Generate Audio (Legacy API) - Hedra

Note: The Hedra v3 API is now available. This guide covers the legacy API and is maintained for existing integrations. For new projects, get started with the Developer Platform →

All examples use the base URL https://api.hedra.com/web-app/public and require an X-API-Key header.

export HEDRA_API_KEY="your_api_key"

Step 1: Pick a voice

List available voices:

curl https://api.hedra.com/web-app/public/voices \
  -H "X-API-Key: $HEDRA_API_KEY"

Step 2: Generate speech

curl -X POST https://api.hedra.com/web-app/public/generations \
  -H "Content-Type: application/json" \
  -H "X-API-Key: $HEDRA_API_KEY" \
  -d '{
    "type": "text_to_speech",
    "voice_id": "f412c62f-e94f-41c0-bfc6-97f63289941c",
    "text": "Hello, welcome to Hedra! This is an example of text-to-speech generation.",
    "stability": 0.5,
    "speed": 1.0,
    "language": "English"
  }'

Required fields

Field	Description
`type`	Set to `"text_to_speech"`
`voice_id`	The voice to use (from `GET /voices`)
`text`	The text to convert to speech

Optional fields

Field	Description
`stability`	`0.0` (most stable) to `1.0` (most variable). Default: `1.0`
`speed`	`0.7` (slowest) to `1.2` (fastest). Default: `1.0`
`language`	e.g. `"English"`, `"Spanish"`, `"French"`, `"Japanese"`. Default: `"auto"`

Step 3: Poll for completion

curl https://api.hedra.com/web-app/public/generations/{generation_id}/status \
  -H "X-API-Key: $HEDRA_API_KEY"

When status is "complete", the response includes an asset_id for the generated audio file.

The public generation endpoint currently supports image, video, and text-to-speech requests. Voice cloning is not available through this endpoint.

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