error instanceof Error ? error.message : String(error)).toLowerCase();
+  return message.includes('already in use') || message.includes('already exists');
+}
+
+export async function ensureJetStreamResources(input: {
+  jsm: JetStreamManager;
+  whisperTimeoutMs: number;
+  pdfTimeoutMs: number;
+  pdfAttempts: number;
+  jobsMaxBytes: number;
+  eventsMaxBytes: number;
+  natsReplicas: number;
+}): Promise<void> {
+  const streamConfig = {
+    name: JOBS_STREAM_NAME,
+    subjects: [WHISPER_JOBS_SUBJECT, LAYOUT_JOBS_SUBJECT],
+    retention: RetentionPolicy.Workqueue,
+    storage: StorageType.File,
+    max_bytes: input.jobsMaxBytes,
+    num_replicas: input.natsReplicas,
+  };
+  try {
+    await input.jsm.streams.add(streamConfig);
+  } catch (error) {
+    if (!isAlreadyExistsError(error)) throw error;
+    await input.jsm.streams.update(JOBS_STREAM_NAME, {
+      subjects: streamConfig.subjects,
+      max_bytes: input.jobsMaxBytes,
+      num_replicas: input.natsReplicas,
+    });
+  }
+
+  const eventsStreamConfig = {
+    name: EVENTS_STREAM_NAME,
+    subjects: [OP_EVENTS_SUBJECT_WILDCARD],
+    retention: RetentionPolicy.Limits,
+    storage: StorageType.File,
+    max_bytes: input.eventsMaxBytes,
+    max_age: nanos(COMPUTE_STATE_TTL_MS),
+    num_replicas: input.natsReplicas,
+  };
+  try {
+    await input.jsm.streams.add(eventsStreamConfig);
+  } catch (error) {
+    if (!isAlreadyExistsError(error)) throw error;
+    await input.jsm.streams.update(EVENTS_STREAM_NAME, {
+      subjects: eventsStreamConfig.subjects,
+      max_bytes: input.eventsMaxBytes,
+      max_age: eventsStreamConfig.max_age,
+      num_replicas: input.natsReplicas,
+    });
+  }
+
+  const ensureConsumer = async (name: string, subject: string, ackWaitMs: number, maxDeliver: number) => {
+    const config = {
+      durable_name: name,
+      ack_policy: AckPolicy.Explicit,
+      deliver_policy: DeliverPolicy.All,
+      replay_policy: ReplayPolicy.Instant,
+      filter_subject: subject,
+      ack_wait: nanos(Math.max(ackWaitMs, 1_000)),
+      max_deliver: maxDeliver,
+    };
+    try {
+      await input.jsm.consumers.add(JOBS_STREAM_NAME, config);
+    } catch (error) {
+      if (!isAlreadyExistsError(error)) throw error;
+      await input.jsm.consumers.update(JOBS_STREAM_NAME, name, {
+        filter_subject: subject,
+        ack_wait: config.ack_wait,
+        max_deliver: maxDeliver,
+      });
+    }
+  };
+
+  await Promise.all([
+    ensureConsumer(WHISPER_CONSUMER_NAME, WHISPER_JOBS_SUBJECT, input.whisperTimeoutMs + 15_000, WHISPER_MAX_DELIVER),
+    ensureConsumer(LAYOUT_CONSUMER_NAME, LAYOUT_JOBS_SUBJECT, input.pdfTimeoutMs + 15_000, input.pdfAttempts),
+  ]);
+}

compute-worker/src/infrastructure/storage.ts

@@ -0,0 +1,127 @@
+import {
+  DeleteObjectCommand,
+  GetObjectCommand,
+  HeadObjectCommand,
+  PutObjectCommand,
+  S3Client,
+} from '@aws-sdk/client-s3';
+import { parsedPdfArtifactKey } from '../storage/artifact-addressing';
+
+export interface ArtifactStorage {
+  readObject(key: string): Promise<ArrayBuffer>;
+  objectExists(key: string): Promise<boolean>;
+  deleteObject(key: string): Promise<void>;
+  putParsedPdf(documentId: string, namespace: string | null, parsed: unknown): Promise<string>;
+}
+
+export interface ArtifactStorageConfig {
+  bucket: string;
+  prefix: string;
+  client: S3Client;
+}
+
+function bodyToBuffer(body: unknown): Promise<Buffer> | Buffer {
+  if (!body) return Buffer.alloc(0);
+  if (body instanceof Uint8Array) return Buffer.from(body);
+  if (ArrayBuffer.isView(body)) return Buffer.from(body.buffer, body.byteOffset, body.byteLength);
+  if (body instanceof ArrayBuffer) return Buffer.from(body);
+  if (typeof body === 'object' && body !== null && 'transformToByteArray' in body) {
+    const maybe = body as { transformToByteArray?: () => Promise<Uint8Array> };
+    if (typeof maybe.transformToByteArray === 'function') {
+      return maybe.transformToByteArray().then((bytes) => Buffer.from(bytes));
+    }
+  }
+  if (typeof body === 'object' && body !== null && 'on' in body) {
+    return (async () => {
+      const chunks: Buffer[] = [];
+      for await (const chunk of body as NodeJS.ReadableStream) {
+        if (Buffer.isBuffer(chunk)) chunks.push(chunk);
+        else if (typeof chunk === 'string') chunks.push(Buffer.from(chunk));
+        else chunks.push(Buffer.from(chunk as Uint8Array));
+      }
+      return Buffer.concat(chunks);
+    })();
+  }
+  throw new Error('Unsupported S3 response body type');
+}
+
+function toArrayBuffer(bytes: Uint8Array): ArrayBuffer {
+  const copy = new Uint8Array(bytes.byteLength);
+  copy.set(bytes);
+  return copy.buffer;
+}
+
+function isNotFound(error: unknown): boolean {
+  const maybe = error as { name?: string; Code?: string; $metadata?: { httpStatusCode?: number } };
+  return maybe.$metadata?.httpStatusCode === 404
+    || maybe.name === 'NotFound'
+    || maybe.name === 'NoSuchKey'
+    || maybe.Code === 'NotFound'
+    || maybe.Code === 'NoSuchKey';
+}
+
+export function normalizeS3Prefix(prefix: string | undefined): string {
+  const value = (prefix || 'openreader').trim();
+  return value ? value.replace(/^\/+|\/+$/g, '') : 'openreader';
+}
+
+export function createS3ClientFromEnv(requireEnv: (name: string) => string): S3Client {
+  return new S3Client({
+    region: requireEnv('S3_REGION'),
+    endpoint: process.env.S3_ENDPOINT?.trim() || undefined,
+    forcePathStyle: ['1', 'true', 'yes', 'on'].includes(process.env.S3_FORCE_PATH_STYLE?.trim().toLowerCase() ?? ''),
+    requestChecksumCalculation: 'WHEN_REQUIRED',
+    responseChecksumValidation: 'WHEN_REQUIRED',
+    credentials: {
+      accessKeyId: requireEnv('S3_ACCESS_KEY_ID'),
+      secretAccessKey: requireEnv('S3_SECRET_ACCESS_KEY'),
+    },
+  });
+}
+
+export function createArtifactStorage(config: ArtifactStorageConfig): ArtifactStorage {
+  const safeKey = (key: string): string => {
+    const trimmed = key.trim();
+    if (!trimmed.startsWith(`${config.prefix}/`)) throw new Error('Object key prefix mismatch');
+    return trimmed;
+  };
+
+  return {
+    async readObject(key) {
+      const response = await config.client.send(new GetObjectCommand({
+        Bucket: config.bucket,
+        Key: safeKey(key),
+      }));
+      return toArrayBuffer(new Uint8Array(await bodyToBuffer(response.Body)));
+    },
+    async objectExists(key) {
+      try {
+        await config.client.send(new HeadObjectCommand({
+          Bucket: config.bucket,
+          Key: safeKey(key),
+        }));
+        return true;
+      } catch (error) {
+        if (isNotFound(error)) return false;
+        throw error;
+      }
+    },
+    async deleteObject(key) {
+      await config.client.send(new DeleteObjectCommand({
+        Bucket: config.bucket,
+        Key: safeKey(key),
+      }));
+    },
+    async putParsedPdf(documentId, namespace, parsed) {
+      const key = parsedPdfArtifactKey({ documentId, namespace, prefix: config.prefix });
+      await config.client.send(new PutObjectCommand({
+        Bucket: config.bucket,
+        Key: key,
+        Body: Buffer.from(JSON.stringify(parsed)),
+        ContentType: 'application/json',
+        ServerSideEncryption: 'AES256',
+      }));
+      return key;
+    },
+  };
+}

compute-worker/src/jobs/handlers.ts

@@ -0,0 +1,126 @@
+import { z } from 'zod';
+import {
+  runPdfLayoutFromPdfBuffer,
+  runWhisperAlignmentFromAudioBuffer,
+} from '../inference/local-runtime';
+import { withIdleTimeoutAndHardCap, withTimeout } from '../inference';
+import type {
+  PdfLayoutJobRequest,
+  PdfLayoutJobResult,
+  PdfLayoutProgress,
+  WhisperAlignJobRequest,
+  WhisperAlignJobResult,
+} from '../api/contracts';
+import type { ArtifactStorage } from '../infrastructure/storage';
+import { persistParsedPdfWhileSourceExists } from './pdf-artifact-persistence';
+import { buildInferProgressForPageParsed, buildInferProgressForPageStart } from './pdf-progress';
+
+const whisperRequestSchema = z.object({
+  text: z.string().trim().min(1),
+  lang: z.string().trim().min(1).max(16).optional(),
+  cacheKey: z.string().trim().min(1).max(256).optional(),
+  audioObjectKey: z.string().trim().min(1).max(2048),
+});
+
+const pdfRequestSchema = z.object({
+  documentId: z.string().trim().min(1),
+  namespace: z.string().trim().min(1).max(128).nullable(),
+  documentObjectKey: z.string().trim().min(1).max(2048),
+});
+
+export interface JobHandlers {
+  runWhisper(payload: WhisperAlignJobRequest, queueWaitMs: number): Promise<WhisperAlignJobResult>;
+  runPdfLayout(
+    payload: PdfLayoutJobRequest,
+    queueWaitMs: number,
+    hooks?: { onProgress?: (progress: PdfLayoutProgress) => Promise<void> },
+  ): Promise<PdfLayoutJobResult>;
+}
+
+export function createJobHandlers(input: {
+  storage: ArtifactStorage;
+  whisperTimeoutMs: number;
+  pdfTimeoutMs: number;
+  pdfHardCapMs: number;
+}): JobHandlers {
+  return {
+    async runWhisper(payload, queueWaitMs) {
+      const parsed = whisperRequestSchema.parse(payload);
+      const s3FetchStartedAt = Date.now();
+      const audioBuffer = await withTimeout(
+        input.storage.readObject(parsed.audioObjectKey),
+        input.whisperTimeoutMs,
+        'whisper s3 fetch',
+      );
+      const s3FetchMs = Date.now() - s3FetchStartedAt;
+      const computeStartedAt = Date.now();
+      const result = await withTimeout(
+        runWhisperAlignmentFromAudioBuffer({
+          audioBuffer,
+          text: parsed.text,
+          cacheKey: parsed.cacheKey,
+          lang: parsed.lang,
+        }),
+        input.whisperTimeoutMs,
+        'whisper alignment job',
+      );
+      return {
+        ...result,
+        timing: { queueWaitMs, s3FetchMs, computeMs: Date.now() - computeStartedAt },
+      };
+    },
+
+    async runPdfLayout(payload, queueWaitMs, hooks) {
+      const parsed = pdfRequestSchema.parse(payload);
+      const s3FetchStartedAt = Date.now();
+      const pdfBytes = await withTimeout(
+        input.storage.readObject(parsed.documentObjectKey),
+        Math.max(input.pdfTimeoutMs, 1_000),
+        'pdf s3 fetch',
+      );
+      const s3FetchMs = Date.now() - s3FetchStartedAt;
+      let lastTotalPages = 0;
+      let lastPagesParsed = 0;
+      const computeStartedAt = Date.now();
+      const result = await withIdleTimeoutAndHardCap({
+        idleTimeoutMs: Math.max(input.pdfTimeoutMs, 1_000),
+        hardCapMs: input.pdfHardCapMs,
+        label: 'pdf layout job',
+        run: async (touchProgress) => runPdfLayoutFromPdfBuffer({
+          documentId: parsed.documentId,
+          pdfBytes,
+          onPageStarted: async ({ pageNumber, totalPages }) => {
+            touchProgress();
+            lastTotalPages = totalPages;
+            await hooks?.onProgress?.(buildInferProgressForPageStart({ pageNumber, totalPages }));
+          },
+          onPageParsed: async ({ pageNumber, totalPages }) => {
+            touchProgress();
+            lastTotalPages = totalPages;
+            lastPagesParsed = pageNumber;
+            await hooks?.onProgress?.(buildInferProgressForPageParsed({ pageNumber, totalPages }));
+          },
+        }),
+      });
+      const computeMs = Date.now() - computeStartedAt;
+      if (hooks?.onProgress && lastTotalPages > 0) {
+        await hooks.onProgress({
+          totalPages: lastTotalPages,
+          pagesParsed: lastPagesParsed,
+          currentPage: lastPagesParsed || undefined,
+          phase: 'merge',
+        });
+      }
+      const parsedObjectKey = await persistParsedPdfWhileSourceExists({
+        sourceObjectKey: parsed.documentObjectKey,
+        sourceExists: input.storage.objectExists,
+        putParsedObject: () => input.storage.putParsedPdf(parsed.documentId, parsed.namespace, result.parsed),
+        deleteParsedObject: input.storage.deleteObject,
+      });
+      return {
+        parsedObjectKey,
+        timing: { queueWaitMs, s3FetchMs, computeMs },
+      };
+    },
+  };
+}

compute-worker/src/jobs/pdf-progress.ts

@@ -1,4 +1,4 @@
-import type { PdfLayoutProgress } from './compute/api-contracts';
+import type { PdfLayoutProgress } from '../api/contracts';
 
 export function buildInferProgressForPageStart(input: {
   pageNumber: number;

compute-worker/src/jobs/worker-loop-policy.ts

@@ -1,4 +1,4 @@
-import type { WorkerOperationKind } from './compute/api-contracts';
+import type { WorkerOperationKind } from '../api/contracts';
 
 export type RetryAction = 'nak_retry' | 'term_fail';
 

compute-worker/src/jobs/worker-loop.ts

@@ -0,0 +1,312 @@
+import type { Consumer, JsMsg } from '@nats-io/jetstream';
+import type {
+  PdfLayoutJobRequest,
+  PdfLayoutJobResult,
+  PdfLayoutProgress,
+  WhisperAlignJobRequest,
+  WhisperAlignJobResult,
+  WorkerJobTiming,
+  WorkerOperationKind,
+} from '../api/contracts';
+import type { JsonCodec } from '../infrastructure/json-codec';
+import type { JobHandlers } from './handlers';
+import { buildQueueWaitTiming, decideRetryAction } from './worker-loop-policy';
+
+const LOOP_ERROR_BACKOFF_MS = 500;
+const RUNNING_HEARTBEAT_MS = 5000;
+const PULL_EXPIRES_MS = 5_000;
+const WHISPER_MAX_DELIVER = 1;
+const SLOW_JOB_LOG_THRESHOLD_MS_BY_KIND: Record<WorkerOperationKind, number> = {
+  whisper_align: 15_000,
+  pdf_layout: 120_000,
+};
+
+export interface QueuedJob<TPayload> {
+  jobId: string;
+  opId: string;
+  opKey: string;
+  kind: WorkerOperationKind;
+  queuedAt: number;
+  payload: TPayload;
+}
+
+interface WorkerLoopOrchestrator {
+  markRunning(input: { opId: string; startedAt?: number; updatedAt?: number; timing?: WorkerJobTiming }): Promise<unknown>;
+  markProgress(input: {
+    opId: string;
+    progress: PdfLayoutProgress;
+    updatedAt?: number;
+    timing?: WorkerJobTiming;
+  }): Promise<unknown>;
+  markSucceeded(input: { opId: string; result: unknown; updatedAt?: number; timing?: WorkerJobTiming }): Promise<unknown>;
+  markFailed(input: {
+    opId: string;
+    error: { message: string; code?: string } | string;
+    updatedAt?: number;
+    timing?: WorkerJobTiming;
+  }): Promise<unknown>;
+}
+
+interface WorkerLogger {
+  info(data: unknown, message?: string): void;
+  warn(data: unknown, message?: string): void;
+  error(data: unknown, message?: string): void;
+}
+
+class ConcurrencyGate {
+  private inFlight = 0;
+  private readonly queue: Array<() => void> = [];
+
+  constructor(private readonly limit: number) {}
+
+  async acquire(): Promise<void> {
+    if (this.inFlight < this.limit) {
+      this.inFlight += 1;
+      return;
+    }
+    await new Promise<void>((resolve) => {
+      this.queue.push(() => {
+        this.inFlight += 1;
+        resolve();
+      });
+    });
+  }
+
+  release(): void {
+    this.inFlight = Math.max(0, this.inFlight - 1);
+    this.queue.shift()?.();
+  }
+}
+
+function sleep(ms: number): Promise<void> {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+function toErrorMessage(error: unknown): string {
+  return error instanceof Error && error.message ? error.message : String(error);
+}
+
+function safeDurationMs(start: number, end: number): number {
+  return Math.max(0, Math.floor(end - start));
+}
+
+function extractTiming(result: unknown): WorkerJobTiming | undefined {
+  if (!result || typeof result !== 'object' || !('timing' in result)) return undefined;
+  return (result as { timing?: WorkerJobTiming }).timing;
+}
+
+function extractResultRef(kind: WorkerOperationKind, result: unknown): string | undefined {
+  if (kind !== 'pdf_layout' || !result || typeof result !== 'object') return undefined;
+  const maybe = result as { parsedObjectKey?: unknown };
+  return typeof maybe.parsedObjectKey === 'string' ? maybe.parsedObjectKey : undefined;
+}
+
+export function createWorkerLoopController(input: {
+  orchestrator: WorkerLoopOrchestrator;
+  handlers: JobHandlers;
+  logger: WorkerLogger;
+  jobConcurrency: number;
+  pdfAttempts: number;
+  whisperCodec: JsonCodec<QueuedJob<WhisperAlignJobRequest>>;
+  pdfCodec: JsonCodec<QueuedJob<PdfLayoutJobRequest>>;
+  isOwnerActive: (owner: object) => boolean;
+  isStopping: () => boolean;
+  markActivity: (reason: string) => void;
+  onInFlightJobsChanged: (delta: number) => void;
+}) {
+  const gate = new ConcurrencyGate(Math.max(1, Math.floor(input.jobConcurrency)));
+  let loops: Promise<void>[] = [];
+  let stopRequested = false;
+
+  type Context<TPayload> = {
+    decoded: QueuedJob<TPayload>;
+    workerLabel: string;
+    startedAt: number;
+    queueWaitTiming?: { queueWaitMs: number };
+    latestProgress?: PdfLayoutProgress;
+  };
+
+  const markRunning = async <TPayload>(context: Context<TPayload>, updatedAt: number): Promise<void> => {
+    if (context.latestProgress) {
+      await input.orchestrator.markProgress({
+        opId: context.decoded.opId,
+        progress: context.latestProgress,
+        updatedAt,
+        ...(context.queueWaitTiming ? { timing: context.queueWaitTiming } : {}),
+      });
+      return;
+    }
+    await input.orchestrator.markRunning({
+      opId: context.decoded.opId,
+      startedAt: context.startedAt,
+      updatedAt,
+      ...(context.queueWaitTiming ? { timing: context.queueWaitTiming } : {}),
+    });
+  };
+
+  const processMessage = async <TPayload, TResult>(work: {
+    msg: JsMsg;
+    codec: JsonCodec<QueuedJob<TPayload>>;
+    run: JobHandlers['runWhisper'] | JobHandlers['runPdfLayout'];
+    workerLabel: string;
+  }): Promise<void> => {
+    let context: Context<TPayload> | null = null;
+    let heartbeat: NodeJS.Timeout | null = null;
+    try {
+      const decoded = work.codec.decode(work.msg.data);
+      const startedAt = Date.now();
+      context = {
+        decoded,
+        workerLabel: work.workerLabel,
+        startedAt,
+        queueWaitTiming: buildQueueWaitTiming(decoded.queuedAt, startedAt),
+      };
+      await markRunning(context, startedAt);
+      input.logger.info({
+        worker: work.workerLabel,
+        kind: decoded.kind,
+        opId: decoded.opId,
+        jobId: decoded.jobId,
+        queueWaitMs: context.queueWaitTiming?.queueWaitMs ?? null,
+        deliveryCount: work.msg.info.deliveryCount,
+      }, 'job.started');
+      heartbeat = setInterval(() => {
+        void markRunning(context!, Date.now()).catch((error) => {
+          input.logger.error({
+            worker: work.workerLabel,
+            opId: context?.decoded.opId,
+            jobId: context?.decoded.jobId,
+            error: toErrorMessage(error),
+          }, 'failed to persist operation heartbeat state');
+        });
+      }, RUNNING_HEARTBEAT_MS);
+      const result = await work.run(decoded.payload as never, context.queueWaitTiming?.queueWaitMs ?? 0, {
+        onProgress: async (progress) => {
+          try {
+            work.msg.working();
+          } catch (error) {
+            input.logger.warn({
+              worker: work.workerLabel,
+              kind: context?.decoded.kind,
+              opId: context?.decoded.opId,
+              jobId: context?.decoded.jobId,
+              error: toErrorMessage(error),
+            }, 'failed to extend JetStream ack wait on progress');
+          }
+          context!.latestProgress = progress;
+          await markRunning(context!, Date.now());
+        },
+      });
+      const timing = extractTiming(result);
+      const now = Date.now();
+      await input.orchestrator.markSucceeded({
+        opId: decoded.opId,
+        result,
+        updatedAt: now,
+        ...(timing ? { timing } : {}),
+      });
+      work.msg.ack();
+      const durationMs = safeDurationMs(startedAt, now);
+      if (durationMs >= SLOW_JOB_LOG_THRESHOLD_MS_BY_KIND[decoded.kind]) {
+        input.logger.info({ worker: work.workerLabel, kind: decoded.kind, opId: decoded.opId, jobId: decoded.jobId, durationMs, timing: timing ?? null }, 'job.stage');
+      }
+      input.logger.info({
+        worker: work.workerLabel,
+        kind: decoded.kind,
+        opId: decoded.opId,
+        jobId: decoded.jobId,
+        status: 'succeeded',
+        durationMs,
+        resultRef: extractResultRef(decoded.kind, result),
+        timing: timing ?? null,
+      }, 'job.terminal');
+    } catch (error) {
+      const errorMessage = toErrorMessage(error);
+      const deliveryCount = work.msg.info.deliveryCount;
+      const kind = context?.decoded.kind ?? 'pdf_layout';
+      const action = decideRetryAction({ kind, deliveryCount, pdfAttempts: input.pdfAttempts, whisperMaxDeliver: WHISPER_MAX_DELIVER });
+      const timing = context ? buildQueueWaitTiming(context.decoded.queuedAt, Date.now()) : undefined;
+      if (context) {
+        const update = action === 'nak_retry'
+          ? markRunning(context, Date.now())
+          : input.orchestrator.markFailed({
+            opId: context.decoded.opId,
+            error: { message: errorMessage },
+            updatedAt: Date.now(),
+            ...(timing ? { timing } : {}),
+          });
+        await update.catch((stateError) => input.logger.error({
+          worker: context?.workerLabel,
+          opId: context?.decoded.opId,
+          jobId: context?.decoded.jobId,
+          error: toErrorMessage(stateError),
+        }, 'failed to persist operation state'));
+      }
+      if (action === 'nak_retry') work.msg.nak();
+      else work.msg.term(errorMessage);
+      input.logger.error({
+        worker: context?.workerLabel,
+        kind: context?.decoded.kind,
+        opId: context?.decoded.opId,
+        jobId: context?.decoded.jobId,
+        status: action === 'nak_retry' ? 'running' : 'failed',
+        error: errorMessage,
+        deliveryCount,
+        retryAction: action === 'nak_retry' ? 'nack_retry' : 'term',
+      }, 'job.terminal');
+    } finally {
+      if (heartbeat) clearInterval(heartbeat);
+    }
+  };
+
+  const runLoop = async <TPayload>(work: {
+    owner: object;
+    consumer: Consumer;
+    codec: JsonCodec<QueuedJob<TPayload>>;
+    run: JobHandlers['runWhisper'] | JobHandlers['runPdfLayout'];
+    workerLabel: string;
+  }): Promise<void> => {
+    const detached = () => input.isStopping() || stopRequested || !input.isOwnerActive(work.owner);
+    while (!detached()) {
+      let msg: JsMsg | null = null;
+      try {
+        try {
+          msg = await work.consumer.next({ expires: PULL_EXPIRES_MS });
+        } catch (error) {
+          if (detached()) return;
+          input.logger.error({ error: toErrorMessage(error), worker: work.workerLabel }, 'worker pull failed');
+          await sleep(LOOP_ERROR_BACKOFF_MS);
+          continue;
+        }
+        if (!msg) continue;
+        input.markActivity(`job_received:${work.workerLabel}`);
+        input.onInFlightJobsChanged(1);
+        await gate.acquire();
+        if (detached()) return;
+        await processMessage({ ...work, msg });
+      } finally {
+        if (msg) {
+          gate.release();
+          input.onInFlightJobsChanged(-1);
+          input.markActivity(`job_completed:${work.workerLabel}`);
+        }
+      }
+    }
+  };
+
+  return {
+    start(owner: object, consumers: { whisper: Consumer; pdfLayout: Consumer }): void {
+      stopRequested = false;
+      loops = [];
+      for (let i = 0; i < input.jobConcurrency; i += 1) {
+        loops.push(runLoop({ owner, consumer: consumers.whisper, codec: input.whisperCodec, run: input.handlers.runWhisper, workerLabel: `whisper-${i + 1}` }));
+        loops.push(runLoop({ owner, consumer: consumers.pdfLayout, codec: input.pdfCodec, run: input.handlers.runPdfLayout, workerLabel: `layout-${i + 1}` }));
+      }
+    },
+    async stop(): Promise<void> {
+      stopRequested = true;
+      await Promise.allSettled(loops);
+      loops = [];
+    },
+  };
+}

compute-worker/src/operations/index.ts

@@ -1,4 +1,4 @@
 export * from './types';
 export * from './state-machine';
-export * from './orchestrator';
+export * from './service';
 export * from './sse';

compute-worker/src/operations/recovery.ts

@@ -4,7 +4,7 @@ import type {
   WorkerJobTiming,
   WorkerJobState,
   WorkerOperationState,
-} from './compute/api-contracts';
+} from '../api/contracts';
 
 export type StreamedOperationState = WorkerOperationState<WhisperAlignJobResult | PdfLayoutJobResult>;
 

compute-worker/src/operations/service.ts

@@ -5,7 +5,7 @@ import type {
   WorkerOperationKind,
   WorkerOperationRequest,
   WorkerOperationState,
-} from '../api-contracts';
+} from '../api/contracts';
 import {
   buildQueuedState,
   createErrorShape,

compute-worker/src/operations/state-machine.ts

@@ -4,7 +4,7 @@ import type {
   WorkerOperationKind,
   WorkerOperationRequest,
   WorkerOperationState,
-} from '../api-contracts';
+} from '../api/contracts';
 
 export function isTerminalStatus(status: WorkerJobState): boolean {
   return status === 'succeeded' || status === 'failed';

compute-worker/src/operations/types.ts

@@ -2,7 +2,7 @@ import type {
   WorkerOperationEvent,
   WorkerOperationKind,
   WorkerOperationState,
-} from '../api-contracts';
+} from '../api/contracts';
 
 export type OperationState<Result = unknown> = WorkerOperationState<Result>;
 export type OperationEvent<Result = unknown> = WorkerOperationEvent<Result>;

compute-worker/src/server.ts

@@ -1,4 +1,4 @@
-import { startComputeWorkerFromEnv } from './runtime';
+import { startComputeWorkerFromEnv } from './api/app';
 
 void startComputeWorkerFromEnv().catch((error) => {
   console.error('[compute-worker] fatal startup error', error);

compute-worker/src/storage/artifact-addressing.ts

@@ -1,5 +1,5 @@
-import { PDF_PARSER_VERSION } from '../compute/pdf/parser-version';
-import { encodeParserVersion } from '../compute/pdf/parser-version-key';
+import { PDF_PARSER_VERSION } from '../inference/pdf/parser-version';
+import { encodeParserVersion } from '../inference/pdf/parser-version-key';
 
 const DOCUMENT_ID_REGEX = /^[a-f0-9]{64}$/i;
 const SAFE_NAMESPACE_REGEX = /^[a-zA-Z0-9._-]{1,128}$/;

compute-worker/tests/api/routes.test.ts

@@ -1,5 +1,5 @@
 import { afterEach, beforeEach, describe, expect, test } from 'vitest';
-import { createComputeWorkerApp } from '../../src/runtime';
+import { createComputeWorkerApp } from '../../src/api/app';
 import { FakeControlPlane } from '../fixtures/fake-control-plane';
 
 const AUTH = { authorization: 'Bearer test-token' };

compute-worker/tests/compute/algorithms/pdf-merge-text-with-regions.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, test } from 'vitest';
-import { mergeTextWithRegions } from '../../../src/compute';
+import { mergeTextWithRegions } from '../../../src/inference';
 
 describe('mergeTextWithRegions', () => {
   test('assigns text items to containing regions by centroid and joins in reading order', () => {

compute-worker/tests/compute/algorithms/pdf-parse-normalize-text-items.test.ts

@@ -1,6 +1,6 @@
 import { describe, expect, test } from 'vitest';
 
-import { normalizeTextItemsForLayout } from '../../../src/compute';
+import { normalizeTextItemsForLayout } from '../../../src/inference';
 import type { TextItem } from 'pdfjs-dist/types/src/display/api';
 
 function makeTextItem(

compute-worker/tests/compute/algorithms/pdf-stitch-cross-page-blocks.test.ts

@@ -1,6 +1,6 @@
 import { describe, expect, test } from 'vitest';
-import { stitchCrossPageBlocks } from '../../../src/compute';
-import type { ParsedPdfBlock, ParsedPdfDocument, ParsedPdfBlockKind } from '../../../src/compute/types';
+import { stitchCrossPageBlocks } from '../../../src/inference';
+import type { ParsedPdfBlock, ParsedPdfDocument, ParsedPdfBlockKind } from '../../../src/inference/types';
 import { makeParsedPdfDocument, makeParsedPdfPage } from './support/document-fixtures';
 
 function makeBlock(

compute-worker/tests/compute/algorithms/support/document-fixtures.ts

@@ -1,5 +1,5 @@
-import type { BaseDocument } from '../../../src/types/documents';
-import type { ParsedPdfBlock, ParsedPdfBlockKind, ParsedPdfDocument, ParsedPdfPage } from '../../../../src/compute/types';
+import type { BaseDocument } from '../../../../../src/types/documents';
+import type { ParsedPdfBlock, ParsedPdfBlockKind, ParsedPdfDocument, ParsedPdfPage } from '../../../../src/inference/types';
 
 export function makeBaseDocument(overrides: Partial<BaseDocument> = {}): BaseDocument {
   return {

compute-worker/tests/compute/algorithms/whisper-alignment-mapping.test.ts

@@ -1,7 +1,7 @@
 import { describe, expect, test } from 'vitest';
 import {
   mapWordsToSentenceOffsets,
-} from '../../../src/compute';
+} from '../../../src/inference';
 
 describe('whisper alignment mapping', () => {
   test('maps words to sentence offsets with punctuation and repeated spaces', () => {

compute-worker/tests/compute/algorithms/whisper-spectral.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, test } from 'vitest';
-import { buildGoertzelCoefficients, goertzelPower } from '../../../src/compute';
+import { buildGoertzelCoefficients, goertzelPower } from '../../../src/inference';
 
 function dftPower(samples: Float32Array, k: number): number {
   const n = samples.length;

compute-worker/tests/compute/algorithms/whisper-token-timestamps.test.ts

@@ -3,7 +3,7 @@ import * as ort from 'onnxruntime-node';
 import {
   buildWordsFromTimestampedTokens,
   extractTokenStartTimestamps,
-} from '../../../src/compute';
+} from '../../../src/inference';
 
 describe('whisper token timestamp alignment', () => {
   test('extracts monotonic token timestamps from cross-attention maps', () => {

compute-worker/tests/compute/control-plane/orchestrator.test.ts

@@ -1,6 +1,6 @@
 import { describe, expect, test } from 'vitest';
-import type { WorkerOperationRequest } from '../../../src/compute/api-contracts';
-import { OperationOrchestrator } from '../../../src/compute/control-plane';
+import type { WorkerOperationRequest } from '../../../src/api/contracts';
+import { OperationOrchestrator } from '../../../src/operations';
 import {
   InMemoryOperationEventStream,
   InMemoryOperationQueue,

compute-worker/tests/compute/control-plane/run-layout-model.test.ts

@@ -70,13 +70,13 @@ vi.mock('@napi-rs/canvas', () => {
   };
 });
 
-vi.mock('../../../src/compute/pdf/model', () => ({
+vi.mock('../../../src/inference/pdf/model', () => ({
   ensureModel: vi.fn(async () => '/tmp/model.onnx'),
   MODEL_CONFIG_PATH: '/tmp/model-config.json',
   MODEL_PREPROCESSOR_PATH: '/tmp/model-preprocessor.json',
 }));
 
-vi.mock('../../../src/compute/config/cpu-budget', () => ({
+vi.mock('../../../src/inference/config/cpu-budget', () => ({
   getOnnxThreadsPerJob: vi.fn(() => 1),
 }));
 
@@ -107,7 +107,7 @@ describe('runLayoutModel', () => {
       },
     };
 
-    const { runLayoutModel } = await import('../../../src/compute/pdf/runLayoutModel');
+    const { runLayoutModel } = await import('../../../src/inference/pdf/runLayoutModel');
     const regions = await runLayoutModel({
       pageWidth: 100,
       pageHeight: 100,
@@ -154,7 +154,7 @@ describe('runLayoutModel', () => {
       },
     };
 
-    const { runLayoutModel } = await import('../../../src/compute/pdf/runLayoutModel');
+    const { runLayoutModel } = await import('../../../src/inference/pdf/runLayoutModel');
     const regions = await runLayoutModel({
       pageWidth: 100,
       pageHeight: 100,

compute-worker/tests/compute/control-plane/sse.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, test } from 'vitest';
-import { encodeSseFrame, parseSseEventId, parseSsePayload } from '../../../src/compute/control-plane/sse';
+import { encodeSseFrame, parseSseEventId, parseSsePayload } from '../../../src/operations/sse';
 
 describe('sse codec', () => {
   test('encodes event id and payload and decodes both reliably', () => {

compute-worker/tests/compute/control-plane/state-machine.test.ts

@@ -1,11 +1,11 @@
 import { describe, expect, test } from 'vitest';
-import type { WorkerOperationState } from '../../../src/compute/api-contracts';
+import type { WorkerOperationState } from '../../../src/api/contracts';
 import {
   explainReplacementReason,
   isInflightStatus,
   isTerminalStatus,
   shouldReuseExistingOperation,
-} from '../../../src/compute/control-plane/state-machine';
+} from '../../../src/operations/state-machine';
 
 function runningState(overrides: Partial<WorkerOperationState> = {}): WorkerOperationState {
   return {

compute-worker/tests/compute/helpers/in-memory-control-plane.ts

@@ -1,5 +1,5 @@
 import { EventEmitter } from 'node:events';
-import type { WorkerOperationKind } from '../../../src/compute/api-contracts';
+import type { WorkerOperationKind } from '../../../src/api/contracts';
 import type {
   OperationEvent,
   OperationEventStream,
@@ -8,7 +8,7 @@ import type {
   OperationState,
   OperationStateStore,
   QueuedOperation,
-} from '../../../src/compute/control-plane/types';
+} from '../../../src/operations/types';
 
 function topicFor(opId: string): string {
   return `op.${opId}`;

compute-worker/tests/fixtures/fake-control-plane.ts

@@ -4,8 +4,8 @@ import type {
   WorkerOperationEvent,
   WorkerOperationRequest,
   WorkerOperationState,
-} from '../../src/compute/api-contracts';
-import type { ComputeWorkerRouteDeps } from '../../src/runtime';
+} from '../../src/api/contracts';
+import type { ComputeWorkerRouteDeps } from '../../src/api/app';
 
 type ComputeResult = WhisperAlignJobResult | PdfLayoutJobResult;
 type ComputeState = WorkerOperationState<ComputeResult>;

compute-worker/tests/unit/jetstream-adapters.test.ts

@@ -1,6 +1,6 @@
 import { describe, expect, test } from 'vitest';
-import { OperationOrchestrator } from '../../src/compute/control-plane';
-import type { WorkerOperationRequest } from '../../src/compute/api-contracts';
+import { OperationOrchestrator } from '../../src/operations';
+import type { WorkerOperationRequest } from '../../src/api/contracts';
 import {
   JetStreamOperationEventStream,
   JetStreamOperationQueue,
@@ -11,7 +11,7 @@ import {
   opStateKvKey,
   type KvEntryLike,
   type KvStoreLike,
-} from '../../src/control-plane/jetstream';
+} from '../../src/infrastructure/nats-adapters';
 
 class FakeKvStore implements KvStoreLike {
   private readonly data = new Map<string, KvEntryLike>();

compute-worker/tests/unit/key-and-progress.test.ts

@@ -1,9 +1,9 @@
 import { describe, expect, test } from 'vitest';
-import { hashOpKey, opIndexKvKey, opStateKvKey } from '../../src/control-plane/jetstream';
+import { hashOpKey, opIndexKvKey, opStateKvKey } from '../../src/infrastructure/nats-adapters';
 import {
   buildInferProgressForPageParsed,
   buildInferProgressForPageStart,
-} from '../../src/pdf-progress';
+} from '../../src/jobs/pdf-progress';
 import { buildPdfOperationKey } from '../../src/api/operation-keys';
 import { parsedPdfArtifactKey } from '../../src/storage/artifact-addressing';
 

compute-worker/tests/unit/orphan-recovery.test.ts

@@ -1,5 +1,5 @@
 import { afterEach, describe, expect, test, vi } from 'vitest';
-import { recoverOrphanedOperations } from '../../src/orphan-recovery';
+import { recoverOrphanedOperations } from '../../src/operations/recovery';
 import { FakeControlPlane } from '../fixtures/fake-control-plane';
 
 describe('orphan recovery', () => {

compute-worker/tests/unit/pdf-artifact-persistence.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, test, vi } from 'vitest';
-import { persistParsedPdfWhileSourceExists } from '../../src/pdf-artifact-persistence';
+import { persistParsedPdfWhileSourceExists } from '../../src/jobs/pdf-artifact-persistence';
 
 describe('PDF artifact persistence', () => {
   test('does not write parsed output after the source was deleted', async () => {

compute-worker/tests/unit/worker-loop-policy.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, test } from 'vitest';
-import { buildQueueWaitTiming, decideRetryAction } from '../../src/worker-loop-policy';
+import { buildQueueWaitTiming, decideRetryAction } from '../../src/jobs/worker-loop-policy';
 
 describe('worker loop policy', () => {
   test('returns queue wait timing with non-negative clamped duration', () => {

scripts/check-next-server-bundle.mjs

@@ -13,7 +13,7 @@ const forbidden = [
   'onnxruntime-node',
   '@huggingface/tokenizers',
   '@openreader/compute-worker',
-  '/compute-worker/src/compute/',
+  '/compute-worker/src/inference/',
 ];
 
 const includeExt = new Set(['.js', '.mjs', '.cjs']);

tests/unit/compute-worker-client-contract.vitest.spec.ts

@@ -1,5 +1,5 @@
 import { afterEach, describe, expect, test } from 'vitest';
-import { createComputeWorkerApp, type ComputeWorkerApp } from '../../compute-worker/src/runtime';
+import { createComputeWorkerApp, type ComputeWorkerApp } from '../../compute-worker/src/api/app';
 import { FakeControlPlane } from '../../compute-worker/tests/fixtures/fake-control-plane';
 import { ComputeWorkerClient } from '../../src/lib/server/compute-worker/client';