diff --git a/docs/api/openapi.yaml b/docs/api/openapi.yaml
index 02f8a3095..780128da3 100644
--- a/docs/api/openapi.yaml
+++ b/docs/api/openapi.yaml
@@ -38529,13 +38529,13 @@ components:
                 account.deletion.not_pending; activity — activity.calendar.future_date, activity.calendar.too_old; ai —
                 ai.budget.exceeded, ai.provider.none, ai.record.notPermitted, ai.unavailable, ai.usage.aboveCeiling,
                 ai.usage.defaultAboveCeiling, ai.usage.invalid, ai.usage.levelTooLow, ai.usage.rateLimited; ai_provider
-                — ai_provider.invalid, ai_provider.no_fields; aiRuns — aiRuns.failed, aiRuns.notFound, aiRuns.timedOut,
-                aiRuns.workerUnavailable; allergy — allergy.invalid; analytics — analytics.invalid_query; anamnesis —
-                anamnesis.auditC.invalid, anamnesis.auditC.notFound, anamnesis.auditC.rateLimited,
-                anamnesis.fact.conflict, anamnesis.fact.currentExists, anamnesis.fact.invalidValue,
-                anamnesis.lifeConfirm.invalid, anamnesis.lifeSections.invalid; auth — auth.account.deletion_pending,
-                auth.admin.required, auth.already_authenticated, auth.mfa.code_invalid, auth.missing,
-                auth.refresh.invalid, auth.refresh.reuse, auth.refresh.revoked, auth.reproof.failed,
+                — ai_provider.invalid, ai_provider.no_fields; aiRuns — aiRuns.failed, aiRuns.notFound,
+                aiRuns.readerBusy, aiRuns.timedOut, aiRuns.workerUnavailable; allergy — allergy.invalid; analytics —
+                analytics.invalid_query; anamnesis — anamnesis.auditC.invalid, anamnesis.auditC.notFound,
+                anamnesis.auditC.rateLimited, anamnesis.fact.conflict, anamnesis.fact.currentExists,
+                anamnesis.fact.invalidValue, anamnesis.lifeConfirm.invalid, anamnesis.lifeSections.invalid; auth —
+                auth.account.deletion_pending, auth.admin.required, auth.already_authenticated, auth.mfa.code_invalid,
+                auth.missing, auth.refresh.invalid, auth.refresh.reuse, auth.refresh.revoked, auth.reproof.failed,
                 auth.reproof.required, auth.reproof.too_weak, auth.scope.insufficient, auth.session.insecure_transport,
                 auth.session.unavailable, auth.stepup.required, auth.token.expired, auth.token.invalid; backup —
                 backup.foreign_reference, backup.key.missing, backup.payload.undecryptable, backup.restore.active,
@@ -75840,7 +75840,8 @@ components:
           description: "Present once `status` is `FAILED`: the `meta.errorCode`, message and HTTP status the queuing route would
             have answered with, or one of the run's own codes: `aiRuns.workerUnavailable` (no worker took the run within
             fifteen minutes), `aiRuns.timedOut` (the read outlived the calls the AI response time allows),
-            `aiRuns.failed` (anything else)."
+            `aiRuns.readerBusy` (the server's document reader was busy past the wait a read gets, or stopped before it
+            answered; nothing was read or charged, try again in a minute), `aiRuns.failed` (anything else)."
         createdAt:
           type: string
         startedAt:
diff --git a/messages/de.json b/messages/de.json
index 96a78eff5..1ee556a07 100644
--- a/messages/de.json
+++ b/messages/de.json
@@ -175,6 +175,9 @@
           "failed": "Das Etikett konnte nicht gelesen werden. Versuch ein schärferes Foto."
         }
       }
+    },
+    "aiRuns": {
+      "readerBusy": "Der Dokumentleser ist gerade mit anderen Aufgaben beschäftigt. Versuch es in einer Minute noch einmal."
     }
   },
   "doctorReport": {
@@ -13258,7 +13261,8 @@
     "backgroundScan": "Wird im Hintergrund gelesen. Mit einem langsamen Modell kann das ein paar Minuten dauern.",
     "waitingForWorker": "Warte auf den Hintergrunddienst. Ändert sich das nicht, läuft der Worker auf dem Server vielleicht nicht.",
     "errorWorkerUnavailable": "Der Hintergrunddienst ist gerade nicht erreichbar. Versuch es gleich noch einmal oder bitte die Person, die den Server betreibt, ihn zu prüfen.",
-    "errorTimedOut": "Das Lesen hat länger gedauert, als deine KI-Antwortzeit erlaubt. Versuch es noch einmal oder erhöhe die Antwortzeit in den KI-Einstellungen."
+    "errorTimedOut": "Das Lesen hat länger gedauert, als deine KI-Antwortzeit erlaubt. Versuch es noch einmal oder erhöhe die Antwortzeit in den KI-Einstellungen.",
+    "errorReaderBusy": "Der Dokumentleser ist gerade mit anderen Aufgaben beschäftigt. Versuch es in einer Minute noch einmal."
   },
   "symptoms": {
     "add": "Neues Symptom",
diff --git a/messages/en.json b/messages/en.json
index bb4cf34c4..c3ab4fd71 100644
--- a/messages/en.json
+++ b/messages/en.json
@@ -175,6 +175,9 @@
           "failed": "The label could not be read. Try a sharper photo."
         }
       }
+    },
+    "aiRuns": {
+      "readerBusy": "The document reader is busy with other work. Try again in a minute."
     }
   },
   "doctorReport": {
@@ -13258,7 +13261,8 @@
     "backgroundScan": "Reading in the background. With a slow model this can take a few minutes.",
     "waitingForWorker": "Waiting for the background worker. If this does not change, the server's worker may not be running.",
     "errorWorkerUnavailable": "The background worker is not available right now. Try again in a moment, or ask the server operator to check it.",
-    "errorTimedOut": "Reading took longer than your AI response time allows. Try again, or raise the response time in the AI settings."
+    "errorTimedOut": "Reading took longer than your AI response time allows. Try again, or raise the response time in the AI settings.",
+    "errorReaderBusy": "The document reader is busy with other work. Try again in a minute."
   },
   "symptoms": {
     "add": "New symptom",
diff --git a/messages/es.json b/messages/es.json
index 5c9056ae2..11c5c0dfd 100644
--- a/messages/es.json
+++ b/messages/es.json
@@ -175,6 +175,9 @@
           "failed": "No se pudo leer la etiqueta. Prueba con una foto más nítida."
         }
       }
+    },
+    "aiRuns": {
+      "readerBusy": "El lector de documentos está ocupado con otras tareas. Inténtalo de nuevo en un minuto."
     }
   },
   "doctorReport": {
@@ -13258,7 +13261,8 @@
     "backgroundScan": "Leyendo en segundo plano. Con un modelo lento puede tardar unos minutos.",
     "waitingForWorker": "Esperando al proceso en segundo plano. Si no cambia, puede que el worker del servidor no esté en marcha.",
     "errorWorkerUnavailable": "El proceso en segundo plano no está disponible ahora mismo. Inténtalo de nuevo en un momento o pide a quien administra el servidor que lo revise.",
-    "errorTimedOut": "La lectura tardó más de lo que permite tu tiempo de respuesta de IA. Inténtalo de nuevo o aumenta el tiempo de respuesta en los ajustes de IA."
+    "errorTimedOut": "La lectura tardó más de lo que permite tu tiempo de respuesta de IA. Inténtalo de nuevo o aumenta el tiempo de respuesta en los ajustes de IA.",
+    "errorReaderBusy": "El lector de documentos está ocupado con otras tareas. Inténtalo de nuevo en un minuto."
   },
   "symptoms": {
     "add": "Nuevo síntoma",
diff --git a/messages/fr.json b/messages/fr.json
index ddc754baf..865cc6f52 100644
--- a/messages/fr.json
+++ b/messages/fr.json
@@ -175,6 +175,9 @@
           "failed": "L’étiquette n’a pas pu être lue. Essayez une photo plus nette."
         }
       }
+    },
+    "aiRuns": {
+      "readerBusy": "Le lecteur de documents est occupé par d'autres tâches. Réessayez dans une minute."
     }
   },
   "doctorReport": {
@@ -13258,7 +13261,8 @@
     "backgroundScan": "Lecture en arrière-plan. Avec un modèle lent, cela peut prendre quelques minutes.",
     "waitingForWorker": "En attente du traitement en arrière-plan. Si rien ne change, le worker du serveur n'est peut-être pas lancé.",
     "errorWorkerUnavailable": "Le traitement en arrière-plan n'est pas disponible pour le moment. Réessayez dans un instant ou demandez à la personne qui gère le serveur de le vérifier.",
-    "errorTimedOut": "La lecture a pris plus de temps que votre délai de réponse IA ne le permet. Réessayez ou augmentez ce délai dans les réglages IA."
+    "errorTimedOut": "La lecture a pris plus de temps que votre délai de réponse IA ne le permet. Réessayez ou augmentez ce délai dans les réglages IA.",
+    "errorReaderBusy": "Le lecteur de documents est occupé par d'autres tâches. Réessayez dans une minute."
   },
   "symptoms": {
     "add": "Nouveau symptôme",
diff --git a/messages/it.json b/messages/it.json
index fe6450c8d..f7daf94b8 100644
--- a/messages/it.json
+++ b/messages/it.json
@@ -175,6 +175,9 @@
           "failed": "Non è stato possibile leggere l'etichetta. Prova con una foto più nitida."
         }
       }
+    },
+    "aiRuns": {
+      "readerBusy": "Il lettore di documenti è occupato con altre attività. Riprova tra un minuto."
     }
   },
   "doctorReport": {
@@ -13258,7 +13261,8 @@
     "backgroundScan": "Lettura in background. Con un modello lento può richiedere qualche minuto.",
     "waitingForWorker": "In attesa del processo in background. Se non cambia, il worker del server potrebbe non essere attivo.",
     "errorWorkerUnavailable": "Il processo in background non è disponibile al momento. Riprova tra poco o chiedi a chi gestisce il server di controllarlo.",
-    "errorTimedOut": "La lettura ha richiesto più tempo di quanto consenta il tuo tempo di risposta dell'IA. Riprova o aumenta il tempo di risposta nelle impostazioni IA."
+    "errorTimedOut": "La lettura ha richiesto più tempo di quanto consenta il tuo tempo di risposta dell'IA. Riprova o aumenta il tempo di risposta nelle impostazioni IA.",
+    "errorReaderBusy": "Il lettore di documenti è occupato con altre attività. Riprova tra un minuto."
   },
   "symptoms": {
     "add": "Nuovo sintomo",
diff --git a/messages/ko.json b/messages/ko.json
index 2ef2164d3..f702d430c 100644
--- a/messages/ko.json
+++ b/messages/ko.json
@@ -175,6 +175,9 @@
           "failed": "라벨을 읽지 못했어요. 더 선명한 사진으로 다시 시도하세요."
         }
       }
+    },
+    "aiRuns": {
+      "readerBusy": "문서 판독기가 다른 작업으로 바빠요. 1분 후에 다시 시도하세요."
     }
   },
   "doctorReport": {
@@ -13258,7 +13261,8 @@
     "backgroundScan": "백그라운드에서 읽고 있어요. 느린 모델이면 몇 분 걸릴 수 있어요.",
     "waitingForWorker": "백그라운드 작업자를 기다리고 있어요. 계속 그대로라면 서버의 작업자가 실행 중이 아닐 수 있어요.",
     "errorWorkerUnavailable": "지금은 백그라운드 작업자를 사용할 수 없어요. 잠시 후 다시 시도하거나 서버 운영자에게 확인을 요청하세요.",
-    "errorTimedOut": "AI 응답 시간 설정보다 읽기가 오래 걸렸어요. 다시 시도하거나 AI 설정에서 응답 시간을 늘려 주세요."
+    "errorTimedOut": "AI 응답 시간 설정보다 읽기가 오래 걸렸어요. 다시 시도하거나 AI 설정에서 응답 시간을 늘려 주세요.",
+    "errorReaderBusy": "문서 판독기가 다른 작업으로 바빠요. 1분 후에 다시 시도하세요."
   },
   "symptoms": {
     "add": "새 증상",
diff --git a/messages/nl.json b/messages/nl.json
index 9bd5560ec..33897f904 100644
--- a/messages/nl.json
+++ b/messages/nl.json
@@ -175,6 +175,9 @@
           "failed": "Het etiket kon niet worden gelezen. Probeer een scherpere foto."
         }
       }
+    },
+    "aiRuns": {
+      "readerBusy": "De documentlezer is met ander werk bezig. Probeer het over een minuut opnieuw."
     }
   },
   "doctorReport": {
@@ -13258,7 +13261,8 @@
     "backgroundScan": "Wordt op de achtergrond gelezen. Met een traag model kan dit een paar minuten duren.",
     "waitingForWorker": "Wachten op het achtergrondproces. Als dit niet verandert, draait het achtergrondproces van de server mogelijk niet.",
     "errorWorkerUnavailable": "Het achtergrondproces is op dit moment niet beschikbaar. Probeer het zo opnieuw, of vraag de beheerder van de server om het te controleren.",
-    "errorTimedOut": "Het lezen duurde langer dan je ingestelde AI-responstijd toestaat. Probeer het opnieuw, of verhoog de responstijd in de AI-instellingen."
+    "errorTimedOut": "Het lezen duurde langer dan je ingestelde AI-responstijd toestaat. Probeer het opnieuw, of verhoog de responstijd in de AI-instellingen.",
+    "errorReaderBusy": "De documentlezer is met ander werk bezig. Probeer het over een minuut opnieuw."
   },
   "symptoms": {
     "add": "Nieuw symptoom",
diff --git a/messages/pl.json b/messages/pl.json
index 2a1673bcd..1c33d3938 100644
--- a/messages/pl.json
+++ b/messages/pl.json
@@ -175,6 +175,9 @@
           "failed": "Nie udało się odczytać etykiety. Spróbuj ostrzejszego zdjęcia."
         }
       }
+    },
+    "aiRuns": {
+      "readerBusy": "Czytnik dokumentów jest zajęty innymi zadaniami. Spróbuj ponownie za minutę."
     }
   },
   "doctorReport": {
@@ -13258,7 +13261,8 @@
     "backgroundScan": "Odczyt w tle. Przy wolnym modelu może to potrwać kilka minut.",
     "waitingForWorker": "Oczekiwanie na proces w tle. Jeśli nic się nie zmienia, worker na serwerze może nie działać.",
     "errorWorkerUnavailable": "Proces w tle jest teraz niedostępny. Spróbuj ponownie za chwilę albo poproś administratora serwera o sprawdzenie go.",
-    "errorTimedOut": "Odczyt trwał dłużej, niż pozwala ustawiony czas odpowiedzi AI. Spróbuj ponownie albo wydłuż czas odpowiedzi w ustawieniach AI."
+    "errorTimedOut": "Odczyt trwał dłużej, niż pozwala ustawiony czas odpowiedzi AI. Spróbuj ponownie albo wydłuż czas odpowiedzi w ustawieniach AI.",
+    "errorReaderBusy": "Czytnik dokumentów jest zajęty innymi zadaniami. Spróbuj ponownie za minutę."
   },
   "symptoms": {
     "add": "Nowy objaw",
diff --git a/messages/pt-BR.json b/messages/pt-BR.json
index cc011e70a..60606bfc6 100644
--- a/messages/pt-BR.json
+++ b/messages/pt-BR.json
@@ -175,6 +175,9 @@
           "failed": "Não foi possível ler o rótulo. Tente uma foto mais nítida."
         }
       }
+    },
+    "aiRuns": {
+      "readerBusy": "O leitor de documentos está ocupado com outras tarefas. Tente novamente em um minuto."
     }
   },
   "doctorReport": {
@@ -13258,7 +13261,8 @@
     "backgroundScan": "Lendo em segundo plano. Com um modelo lento, isso pode levar alguns minutos.",
     "waitingForWorker": "Aguardando o worker em segundo plano. Se isso não mudar, o worker do servidor pode não estar em execução.",
     "errorWorkerUnavailable": "O worker em segundo plano não está disponível agora. Tente novamente em instantes, ou peça ao operador do servidor para verificá-lo.",
-    "errorTimedOut": "A leitura demorou mais do que o seu tempo de resposta de IA permite. Tente novamente, ou aumente o tempo de resposta nas configurações de IA."
+    "errorTimedOut": "A leitura demorou mais do que o seu tempo de resposta de IA permite. Tente novamente, ou aumente o tempo de resposta nas configurações de IA.",
+    "errorReaderBusy": "O leitor de documentos está ocupado com outras tarefas. Tente novamente em um minuto."
   },
   "symptoms": {
     "add": "Novo sintoma",
diff --git a/src/components/documents/use-document-assist.ts b/src/components/documents/use-document-assist.ts
index c47fb646f..999590bca 100644
--- a/src/components/documents/use-document-assist.ts
+++ b/src/components/documents/use-document-assist.ts
@@ -228,6 +228,8 @@ export function documentAiErrorKey(err: unknown): string {
         return "aiRuns.errorWorkerUnavailable";
       case "aiRuns.timedOut":
         return "aiRuns.errorTimedOut";
+      case "aiRuns.readerBusy":
+        return "aiRuns.errorReaderBusy";
       case "consent.ai.required":
         return "documents.assist.errorConsent";
       case "ai.provider.none":
diff --git a/src/components/labs/ocr-review-dialog.tsx b/src/components/labs/ocr-review-dialog.tsx
index e98317b24..f2310f561 100644
--- a/src/components/labs/ocr-review-dialog.tsx
+++ b/src/components/labs/ocr-review-dialog.tsx
@@ -117,6 +117,8 @@ export function extractErrorMessage(
         return t("aiRuns.errorWorkerUnavailable");
       case "aiRuns.timedOut":
         return t("aiRuns.errorTimedOut");
+      case "aiRuns.readerBusy":
+        return t("aiRuns.errorReaderBusy");
       default:
         break;
     }
diff --git a/src/lib/documents/ai-route-support.ts b/src/lib/documents/ai-route-support.ts
index 5a903e484..9f89710f8 100644
--- a/src/lib/documents/ai-route-support.ts
+++ b/src/lib/documents/ai-route-support.ts
@@ -154,9 +154,14 @@ export type VisionInput =
       // Refs #776 — `rasterFailed` (this PDF would not render on a raster-
       // capable build) is distinct from `pdfNeedsAnthropic` (this build /
       // provider cannot take a PDF at all): they need different fixes, so
-      // they must not share a label.
+      // they must not share a label. `readerBusy` is neither: the reader
+      // could not take the document now, and the work is tried again.
       reason:
-        "decryptFailed" | "fileType" | "pdfNeedsAnthropic" | "rasterFailed";
+        | "decryptFailed"
+        | "fileType"
+        | "pdfNeedsAnthropic"
+        | "rasterFailed"
+        | "readerBusy";
     };
 
 /**
@@ -211,6 +216,9 @@ export async function prepareVisionInput(
     if (raster.ok) {
       return { ok: true, images: raster.images, documents: [] };
     }
+    if (raster.reason === "busy" || raster.reason === "interrupted") {
+      return { ok: false, reason: "readerBusy" };
+    }
     // Refs #776 — a build that cannot rasterize at all is a capability gap a
     // PDF-native (Anthropic) provider would cover; a render failure on a
     // capable build is a property of THIS document. Report them apart.
diff --git a/src/lib/documents/ai-runs/extract-run.ts b/src/lib/documents/ai-runs/extract-run.ts
index c968e0d54..3d34a1768 100644
--- a/src/lib/documents/ai-runs/extract-run.ts
+++ b/src/lib/documents/ai-runs/extract-run.ts
@@ -52,6 +52,7 @@ import { dateOnlyAtNoonUtc } from "@/lib/tz/date-only";
 import { refusalAsFailure } from "./http";
 import { meteredReadBudget } from "./metered-budget";
 import {
+  readerBusyFailure,
   runFailure,
   unreadableDocument,
   type DocumentTextPick,
@@ -306,7 +307,9 @@ export async function executeDocumentExtract(args: {
     source = { mode: "text", text: input.text };
   }
   const plan = await planInboundReads(source, schedule);
-  if (!plan.ok) return refused(pdfUnreadable());
+  if (!plan.ok) {
+    return refused(plan.busy ? readerBusyFailure() : pdfUnreadable());
+  }
   await schedule.arm(plan.args.chunks.length * OCR_EXTRACT_MODEL_CALLS);
 
   let result: InboundExtractionResult;
diff --git a/src/lib/documents/ai-runs/index-run.ts b/src/lib/documents/ai-runs/index-run.ts
index 64cf2251c..c04c6ec43 100644
--- a/src/lib/documents/ai-runs/index-run.ts
+++ b/src/lib/documents/ai-runs/index-run.ts
@@ -32,6 +32,7 @@ import { recordIndexAttempt } from "@/lib/documents/index-document";
 import type { requireDocumentVisionProvider } from "@/lib/documents/provider-order";
 import { annotate } from "@/lib/logging/context";
 
+import { readerBusyFailure } from "./run-support";
 import { settleAiRunBudget } from "./store";
 import type {
   AiRunBudget,
@@ -157,6 +158,8 @@ export async function executeDocumentIndex(args: {
     // gone.
     await settleAiRunBudget(userId, budget, 0, null);
     await refundDocumentAiSlot(userId);
+    // A busy reader says nothing about the document: no attempt is recorded.
+    if (vision.reason === "readerBusy") return readerBusyFailure();
     if (vision.reason === "pdfNeedsAnthropic") {
       await recordIndexAttempt(userId, document.id, {
         indexed: false,
diff --git a/src/lib/documents/ai-runs/run-support.ts b/src/lib/documents/ai-runs/run-support.ts
index 340f86b10..0aa291830 100644
--- a/src/lib/documents/ai-runs/run-support.ts
+++ b/src/lib/documents/ai-runs/run-support.ts
@@ -13,7 +13,7 @@ import type {
 } from "@/lib/documents/provider-order";
 import type { VisionInput } from "@/lib/documents/ai-route-support";
 
-import type { AiRunOutcome } from "./types";
+import { AI_RUN_ERROR_CODES, type AiRunOutcome } from "./types";
 
 export type DocumentVisionPick = Awaited<
   ReturnType<typeof requireDocumentVisionProvider>
@@ -44,6 +44,19 @@ export function unreadableDocument(parseError: boolean): AiRunOutcome<never> {
   });
 }
 
+/**
+ * The document reader was busy with other work for longer than a person's
+ * read waits, or its process ended for no reason it measured. Nothing was
+ * read and nothing is charged; asking again in a minute is the answer.
+ */
+export function readerBusyFailure(): AiRunOutcome<never> {
+  return runFailure({
+    status: 503,
+    message: "The document reader is busy. Try again in a minute.",
+    errorCode: AI_RUN_ERROR_CODES.readerBusy,
+  });
+}
+
 /**
  * A stored original that could not become a provider input, as the summary
  * and suggest routes have always answered it.
@@ -59,6 +72,7 @@ export function visionPreparationFailure(
       errorCode: "documents.inbound.pdfNeedsAnthropic",
     });
   }
+  if (reason === "readerBusy") return readerBusyFailure();
   if (reason === "fileType") {
     return runFailure({
       status: 422,
diff --git a/src/lib/documents/ai-runs/types.ts b/src/lib/documents/ai-runs/types.ts
index 69d22ddd6..79155281a 100644
--- a/src/lib/documents/ai-runs/types.ts
+++ b/src/lib/documents/ai-runs/types.ts
@@ -74,6 +74,7 @@ export const AI_RUN_ERROR_CODES = {
   workerUnavailable: "aiRuns.workerUnavailable",
   timedOut: "aiRuns.timedOut",
   failed: "aiRuns.failed",
+  readerBusy: "aiRuns.readerBusy",
 } as const;
 
 /** How long a queued run waits for a worker before it is failed. */
diff --git a/src/lib/documents/extract.ts b/src/lib/documents/extract.ts
index 361faa61a..a1660adf5 100644
--- a/src/lib/documents/extract.ts
+++ b/src/lib/documents/extract.ts
@@ -484,7 +484,7 @@ export function planInboundTextReads(
 export async function planInboundReads(
   source: InboundReadSource,
   schedule: OcrSchedule,
-): Promise<({ ok: true } & InboundReads) | { ok: false }> {
+): Promise<({ ok: true } & InboundReads) | { ok: false; busy?: true }> {
   if (source.mode === "text") {
     return { ok: true, ...planInboundTextReads(source.text, schedule) };
   }
@@ -494,7 +494,7 @@ export async function planInboundReads(
     source.pdfSupported,
     schedule,
   );
-  if (!plan.ok) return { ok: false };
+  if (!plan.ok) return plan;
   return {
     ok: true,
     args: { mode: "vision", chunks: plan.chunks, totalPages: plan.totalPages },
diff --git a/src/lib/documents/index-document.ts b/src/lib/documents/index-document.ts
index 69ae2ff41..cd9f6e259 100644
--- a/src/lib/documents/index-document.ts
+++ b/src/lib/documents/index-document.ts
@@ -58,6 +58,7 @@ import {
 import { transcribeDocument } from "@/lib/documents/describe";
 import { documentAutoReadEnabled } from "@/lib/documents/document-settings";
 import { localExtractText } from "@/lib/documents/local-extract";
+import { PdfReaderUnavailableError } from "@/lib/documents/pdfjs";
 import { resolveDocumentVisionProvider } from "@/lib/documents/provider-order";
 import { decryptDocumentContent } from "@/lib/documents/store";
 import { prisma } from "@/lib/db";
@@ -238,6 +239,12 @@ async function tryProviderIndex(
     if (vision.reason === "rasterFailed") {
       return { outcome: null, note: "raster-failed" };
     }
+    if (vision.reason === "readerBusy") {
+      // The reader could not take the document now. Falling back to the
+      // local text layer would settle for the lesser read for good; the job
+      // runs again instead.
+      throw new PdfReaderUnavailableError("busy");
+    }
     if (vision.reason === "pdfNeedsAnthropic") {
       return { outcome: null, note: "pdf-needs-anthropic" };
     }
diff --git a/src/lib/documents/ocr-plan.ts b/src/lib/documents/ocr-plan.ts
index f46242133..b23a108f1 100644
--- a/src/lib/documents/ocr-plan.ts
+++ b/src/lib/documents/ocr-plan.ts
@@ -170,7 +170,12 @@ export type OcrVisionPlan =
       /** Set when the PDF is longer than the page cap: only the first pages are read. */
       pageCoverage?: { read: number; total: number };
     }
-  | { ok: false };
+  /**
+   * `busy`: the reader could not take the PDF now (busy past the wait a read
+   * gets, or its process ended for no measured reason). Not a verdict on the
+   * file; the person asks again.
+   */
+  | { ok: false; busy?: true };
 
 /**
  * Plan the reads of an image or a PDF. Every PDF is rendered first: a report
@@ -226,7 +231,12 @@ export async function planVisionReads(
         : {}),
     };
   }
-  if (!pdfSupported) return { ok: false };
+  if (!pdfSupported) {
+    return !raster.ok &&
+      (raster.reason === "busy" || raster.reason === "interrupted")
+      ? { ok: false, busy: true }
+      : { ok: false };
+  }
   return {
     ok: true,
     chunks: [
diff --git a/src/lib/jobs/__tests__/document-ai-run.test.ts b/src/lib/jobs/__tests__/document-ai-run.test.ts
index a4cd54d32..7de034a2d 100644
--- a/src/lib/jobs/__tests__/document-ai-run.test.ts
+++ b/src/lib/jobs/__tests__/document-ai-run.test.ts
@@ -285,6 +285,32 @@ describe("runDocumentAiRun", () => {
     );
   });
 
+  it("reads as interactive work of the run's owner, so the document reader serves it first", async () => {
+    let seen: unknown = null;
+    executeDocumentIndex.mockImplementation(async () => {
+      const { currentPdfWork } = await import("@/lib/documents/pdf-isolation");
+      seen = currentPdfWork();
+      return { ok: true, data: {} };
+    });
+    await runDocumentAiRun("run1", NOW + 2_700_000, now);
+    expect(seen).toEqual({ owner: "u1", lane: "interactive" });
+  });
+
+  it("answers a busy document reader with a retryable code and hands the reservation back", async () => {
+    const { PdfReaderUnavailableError } = await import("@/lib/documents/pdfjs");
+    executeDocumentIndex.mockRejectedValue(
+      new PdfReaderUnavailableError("busy"),
+    );
+    expect(await runDocumentAiRun("run1", NOW + 2_700_000, now)).toBe("failed");
+    expect(settleAiRunBudget).toHaveBeenCalledWith("u1", budget, 0, null);
+    expect(failAiRun).toHaveBeenCalledWith(
+      "run1",
+      expect.objectContaining({ status: 503, errorCode: "aiRuns.readerBusy" }),
+      "RUNNING",
+      new Date(NOW),
+    );
+  });
+
   it("fails a run whose document is gone and hands the reservation back", async () => {
     loadOwnedDocument.mockResolvedValue(null);
     expect(await runDocumentAiRun("run1", NOW + 2_700_000, now)).toBe("failed");
diff --git a/src/lib/jobs/document-ai-run.ts b/src/lib/jobs/document-ai-run.ts
index 4df270a6a..69949a2b0 100644
--- a/src/lib/jobs/document-ai-run.ts
+++ b/src/lib/jobs/document-ai-run.ts
@@ -42,6 +42,8 @@ import { loadOwnedDocument } from "@/lib/documents/ai-route-support";
 import { loadDocumentChatText } from "@/lib/documents/content-index";
 import { refusalAsFailure } from "@/lib/documents/ai-runs/http";
 import { executeDocumentExtract } from "@/lib/documents/ai-runs/extract-run";
+import { withPdfWork } from "@/lib/documents/pdf-isolation";
+import { PdfReaderUnavailableError } from "@/lib/documents/pdfjs";
 import {
   DOCUMENT_INDEX_MODEL_CALLS,
   executeDocumentIndex,
@@ -614,7 +616,12 @@ export async function runDocumentAiRun(
 
   let outcome: AiRunOutcome<AiRunResult>;
   try {
-    outcome = await RUN_DISPATCH[run.kind](run, deadlineAt, now);
+    // A person asked for this read and is waiting on it: the document
+    // reader serves it ahead of background work, in turn with other people.
+    outcome = await withPdfWork(
+      { owner: run.userId, lane: "interactive" },
+      () => RUN_DISPATCH[run.kind](run, deadlineAt, now),
+    );
   } catch (err) {
     // Everything that throws here threw before the body took over the
     // reservation, so it goes back here.
@@ -622,6 +629,13 @@ export async function runDocumentAiRun(
     const failure: AiRunFailure = (err instanceof RunRefused
       ? err.failure
       : null) ??
+      (err instanceof PdfReaderUnavailableError
+        ? {
+            status: 503,
+            errorCode: AI_RUN_ERROR_CODES.readerBusy,
+            message: "The document reader is busy. Try again in a minute.",
+          }
+        : null) ??
       refusalAsFailure(err) ?? {
         status: 500,
         errorCode: AI_RUN_ERROR_CODES.failed,
diff --git a/src/lib/jobs/document-content-index-backfill.ts b/src/lib/jobs/document-content-index-backfill.ts
index 45fc3d078..35a062761 100644
--- a/src/lib/jobs/document-content-index-backfill.ts
+++ b/src/lib/jobs/document-content-index-backfill.ts
@@ -55,6 +55,7 @@ import {
   upsertContentIndex,
 } from "@/lib/documents/content-index";
 import { transcribeDocument } from "@/lib/documents/describe";
+import { withPdfWork } from "@/lib/documents/pdf-isolation";
 import { getGlobalBoss } from "@/lib/jobs/boss-instance";
 import { resolveDocumentVisionProvider } from "@/lib/documents/provider-order";
 import { annotate } from "@/lib/logging/context";
@@ -320,7 +321,10 @@ export async function runContentIndexBackfillForUser(
         skipped += 1;
         continue;
       }
-      const vision = await prepareVisionInput(document, pick.pdfSupported);
+      const vision = await withPdfWork(
+        { owner: userId, lane: "background" },
+        () => prepareVisionInput(document, pick.pdfSupported),
+      );
       if (!vision.ok) {
         // Not vision-indexable after all (undecryptable, unreadable bytes,
         // or a PDF the rasteriser could not render) — refund and move on so
diff --git a/src/lib/jobs/document-index.ts b/src/lib/jobs/document-index.ts
index 710e3552c..ca5d027e9 100644
--- a/src/lib/jobs/document-index.ts
+++ b/src/lib/jobs/document-index.ts
@@ -15,6 +15,7 @@
 import { STATUS_MODEL_CALLS } from "@/lib/ai/ai-budgets";
 import { maybeAutoStageLabFacts } from "@/lib/documents/auto-stage-labs";
 import { indexDocumentContent } from "@/lib/documents/index-document";
+import { withPdfWork } from "@/lib/documents/pdf-isolation";
 import type { OcrSchedule } from "@/lib/documents/ocr-plan";
 import { ocrReadCallMs } from "@/lib/documents/ocr-read";
 import { prisma } from "@/lib/db";
@@ -50,9 +51,9 @@ export async function runDocumentIndex(
   const { userId, documentId } = payload;
   if (!userId || !documentId) return;
   const localOnly = payload.localOnly === true;
-  const outcome = await indexDocumentContent(userId, documentId, {
-    localOnly,
-  });
+  const outcome = await withPdfWork({ owner: userId, lane: "background" }, () =>
+    indexDocumentContent(userId, documentId, { localOnly }),
+  );
   annotate({
     action: { name: "documents.autoIndex.run" },
     meta: outcome.indexed
@@ -72,9 +73,9 @@ export async function runDocumentIndex(
       options.deadlineAt === undefined
         ? undefined
         : await stagingSchedule(userId, options.deadlineAt, options.now);
-    await maybeAutoStageLabFacts(userId, documentId, { schedule }).catch(
-      caughtAs("documents.auto_index.lab_staging_failed"),
-    );
+    await withPdfWork({ owner: userId, lane: "background" }, () =>
+      maybeAutoStageLabFacts(userId, documentId, { schedule }),
+    ).catch(caughtAs("documents.auto_index.lab_staging_failed"));
   }
 }
 
diff --git a/src/lib/jobs/document-summary.ts b/src/lib/jobs/document-summary.ts
index a1a9bbb84..9b421da34 100644
--- a/src/lib/jobs/document-summary.ts
+++ b/src/lib/jobs/document-summary.ts
@@ -43,6 +43,8 @@ import type { Locale } from "@/lib/i18n/config";
 import { resolveJobLocale } from "@/lib/i18n/job-locale";
 import { documentAutoReadEnabled } from "@/lib/documents/document-settings";
 import { resolveDocumentVisionProvider } from "@/lib/documents/provider-order";
+import { withPdfWork } from "@/lib/documents/pdf-isolation";
+import { PdfReaderUnavailableError } from "@/lib/documents/pdfjs";
 import { encryptDocumentSummary } from "@/lib/documents/store";
 import { prisma } from "@/lib/db";
 import { getGlobalBoss } from "@/lib/jobs/boss-instance";
@@ -81,6 +83,25 @@ export interface DocumentSummaryPayload {
   enqueuedAt?: string;
 }
 
+/**
+ * The stored original as provider input, read as this account's background
+ * work. A busy reader is not a property of the document: the job throws, and
+ * pg-boss runs it again.
+ */
+async function prepareSummaryVision(
+  userId: string,
+  document: Parameters<typeof prepareVisionInput>[0],
+  pick: { pdfSupported: boolean },
+): Promise<ReturnType<typeof prepareVisionInput>> {
+  const vision = await withPdfWork({ owner: userId, lane: "background" }, () =>
+    prepareVisionInput(document, pick.pdfSupported),
+  );
+  if (!vision.ok && vision.reason === "readerBusy") {
+    throw new PdfReaderUnavailableError("busy");
+  }
+  return vision;
+}
+
 /**
  * Generate + persist ONE document's background summary (owner-scoped). Never
  * throws for an expected outcome — every gate that fails resolves to a tagged
@@ -210,7 +231,7 @@ export async function runDocumentSummaryJob(
   const document = await loadOwnedDocument(userId, documentId);
   if (!document) return;
 
-  const vision = await prepareVisionInput(document, pick.pdfSupported);
+  const vision = await prepareSummaryVision(userId, document, pick);
   if (!vision.ok) {
     // Cannot read this file with the picked provider (decrypt miss, unsupported
     // type, or a PDF needing an Anthropic provider). Graceful no-op.
diff --git a/src/lib/labs/ocr-run.ts b/src/lib/labs/ocr-run.ts
index 75b668be5..b122cd55b 100644
--- a/src/lib/labs/ocr-run.ts
+++ b/src/lib/labs/ocr-run.ts
@@ -20,6 +20,7 @@ import { AI_BUDGETS } from "@/lib/ai/ai-budgets";
 import { refusalAsFailure } from "@/lib/documents/ai-runs/http";
 import type { ProviderChainType } from "@/lib/ai/provider-chain";
 import { meteredReadBudget } from "@/lib/documents/ai-runs/metered-budget";
+import { readerBusyFailure } from "@/lib/documents/ai-runs/run-support";
 import {
   AI_RUN_ERROR_CODES,
   type AiRunBudget,
@@ -221,6 +222,10 @@ export async function executeOcrExtraction(args: {
     input.pick.pdfSupported,
     schedule,
   );
+  if (!plan.ok && plan.busy) {
+    await settle(false);
+    return readerBusyFailure();
+  }
   if (!plan.ok) {
     annotate({
       action: { name: "labs.ocr.fileRejected" },
diff --git a/src/lib/medications/ingredients/label-extract.ts b/src/lib/medications/ingredients/label-extract.ts
index 14430b10c..2379f5afd 100644
--- a/src/lib/medications/ingredients/label-extract.ts
+++ b/src/lib/medications/ingredients/label-extract.ts
@@ -29,6 +29,7 @@ import {
   type AIProvider,
   type CompletionParams,
 } from "@/lib/ai/types";
+import { readerBusyFailure } from "@/lib/documents/ai-runs/run-support";
 import { settleAiRunBudget } from "@/lib/documents/ai-runs/store";
 import type {
   AiRunBudget,
@@ -232,6 +233,13 @@ export async function executeSupplementLabelExtraction(args: {
       ];
     } else {
       const raster = await rasterizePdf(bytes);
+      if (
+        !raster.ok &&
+        (raster.reason === "busy" || raster.reason === "interrupted")
+      ) {
+        await settleAiRunBudget(userId, budget, 0, null);
+        return readerBusyFailure();
+      }
       if (!raster.ok) {
         await settleAiRunBudget(userId, budget, 0, null);
         return failure({
diff --git a/src/lib/openapi/error-codes.ts b/src/lib/openapi/error-codes.ts
index 2b49765fd..a36ad0286 100644
--- a/src/lib/openapi/error-codes.ts
+++ b/src/lib/openapi/error-codes.ts
@@ -57,6 +57,7 @@ export const ERROR_CODE_CATALOGUE: Readonly<Record<string, readonly string[]>> =
     aiRuns: [
       "aiRuns.failed",
       "aiRuns.notFound",
+      "aiRuns.readerBusy",
       "aiRuns.timedOut",
       "aiRuns.workerUnavailable",
     ],
diff --git a/src/lib/openapi/routes/ai-runs.ts b/src/lib/openapi/routes/ai-runs.ts
index 1be07ade9..8be799378 100644
--- a/src/lib/openapi/routes/ai-runs.ts
+++ b/src/lib/openapi/routes/ai-runs.ts
@@ -64,7 +64,7 @@ const aiRun = z
       })
       .nullable()
       .describe(
-        "Present once `status` is `FAILED`: the `meta.errorCode`, message and HTTP status the queuing route would have answered with, or one of the run's own codes: `aiRuns.workerUnavailable` (no worker took the run within fifteen minutes), `aiRuns.timedOut` (the read outlived the calls the AI response time allows), `aiRuns.failed` (anything else).",
+        "Present once `status` is `FAILED`: the `meta.errorCode`, message and HTTP status the queuing route would have answered with, or one of the run's own codes: `aiRuns.workerUnavailable` (no worker took the run within fifteen minutes), `aiRuns.timedOut` (the read outlived the calls the AI response time allows), `aiRuns.readerBusy` (the server's document reader was busy past the wait a read gets, or stopped before it answered; nothing was read or charged, try again in a minute), `aiRuns.failed` (anything else).",
       ),
     createdAt: z.string(),
     startedAt: z.string().nullable(),