Voice Assistant
Handle phone calls with AI-powered voice agents
Overview
Happ's Voice Assistant handles inbound phone calls with AI. Customers call your phone number and speak with a voice agent that answers questions, takes bookings, and performs actions through natural voice conversation.
How It Works
- A customer calls your connected SIP phone number
- The voice assistant answers with a greeting (the assistant's
firstMessage) - The caller speaks naturally — real-time speech-to-text processes their input
- The AI generates a response based on prompt, knowledge, and tools
- Text-to-speech converts the response to natural speech
- The assistant can call tools during the call (bookings, lookups, CRM updates)
- After the call ends, post-call webhooks can trigger follow-up actions
Requirements
- A SIP-compatible phone number from a supported telephony provider
- An AI assistant configured for voice (voice, audio format, timing settings)
- An AI provider integration (OpenAI, Claude, etc.)
- Optional: ElevenLabs for premium voice quality
Quick Start
- Set up a phone number with SIP credentials
- Configure your assistant's voice settings (voice selection, eagerness, audio format)
- Connect a telephony provider integration
- Call the phone number to test
Key Features
Natural Conversation
Real-time speech recognition and synthesis. Configure response speed with eagerness settings:
| Setting | Behavior |
|---|---|
| Eager | Responds quickly, best for simple Q&A |
| Normal | Balanced timing (default) |
| Patient | Waits longer, best for complex questions |
Multiple Voices
Choose from 30 built-in voices or use ElevenLabs premium voices with multiple languages and accents.
Tool Execution During Calls
The assistant can call webhook tools during live calls — make bookings, look up data, update CRM records. Configure tool call sounds (elevator bells, typing) for audio feedback while the caller waits.
Post-Call Webhooks
Use webhook_postcall tools to trigger actions after calls end — save summaries, update CRM, send follow-up messages.
Human Handoff
The AI can transfer calls to a human using the built-in turnOffAiMode tool. Combined with Telegram Push Notifications, your team gets instant alerts.
Call Recording & Transcription
Automatic call recording and transcription (when configured with your telephony provider).
Supported Audio Codecs
| Codec | Use Case |
|---|---|
| A-law (default) | Standard international telephony |
| μ-law | Standard North American telephony |
Both codecs operate at 8000 Hz, matching standard phone call quality.
Next Steps
- Set up a phone number — Configure SIP credentials
- Telephony providers — Binotel, Ringostat, Phonet, Unitalk, ElevenLabs
- Configure tools — Add actions the voice assistant can perform during calls