curl -X POST 'https://api.elevenlabs.io/v1/audio-native/project-id/content' \
  -H "xi-api-key: $ELEVENLABS_API_KEY" \
  -F 'file=@sample.bin' \
  -F 'auto_convert=false' \
  -F 'auto_publish=false'

# POST /v1/audio-native/{project_id}/content (ElevenLabs API)
Base URL: https://api.elevenlabs.io
Auth: xi-api-key: <ELEVENLABS_API_KEY>
Last verified: 2026-09-03

> Update Audio-Native Project Content

## Critical Gotchas
* Authentication uses the non-standard `xi-api-key` header, not `Authorization: Bearer`. Sending a Bearer token returns HTTP 401.
* Text-to-speech responses are raw binary audio, not JSON. Write the body to a file (`--output speech.mp3`) rather than parsing it.

## cURL
curl -X POST 'https://api.elevenlabs.io/v1/audio-native/project-id/content' \
  -H "xi-api-key: $ELEVENLABS_API_KEY" \
  -F 'file=@sample.bin' \
  -F 'auto_convert=false'

## Parameters
| Name | In | Type | Required | Description |
| :--- | :--- | :--- | :--- | :--- |
| project_id | path | string | Yes | The ID of the Studio project. |
| file | body | string | No | Either txt or HTML input file contain... |
| auto_convert | body | boolean | No | Whether to auto convert the project t... |

## Response (200 OK)
{"converting":false,"html_snippet":"<div id='audio-native-player'></div>"}

---
Need an API key? Get one at https://elevenlabs.io/app/sign-up

POST

/v1/audio-native/{project_id}/content

ElevenLabs API

Update Audio-Native Project Content

Base URL: https://api.elevenlabs.io
Auth: xi-api-key: <ELEVENLABS_API_KEY>
Last verified: 2026-09-03 · upstream hash matched

Actions

Agents: curl -H "Accept: text/markdown" this URL
→ 215 tokens · Vary: Accept

Critical gotchas

Authentication uses the non-standard xi-api-key header, not Authorization: Bearer. Sending a Bearer token returns HTTP 401.

Text-to-speech responses are raw binary audio, not JSON. Write the body to a file (--output speech.mp3) rather than parsing it.

cURL

curl -X POST 'https://api.elevenlabs.io/v1/audio-native/project-id/content' \  -H "xi-api-key: $ELEVENLABS_API_KEY" \  -F 'file=@sample.bin' \  -F 'auto_convert=false' \  -F 'auto_publish=false'

Get a free ElevenLabs API key → sponsored

Parameters

Name	In	Type	Required	Description
project_id	path	string	Yes	The ID of the Studio project.
file	body	string	No	Either txt or HTML input file containing the article content. HTML should be formatted as follows '<html><body><div><p>Your content</p><h5>More of your content</h5><p>Some more of your content</p></div></body></html>'
auto_convert	body	boolean	No	Whether to auto convert the project to audio or not.
auto_publish	body	boolean	No	Whether to auto publish the new project snapshot after it's converted.

Response 200 OK

{
  "converting": false,
  "html_snippet": "<div id='audio-native-player'></div>",
  "project_id": "JBFqnCBsd6RMkjVDRZzb",
  "publishing": false
}