diff --git a/src/app/api/audiobook/chapter/route.ts b/src/app/api/audiobook/chapter/route.ts
index dfca613..20b48e5 100644
--- a/src/app/api/audiobook/chapter/route.ts
+++ b/src/app/api/audiobook/chapter/route.ts
@@ -333,7 +333,6 @@ export async function POST(request: NextRequest) {
       if (!existingResult.settings) {
         serverLogger.error({
           event: 'audiobook.chapter.meta_settings.invalid',
-          errorCode: 'AUDIOBOOK_CHAPTER_META_SETTINGS_INVALID',
           bookId,
           storageUserId,
           error: {
diff --git a/src/app/api/documents/[id]/parsed/events/route.ts b/src/app/api/documents/[id]/parsed/events/route.ts
index 0edb57c..7d2109c 100644
--- a/src/app/api/documents/[id]/parsed/events/route.ts
+++ b/src/app/api/documents/[id]/parsed/events/route.ts
@@ -269,7 +269,6 @@ export async function GET(req: NextRequest, ctx: { params: Promise<{ id: string
               if (closed) return;
               logger.warn({
                 event: 'documents.parsed.events.db_resync_failed',
-                errorCode: 'DOCUMENTS_PARSED_EVENTS_DB_RESYNC_FAILED',
                 degraded: true,
                 step: 'db_resync',
                 documentId: id,
@@ -347,7 +346,6 @@ export async function GET(req: NextRequest, ctx: { params: Promise<{ id: string
               const upstreamResponseBody = await response.text().catch(() => '');
               logger.warn({
                 event: 'documents.parsed.events.worker_stream_request_failed',
-                errorCode: 'DOCUMENTS_PARSED_EVENTS_WORKER_STREAM_REQUEST_FAILED',
                 degraded: true,
                 step: 'worker_stream_request',
                 documentId: id,
@@ -365,7 +363,6 @@ export async function GET(req: NextRequest, ctx: { params: Promise<{ id: string
             if (!response.body) {
               logger.warn({
                 event: 'documents.parsed.events.worker_stream_missing_body',
-                errorCode: 'DOCUMENTS_PARSED_EVENTS_WORKER_STREAM_MISSING_BODY',
                 degraded: true,
                 step: 'worker_stream_body',
                 documentId: id,
@@ -474,7 +471,6 @@ export async function GET(req: NextRequest, ctx: { params: Promise<{ id: string
             logger.error({
               event: 'documents.parsed.events.worker_proxy_crashed',
               documentId: id,
-              errorCode: 'DOCUMENTS_PARSED_EVENTS_WORKER_PROXY_CRASHED',
               error: errorToLog(error),
             }, 'Worker proxy crashed while streaming parse events');
             if (!closed) {
@@ -505,7 +501,6 @@ export async function GET(req: NextRequest, ctx: { params: Promise<{ id: string
   } catch (error) {
     logger.error({
       event: 'documents.parsed.events.route_failed',
-      errorCode: 'DOCUMENTS_PARSED_EVENTS_ROUTE_FAILED',
       error: errorToLog(error),
     }, 'Parsed events route failed');
     return NextResponse.json({ error: 'Failed to stream parsed PDF progress' }, { status: 500 });
diff --git a/src/app/api/documents/[id]/parsed/route.ts b/src/app/api/documents/[id]/parsed/route.ts
index 3398a96..d3e8539 100644
--- a/src/app/api/documents/[id]/parsed/route.ts
+++ b/src/app/api/documents/[id]/parsed/route.ts
@@ -220,7 +220,6 @@ export async function GET(req: NextRequest, ctx: { params: Promise<{ id: string
       }
       logger.warn({
         event: 'documents.parsed.requested_op_unavailable',
-        errorCode: 'DOCUMENTS_PARSED_REQUESTED_OP_UNAVAILABLE',
         degraded: true,
         step: 'requested_op_lookup',
         documentId: id,
@@ -314,7 +313,6 @@ export async function GET(req: NextRequest, ctx: { params: Promise<{ id: string
   } catch (error) {
     logger.error({
       event: 'documents.parsed.get_failed',
-      errorCode: 'DOCUMENTS_PARSED_GET_FAILED',
       error: errorToLog(error),
     }, 'Failed to read parsed PDF');
     return NextResponse.json({ error: 'Failed to read parsed PDF' }, { status: 500 });
@@ -395,7 +393,6 @@ export async function POST(req: NextRequest, ctx: { params: Promise<{ id: string
   } catch (error) {
     logger.error({
       event: 'documents.parsed.force_refresh_failed',
-      errorCode: 'DOCUMENTS_PARSED_FORCE_REFRESH_FAILED',
       error: errorToLog(error),
     }, 'Failed to force PDF refresh');
     return NextResponse.json({ error: 'Failed to force PDF refresh' }, { status: 500 });
diff --git a/src/app/api/tts/segments/audio/fallback/route.ts b/src/app/api/tts/segments/audio/fallback/route.ts
index 5b92539..159713d 100644
--- a/src/app/api/tts/segments/audio/fallback/route.ts
+++ b/src/app/api/tts/segments/audio/fallback/route.ts
@@ -52,7 +52,6 @@ export async function GET(request: NextRequest) {
   } catch (error) {
     logger.error({
       event: 'tts.segments.audio_fallback_failed',
-      errorCode: 'TTS_SEGMENT_AUDIO_FALLBACK_FAILED',
       error: errorToLog(error),
     }, 'Failed to load segment audio from fallback route');
     return NextResponse.json({ error: 'Failed to load segment audio' }, { status: 500 });
diff --git a/src/app/api/tts/segments/clear/route.ts b/src/app/api/tts/segments/clear/route.ts
index 0245113..c794bbf 100644
--- a/src/app/api/tts/segments/clear/route.ts
+++ b/src/app/api/tts/segments/clear/route.ts
@@ -41,7 +41,6 @@ export async function POST(request: NextRequest) {
   } catch (error) {
     logger.error({
       event: 'tts.segments.clear_failed',
-      errorCode: 'TTS_SEGMENTS_CLEAR_FAILED',
       error: errorToLog(error),
     }, 'Failed to clear TTS segment cache');
     return NextResponse.json({ error: 'Failed to clear TTS segment cache' }, { status: 500 });
diff --git a/src/app/api/tts/segments/ensure/route.ts b/src/app/api/tts/segments/ensure/route.ts
index ec2c475..7e4f48f 100644
--- a/src/app/api/tts/segments/ensure/route.ts
+++ b/src/app/api/tts/segments/ensure/route.ts
@@ -423,7 +423,6 @@ export async function POST(request: NextRequest) {
               documentId: parsed.documentId,
               segmentId: segment.segmentId,
               aborted,
-              errorCode: 'TTS_SEGMENT_ALIGNMENT_UNAVAILABLE',
               ...(aborted ? {} : { degraded: true }),
               step: 'whisper_align',
               error: errorToLog(alignError),
@@ -668,7 +667,6 @@ export async function POST(request: NextRequest) {
               documentId: parsed.documentId,
               segmentId: segment.segmentId,
               aborted,
-              errorCode: 'TTS_SEGMENT_ALIGNMENT_UNAVAILABLE',
               ...(aborted ? {} : { degraded: true }),
               step: 'whisper_align',
               error: errorToLog(alignError),
@@ -720,7 +718,7 @@ export async function POST(request: NextRequest) {
         const retryAfterSeconds = upstreamStatus === 429
           ? getUpstreamRetryAfterSeconds(error)
           : undefined;
-        const errorCode = upstreamStatus === 429
+        const failureCode = upstreamStatus === 429
           ? 'UPSTREAM_RATE_LIMIT'
           : upstreamStatus && upstreamStatus >= 500
             ? 'UPSTREAM_TTS_ERROR'
@@ -735,7 +733,6 @@ export async function POST(request: NextRequest) {
             elapsedMs: Date.now() - segmentStartedAt,
             stageTimings,
             aborted: true,
-            errorCode,
             error: errorToLog(error),
             completedSoFar: manifest.length,
             totalRequested: normalized.length,
@@ -752,7 +749,6 @@ export async function POST(request: NextRequest) {
             aborted: false,
             upstreamStatus,
             retryAfterSeconds,
-            errorCode,
             error: errorToLog(error),
           }, 'TTS segment generation failed');
         }
@@ -762,7 +758,7 @@ export async function POST(request: NextRequest) {
             status: aborted ? 'pending' : 'error',
             error: aborted ? null : (
               upstreamStatus
-                ? `${errorCode}${retryAfterSeconds ? ` (retry after ${retryAfterSeconds}s)` : ''}: ${errorMessage}`
+                ? `${failureCode}${retryAfterSeconds ? ` (retry after ${retryAfterSeconds}s)` : ''}: ${errorMessage}`
                 : errorMessage
             ),
             updatedAt: Date.now(),
@@ -785,7 +781,7 @@ export async function POST(request: NextRequest) {
           error: aborted
             ? null
             : {
-              code: errorCode,
+              code: failureCode,
               detail: errorMessage,
               ...(typeof upstreamStatus === 'number' ? { upstreamStatus } : {}),
               ...(typeof retryAfterSeconds === 'number' ? { retryAfterSeconds } : {}),
@@ -804,7 +800,6 @@ export async function POST(request: NextRequest) {
     if (errorItems.length > 0) {
       logger.error({
         event: 'tts.segments.ensure.partial_result',
-        errorCode: 'TTS_SEGMENT_PARTIAL_FAILURE',
         requestId,
         documentId: parsed.documentId,
         total: manifest.length,
@@ -835,7 +830,6 @@ export async function POST(request: NextRequest) {
   } catch (error) {
     logger.error({
       event: 'tts.segments.ensure.route_failed',
-      errorCode: 'TTS_SEGMENTS_ENSURE_ROUTE_FAILED',
       error: errorToLog(error),
     }, 'TTS segments ensure route failed');
     const response = NextResponse.json({ error: 'Failed to ensure TTS segments' }, { status: 500 });
diff --git a/src/app/api/tts/segments/manifest/route.ts b/src/app/api/tts/segments/manifest/route.ts
index 017334b..b8cad65 100644
--- a/src/app/api/tts/segments/manifest/route.ts
+++ b/src/app/api/tts/segments/manifest/route.ts
@@ -388,7 +388,6 @@ export async function GET(request: NextRequest) {
   } catch (error) {
     logger.error({
       event: 'tts.segments.manifest.list_failed',
-      errorCode: 'TTS_SEGMENTS_MANIFEST_LIST_FAILED',
       error: errorToLog(error),
     }, 'Failed to list TTS segments');
     return NextResponse.json({ error: 'Failed to list TTS segments' }, { status: 500 });
diff --git a/src/lib/server/admin/email-sync.ts b/src/lib/server/admin/email-sync.ts
index 02c602b..3085584 100644
--- a/src/lib/server/admin/email-sync.ts
+++ b/src/lib/server/admin/email-sync.ts
@@ -63,7 +63,6 @@ export async function syncAdminFlag(
   } catch (error) {
     serverLogger.warn({
       event: 'admin.email_sync.user_flag_update.failed',
-      errorCode: 'ADMIN_EMAIL_SYNC_USER_FLAG_UPDATE_FAILED',
       userIdHash: hashForLog(userId),
       degraded: true,
       error: errorToLog(error),
diff --git a/src/lib/server/admin/seed.ts b/src/lib/server/admin/seed.ts
index 87b9a76..5057201 100644
--- a/src/lib/server/admin/seed.ts
+++ b/src/lib/server/admin/seed.ts
@@ -33,7 +33,6 @@ export async function ensureAdminSeed(): Promise<void> {
     seedPromise = runSeed().catch((error) => {
       serverLogger.warn({
         event: 'admin.seed.run.failed',
-        errorCode: 'ADMIN_SEED_RUN_FAILED',
         degraded: true,
         error: errorToLog(error),
       }, 'Admin seed run failed');
@@ -66,7 +65,6 @@ async function seedDefaultAdminProvider(): Promise<void> {
   } catch (error) {
     serverLogger.warn({
       event: 'admin.seed.providers.check_failed',
-      errorCode: 'ADMIN_SEED_PROVIDERS_CHECK_FAILED',
       degraded: true,
       error: errorToLog(error),
     }, 'Could not check admin_providers');
@@ -104,7 +102,6 @@ async function seedDefaultAdminProvider(): Promise<void> {
       } catch (fallbackError) {
         serverLogger.warn({
           event: 'admin.seed.restrict_user_api_keys.fallback_write_failed',
-          errorCode: 'ADMIN_SEED_RESTRICT_USER_API_KEYS_FALLBACK_WRITE_FAILED',
           degraded: true,
           error: errorToLog(fallbackError),
         }, 'Failed to write restrictUserApiKeys fallback after encryption failure');
@@ -112,7 +109,6 @@ async function seedDefaultAdminProvider(): Promise<void> {
     }
     serverLogger.warn({
       event: 'admin.seed.provider_key_encrypt.failed',
-      errorCode: 'ADMIN_SEED_PROVIDER_KEY_ENCRYPT_FAILED',
       degraded: true,
       error: errorToLog(error),
     }, 'Failed to encrypt default provider API key');
@@ -141,7 +137,6 @@ async function seedDefaultAdminProvider(): Promise<void> {
   } catch (error) {
     serverLogger.warn({
       event: 'admin.seed.provider_insert.failed',
-      errorCode: 'ADMIN_SEED_PROVIDER_INSERT_FAILED',
       degraded: true,
       providerSlug: 'default-openai',
       error: errorToLog(error),
@@ -171,7 +166,6 @@ async function cleanupLegacyDefaultTtsProviderSeedRow(): Promise<void> {
   } catch (error) {
     serverLogger.warn({
       event: 'admin.seed.legacy_default_provider_cleanup.failed',
-      errorCode: 'ADMIN_SEED_LEGACY_DEFAULT_PROVIDER_CLEANUP_FAILED',
       degraded: true,
       error: errorToLog(error),
     }, 'Failed to cleanup legacy defaultTtsProvider seed row');
@@ -186,7 +180,6 @@ async function cleanupLegacyDefaultTtsModelRows(): Promise<void> {
   } catch (error) {
     serverLogger.warn({
       event: 'admin.seed.legacy_default_model_cleanup.failed',
-      errorCode: 'ADMIN_SEED_LEGACY_DEFAULT_MODEL_CLEANUP_FAILED',
       degraded: true,
       error: errorToLog(error),
     }, 'Failed to cleanup legacy defaultTtsModel rows');
diff --git a/src/lib/server/admin/settings.ts b/src/lib/server/admin/settings.ts
index c30b29c..471f502 100644
--- a/src/lib/server/admin/settings.ts
+++ b/src/lib/server/admin/settings.ts
@@ -116,7 +116,6 @@ async function resolveImplicitDefaultTtsProvider(): Promise<string | undefined>
   } catch (error) {
     serverLogger.warn({
       event: 'admin.runtime_config.default_provider_lookup.failed',
-      errorCode: 'ADMIN_RUNTIME_CONFIG_DEFAULT_PROVIDER_LOOKUP_FAILED',
       degraded: true,
       error: errorToLog(error),
     }, 'Implicit defaultTtsProvider lookup failed');
@@ -149,7 +148,6 @@ async function readAllRows(): Promise<Map<string, { value: unknown; source: stri
   } catch (error) {
     serverLogger.warn({
       event: 'admin.runtime_config.read.failed',
-      errorCode: 'ADMIN_RUNTIME_CONFIG_READ_FAILED',
       degraded: true,
       error: errorToLog(error),
     }, 'Runtime config read failed');
@@ -310,7 +308,6 @@ export async function seedRuntimeConfigFromEnv(): Promise<{ seeded: RuntimeConfi
     } catch (error) {
       serverLogger.warn({
         event: 'admin.runtime_config.seed.failed',
-        errorCode: 'ADMIN_RUNTIME_CONFIG_SEED_FAILED',
         degraded: true,
         key,
         error: errorToLog(error),
diff --git a/src/lib/server/auth/auth.ts b/src/lib/server/auth/auth.ts
index a4189b3..baed871 100644
--- a/src/lib/server/auth/auth.ts
+++ b/src/lib/server/auth/auth.ts
@@ -96,7 +96,6 @@ const createAuth = () => betterAuth({
         } catch (error) {
           serverLogger.warn({
             event: 'auth.user_delete.storage_cleanup_failed',
-            errorCode: 'AUTH_USER_DELETE_STORAGE_CLEANUP_FAILED',
             degraded: true,
             step: 'delete_user_storage',
             userIdHash: hashForLog(user.id),
@@ -180,7 +179,6 @@ const createAuth = () => betterAuth({
               } catch (error) {
                 serverLogger.warn({
                   event: 'auth.link_account.transfer.rate_limit.failed',
-                  errorCode: 'AUTH_LINK_ACCOUNT_TRANSFER_RATE_LIMIT_FAILED',
                   degraded: true,
                   step: 'transfer_rate_limit',
                   anonymousUserIdHash: hashForLog(anonymousUser.user.id),
@@ -204,7 +202,6 @@ const createAuth = () => betterAuth({
               } catch (error) {
                 serverLogger.warn({
                   event: 'auth.link_account.transfer.audiobooks.failed',
-                  errorCode: 'AUTH_LINK_ACCOUNT_TRANSFER_AUDIOBOOKS_FAILED',
                   degraded: true,
                   step: 'transfer_audiobooks',
                   anonymousUserIdHash: hashForLog(anonymousUser.user.id),
@@ -228,7 +225,6 @@ const createAuth = () => betterAuth({
               } catch (error) {
                 serverLogger.warn({
                   event: 'auth.link_account.transfer.documents.failed',
-                  errorCode: 'AUTH_LINK_ACCOUNT_TRANSFER_DOCUMENTS_FAILED',
                   degraded: true,
                   step: 'transfer_documents',
                   anonymousUserIdHash: hashForLog(anonymousUser.user.id),
@@ -252,7 +248,6 @@ const createAuth = () => betterAuth({
               } catch (error) {
                 serverLogger.warn({
                   event: 'auth.link_account.transfer.preferences.failed',
-                  errorCode: 'AUTH_LINK_ACCOUNT_TRANSFER_PREFERENCES_FAILED',
                   degraded: true,
                   step: 'transfer_preferences',
                   anonymousUserIdHash: hashForLog(anonymousUser.user.id),
@@ -276,7 +271,6 @@ const createAuth = () => betterAuth({
               } catch (error) {
                 serverLogger.warn({
                   event: 'auth.link_account.transfer.progress.failed',
-                  errorCode: 'AUTH_LINK_ACCOUNT_TRANSFER_PROGRESS_FAILED',
                   degraded: true,
                   step: 'transfer_progress',
                   anonymousUserIdHash: hashForLog(anonymousUser.user.id),
@@ -288,7 +282,6 @@ const createAuth = () => betterAuth({
             } catch (error) {
               serverLogger.error({
                 event: 'auth.link_account.failed',
-                errorCode: 'AUTH_LINK_ACCOUNT_FAILED',
                 error: errorToLog(error),
               }, 'onLinkAccount callback failed');
               // Don't throw here to prevent blocking the account linking process
diff --git a/src/lib/server/compute/worker-op-state.ts b/src/lib/server/compute/worker-op-state.ts
index 52f0300..7cfe88b 100644
--- a/src/lib/server/compute/worker-op-state.ts
+++ b/src/lib/server/compute/worker-op-state.ts
@@ -16,7 +16,6 @@ export async function fetchWorkerOperationState<Result>(
   } catch (error) {
     serverLogger.warn({
       event: 'compute.worker_op_state.config.invalid',
-      errorCode: 'COMPUTE_WORKER_OP_STATE_CONFIG_INVALID',
       opId: normalized,
       degraded: true,
       step: 'read_worker_config',
@@ -43,7 +42,6 @@ export async function fetchWorkerOperationState<Result>(
       const upstreamResponseBody = await res.text().catch(() => '');
       serverLogger.warn({
         event: 'compute.worker_op_state.fetch.failed',
-        errorCode: 'COMPUTE_WORKER_OP_STATE_FETCH_FAILED',
         opId: normalized,
         status: res.status,
         upstreamResponseBody,
@@ -60,7 +58,6 @@ export async function fetchWorkerOperationState<Result>(
     if (!parsed || typeof parsed !== 'object' || parsed.opId !== normalized) {
       serverLogger.warn({
         event: 'compute.worker_op_state.response.invalid',
-        errorCode: 'COMPUTE_WORKER_OP_STATE_RESPONSE_INVALID',
         opId: normalized,
         degraded: true,
         step: 'validate_worker_op_response',
@@ -71,7 +68,6 @@ export async function fetchWorkerOperationState<Result>(
   } catch (error) {
     serverLogger.warn({
       event: 'compute.worker_op_state.fetch.error',
-      errorCode: 'COMPUTE_WORKER_OP_STATE_FETCH_ERROR',
       opId: normalized,
       degraded: true,
       step: 'fetch_worker_op',
diff --git a/src/lib/server/compute/worker.ts b/src/lib/server/compute/worker.ts
index 70298b2..df914db 100644
--- a/src/lib/server/compute/worker.ts
+++ b/src/lib/server/compute/worker.ts
@@ -300,7 +300,6 @@ export class WorkerComputeBackend implements ComputeBackend {
         return { alignments: final.result.alignments };
       }, ({ attempt, maxAttempts, willRetry, delayMs, error }) => {
         logWorker(willRetry ? 'warn' : 'error', 'align.request.attempt_error', {
-          errorCode: 'COMPUTE_WORKER_ALIGN_REQUEST_ATTEMPT_ERROR',
           traceId,
           kind: 'whisper_align',
           opKeyHash,
@@ -321,7 +320,6 @@ export class WorkerComputeBackend implements ComputeBackend {
       return result;
     } catch (error) {
       logWorker('error', 'align.request.failed', {
-        errorCode: 'COMPUTE_WORKER_ALIGN_REQUEST_FAILED',
         traceId,
         kind: 'whisper_align',
         opKeyHash,
@@ -400,7 +398,6 @@ export class WorkerComputeBackend implements ComputeBackend {
         throw new Error('PDF layout worker operation completed without parsed output');
       }, ({ attempt, maxAttempts, willRetry, delayMs, error }) => {
         logWorker(willRetry ? 'warn' : 'error', 'pdf_layout.request.attempt_error', {
-          errorCode: 'COMPUTE_WORKER_PDF_LAYOUT_REQUEST_ATTEMPT_ERROR',
           traceId,
           kind: 'pdf_layout',
           opKeyHash,
@@ -423,7 +420,6 @@ export class WorkerComputeBackend implements ComputeBackend {
       return result;
     } catch (error) {
       logWorker('error', 'pdf_layout.request.failed', {
-        errorCode: 'COMPUTE_WORKER_PDF_LAYOUT_REQUEST_FAILED',
         traceId,
         kind: 'pdf_layout',
         opKeyHash,
@@ -468,7 +464,6 @@ export class WorkerComputeBackend implements ComputeBackend {
         retryAfterMs,
       );
       logWorker(res.status >= 500 ? 'warn' : 'error', 'http.request.failed', {
-        errorCode: 'COMPUTE_WORKER_HTTP_REQUEST_FAILED',
         ...context,
         traceId,
         method,
@@ -547,7 +542,6 @@ export class WorkerComputeBackend implements ComputeBackend {
             retryAfterMs,
           );
           logWorker(res.status >= 500 ? 'warn' : 'error', 'sse.wait.http_failed', {
-            errorCode: 'COMPUTE_WORKER_SSE_WAIT_HTTP_FAILED',
             ...context,
             traceId,
             opId,
@@ -669,7 +663,6 @@ export class WorkerComputeBackend implements ComputeBackend {
       }
 
       logWorker('error', 'sse.wait.ended_without_terminal', {
-        errorCode: 'COMPUTE_WORKER_SSE_WAIT_ENDED_WITHOUT_TERMINAL',
         ...context,
         traceId,
         opId,
@@ -684,7 +677,6 @@ export class WorkerComputeBackend implements ComputeBackend {
       throw new Error(`Operation stream ended before terminal state for op ${opId}`);
     } catch (error) {
       logWorker('error', 'sse.wait.failed', {
-        errorCode: 'COMPUTE_WORKER_SSE_WAIT_FAILED',
         ...context,
         traceId,
         opId,
diff --git a/src/lib/server/documents/previews.ts b/src/lib/server/documents/previews.ts
index a061ede..3ed21dc 100644
--- a/src/lib/server/documents/previews.ts
+++ b/src/lib/server/documents/previews.ts
@@ -377,7 +377,6 @@ export async function ensureDocumentPreview(doc: PreviewSourceDocument, namespac
     } catch (error) {
       serverLogger.error({
         event: 'documents.preview.generate.failed',
-        errorCode: 'DOCUMENTS_PREVIEW_GENERATE_FAILED',
         documentId: doc.id,
         documentType: doc.type,
         error: errorToLog(error),
diff --git a/src/lib/server/jobs/user-pdf-layout-job.ts b/src/lib/server/jobs/user-pdf-layout-job.ts
index d3a78c1..303d17d 100644
--- a/src/lib/server/jobs/user-pdf-layout-job.ts
+++ b/src/lib/server/jobs/user-pdf-layout-job.ts
@@ -390,7 +390,6 @@ export async function parsePdfJob(input: UserPdfLayoutJobRequest): Promise<void>
     } catch (statusError) {
       serverLogger.error({
         event: 'documents.parse.status_write.failed',
-        errorCode: 'DOCUMENTS_PARSE_STATUS_WRITE_FAILED',
         documentId: input.documentId,
         parseStatus,
         error: errorToLog(statusError),
@@ -398,7 +397,6 @@ export async function parsePdfJob(input: UserPdfLayoutJobRequest): Promise<void>
     }
     serverLogger.error({
       event: 'documents.parse.job.failed',
-      errorCode: 'DOCUMENTS_PARSE_JOB_FAILED',
       documentId: input.documentId,
       parseStatus,
       error: errorToLog(error),
@@ -415,7 +413,6 @@ export function enqueueParsePdfJob(input: UserPdfLayoutJobRequest): void {
       serverLogger.error({
         event: 'documents.parse.job.uncaught_error',
         documentId: input.documentId,
-        errorCode: 'DOCUMENTS_PARSE_JOB_UNCAUGHT_ERROR',
         error: errorToLog(error),
       }, 'Parse job uncaught error');
     });
diff --git a/src/lib/server/logger.ts b/src/lib/server/logger.ts
index 8d67dca..aff248d 100644
--- a/src/lib/server/logger.ts
+++ b/src/lib/server/logger.ts
@@ -17,7 +17,6 @@ export type ServerErrorClass =
   | 'unknown';
 
 export type ServerErrorContract = {
-  errorCode: string;
   errorClass: ServerErrorClass;
   retryable: boolean;
   httpStatus: number;
@@ -28,7 +27,6 @@ export type ServerErrorContract = {
 
 export type ServerApiErrorBody = {
   error: string;
-  errorCode: string;
   retryable?: boolean;
   details?: Record<string, unknown>;
 };
@@ -144,11 +142,10 @@ export function errorToLog(error: unknown, depth = 0): LoggedError {
 }
 
 export function apiErrorBody(
-  input: Omit<ServerApiErrorBody, 'errorCode'> & { errorCode: string },
+  input: ServerApiErrorBody,
 ): ServerApiErrorBody {
   return {
     error: input.error,
-    errorCode: input.errorCode,
     ...(typeof input.retryable === 'boolean' ? { retryable: input.retryable } : {}),
     ...(input.details ? { details: input.details } : {}),
   };
diff --git a/src/lib/server/tts/segments-cache.ts b/src/lib/server/tts/segments-cache.ts
index 31e856b..858bef9 100644
--- a/src/lib/server/tts/segments-cache.ts
+++ b/src/lib/server/tts/segments-cache.ts
@@ -68,7 +68,6 @@ export async function clearTtsSegmentCache(
       warning = error instanceof Error ? error.message : 'Failed deleting some audio objects';
       serverLogger.warn({
         event: 'tts.segments.cache.audio_cleanup_failed',
-        errorCode: 'TTS_SEGMENTS_CACHE_AUDIO_CLEANUP_FAILED',
         degraded: true,
         step: 'delete_tts_audio_objects',
         documentId: input.documentId,
diff --git a/src/lib/server/tts/voice-resolution.ts b/src/lib/server/tts/voice-resolution.ts
index f4bc9ee..e0d014d 100644
--- a/src/lib/server/tts/voice-resolution.ts
+++ b/src/lib/server/tts/voice-resolution.ts
@@ -195,7 +195,6 @@ async function fetchReplicateOpenApiSchema(apiKey: string, model: string): Promi
     }
     serverLogger.error({
       event: 'tts.voice_resolution.replicate_schema_fetch.failed',
-      errorCode: 'TTS_VOICE_RESOLUTION_REPLICATE_SCHEMA_FETCH_FAILED',
       error: errorToLog(error),
     }, 'Failed fetching Replicate model schema');
     return null;
@@ -290,7 +289,6 @@ async function fetchDeepinfraVoices(apiKey: string): Promise<string[]> {
     }
     serverLogger.error({
       event: 'tts.voice_resolution.deepinfra_voices_fetch.failed',
-      errorCode: 'TTS_VOICE_RESOLUTION_DEEPINFRA_VOICES_FETCH_FAILED',
       error: errorToLog(error),
     }, 'Failed fetching Deepinfra voices');
     return [];
diff --git a/src/lib/server/user/data-cleanup.ts b/src/lib/server/user/data-cleanup.ts
index 2aed3a0..54aa488 100644
--- a/src/lib/server/user/data-cleanup.ts
+++ b/src/lib/server/user/data-cleanup.ts
@@ -52,7 +52,6 @@ export async function deleteUserStorageData(
       } catch (error) {
         serverLogger.warn({
           event: 'user.data_cleanup.document_blob_delete.failed',
-          errorCode: 'USER_DATA_CLEANUP_DOCUMENT_BLOB_DELETE_FAILED',
           degraded: true,
           step: 'delete_document_blob',
           documentId: doc.id,
@@ -66,7 +65,6 @@ export async function deleteUserStorageData(
       } catch (error) {
         serverLogger.warn({
           event: 'user.data_cleanup.document_preview_delete.failed',
-          errorCode: 'USER_DATA_CLEANUP_DOCUMENT_PREVIEW_DELETE_FAILED',
           degraded: true,
           step: 'delete_document_preview_artifacts',
           documentId: doc.id,
@@ -82,7 +80,6 @@ export async function deleteUserStorageData(
     } catch (error) {
       serverLogger.warn({
         event: 'user.data_cleanup.document_preview_rows_delete.failed',
-        errorCode: 'USER_DATA_CLEANUP_DOCUMENT_PREVIEW_ROWS_DELETE_FAILED',
         degraded: true,
         step: 'delete_document_preview_rows',
         documentId: doc.id,
@@ -109,7 +106,6 @@ export async function deleteUserStorageData(
     } catch (error) {
       serverLogger.warn({
         event: 'user.data_cleanup.audiobook_blobs_delete.failed',
-        errorCode: 'USER_DATA_CLEANUP_AUDIOBOOK_BLOBS_DELETE_FAILED',
         degraded: true,
         step: 'delete_audiobook_prefix',
         bookId: book.id,
@@ -132,7 +128,6 @@ export async function deleteUserStorageData(
     } catch (error) {
       serverLogger.warn({
         event: 'user.data_cleanup.tts_segments_delete.failed',
-        errorCode: 'USER_DATA_CLEANUP_TTS_SEGMENTS_DELETE_FAILED',
         degraded: true,
         step: 'delete_tts_segment_prefixes',
         userIdHash: hashForLog(userId),