# Configuration Reference All call-related settings can be managed via `assistant config`: | Setting | Description | Default | | ------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------- | | `calls.enabled` | Master switch for the calling feature | `true` | | `calls.provider` | Voice provider (currently only `twilio`) | `twilio` | | `calls.maxDurationSeconds` | Maximum call length in seconds | `3600` (1 hour) | | `calls.userConsultTimeoutSeconds` | How long to wait for user answers | `120` (2 min) | | `calls.disclosure.enabled` | Whether the AI announces itself at call start | `true` | | `calls.disclosure.text` | The disclosure message spoken at call start | `"At the very beginning of the call, introduce yourself as an assistant calling on behalf of my human."` | | `llm.callSites.callAgent.model` | Override LLM model for call orchestration | _(unset — falls back to the resolved call-site default)_ | | `calls.callerIdentity.allowPerCallOverride` | Allow per-call caller identity selection | `true` | | `calls.callerIdentity.userNumber` | E.164 phone number for user-number mode | _(empty)_ | | `services.stt.language` | Spoken language for transcription (BCP-47 code, or unset for the provider's multilingual default). Per-language TTS voices are configured via `services.tts.providers..languageVoices` (supported on the elevenlabs, deepgram, and vellum provider blocks). | _(unset)_ | | `services.stt.provider` | STT provider for transcription and telephony. The assistant transcribes call audio itself over the Twilio media stream (streaming when the provider supports it, batch otherwise), so calls require a working API key for this provider. | `deepgram` | | `services.tts.provider` | Active TTS provider for speech synthesis. Must be a provider ID from the catalog (`elevenlabs`, `fish-audio`, `deepgram`, `xai`). New providers can be added via the catalog without code changes to call routing. | `elevenlabs` | | `services.tts.providers..*` | Provider-specific settings block. Each catalog provider has its own settings namespace under `services.tts.providers.`. See voice settings in the desktop/iOS app or run `assistant config list` for available settings per provider. | _(per-provider defaults)_ | ## TTS provider call-path behavior During phone calls the assistant synthesizes audio server-side via the configured provider's API, transcodes it to mu-law, and streams it to Twilio over the media stream. Each provider's catalog entry declares its playback format: | Provider | Playback format | Description | | ------------ | --------------- | ------------------------------------------------------------------------------------------------ | | `elevenlabs` | `pcm` | Synthesizes PCM audio via the ElevenLabs API. | | `fish-audio` | `wav` | Synthesizes WAV audio via Fish Audio's HTTP API. Requires a configured `referenceId`. | | `deepgram` | `pcm` | Synthesizes PCM audio via Deepgram's HTTP API. Uses the same API key as Deepgram speech-to-text. | | `xai` | `pcm` | Streams PCM audio via xAI's WebSocket endpoint. | Calls require a media-stream-playable TTS provider with a working API key. When the configured provider is not playable (unsupported format or missing credentials), the assistant falls back to a credentialed playable provider rather than letting the call go silent; if none exists, calls are blocked up front with a setup-required message. ## Adjusting settings ```bash # Increase max call duration to 2 hours assistant config set calls.maxDurationSeconds 7200 # Disable AI disclosure (check local regulations first) assistant config set calls.disclosure.enabled false # Custom disclosure message assistant config set calls.disclosure.text "Just so you know, this is an assistant calling on behalf of my human." # Give more time for user consultation assistant config set calls.userConsultTimeoutSeconds 300 ``` # Call Quality Tips When crafting tasks for the AI voice agent, follow these guidelines for the best call experience: ## Writing good task descriptions - **Be specific about the objective**: "Make a dinner reservation for 2 at 7pm tonight" is better than "Call the restaurant" - **Include relevant context**: Names, account numbers, appointment details - anything the agent might need - **Specify what information to collect**: "Ask about their return policy and store hours" tells the agent what to gather - **Set clear completion criteria**: The agent knows to end the call when the task is fulfilled ## Providing context The `context` field is powerful - use it to give the agent background that helps it sound natural: - User's name and identifying details (for making appointments, verifying accounts) - Preferences and constraints (dietary restrictions, budget limits, scheduling conflicts) - Previous interaction history ("I called last week and spoke with Sarah about...") - Special instructions ("If they put you on hold for more than 5 minutes, hang up and we'll try again later") ## Things the AI voice agent handles well **Outbound calls:** - Making reservations and appointments - Checking business hours, availability, or pricing - Confirming or rescheduling existing appointments - Gathering information (store policies, product availability) - Simple customer service interactions - Leaving voicemails (it will speak the message if voicemail picks up) **Inbound calls:** - Answering as a receptionist and routing caller requests to the user via ASK_GUARDIAN - Taking messages when the user is unavailable - Answering questions the assistant already knows from memory/context - Screening calls with guardian voice verification ## Things to be aware of - Calls have a maximum duration (configurable via `calls.maxDurationSeconds`, default: 1 hour) - The agent gives a 2-minute warning before the time limit - Emergency numbers (911, 112, 999, etc.) are blocked and cannot be called - The AI disclosure setting (`calls.disclosure.enabled`) controls whether the agent announces it's an AI at the start of the call