Mux video.asset.ready webhook payload example

Mux · event: video.asset.ready · content type: application/json

This is a representative sample — fake IDs, real structure. To see a payload with your data, point the provider at a capture URL (button below).

Headers

content-type: application/json
user-agent: Mux Webhooks
mux-signature: t=1788518532,v1=6527e21900964221b9bedaadc871fe7f2e306afd6903d6d1f4a36d683b106f30

Body

{
  "type": "video.asset.ready",
  "object": {
    "type": "asset",
    "id": "l02fMrbCu0002269XRD7LpcHhrm01p02fGKPE7"
  },
  "id": "9d5a78f0-85c1-11f1-b6a4-2e7d9c3f5b18",
  "environment": {
    "name": "Production",
    "id": "qp3vk7"
  },
  "data": {
    "tracks": [
      {
        "type": "video",
        "max_width": 1920,
        "max_height": 1080,
        "max_frame_rate": 29.97,
        "id": "l02fMrbCu0002269XRD7LpcHhrm01p02fGKPE7",
        "duration": 23.857167
      },
      {
        "type": "audio",
        "max_channels": 2,
        "max_channel_layout": "stereo",
        "id": "Qju5vBizvFzB9502bYNqOVzNWRrVo5Sn",
        "duration": 23.823
      }
    ],
    "status": "ready",
    "playback_ids": [
      {
        "id": "vNWRrVo5SnQju5vBizv02bYNqOFzB95Qz",
        "policy": "public"
      }
    ],
    "max_stored_resolution": "HD",
    "max_stored_frame_rate": 29.97,
    "id": "l02fMrbCu0002269XRD7LpcHhrm01p02fGKPE7",
    "duration": 23.857167,
    "created_at": "2026-08-30T10:41:07.000Z",
    "aspect_ratio": "16:9"
  },
  "created_at": "2026-08-30T10:42:12.000Z",
  "accessor_source": null,
  "accessor": null,
  "request_id": null
}

Things that bite people

• This example's signature actually verifies: paste the body, the whole Mux-Signature header and the secret hookden-mux-sample-signing-secret into the signature debugger (Mux scheme), or set the Mux scheme on a capture bin for live ✓/✗ badges. It's t=<unix>,v1=<hex> — hex HMAC-SHA256 over timestamp.rawBody, i.e. Stripe's exact wire format under a different header; Stripe verification code works if you swap the header name. v1 is the only valid scheme today. Mux SDKs default to a 5-minute timestamp tolerance (verified vs mux.com docs, 2026-08-30).
• The signing secret is per-endpoint — every webhook you configure gets its own. Dashboard-created webhooks show it on the webhooks settings page; API-created webhooks return signing_secret once, in the create response only — you cannot retrieve it again (same trap as Frame.io). Verifying with the secret of your other environment's endpoint is a classic silent failure.
• Webhooks are scoped per environment. Configured in Production but testing in Development? Nothing arrives — Mux's own docs call this out as the first thing to check. Once configured, an endpoint receives all events for that environment; filter on type yourself. The environment object in the payload tells you which one fired.
• Retries & dupes: a delivery attempt times out after 5 seconds; non-2xx (or timeout) is retried for the next 24 hours with increasing delay. And the docs warn explicitly that duplicates can arrive even after you returned 2xx — dedupe on the top-level event id (a UUID), not on receipt. Mux also rate limits GET /assets precisely so you don't poll instead of listening.
• data mirrors the Asset object: status: "ready" means you can stream via playback_ids[0].id — but playback_ids is only present if the asset was created with a playback policy (the docs' own sample payload omits it); don't make your handler require it. video.asset.created can arrive with status still preparing — gate downstream work on ready, and handle video.asset.errored (bad input URL / not-a-video are the common causes).
• Local dev: the Mux CLI forwards events (mux webhooks listen --forward-to localhost…) and can fire synthetic ones (mux webhooks trigger video.asset.ready) — but CLI forwarding is explicitly for local dev with no delivery guarantees. For a durable record, point Mux at a capture bin and relay to localhost — byte-identical bodies, so the signature above still verifies downstream.

Send it yourself

Reproduce this delivery against any endpoint (your handler, a bin, staging):

$ curl -X POST https://your-endpoint.example/hook \
  -H 'content-type: application/json' \
  -H 'user-agent: Mux Webhooks' \
  -H 'mux-signature: t=1788518532,v1=6527e21900964221b9bedaadc871fe7f2e306afd6903d6d1f4a36d683b106f30' \
 -d '{
  "type": "video.asset.ready",
  "object": {
    "type": "asset",
    "id": "l02fMrbCu0002269XRD7LpcHhrm01p02fGKPE7"
  },
  "id": "9d5a78f0-85c1-11f1-b6a4-2e7d9c3f5b18",
  "environment": {
    "name": "Production",
    "id": "qp3vk7"
  },
  "data": {
    "tracks": [
      {
        "type": "video",
        "max_width": 1920,
        "max_height": 1080,
        "max_frame_rate": 29.97,
        "id": "l02fMrbCu0002269XRD7LpcHhrm01p02fGKPE7",
        "duration": 23.857167
      },
      {
        "type": "audio",
        "max_channels": 2,
        "max_channel_layout": "stereo",
        "id": "Qju5vBizvFzB9502bYNqOVzNWRrVo5Sn",
        "duration": 23.823
      }
    ],
    "status": "ready",
    "playback_ids": [
      {
        "id": "vNWRrVo5SnQju5vBizv02bYNqOFzB95Qz",
        "policy": "public"
      }
    ],
    "max_stored_resolution": "HD",
    "max_stored_frame_rate": 29.97,
    "id": "l02fMrbCu0002269XRD7LpcHhrm01p02fGKPE7",
    "duration": 23.857167,
    "created_at": "2026-08-30T10:41:07.000Z",
    "aspect_ratio": "16:9"
  },
  "created_at": "2026-08-30T10:42:12.000Z",
  "accessor_source": null,
  "accessor": null,
  "request_id": null
}'

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