diff --git a/apps/server/src/scheduledTasks/ScheduledTaskService.ts b/apps/server/src/scheduledTasks/ScheduledTaskService.ts
index 4dab48a05b2a5..afeb73de3df96 100644
--- a/apps/server/src/scheduledTasks/ScheduledTaskService.ts
+++ b/apps/server/src/scheduledTasks/ScheduledTaskService.ts
@@ -66,6 +66,7 @@ import {
   acceptImmediateWebhookDedupe,
   releaseWebhookReplay,
   decodePendingTask,
+  encodePendingTask,
   decodePendingRequest,
   dedupeError,
 } from "./webhookDedupe.ts";
@@ -880,7 +881,6 @@ export const layer = Layer.effect(
             : `${active.id}:webhook:${webhook.deliveryId}`;
         const commandId = CommandId.make(`scheduled-task:${fireKey}`);
         const messageId = MessageId.make(`scheduled-task-message:${fireKey}`);
-        // A webhook prompt was rendered from the row when the request arrived.
         const prompt = webhook?.prompt ?? active.prompt;
 
         // A bound thread can move to another project (No project to a project) while
@@ -2331,10 +2331,21 @@ export const layer = Layer.effect(
                 continue;
               }
               const prepared = yield* Effect.gen(function* () {
-                const task = yield* decodePendingTask(entry.task_json);
+                // A running row was already sent, so recovery keeps the prompt it was sent with.
+                const current = entry.state === "dispatching" ? yield* findTask(taskId) : null;
+                const snapshot = yield* decodePendingTask(entry.task_json);
+                // The snapshot keeps the identity runTask checks; the prompt is the one saved now.
+                const task =
+                  current?.createdAt === snapshot.createdAt && current.prompt !== snapshot.prompt
+                    ? { ...snapshot, prompt: current.prompt }
+                    : snapshot;
                 const request = yield* decodePendingRequest(entry.request_json);
                 const frameId = Buffer.from(yield* random.randomBytes(6)).toString("hex");
-                return { task, rendered: renderWebhookPrompt(task.prompt, request, frameId) };
+                return {
+                  task,
+                  taskJson: task === snapshot ? null : yield* encodePendingTask(task),
+                  rendered: renderWebhookPrompt(task.prompt, request, frameId),
+                };
               }).pipe(Effect.exit);
               if (Exit.isFailure(prepared)) {
                 if (Cause.hasInterruptsOnly(prepared.cause))
@@ -2347,11 +2358,13 @@ export const layer = Layer.effect(
                 yield* remove;
                 continue;
               }
-              const { task, rendered } = prepared.value;
+              const { task, taskJson, rendered } = prepared.value;
               if (rendered.prompt.trim().length > PROVIDER_SEND_TURN_MAX_INPUT_CHARS) {
                 yield* markDeliveryFailed(entry.delivery_id, PROMPT_TOO_LONG);
                 yield* releaseFailedDelivery(entry.delivery_id);
               } else {
+                if (taskJson !== null)
+                  yield* sql`UPDATE scheduled_task_webhook_pending SET task_json = ${taskJson} WHERE delivery_id = ${entry.delivery_id}`;
                 yield* sql`UPDATE scheduled_task_webhook_deliveries SET outcome = 'accepted', error = NULL, rendered_prompt = ${rendered.prompt.slice(0, WEBHOOK_DELIVERY_LOG_PROMPT_LIMIT)}, missing_fields_json = ${encodeMissingFieldsJson(rendered.missing)} WHERE delivery_id = ${entry.delivery_id}`;
                 if (!(yield* runWebhookDelivery(task, entry.delivery_id, rendered.prompt))) return;
               }
diff --git a/apps/server/src/scheduledTasks/ScheduledTaskService.webhook.test.ts b/apps/server/src/scheduledTasks/ScheduledTaskService.webhook.test.ts
index bfafd3893e170..6303b38c05ce6 100644
--- a/apps/server/src/scheduledTasks/ScheduledTaskService.webhook.test.ts
+++ b/apps/server/src/scheduledTasks/ScheduledTaskService.webhook.test.ts
@@ -1031,6 +1031,106 @@ it.effect.each([1, 3])(
   },
 );
 
+it.effect("a coalesced window dispatches the prompt saved after it opened", () => {
+  const workers = new Map<string, Effect.Effect<void>>();
+  return withService(
+    ({ service, launches }) =>
+      Effect.gen(function* () {
+        const schedule = {
+          type: "webhook",
+          dedupe: { coalesceKey: "{{body.id}}", coalesceWindowSeconds: 10 },
+        };
+        const { task } = yield* service.upsert(
+          yield* webhookTaskInput({ prompt: "Use the original instructions.", schedule }),
+        );
+        const bodyText = JSON.stringify({ id: "review" });
+        yield* service.triggerWebhook(
+          requestFor(task, { bodyText, body: new TextEncoder().encode(bodyText) }),
+        );
+        yield* service.upsert(
+          yield* webhookTaskInput({ prompt: "Use the updated instructions.", schedule }),
+        );
+        yield* TestClock.adjust("10 seconds");
+        yield* workers.get("webhook-coalescing")!;
+        const launched = yield* Queue.take(launches);
+        assert.equal(launched.initialMessage?.text, "Use the updated instructions.");
+        const owner = (yield* service.listWebhookDeliveries({ id: task.id })).deliveries[0]!;
+        const { delivery } = yield* service.getWebhookDelivery({
+          id: task.id,
+          deliveryId: owner.id,
+        });
+        assert.equal(delivery.renderedPrompt, "Use the updated instructions.");
+      }),
+    { workers },
+  );
+});
+
+it.effect("retrying a running window keeps the prompt it was dispatched with", () => {
+  const workers = new Map<string, Effect.Effect<void>>();
+  return withService(
+    ({ service, sql, launches }) =>
+      Effect.gen(function* () {
+        const schedule = {
+          type: "webhook",
+          dedupe: { coalesceKey: "{{body}}", coalesceWindowSeconds: 10 },
+        };
+        const save = (prompt: string) =>
+          Effect.flatMap(webhookTaskInput({ prompt, schedule }), service.upsert);
+        const { task } = yield* save("Prompt when the window opened");
+        yield* service.triggerWebhook(requestFor(task));
+        yield* save("Prompt at dispatch");
+        yield* sql`CREATE TRIGGER fail_completion BEFORE UPDATE ON scheduled_tasks
+          WHEN NEW.last_run_status = 'succeeded' BEGIN SELECT RAISE(FAIL, 'completion unavailable'); END`;
+        yield* TestClock.adjust("10 seconds");
+        yield* drainPendingDispatch(workers);
+        const launched = yield* Queue.take(launches);
+        assert.equal(launched.initialMessage?.text, "Prompt at dispatch");
+        yield* save("Prompt saved after dispatch");
+        yield* sql`DROP TRIGGER fail_completion`;
+        yield* drainPendingDispatch(workers);
+        assert.equal((yield* sql`SELECT 1 FROM scheduled_task_webhook_pending`).length, 0);
+        const owner = (yield* service.listWebhookDeliveries({ id: task.id })).deliveries[0]!;
+        const { delivery } = yield* service.getWebhookDelivery({
+          id: task.id,
+          deliveryId: owner.id,
+        });
+        assert.equal(delivery.renderedPrompt, "Prompt at dispatch");
+      }),
+    { workers },
+  );
+});
+
+it.effect("a coalesced window fails its delivery when the task row cannot be read", () => {
+  const workers = new Map<string, Effect.Effect<void>>();
+  return withService(
+    ({ service, sql, launches }) =>
+      Effect.gen(function* () {
+        const { task } = yield* service.upsert(
+          yield* webhookTaskInput({
+            schedule: {
+              type: "webhook",
+              dedupe: { coalesceKey: "{{body}}", coalesceWindowSeconds: 10 },
+            },
+          }),
+        );
+        yield* service.triggerWebhook(requestFor(task));
+        yield* sql`UPDATE scheduled_tasks SET model_selection_json = 'not json' WHERE task_id = ${task.id}`;
+        yield* TestClock.adjust("10 seconds");
+        yield* drainPendingDispatch(workers);
+        assert.equal(yield* Queue.size(launches), 0);
+        assert.equal((yield* sql`SELECT 1 FROM scheduled_task_webhook_pending`).length, 0);
+        const [delivery] = yield* sql<{
+          outcome: string;
+          error: string | null;
+        }>`SELECT outcome, error FROM scheduled_task_webhook_deliveries`;
+        assert.equal(delivery?.outcome, "dispatch_failed");
+        // Failing before dispatch means a later successful read cannot send the stale snapshot.
+        assert.equal(delivery?.error, "The pending webhook payload could not be prepared.");
+      }),
+    { workers },
+  );
+});
+
 it.effect("recovers a persisted coalescing window after restarting the service", () => {
   const workers = new Map<string, Effect.Effect<void>>();
   return withService(
diff --git a/apps/server/src/scheduledTasks/webhookDedupe.ts b/apps/server/src/scheduledTasks/webhookDedupe.ts
index 21d40b25ac5ed..76f04a97e6dfe 100644
--- a/apps/server/src/scheduledTasks/webhookDedupe.ts
+++ b/apps/server/src/scheduledTasks/webhookDedupe.ts
@@ -111,7 +111,7 @@ export const acceptImmediateWebhookDedupe = Effect.fn(
 });
 
 const PendingTaskJson = Schema.fromJsonString(ScheduledTask);
-const encodePendingTask = Schema.encodeEffect(PendingTaskJson);
+export const encodePendingTask = Schema.encodeEffect(PendingTaskJson);
 export const decodePendingTask = Schema.decodeUnknownEffect(PendingTaskJson);
 const PendingRequestJson = Schema.fromJsonString(
   Schema.Struct({