> ## Documentation Index
> Fetch the complete documentation index at: https://docs.snapgen.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Suno Concat

> Join a Suno extension and its source into one full song. $0.006 per request.

`suno-concat` joins an extension with the song it continues, producing one full-length track.

| Property | Value |
| - | - |
| Model ID | `suno-concat` |
| Endpoint | `POST /v1/music/generations` (asynchronous task) |
| Group | Suno > Edit |
| Input | A track from one of your earlier `suno-extend` or `suno-upload-extend` tasks |
| Result | Tracks in `result.tracks` with `audio_url` |
| Price | \$0.006 per request (0.6 credits) |

Confirm live rates on the [SnapGen models page](https://snapgen.org/models). Failed tasks are not charged.

<ParamField body="model" type="string" required>
  Set to `suno-concat`.
</ParamField>

<ParamField body="source_task_id" type="string" required>
  The `id` of your earlier task that holds the source track. It must be your own task, must have succeeded, and must come from a model listed in [Source tracks](#source-tracks).
</ParamField>

<ParamField body="source_index" type="integer" default="1">
  Position of the source track in that task's `result.tracks`, counting from `1` (up to `8`).
</ParamField>

<ParamField body="audio_format" type="string">
  Output format: `mp3`, `m4a`, or `wav`. The provider picks one if you omit it.
</ParamField>

<ParamField body="webhook" type="string">
  Optional public `https` URL that receives one signed event when the task finishes. See [Task webhooks](/api-reference/webhooks).
</ParamField>

<ParamField body="webhook_secret" type="string">
  Required with `webhook`: 16 to 256 characters, used to sign the delivery.
</ParamField>

## Source tracks

The source task must be your own succeeded task from one of these models:

[`suno-extend`](/api-manual/audio/suno-extend), [`suno-upload-extend`](/api-manual/audio/suno-upload-extend).

Send the task `id` as `source_task_id` and pick the track with `source_index`. Never send provider track or clip IDs. See [Reference earlier tasks](/api-reference/music-generations#reference-earlier-tasks).

## Request

```bash theme={null}
curl https://api.snapgen.org/v1/music/generations \
  -H "Authorization: Bearer $SNAPGEN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "suno-concat",
    "source_task_id": "task_2f8KcX1mQpR7vT0yZa9Lb3",
    "source_index": 1
  }'
```

The response is HTTP `202` with a task object and a `Location: /v1/tasks/{id}` header. Poll [`GET /v1/tasks/{id}`](/api-reference/task-status) every 10 to 20 seconds until `status` is `succeeded` or `failed`.

## Result

`result.tracks[]` lists every track in its original order, each with its `index` and `audio_url`, plus `title`, `image_url`, `duration_seconds`, `lyrics`, and `tags` when the provider returns them. `result.urls` lists the audio URLs.

```json theme={null}
{
  "urls": [
    "https://cdn.example.com/music/night-drive.mp3"
  ],
  "tracks": [
    {
      "index": 1,
      "id": "clip_8f3a2c",
      "title": "Night Drive",
      "audio_url": "https://cdn.example.com/music/night-drive.mp3",
      "image_url": "https://cdn.example.com/music/night-drive.jpg",
      "duration_seconds": 184.6,
      "tags": "lo-fi, soft piano, rain"
    }
  ]
}
```

<Note>
  Result URLs are kept for about 72 hours. Download the files you want to keep.
  See [Music generation tasks](/api-reference/music-generations) for the task lifecycle, result fields, webhooks, and errors.
</Note>