AI receptionist API for phone appointment booking
Booking calls come in while you are busy with a customer or closed for the day, and a missed call is often a lost booking. For clinics, salons, workshops and any business that takes bookings by phone: an agent on your existing number answers, offers the hours and slot lengths you gave it, and creates the appointment. You pay per second of the call from a prepaid balance; the phone line is your own trunk at carrier cost.
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How do you build an AI appointment-booking agent with Wixzel Voice?
- 01POST /v1/sip-trunks
Connect the trunk your number already lives on and point its inbound route at the platform.
- 02POST /v1/agents
Create the receptionist: a prompt with your services, the hours and slot lengths it may offer, and a voice engine.
- 03GET /v1/appointments
Each booking the agent makes is an appointment you can list, read and cancel through the API.
- 04GET /v1/calls/{id}
Read the status and transcript of every call, and delete the ones you do not need to keep.
Which voice engine fits appointment booking?
Use the classic engine on Wixzel Voice, at $0.0865 per connected minute. English bookings need accurate names and dates; Nova-3 transcription with GPT-6 Luna is the cheapest reliable pairing. Switch the stt language for other languages, or the sarvam engine for Indian ones.
What does appointment booking cost on Wixzel Voice?
Wixzel Voice engine time for 3-minute calls on the classic engine, at typical speech rates, billed per second of actual usage. Telephony is your own trunk at your carrier’s rate and is not included, and shorter calls cost proportionally less.
| Calls per month | Connected minutes | Engine cost per month |
|---|---|---|
| 200 | 600 | $51.90 |
| 1,000 | 3,000 | $260 |
| 5,000 | 15,000 | $1,298 |
Prepaid: add credit from $5 and the calls spend it. Estimate your own mix.
Which guides show how to build an AI appointment-booking agent on Wixzel Voice?
Answer your existing Twilio number with an AI receptionist that books appointments, using a Twilio Elastic SIP trunk and the Wixzel Voice TypeScript SDK.
Four requests to a ringing phone, what a call record returns, and what a call costs.
Twilio, Telnyx, Plivo, Vonage, Bandwidth, Exotel, Vobiz, Mobily or any SIP provider: what to set at the carrier.
Frequently asked questions
Can a Wixzel Voice agent book appointments over the phone?
Can the agent answer calls on my existing phone number?
What does a three-minute booking call cost?
Can the agent hand off to a person?
What else do agencies and developers build on Wixzel Voice?
Upload leads, start a campaign, and have an agent call each one over your own SIP trunk and ask your qualifying questions. Every call is a record with its status and transcript, linked to the lead.
Answer a support number with an agent that reads from a knowledge base you upload, handles the common questions, and leaves a transcript of every call.
Run phone agents in Indian languages on models built for them, with the sarvam engine covering speech-to-text, the language model and text-to-speech end to end.
Put an agent in a browser page, a Flutter app or a kiosk with no SIP trunk and no phone number: your server mints a one-minute session, the app streams audio over a WebSocket, and the session is billed like a call.
Put a talking AI assistant on your website with one script tag: an agent made from your site, with an animated mascot visitors call from the browser, caller details, who-can-call settings and daily caps.
Connect Claude Code, Codex, Cursor or any MCP client to your account, and let an AI agent connect a carrier, build a voice agent, place calls, run campaigns and read transcripts, with every tool that spends money asking first.
Run AI phone calls for a few cents a minute: per-second billing from prepaid credit, no subscription or minimum, your own SIP trunk with no telephony markup, and every charge itemised.
Give a voice agent a face: an animated avatar that lip-syncs to the agent, for a website, a share link, a web app or a Flutter app, with no fee for the avatar.
Build a phone agent for each client on their own account and carrier, in their language, and charge a retainer on a cost billed per second.
Operator, prices, limits, refunds and data location, on one page.
Build your first voice agent