ElevenLabs TTS

ElevenLabs Text to Speech (TTS)

The ElevenLabs TTS API converts text into natural-sounding speech using ElevenLabs' advanced text-to-speech models. This endpoint provides high-quality voice synthesis with customizable voice selection, speech speed, and output formats.

Base URL: https://api.openmind.com

Authentication: OpenMind API key is required. Include the key in the x-api-key or Authorization header.

Endpoints Overview

Method	Endpoint	Description
POST	/elevenlabs/tts	Generate speech from text using ElevenLabs TTS
POST	/elevenlabs/tts/audio/speech	Stream speech from text using ElevenLabs TTS

Generate Speech

Convert text to speech using the ElevenLabs TTS engine with customizable voice and output options.

Endpoint: POST /elevenlabs/tts

Request

curl -X POST https://api.openmind.com/elevenlabs/tts \
  -H "Content-Type: application/json" \
  -H "x-api-key: YOUR_API_KEY" \
  -d '{
    "input": "Hello, this is a test of the ElevenLabs text to speech API."
  }'

Request Body

Field	Type	Required	Default	Description
input	string	Yes	-	The text to convert to speech
voice	string or object	No	JBFqnCBsd6RMkjVDRZzb	ElevenLabs voice ID (string) or voice object
model	string	No	eleven_flash_v2_5	ElevenLabs model ID to use for synthesis
response_format	string	No	mp3_44100_128	Audio output format specification
speed	float	No	1.0	Speech speed multiplier (0.5 - 2.0)
elevenlabs_api_key	string	No	-	Optional ElevenLabs API key override

Response

Success (200 OK):

{
  "text": "Hello, this is a test of the ElevenLabs text to speech API.",
  "response": "SUQzBAAAAAAAI1RTU0UAAAAPAAADTGF2ZjU4Ljc2LjEwMAAAAAAAAAAAAAAA//tQAAAAAAAAAAAA...",
  "format": "mp3_44100_128"
}

Response Fields

Field	Type	Description
text	string	The original input text
response	string	Base64-encoded audio data ready for decoding and playback
format	string	Audio format of the returned data (e.g., "mp3_44100_128")

Error Responses:

// 400 Bad Request - Missing or invalid input
{
  "error": "Missing or invalid JSON in request"
}

// 503 Service Unavailable - API key not configured
{
  "error": "ElevenLabs API key not configured"
}

// 503 Service Unavailable - Connection failure
{
  "error": "Failed to connect to ElevenLabs server"
}

// 500 Internal Server Error
{
  "error": "Failed to read response body"
}

Note: The returned audio is base64-encoded. You must decode it before playback or saving to a file.

Stream Speech

Convert text to speech and stream the audio directly. This endpoint is ideal for real-time applications where low latency is critical.

Endpoint: POST /elevenlabs/tts/audio/speech

Request

The request body parameters are identical to the /elevenlabs/tts endpoint.

Response

Success (200 OK):

The response is a binary stream of the audio file.

Headers:

• Content-Type: audio/mpeg (depending on requested format)

Error Responses:

See Error Responses for /elevenlabs/tts.

Usage Examples

Basic Text-to-Speech

Convert simple text to speech using default settings:

curl -X POST https://api.openmind.com/elevenlabs/tts \
  -H "Content-Type: application/json" \
  -H "x-api-key: YOUR_API_KEY" \
  -d '{
    "input": "Welcome to OpenMind AGI. This is a demonstration of text to speech conversion."
  }'

Custom Voice and Speed

Use a specific voice with faster speech rate:

curl -X POST https://api.openmind.com/elevenlabs/tts \
  -H "Content-Type: application/json" \
  -H "x-api-key: YOUR_API_KEY" \
  -d '{
    "input": "This speech is faster than normal and uses a custom voice.",
    "voice": "JBFqnCBsd6RMkjVDRZzb",
    "speed": 1.3
  }'

Full Configuration

Customize all available parameters:

curl -X POST https://api.openmind.com/elevenlabs/tts \
  -H "Content-Type: application/json" \
  -H "x-api-key: YOUR_API_KEY" \
  -d '{
    "input": "Fully customized text to speech with all parameters specified.",
    "voice": "your_voice_id",
    "model": "eleven_flash_v2_5",
    "response_format": "mp3_44100_128",
    "speed": 0.9,
    "elevenlabs_api_key": "your_elevenlabs_api_key"
  }'

Save Audio to File

Generate speech and save directly to an MP3 file:

curl -X POST https://api.openmind.com/elevenlabs/tts \
  -H "Content-Type: application/json" \
  -H "x-api-key: YOUR_API_KEY" \
  -d '{
    "input": "This audio will be saved to a file on your local machine."
  }' | jq -r '.response' | base64 -d > output.mp3

With Environment Variables

Store your configuration in environment variables for easier management:

# Set environment variables
export TTS_VOICE_ID="JBFqnCBsd6RMkjVDRZzb"
export TTS_SPEED="1.1"

# Use in request
curl -X POST https://api.openmind.com/elevenlabs/tts \
  -H "Content-Type: application/json" \
  -H "x-api-key: YOUR_API_KEY" \
  -d "{
    \"input\": \"Using environment variables for configuration.\",
    \"voice\": \"$TTS_VOICE_ID\",
    \"speed\": $TTS_SPEED
  }"

Stream to File

Stream the audio directly to a file using the streaming endpoint:

curl -X POST https://api.openmind.com/elevenlabs/tts/audio/speech \
  -H "Content-Type: application/json" \
  -H "x-api-key: YOUR_API_KEY" \
  -d '{
    "input": "This is a streaming response."
  }' > stream_output.mp3

Voice Configuration

Default Voice

The default voice ID is JBFqnCBsd6RMkjVDRZzb. This voice provides clear, natural-sounding English speech suitable for most applications.

Custom Voices

You can use any ElevenLabs voice ID by specifying it in the voice parameter. Visit the ElevenLabs Voice Library to explore available voices.

Speed Control

The speed parameter accepts values between 0.5 (half speed) and 2.0 (double speed):

• 0.5 - 50% slower (more deliberate)

• 1.0 - Normal speed (default)

• 1.5 - 50% faster

• 2.0 - Double speed (maximum)

Output Formats

The default output format is mp3_44100_128. The response_format parameter allows you to specify other formats if needed.

Error Handling

All endpoints follow consistent error response patterns:

HTTP Status Codes

Code	Description
200	Success - Audio generated successfully
400	Bad Request - Missing required fields, invalid JSON, or unsupported format
503	Service Unavailable - ElevenLabs API unavailable or not configured
500	Internal Server Error - Server-side processing error

Error Response Format

{
  "error": "Descriptive error message"
}

Common Error Scenarios

Missing Input Field:

# This will fail - input is required
curl -X POST https://api.openmind.com/elevenlabs/tts \
  -H "Content-Type: application/json" \
  -H "x-api-key: YOUR_API_KEY" \
  -d '{}'

# Response: {"error": "Missing or invalid JSON in request"}

API Key Not Configured: If the server-side ElevenLabs API key is not configured and you don't provide one in the request, you'll receive:

{
  "error": "ElevenLabs API key not configured"
}

Connection Issues: If the service cannot reach the ElevenLabs API:

{
  "error": "Failed to connect to ElevenLabs server",
  "details": "additional error information"
}

Best Practices

Audio Decoding

The API returns base64-encoded audio data. Always decode it before use:

# Decode and save to file
echo "SUQzBAAAAAAAI1RTU0UAAAA..." | base64 -d > audio.mp3

# Or use jq to extract from JSON response
curl ... | jq -r '.response' | base64 -d > audio.mp3

Note: Note the following best practices when using the ElevenLabs TTS API:

• Audio responses are base64-encoded and must be decoded before playback

• The ElevenLabs API key can be configured server-side or provided per-request

• Default voice and model settings are optimized for English speech

• Large text inputs may take longer to process