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

> Update Studio 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/studio/projects/project-id/content' \
  -H "xi-api-key: $ELEVENLABS_API_KEY" \
  -F 'from_url=string' \
  -F 'from_document=@sample.bin'

## Parameters
| Name | In | Type | Required | Description |
| :--- | :--- | :--- | :--- | :--- |
| project_id | path | string | Yes | The ID of the Studio project. |
| from_url | body | string | No | An optional URL from which we will ex... |
| from_document | body | string | No | An optional .epub, .pdf, .txt or simi... |

## Response (200 OK)
{"project":{"access_level":"viewer","author":"John Doe"}}

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