---
title: "Extend"
method: POST
path: "/v1/generations/extend"
---

# Extend

`POST /v1/generations/extend`

## Query parameters

- `credits_check` boolean

## Headers

- `authorization` string

## Request body

- PubAPIV2ExtendRequest
  - `webhook_url` string, nullable
  - `output_format` 'flac' | 'mp3' | 'wav' | 'ogg' | 'm4a'
  - `output_bit_rate` 128 | 192 | 256 | 320, nullable
  - `align_lyrics` boolean
  - `num_songs` integer
  - `audio_url` string, nullable
  - `audio_base64` string, nullable
  - `tags` string[]
  - `lyrics` string
  - `prompt` string, nullable
  - `instrumental` boolean
  - `prompt_strength` number
  - `side` 'left' | 'right', required
  - `crop_duration` number
  - `balance_strength` number
  - `seed` integer, nullable
  - `extend_duration` number, nullable
  - `start_end_song` 'start' | 'end', nullable — Force song start/end tokens

## Response `200`

Successful Response

- unknown

## Other responses

- `422` — Validation Error

---

[API](https://skmtc.dev/sonauto/apis/fastapi.md) · [All operations](https://skmtc.dev/sonauto/apis/fastapi/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/sonauto/fastapi/revisions/2851daf2d69a/schema)