---
title: "Upload And Extend Audio"
method: POST
path: "/api/v1/generate/upload-extend"
---

# Upload And Extend Audio

`POST /api/v1/generate/upload-extend`

## Request body

- object
  - `uploadUrl` string, uri, required — The URL for uploading audio files, required regardless of whether defaultParamFlag is true or false. Ensure the uploaded audio does not exceed 8 minutes in length.
  - `defaultParamFlag` boolean, required — Enable custom mode for advanced audio generation settings. - Set to `true` to use custom parameter mode (requires `style`, `title`, and `uploadUrl`; if `instrumental` is `false`, `uploadUrl` and `prompt` are required). If `instrumental` is `false`, the prompt will be strictly used as lyrics. - Set to `false` to use non-custom mode (only `uploadUrl` required). Lyrics will be automatically generated based on the prompt.
  - `instrumental` boolean — Determines whether the audio is instrumental (without lyrics). - In custom parameter mode (`defaultParamFlag: true`): - If `true`: only `style`, `title`, and `uploadUrl` are required. - If `false`: `style`, `title`, `prompt` (`prompt` will be used as exact lyrics), and `uploadUrl` are required. - In non-custom parameter mode (`defaultParamFlag: false`): does not affect required fields (only `uploadUrl` needed). If `false`, lyrics will be automatically generated.
  - `prompt` string — Description of how the music should be extended. Required when defaultParamFlag is true. Character limits by model: - **V4**: Maximum 3000 characters - **V4_5, V4_5PLUS, V4_5ALL, V5 & V5_5**: Maximum 5000 characters
  - `style` string — Music style, e.g., Jazz, Classical, Electronic. Character limits by model: - **V4**: Maximum 200 characters - **V4_5, V4_5PLUS, V4_5ALL, V5 & V5_5**: Maximum 1000 characters
  - `title` string — Music title. Character limits by model: - **V4 & V4_5ALL**: Maximum 80 characters - **V4_5, V4_5PLUS, V5 & V5_5**: Maximum 100 characters
  - `continueAt` number — The time point (in seconds) from which to start extending the music. - Required when `defaultParamFlag` is `true`. - Value range: greater than 0 and less than the total duration of the uploaded audio. - Specifies the position in the original track where the extension should begin.
  - `personaId` string — Only available when custom parameters are enabled. Persona ID to apply to the generated music. Optional. You can use either: - A Persona ID generated by the [Generate Persona](https://docs.sunoapi.org/suno-api/generate-persona) endpoint. Use `personaModel: style_persona` or omit `personaModel` to use the default. - A `voiceId` generated by the [Suno Voice](https://docs.sunoapi.org/suno-api/suno-voice-generate) workflow. When using a voice-generated ID, you must set `personaModel: voice_persona`.
  - `personaModel` 'style_persona' | 'voice_persona' — Persona model type to apply when using `personaId`. Optional. - `style_persona` (default): Use this for Persona IDs generated by the Generate Persona endpoint. - `voice_persona`: Use this when `personaId` is a `voiceId` generated by Suno Voice. This option is only available with V5 and V5_5 models.
  - `model` 'V4' | 'V4_5' | 'V4_5PLUS' | 'V4_5ALL' | 'V5' | 'V5_5', required — Model version to use, must be consistent with the source audio
  - `negativeTags` string — Music styles to exclude from generation
  - `vocalGender` 'm' | 'f' — Preferred vocal gender for generated vocals. Optional.
  - `styleWeight` number — Weight of the provided style guidance. Range 0.00–1.00.
  - `weirdnessConstraint` number — Constraint on creative deviation/novelty. Range 0.00–1.00.
  - `audioWeight` number — Weight of the input audio influence (where applicable). Range 0.00–1.00.
  - `callBackUrl` string, uri, required — The URL to receive task completion notifications when music extension is complete. - For detailed callback format and implementation guide, see [Upload and Extend Audio Callbacks](https://docs.sunoapi.org/suno-api/upload-and-extend-audio-callbacks) - Alternatively, you can use the get music generation details endpoint to poll task status

## Response `200`

Request successful

- object
  - `code` 200 | 400 | 401 | 404 | 405 | 413 | 429 | 430 | 455 | 500 — # Status Codes - ✅ 200 - Request successful - ⚠️ 400 - Invalid parameters - ⚠️ 401 - Unauthorized access - ⚠️ 404 - Invalid request method or path - ⚠️ 405 - Rate limit exceeded - ⚠️ 413 - Theme or prompt too long - ⚠️ 429 - Insufficient credits - ⚠️ 430 - Your call frequency is too high. Please try again later. - ⚠️ 455 - System maintenance - ❌ 500 - Server error
  - `msg` string — Error message when code != 200
  - `data` object
    - `taskId` string — Task ID for tracking task status

## Other responses

- `500` — Server error

---

[API](https://skmtc.net/sunoapi/apis/file-upload-api.md) · [All operations](https://skmtc.net/sunoapi/apis/file-upload-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/sunoapi/file-upload-api/versions/22d45ee33a4a/schema)