Providers - TurnCall

TurnCall supports multiple providers for each stage of the voice pipeline. Configure them per-agent.

Provider Matrix

Role	Providers
STT	`deepgram` (default, streaming), `openai`, `elevenlabs`, `cartesia` (Ink, streaming)
LLM	`openai` (default), `anthropic` (Claude), `ollama` (local), `custom_openai` (any OpenAI-compatible), `openrouter` (multi-model + fallback routing, voice only)
TTS	`deepgram` (default), `openai`, `elevenlabs`, `cartesia` (Sonic-3, streaming, 60+ emotions)
S2S	`openai` (Realtime API — optional `base_url` targets an OpenAI-Realtime gateway like Vercel AI Gateway / LiteLLM / xAI, e.g. Grok), `google` (Gemini Live)

STT Configuration

"stt": {"provider": "deepgram", "model": "nova-2", "language": "en"}

"stt": {"provider": "openai", "model": "whisper-1"}

"stt": {"provider": "elevenlabs"}

"stt": {"provider": "cartesia"}

LLM Configuration

"llm": {"provider": "openai", "model": "gpt-4o-mini"}

"llm": {"provider": "anthropic", "model": "claude-sonnet-4-20250514"}

"llm": {"provider": "ollama", "model": "gemma3:12b"}

"llm": {
  "provider": "custom_openai",
  "model": "meta-llama/Llama-3-70b",
  "base_url": "https://api.together.xyz/v1",
  "api_key": "your-key"
}

"llm": {
  "provider": "openrouter",
  "model": "anthropic/claude-3.5-sonnet",
  "fallback_models": ["openai/gpt-4o", "google/gemini-flash-1.5"]
}

OpenRouter routes through openrouter.ai with automatic failover — if the primary model rate-limits or errors mid-call, it falls over to the next model in fallback_models. Voice only (WebRTC / Twilio / WhatsApp voice); not supported on the SMS/Chat text path. The model that answered each turn is recorded on transcript.final events.

LLM Options

Field	Required	Description
`provider`	Yes	`openai`, `anthropic`, `ollama`, `custom_openai`, or `openrouter`
`model`	Yes	Model name
`base_url`	For `custom_openai`	OpenAI-compatible API base URL
`api_key`	No	API key for `custom_openai` (masked in responses)
`fallback_models`	For `openrouter`	Ordered list of fallback models (voice only)
`temperature`	No	0.0–2.0 (default: 0.7)
`max_tokens`	No	1–128000 (default: 1024)

TTS Configuration

"tts": {"provider": "deepgram", "voice": "aura-2-helena-en"}

"tts": {"provider": "openai", "voice": "alloy"}

"tts": {"provider": "elevenlabs", "voice": "rachel"}

"tts": {"provider": "cartesia", "voice": "sonic-english-female"}

Required API Keys

Provider	Environment Variable
Deepgram	`DEEPGRAM_API_KEY`
OpenAI	`OPENAI_API_KEY`
Anthropic	`ANTHROPIC_API_KEY`
ElevenLabs	`ELEVENLABS_API_KEY`
Cartesia	`CARTESIA_API_KEY`
Google (Gemini)	`GOOGLE_API_KEY`
OpenRouter	`OPENROUTER_API_KEY`
HeyGen (video avatar)	`HEYGEN_LIVE_AVATAR_API_KEY`
Tavus (video avatar)	`TAVUS_API_KEY`

Ollama requires no API key — just install it locally and run ollama pull <model>.