---
title: "Extend Audio Using Prompt and Optional Lyrics"
method: POST
path: "/v1/extend"
---

# Extend Audio Using Prompt and Optional Lyrics

`POST /v1/extend`

This endpoint allows users to extend an existing audio file or stream by appending new audio content after a specific timestamp. The new audio is generated using a prompt (e.g., describing the desired sound) and optional lyrics.

## Response `200`

Successfully initiated extend task

- object
  - `success` boolean
  - `message` string
  - `task_id` string
  - `conversion_id_1` string
  - `conversion_id_2` string
  - `eta` integer — Estimated processing time in seconds
  - `credit_estimate` number, float

## Other responses

- `422` — Validation Error
- `500` — Server Error

---

[API](https://skmtc.net/musicgpt/apis/musicgpt-api.md) · [All operations](https://skmtc.net/musicgpt/apis/musicgpt-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/musicgpt/musicgpt-api/versions/6753dccf4c5d/schema)