> ## Documentation Index
> Fetch the complete documentation index at: https://docs.crun.ai/llms.txt
> Use this file to discover all available pages before exploring further.
# Suno API: Extend Music
> Extend or modify existing music by creating a continuation based on a source suno music track.
### Important Notes
* This endpoint requires a valid `suno_id` that references an existing Suno music. If you need to upload an audio
extension, please refer to: [upload audio extend](/suno-api/extend-music-upload).
* Supports two extension modes: `simple` and `custom`
* In `simple` mode, other optional parameters inherit from the original `suno_id`
* In `custom` mode, `continue_at`, `title`, `tags`, and `prompt` are required
If you are extending an existing track with minimal changes, recommend start with `mode=simple`.
### Extend Music (Simple Mode)
Extend an existing Suno song using its `suno_id`. Optional parameters are inherited from the original song.
```json simple extend theme={null} theme={null}
{
"model": "suno/music-extend",
"callback_url": "",
"input": {
"suno_id": "suno_abc123",
"mode": "simple",
"model": "v5"
}
}
```
```json simple extend with continue_at theme={null} theme={null}
{
"model": "suno/music-extend",
"callback_url": "",
"input": {
"suno_id": "suno_abc123",
"mode": "simple",
"model": "v5",
"continue_at": 30
}
}
```
### Extend Music (Custom Mode)
Custom extension lets you control the continuation point and content. You must specify `continue_at`, `title`, `tags`,
and `prompt`.
```json custom extend theme={null} theme={null}
{
"model": "suno/music-extend",
"callback_url": "",
"input": {
"suno_id": "suno_abc123",
"mode": "custom",
"model": "v5",
"continue_at": 30,
"title": "Midnight Addiction (Extended)",
"tags": "Western R&B, female vocal, dark, sensual",
"prompt": "Keep the same dark R&B mood and extend with a new bridge and outro.",
"vocal_gender": "f",
"style_weight": 0.85,
"audio_weight": 0.6,
"weirdness_constraint": 0.2,
"negative_tags": "metal, aggressive"
}
}
```
### Get Task Result
After submitting a task, use the unified query endpoint to check progress and retrieve results:
Learn how to query suno task status and retrieve generation results
## OpenAPI
````yaml suno-api/extend-music.json post /api/v1/client/job/CreateTask
openapi: 3.0.0
info:
title: Crun Suno Music Extend API
description: crun.ai Suno Music Extend API Documentation
version: 1.0.0
contact:
name: Technical Support
email: support@crun.ai
servers:
- url: https://api.crun.ai
description: API Server
security:
- ApiKeyAuth: []
paths:
/api/v1/client/job/CreateTask:
post:
summary: Suno music extension
operationId: suno/music-extend
requestBody:
required: true
content:
application/json:
schema:
type: object
required:
- model
- input
properties:
model:
type: string
enum:
- suno/music-extend
description: |-
The model name to use for generation. Required field.
- Must be `suno/music-extend` for this endpoint
callback_url:
type: string
format: uri
description: >-
Optional. Callback URL for receiving task completion
notifications.
- System will POST task status and results to this URL when
generation completes
- Callback payloads structure is consistent with the `data`
object returned by the task status query
- Your callback endpoint should accept POST requests with
JSON payload containing results
- It returns an HTTP 200 status code upon successful receipt
example: https://your-domain.com/api/callback
input:
$ref: '#/components/schemas/SunoMusicExtendInput'
example:
model: suno/music-extend
callback_url: https://your-domain.com/api/callback
input:
suno_id: suno_abc123
mode: custom
model: v5
continue_at: 30
title: Midnight Addiction (Extended)
tags: Western R&B, female vocal, dark, sensual
prompt: >-
Keep the same dark R&B mood and extend with a new bridge and
outro.
vocal_gender: f
style_weight: 0.85
audio_weight: 0.6
weirdness_constraint: 0.2
negative_tags: metal, aggressive
responses:
'200':
description: Request successful
content:
application/json:
schema:
allOf:
- $ref: '#/components/schemas/ApiResponse'
- type: object
properties:
data:
type: object
properties:
task_id:
type: string
description: >-
Task ID, can be used with Get Task Details
endpoint to query task status
example: task_12345678
example:
code: 200
message: success
data:
task_id: task_12345678
'422':
description: Validation Error
content:
application/json:
schema:
allOf:
- $ref: '#/components/schemas/ApiResponse'
- type: object
properties:
errors:
type: array
description: Detailed validation error messages
items:
type: string
example:
- specific error field message
example:
code: 422
message: Missing Params or Type Error
errors:
- specific error field message
'500':
$ref: '#/components/responses/Error'
components:
schemas:
SunoMusicExtendInput:
type: object
description: >-
Input parameters for Suno music extension.
Rules:
- `suno_id` is required and must reference an existing Suno song.
- `mode=simple`: other optional fields inherit from the original
`suno_id`.
- `mode=custom`: `continue_at`, `title`, `tags`, and `prompt` are
required.
- `model=v4`: `tags` max length is 200 and `prompt` max length is 3000;
other models: `tags` max length 1000 and `prompt` max length 5000.
properties:
suno_id:
type: string
description: Suno song ID to extend.
example: suno_abc123
mode:
type: string
enum:
- simple
- custom
description: Extension mode.
example: simple
model:
type: string
enum:
- v5.5
- v5
- v4.5plus
- v4.5
- v4.5all
- v4
description: >-
Suno music model version.
- **v5.5**: A tailor-made model crafted to match your unique taste.
- **v5**: Superior musical expression, faster generation.
- **v4.5plus**: v4.5+ delivers richer sound, new ways to create, max
8 min.
- **v4.5**: enables smarter prompts, faster generations, max 8 min.
- **v4.5all**: enables smarter prompts, faster generations, max 8
min.
- **v4**: improves vocal quality, max 4 min.
example: v5
continue_at:
type: integer
minimum: 1
description: >-
Start extending at this second (must be > 0). Required in `custom`
mode.
example: 30
title:
type: string
maxLength: 80
description: Music title. Required in `custom` mode.
example: Midnight Addiction (Extended)
prompt:
type: string
maxLength: 5000
description: >-
Describes how the music should continue or change in the extension.
Required in `custom` mode. For model `v4`, max length is 3000,
others 5000.
example: Keep the same dark R&B mood and extend with a new bridge and outro.
tags:
type: string
maxLength: 1000
description: >-
Music style tags. Required in `custom` mode. For model `v4`, max
length is 200, others 1000.
example: Western R&B, female vocal, dark, sensual
negative_tags:
type: string
maxLength: 1000
description: Music styles to exclude.
example: metal, aggressive, harsh vocals
vocal_gender:
type: string
enum:
- m
- f
description: 'Vocal gender preference: `m` for male, `f` for female.'
example: f
style_weight:
type: number
minimum: 0
maximum: 1
description: Style reference strength, from 0.0 to 1.0.
example: 0.85
audio_weight:
type: number
minimum: 0
maximum: 1
description: Balance weight for audio features vs other factors, from 0.0 to 1.0.
example: 0.6
weirdness_constraint:
type: number
minimum: 0
maximum: 1
description: Controls experimental/creative deviation, from 0.0 to 1.0.
example: 0.2
persona_id:
type: string
description: >-
Persona ID for the selected persona model. Create via [Suno Persona
Generate](/suno-api/suno-persona-generate).
example: persona_123456
persona_model:
type: string
enum:
- style_persona
- voice_persona
description: |-
Persona model type. Use with `persona_id` to apply a saved persona.
- **style_persona**: Applies style-focused persona characteristics.
- **voice_persona**: Applies voice-focused persona characteristics (only available with v5 model).
default: style_persona
example: style_persona
required:
- suno_id
- mode
- model
ApiResponse:
type: object
properties:
code:
type: integer
enum:
- 200
- 401
- 402
- 404
- 422
- 429
- 455
- 500
- 501
- 505
description: >-
Response status code
- **200**: Success - Request has been processed successfully
- **401**: Unauthorized - Authentication credentials are missing or
invalid
- **402**: Insufficient Credits - Account does not have enough
credits to perform the operation
- **404**: Not Found - The requested resource or endpoint does not
exist
- **422**: Validation Error - The request parameters failed
validation checks
- **429**: Rate Limited - Request limit has been exceeded for this
resource
- **455**: Service Unavailable - System is currently undergoing
maintenance
- **500**: Server Error - An unexpected error occurred while
processing the request
- **501**: Generation Failed - Content generation task failed
- **505**: Feature Disabled - The requested feature is currently
disabled
message:
type: string
description: Response message, error description when failed
example: success
responses:
Error:
description: Server Error
securitySchemes:
ApiKeyAuth:
type: apiKey
in: header
name: x-api-key
description: >-
All APIs require authentication via API Key.
Get API Key:
1. Visit [API Key Management Page](https://crun.ai/user-api-key) to get
your API Key
Usage:
Add to request header:
x-api-key: YOUR_API_KEY
Note:
- Keep your API Key secure and do not share it with others
- If you suspect your API Key has been compromised, reset it immediately
in the management page
````