---
title: "Sent when a separation fails. The charge is refunded automatically."
method: POST
path: "separation.failed"
---

# Sent when a separation fails. The charge is refunded automatically.

`POST separation.failed` (webhook)

The run did not produce stems. The song goes back to uploaded so you can retry it, and the credits taken when the job was accepted have already been returned.

Delivered to every enabled endpoint subscribed to this event.

**Verify the signature.** Compute
`HMAC-SHA256(secret, timestamp + '.' + rawBody)` as hex and compare it
to the value in `x-vocaless-signature` (after the `v1=` prefix) using a
constant-time comparison. Reject a `x-vocaless-timestamp` far from your
own clock to prevent replay.

**Deduplicate on `x-vocaless-delivery`.** A delivery is retried up to 4
times (1m, 5m, 25m) until it gets a 2xx, and a worker that dies
mid-request may resend one that already arrived.

Download URLs are deliberately absent: they are short-lived, so call
`GET /songs/{id}` when you are ready to fetch the audio.

## Headers

- `x-vocaless-signature` string, required
- `x-vocaless-timestamp` string, required
- `x-vocaless-delivery` string, required

## Payload

- object
  - `id` string, uuid, required: Delivery id, same as the header.
  - `type` 'separation.failed', required
  - `created_at` string, date-time, required
  - `data` object, required
    - `song` WebhookSong, required
      - `duration_seconds` number, nullable, required
      - `id` string, required
      - `name` string, required
      - `status` 'error' | 'ready' | 'separating' | 'uploaded' | 'uploading', required

## Acknowledgement `2xx`

Any 2xx marks the delivery successful. Anything else is retried.

---

[API](https://skmtc.dev/vocaless/apis/vocaless-api.md) · [All operations](https://skmtc.dev/vocaless/apis/vocaless-api/llms.txt) · [OpenAPI document](https://skmtc.dev/vocaless/apis/vocaless-api/revisions/db15b6df3aa2?raw)