diff --git a/services/mam-api/src/routes/recorders.js b/services/mam-api/src/routes/recorders.js
index 017ac83..19e5868 100644
--- a/services/mam-api/src/routes/recorders.js
+++ b/services/mam-api/src/routes/recorders.js
@@ -1,16 +1,30 @@
 import express from 'express';
 import http from 'http';
 import fs from 'fs';
+import { createReadStream, existsSync } from 'fs';
+import { stat } from 'fs/promises';
 import net from 'net';
 import dgram from 'dgram';
 import pool from '../db/pool.js';
-import { getS3Bucket } from '../s3/client.js';
+import { s3Client, getS3Bucket } from '../s3/client.js';
+import { Upload } from '@aws-sdk/lib-storage';
 import { validateUuid } from '../middleware/errors.js';
 import { assertProjectAccess, accessibleProjectIds } from '../auth/authz.js';
 import { v4 as uuidv4 } from 'uuid';
+import { Queue } from 'bullmq';
 
 const router = express.Router();
 
+// BullMQ proxy queue — used by the growing-file stop handler to queue proxy
+// jobs when the capture container's finalize call races with the S3 upload.
+const parseRedisUrl = (url) => {
+  const parsed = new URL(url);
+  return { host: parsed.hostname, port: parseInt(parsed.port, 10) || 6379 };
+};
+const proxyQueue = new Queue('proxy', {
+  connection: parseRedisUrl(process.env.REDIS_URL || 'redis://queue:6379'),
+});
+
 // Every /:id recorder route is scoped to the recorder's project. The param
 // handler validates the UUID, resolves the owning project_id, and asserts the
 // 'view' baseline; mutating routes escalate to 'edit' via requireRecorderEdit.
@@ -692,6 +706,28 @@ router.post('/:id/stop', requireRecorderEdit, async (req, res, next) => {
       }
     }
 
+    // ── Growing-files S3 promotion ────────────────────────────────────────────
+    // When growing_enabled=true the capture container writes the master file to
+    // /growing/{projectId}/{clipName}.{ext} (a host bind-mount that the mam-api
+    // container also has at /growing).  The capture container's graceful-shutdown
+    // handler (triggered by the Docker stop above) calls POST /assets/:id/finalize
+    // with the expected S3 key, which queues the proxy job — but the file was
+    // never uploaded to S3, so the proxy worker fails with "unable to open file".
+    //
+    // Fix: after the container has exited (ffmpeg is done flushing), upload the
+    // growing file to the canonical S3 key from here.  This is synchronous and
+    // completes before the HTTP response reaches the client, so the already-queued
+    // proxy job will find a valid S3 object when the worker dequeues it.
+    //
+    // Only applies to LOCAL recorders — remote recorders write to a different
+    // node's /growing mount which this process cannot access.
+    if (!isRemote && recorder.growing_enabled === true && recorder.current_session_id) {
+      await promoteGrowingFileToS3(recorder).catch(err => {
+        // Non-fatal — log and continue so the stop always succeeds.
+        console.error('[recorders/stop] growing-file promotion failed (non-fatal):', err.message);
+      });
+    }
+
     const updateResult = await pool.query(
       `UPDATE recorders
        SET container_id = NULL, status = $1, updated_at = NOW()
@@ -706,6 +742,109 @@ router.post('/:id/stop', requireRecorderEdit, async (req, res, next) => {
   }
 });
 
+/**
+ * Upload a completed growing-file master from /growing to S3 so the proxy
+ * worker can find it at the expected original_s3_key.
+ *
+ * The capture container writes to:
+ *   /growing/{projectId}/{clipName}.{ext}
+ *
+ * The canonical S3 key (set on the asset row at recording start) is:
+ *   projects/{projectId}/masters/{clipName}.{ext}
+ *
+ * We look up the live/processing asset to derive both paths, do a multipart
+ * upload, update the asset's original_s3_key and file_size to match what we
+ * actually uploaded, then ensure a proxy job exists for it.
+ */
+async function promoteGrowingFileToS3(recorder) {
+  const clipName  = recorder.current_session_id;
+  const container = recorder.recording_container || 'mov';
+
+  // Find the asset that was pre-created at recording start.  It could be in
+  // 'live' (finalize hasn't fired yet) or 'processing' (finalize already ran
+  // from the container's SIGTERM handler).  We need both its id and its
+  // project_id to reconstruct the growing path.
+  const assetRes = await pool.query(
+    `SELECT id, project_id, status, original_s3_key
+       FROM assets
+      WHERE display_name = $1
+        AND status IN ('live', 'processing', 'error')
+      ORDER BY created_at DESC
+      LIMIT 1`,
+    [clipName]
+  );
+
+  if (assetRes.rows.length === 0) {
+    console.warn(`[recorders/stop] no asset found for clip "${clipName}" — skipping growing-file promotion`);
+    return;
+  }
+
+  const asset      = assetRes.rows[0];
+  const projectId  = asset.project_id;
+  const growingDir = process.env.GROWING_DIR || '/growing';
+  const localPath  = `${growingDir}/${projectId}/${clipName}.${container}`;
+  const s3Key      = `projects/${projectId}/masters/${clipName}.${container}`;
+
+  if (!existsSync(localPath)) {
+    console.warn(`[recorders/stop] growing file not found at ${localPath} — nothing to promote (empty recording?)`);
+    return;
+  }
+
+  const fileStat = await stat(localPath);
+  if (fileStat.size === 0) {
+    console.warn(`[recorders/stop] growing file at ${localPath} is empty — skipping promotion`);
+    return;
+  }
+
+  console.log(`[recorders/stop] promoting growing file ${localPath} (${fileStat.size} bytes) → s3://${getS3Bucket()}/${s3Key}`);
+
+  const upload = new Upload({
+    client: s3Client,
+    params: {
+      Bucket: getS3Bucket(),
+      Key:    s3Key,
+      Body:   createReadStream(localPath),
+    },
+    queueSize:  4,
+    partSize:   8 * 1024 * 1024,
+  });
+  await upload.done();
+
+  console.log(`[recorders/stop] S3 upload complete for ${s3Key}`);
+
+  // Ensure the asset row reflects the correct S3 key and file size.  The
+  // capture container's finalize call may have already set original_s3_key to
+  // this same value (it was pre-set at start), but update file_size which
+  // finalize doesn't touch.
+  await pool.query(
+    `UPDATE assets
+        SET original_s3_key = $1,
+            file_size        = $2,
+            updated_at       = NOW()
+      WHERE id = $3`,
+    [s3Key, fileStat.size, asset.id]
+  );
+
+  // If the asset is still 'live' (capture container's finalize hasn't fired or
+  // failed), flip it to 'processing' and queue the proxy job ourselves so the
+  // clip doesn't get stuck in the library as "Recording…".
+  if (asset.status === 'live') {
+    console.log(`[recorders/stop] finalize not yet called — queueing proxy and flipping asset ${asset.id} to processing`);
+    await pool.query(
+      `UPDATE assets SET status = 'processing', updated_at = NOW() WHERE id = $1`,
+      [asset.id]
+    );
+    await proxyQueue.add('generate', {
+      assetId:   asset.id,
+      inputKey:  s3Key,
+      outputKey: `proxies/${asset.id}.mp4`,
+    });
+  }
+  // If status is already 'processing', the capture container's finalize already
+  // ran and queued the proxy job.  The S3 upload we just did ensures the worker
+  // will find a valid object when it dequeues that job — nothing else to do.
+}
+
 // GET /:id/status - Get live status
 router.get('/:id/status', async (req, res, next) => {
   try {