Speech & Sound

Convert text to speech or generate sound effects using ElevenLabs and other providers.

List Voices

Discover available voices before generating speech. Returns both platform preset voices and your custom cloned/designed voices.

Endpoint

GET /api/v1/voices

Query Parameters

Parameter	Type	Description
`provider`	string	Filter by provider (e.g., `"elevenLabs"`, `"google"`)
`language`	string	Filter by language name or code (e.g., `"English"`, `"en-US"`)
`gender`	string	Filter by gender (e.g., `"Female"`, `"Male"`)

Example

curl https://api.kolbo.ai/api/v1/voices?gender=Female \
  -H "X-API-Key: kolbo_live_..."

Response

{
  "success": true,
  "voices": [
    {
      "voice_id": "EXAVITQu4vr4xnSDxMaL",
      "name": "Rachel",
      "provider": "elevenLabs",
      "language": "English",
      "language_code": "en-US",
      "gender": "Female",
      "accent": "American",
      "preview_url": "https://...",
      "styles": ["conversational", "calm"],
      "custom": false
    },
    {
      "voice_id": "custom_abc123",
      "name": "My Cloned Voice",
      "provider": "elevenlabs",
      "language": "auto",
      "language_code": null,
      "gender": null,
      "accent": null,
      "preview_url": null,
      "styles": [],
      "custom": true
    }
  ],
  "count": 152
}

Use the voice_id from this response as the voice parameter in the speech endpoint. You can also pass a voice name (e.g., "Rachel") and the API will resolve it automatically.

Text to Speech

Endpoint

POST /api/v1/generate/speech

Request Body

Field	Type	Required	Description
`text`	string	Yes	Text to convert to speech
`voice`	string	No	Voice ID or name (default: `"Rachel"`)
`model`	string	No	TTS model (default: `"eleven_v3"`)
`language`	string	No	Language code, e.g. `"en-US"`, `"he-IL"` (default: `"en-US"`)

Example

curl -X POST https://api.kolbo.ai/api/v1/generate/speech \
  -H "X-API-Key: kolbo_live_..." \
  -H "Content-Type: application/json" \
  -d '{
    "text": "Welcome to Kolbo AI, the all-in-one creative platform.",
    "voice": "Rachel",
    "language": "en-US"
  }'

Response

Generation Started

{
  "success": true,
  "generation_id": "tts123",
  "type": "speech",
  "model": "eleven_v3",
  "credits_charged": 2,
  "poll_url": "/api/v1/generate/tts123/status",
  "poll_interval_hint": 3
}

Completed Status

{
  "success": true,
  "generation_id": "tts123",
  "state": "completed",
  "progress": 100,
  "result": {
    "urls": ["https://cdn.kolbo.ai/audio/..."],
    "model": "eleven_v3",
    "voice": "Rachel",
    "duration": 4.5
  }
}

Credits

Speech credits are character-based: ceil(text.length / 100) x model.credit

For example, a 250-character text with a model that costs 1 credit per 100 chars: ceil(250 / 100) x 1 = 3 credits.

Sound Effects

Endpoint

POST /api/v1/generate/sound

Request Body

Field	Type	Required	Description
`prompt`	string	Yes	Description of the sound effect
`duration`	number	No	Duration in seconds (omit for auto)

Example

curl -X POST https://api.kolbo.ai/api/v1/generate/sound \
  -H "X-API-Key: kolbo_live_..." \
  -H "Content-Type: application/json" \
  -d '{"prompt": "Thunder clap followed by heavy rain"}'

Response

Generation Started

{
  "success": true,
  "generation_id": "snd123",
  "type": "sound",
  "model": "auto",
  "credits_charged": 5,
  "poll_url": "/api/v1/generate/snd123/status",
  "poll_interval_hint": 5
}

Completed Status

{
  "success": true,
  "generation_id": "snd123",
  "state": "completed",
  "progress": 100,
  "result": {
    "urls": ["https://cdn.kolbo.ai/audio/..."],
    "model": "elevenlabs-sound",
    "duration": 8
  }
}

Tips

Speech generation is fast (5-30 seconds)
Sound effects typically take 5-30 seconds
Both return audio URLs that can be downloaded or streamed

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