Suno: extend

Continue an existing track.

Action facts

Property	Value
Model	`suno`
Action	`extend`
Endpoint	`POST /api/v1/generation/create`
Result	audio in `files`
Pricing	View current pricing

Minimal request


curl -X POST https://api.api-stock.com/api/v1/generation/create \
  -H "Authorization: Bearer $API_STOCK_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "suno",
  "input": {
    "action": "extend",
    "sourceTaskId": "019ca881-9503-7270-a560-f00fc2b15785",
    "continueAt": 30
  }
}'


{
  "code": 200,
  "data": {
    "taskId": "019ca881-9503-7270-a560-f00fc2b15785",
    "status": "not_started",
    "createdAt": "2026-08-22T12:00:00.000Z"
  }
}

Parameters

Parameter	Type	Required	Default	Description
`action`	“music” \| “extend” \| “cover” \| “add-instrumental” \| “add-vocals” \| “sound” \| “stems” \| “stems-all” \| “wav” \| “lyrics” \| “voice” \| “timestamped-lyrics” \| “boost-style” \| “music-cover” \| “replace-section” \| “music-video” \| “inspo” \| “upload” \| “remaster” \| “add-stem” \| “vox” \| “remove-section” \| “crop” \| “fade-in” \| “fade-out” \| “adjust-speed” \| “concat” \| “mashup” \| “sample” \| “midi” \| “bpm” \| “custom-model”	Yes	`"music"`	Suno operation
`mv`	string	No	—	Engine version. Audio actions: v6 (default) \| v6-wild \| v6-mini \| custom. The retired versions v3.5 … v5.5 are still accepted and run on v6. lyrics: remi-v1 \| default. Not used by stems/stems-all/wav/voice. variety, maxMode, audioFormat, duration and customModelId need a V6 engine (any value except custom).
`custom`	boolean	No	—	false for simple mode, true for custom mode
`gptDescriptionPrompt`	string	No	—	Simple mode: song / effect description (with optional lyrics)
`prompt`	string	No	—	Custom mode: detailed lyrics / prompt (also the lyrics or sound description)
`tags`	string	No	—	Custom mode: genre / style tags
`title`	string	No	—	Title for the result
`negativeTags`	string	No	—	Styles to avoid (custom mode / sound)
`personaId`	string	No	—	ID of a custom voice (persona) to sing the generated music
`customModel`	object	No	—	Inline custom model definition (required when mv=custom). Shape: { name: string, audioUrls: string[6..24] }.
`customModelId`	string	No	—	Id of a reusable custom model created by the `custom-model` action (its `output.customModelId`). Generates in that model’s style; cannot be combined with mv or personaId.
`variety`	“off” \| “normal” \| “high” \| “extra” \| “max”	No	—	Style variation: off \| normal \| high \| extra \| max. V6 generative actions.
`maxMode`	boolean	No	`false`	Max mode: higher-quality V6 generation, billed at twice the regular price. Requires custom mode, except on inspo and replace-section.
`audioFormat`	“mp3” \| “m4a” \| “wav”	No	—	Output audio format: mp3 \| m4a \| wav. V6 generative actions plus sound, remaster, stems and stems-all.
`duration`	number	No	—	music / extend / cover: target length in seconds (10–360), custom mode only. The actual length is decided by the model. min 10, max 360
`audioUrl`	string	No	—	Audio file URL to operate on
`continueAt`	number	Yes	—	extend: time in seconds where the extension should begin (at least 1 for a sourceTaskId or audioUrl source)
`sourceTaskId`	string	Yes	—	Reference to one of your prior Suno generations (its taskId), used by stateful actions such as extend, music-cover, replace-section, timestamped-lyrics, music-video, voice and wav.
`audioId`	string	No	—	The track to operate on, identified by its id (as returned in a prior generation’s `output.tracks[].audioId`). A generation usually produces 2 tracks; omit to use the first.

Conditional rules: Requires a source (audioId, audioUrl, or sourceTaskId) and continueAt (at least 1 for sourceTaskId or audioUrl). Omitting custom continues in custom mode unless only gptDescriptionPrompt is sent. A public audioUrl combined with the V6 options (variety, maxMode, audioFormat, duration, customModelId) is always extended in custom mode.

Only send fields relevant to this action. When a request references sourceTaskId, the source must be a successful Suno task owned by the same account.

Result


curl https://api.api-stock.com/api/v1/task/status/$TASK_ID \
  -H "Authorization: Bearer $API_STOCK_KEY"

You can instead provide a top-level webhook. The task reaches finished, failed or expired; failed generations are refunded automatically. Data actions return output, while media actions return files.


{
  "code": 200,
  "data": {
    "taskId": "019ca881-9503-7270-a560-f00fc2b15785",
    "status": "finished",
    "files": [
      {
        "fileUrl": "https://s3.api-stock.com/result.mp3",
        "fileType": "music"
      }
    ],
    "createdTime": "2026-08-22T12:00:00.000Z"
  }
}

Back to all Suno actions