SpeechifyAI Build API

REST endpoints for text-to-speech, streaming, and voice cloning

The SpeechifyAI Build API is a REST API at https://api.speechify.ai. Use it to generate speech from text, stream long-form audio, and clone voices from a short reference sample.

A minimal call. The request and response are generated from the API spec, so they stay in sync with the live endpoint.

POST
/v1/audio/speech
1curl -X POST https://api.speechify.ai/v1/audio/speech \
2     -H "Authorization: Bearer <token>" \
3     -H "Content-Type: application/json" \
4     -d '{
5  "input": "Hello! This is the Speechify text-to-speech API.",
6  "voice_id": "george",
7  "audio_format": "mp3",
8  "model": "simba-english"
9}'
Try it
Response
1{
2  "audio_data": "example",
3  "audio_format": "wav",
4  "billable_characters_count": 10,
5  "speech_marks": {
6    "chunks": [
7      {}
8    ],
9    "end": 1,
10    "end_time": 1,
11    "start": 1,
12    "start_time": 1,
13    "type": "example",
14    "value": "example"
15  }
16}

Explore

Text to Speech

Synthesize speech with POST /v1/audio/speech or stream long-form audio with POST /v1/audio/stream. Up to 2,000 characters per synthesis; up to 20,000 for streaming.

Voice

List, create, delete, and preview voices - including clones minted from a 10-30 second sample. Cloned voices work across every supported language.

Response format

Non-streaming endpoints return JSON. Speech synthesis returns base64-encoded audio in audio_data. The streaming endpoint returns raw audio chunks via HTTP chunked transfer encoding.

Errors

Every non-2xx response uses the same JSON envelope:

1{
2  "error": {
3    "code": "voice_not_found",
4    "message": "Voice 'voice_demo0001' does not exist."
5  },
6  "request_id": "7f3a2c1b4d5e6f7a"
7}

Check error.code in your SDK exception handler - it is a stable, machine-readable identifier you can branch on. error.message is human-friendly and may change between releases. error.fields carries per-field validation errors when relevant. request_id echoes the X-Request-ID response header; quote it when filing support tickets.

See Get started for authentication and limits, and Idempotency for retry-safe writes.