Track Upload Progress with Subscriptions

After you upload a file to the pre-signed S3 URL, the platform continues processing it asynchronously.

Use subscribeUserFeed to receive real-time upload events instead of polling.

For the general event schema, see Subscription Event Format.

Feed and Category

Upload events are delivered on:

• subscribeUserFeed

They use:

• category: "upload"

Event Names

Upload processing emits a sequence of events such as:

• uploadScanned
• uploadTypeChecked
• uploadConverting
• uploadFlattened
• uploadTagsParsed
• uploadPdfMetaExtracted
• uploadCompleted
• uploadFailed

Upload Event Payload

Upload payloads use this base shape:

{
  "version": "1.0",
  "eventId": "evt...",
  "timestamp": "2026-04-24T10:38:36.822Z",
  "level": "INFO",
  "event": "uploadCompleted",
  "category": "upload",
  "groupId": null,
  "userId": "usr...",
  "requestId": null,
  "batchId": null,
  "error": null,
  "data": {
    "id": "tmp...",
    "key": "upload/usr.../tmp....pdf",
    "code": "UPLOADOK"
  }
}

data.code preserves the lower-level processing code during migration and compatibility.

Subscription Operation

subscription SubscribeUserFeed {
  subscribeUserFeed {
    userId
    data
  }
}

JavaScript Example

const parseEnvelope = (payload) => {
  const raw = payload?.data;
  if (!raw) return null;
  return typeof raw === 'string' ? JSON.parse(raw) : raw;
};

const handleUserFeed = ({ data }) => {
  const wrapper = data?.subscribeUserFeed;
  const event = parseEnvelope(wrapper);

  if (event?.category !== 'upload') return;

  switch (event.event) {
    case 'uploadCompleted':
      console.log('upload complete', event.data.id, event.data.key);
      break;
    case 'uploadFailed':
      console.error('upload failed', event.data.code, event.data.key);
      break;
    default:
      console.log('upload progress', event.event, event.data.code);
  }
};

When to Use This

This is most useful when you want to:

• show a progress drawer or upload status timeline
• detect asynchronous validation failures after the S3 PUT succeeded
• react immediately when a template or uploaded asset is ready