Low-cost AI phone call API, billed per second
The cost of AI phone calls adds up in several places: calls rounded up to the whole minute, a platform fee on top of the model costs, phone minutes resold at a markup, and a monthly plan you pay for even in a quiet month. For developers and agencies who need AI phone calls to cost little and be easy to predict. Wixzel Voice bills per second of actual usage from prepaid credit, with no subscription, no seat price and no minimum monthly spend. The cheapest engine, gemini-live, is $0.0491 per connected minute, and sarvam, built for Indian languages, is $0.0617; both include the orchestration fee. Calls go over your own SIP trunk, so the phone minutes are your carrier's rate with no markup, and every charge is itemised in GET /v1/usage/events.
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How do you build AI phone calls that cost little with Wixzel Voice?
- 01POST /v1/sip-trunks
Connect your carrier account: Twilio, Telnyx, Plivo, Vonage, Bandwidth, Exotel, Vobiz or any SIP provider. Your carrier bills the phone minutes at its own rate. Wixzel Voice does not resell or mark them up.
- 02GET /v1/engines
The live price of every engine per connected minute. gemini-live is the cheapest; sarvam is for Hindi and other Indian languages.
- 03POST /v1/agents
Create the agent on the engine you chose. A short prompt and a short greeting keep calls short, and a call costs only the seconds it lasts.
- 04POST /v1/calls
Place the call. Credit is reserved before it dials and spent per second while it is live, at prices frozen when the call starts.
- 05GET /v1/usage/events
Every charge, itemised: seconds of speech recognised, tokens in and out of the model, characters spoken and the orchestration fee. GET /v1/usage/summary totals a period.
Which voice engine fits a low-cost AI phone call?
Use the gemini-live engine on Wixzel Voice, at $0.0491 per connected minute. It is the cheapest engine per minute, and one realtime model listens, thinks and speaks, so replies come quickly. For callers who speak Hindi, Tamil, Malayalam or another Indian language, the sarvam engine is built for 11 Indian languages end to end.
What does a low-cost AI phone call cost on Wixzel Voice?
Wixzel Voice engine time for 2-minute calls on the gemini-live 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 |
|---|---|---|
| 500 | 1,000 | $49.10 |
| 2,500 | 5,000 | $246 |
| 10,000 | 20,000 | $982 |
Prepaid: add credit from $5 and the calls spend it. Estimate your own mix.
Which guides show how to build AI phone calls that cost little on Wixzel Voice?
Frequently asked questions
What is the cheapest way to run AI phone calls on Wixzel Voice?
What does a three-minute AI phone call cost?
Are calls rounded up to the next minute?
Is there a monthly fee, a plan or a minimum spend?
Are the phone minutes included in the price?
Is there a free tier?
Can Claude or another AI agent place these calls?
What else do developers build on Wixzel Voice?
Build an agent that answers the phone, checks availability and books an appointment, over your own SIP trunk, with the booking written back through the API.
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.
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.
Operator, prices, limits, refunds and data location, on one page.
Build your first voice agent