Voices API

The Voices API is a set of utility / discovery endpoints. They are read-only helpers and do not consume credits.

What you can do

List supported providers — GET /voices/providers
List a provider’s TTS models — GET /voices/{provider}/models
Search voices across all providers with filtering and pagination — GET /voices
Browse a single provider’s catalog — GET /voices/{provider}
Get a single voice’s metadata + preview MP3 — GET /voices/{provider}/{voiceId}
Buy / import / release Twilio phone numbers — POST /utils/buy-twilio-number, POST /utils/import-twilio-number, POST /utils/twilio/release-number
Repair Twilio webhooks — POST /utils/twilio/check-number
Assign a Twilio number to an agent for SMS — POST /utils/twilio/sync-sms

Supported providers

elevenlabs, deepgram, cartesia, rime-ai, openai, google-cloud, google-live (Gemini Live), ultravox, minimax, playht, azure. Every voice returned across providers is normalized to the same shape:

{
  "voiceId": "21m00Tcm4TlvDq8ikWAM",
  "name": "Rachel",
  "provider": "elevenlabs",
  "previewUrl": "https://...mp3",
  "filters": {
    "accent": "American",
    "gender": "female",
    "useCase": "narration",
    "language": "en"
  }
}

Workspace API keys

Each provider can be used with either:

The platform’s server-side API key (default fallback), or
Your own workspace key — saved under workspaceData.secrets.<KEY_NAME> (e.g. ELEVENLABS_API_KEY, CARTESIA_API_KEY).

GET /voices/providers returns the exact workspaceSecretKey to use for each provider, plus a requiresWorkspaceApiKey flag for providers without a platform fallback.

Filtering & search

The voice listing endpoints (GET /voices and GET /voices/{provider}) all support:

Param	Example	Behavior
`language`	`en` / `en-US` / `English` / `de`	Inclusive match — `en` matches `en-US`, `en-GB`, `English`, etc.
`gender`	`male` / `female` / `neutral`	Case-insensitive; aliases `masculine` / `feminine` / `m` / `f` accepted
`accent`	`american` / `british`	Case-insensitive substring match
`modelId`	`aura-2` / `eleven_multilingual_v2`	Filters voice catalog for providers with model-specific voices
`limit`	`100` (default)	1-500
`offset`	`0` (default)	For pagination
`providers`	`elevenlabs,cartesia` (unified)	Comma-separated provider slugs (unified endpoint only)

API Reference

V3

Message Agent

V2 (Legacy)

What you can do

Supported providers

Workspace API keys

Filtering & search

​What you can do

​Supported providers

​Workspace API keys

​Filtering & search

What you can do

Supported providers

Workspace API keys

Filtering & search