# PATCH /v1/speech-engine/{speech_engine_id} (ElevenLabs API)
Base URL: https://api.elevenlabs.io
Auth: xi-api-key: <ELEVENLABS_API_KEY>
Last verified: 2026-09-03

> Update Speech Engine

## 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 PATCH 'https://api.elevenlabs.io/v1/speech-engine/speech-engine-id' \
  -H "xi-api-key: $ELEVENLABS_API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{"name":"string","speech_engine":{"ws_url":"string","request_headers":{}}}'

## Parameters
| Name | In | Type | Required | Description |
| :--- | :--- | :--- | :--- | :--- |
| speech_engine_id | path | string | Yes | The speech engine ID (accepts seng_ or agent_ prefix) |
| name | body | string | No | Request body field name. |
| speech_engine | body | object | No | Request body field speech_engine. |
| asr | body | object | No | Request body field asr. |

## Response (200 OK)
{"asr":{"keywords":[],"provider":"elevenlabs"},"call_limits":{"agent_concurrency_limit":-1,"bursting_enabled":true}}

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