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Give your product a voice

Build voice agents for phone calls and apps, with one API key.

From $5 · Billed per second · Bring your own SIP trunk

Front desk agent
0:12
Geminigemini-live
  1. Hi, thanks for calling. How can I help?
  2. Can I come in tomorrow morning?
  3. There’s a slot at 10:30. Shall I book it?
  4. Yes, please.
Cost so far $0.0098$0.0491/min

Works with

  • ModelsGeminiDeepgramElevenLabsSarvamOpenRouter
  • CarriersVonageBandwidthExotel
  • ClientsClaude CodeCursor
Get started

Set up your first agent in four steps

Make the agent and talk to it in your browser. Then pick where it answers.

  1. 1Describe your agent
  2. 2Pick a voice
  3. 3Talk to it in your browser
  4. 4Put it live
Vonage
+1 415 555 0142San Francisco · $1.15 a monthBuy
Example. Billed by your carrier, on your account.

Put it live: a phone number

Paste your carrier keys, pick or buy a number, and call it.

// in the browser
await RealtimeSession.connect(session);

Put it live: your website or app

Your server makes a session and your page talks to the agent.

$ claude mcp add --transport http \
    wixzel-voice \
    https://mcp.voice.wixzel.com/mcp

Put it live: your coding agent

Add the MCP server in one click and ask for the agent.

Live demo

Talk to an agent now

Pick an engine and start talking. It uses your microphone, lasts a minute, and nothing is recorded.

The demo speaks the languages it has an opening line written for. Your own agents can use every language and voice an engine supports: see the full list.

Wixzel Voice demo agent
Gemini Live engine
Ready

Google’s native-audio model, in any of two dozen languages. The quickest replies at the lowest price.

“How is this priced?”“Which engine should I use?”“Pretend you’re a dental clinic receptionist.”

Uses your microphone · 60 seconds · nothing is recorded

Integrations

Your agent can use the apps you already use

Connect an app that hosts an MCP server. The agent calls its tools while the caller is on the line.

33 apps with one-click setup, or any MCP server of your own. Tool calls are free; only the extra model tokens are metered.

Your agent
HubSpotTools the agent can call
+ more

Search contacts, companies and deals, for example by phone number.

MCP server

Add Wixzel Voice to your AI assistant

Connect Claude, ChatGPT, Cursor or any MCP client. Every API endpoint becomes a tool.

1. Copy the server URL

No install link yet. Paste this.

https://mcp.voice.wixzel.com/mcp

2. Add it in ChatGPT

Plugins → Add → Add custom MCP server. Paste the URL, keep OAuth, sign in.

API

Or call the API yourself

REST, plus SDKs for TypeScript and Dart.

import { WixzelVoice } from 'wixzel-voice';
const client = new WixzelVoice({ apiKey: process.env.WIXZEL_API_KEY });

const agent = await client.agents.create({
  name: 'Front desk',
  system_prompt: 'You book appointments for a clinic.',
  opening_message: 'Hi, how can I help?',
  voice: { realtime: { model: 'google/gemini-live' } },
});

// Over the SIP trunk and number you connected
const call = await client.calls.create({
  to: '+14155551234',
  agent_id: agent.id,
});

const { transcript, cost_micros } = await client.calls.retrieve(call.id);
Why Wixzel Voice

One key, your own carrier, and a bill you can read

Every engine on one API key. Calls run on your carrier. Costs are itemised per second.

  • DeepgramElevenLabsclassic$0.0867/min
  • sarvam$0.0623/min
  • Geminigemini-live$0.0491/min
  • DeepgramElevenLabsdeepgram-agent$0.1851/min

One key, every engine

Switch engines by changing one field. No provider accounts.

Your carrier
Wixzel Voice
Your agent

Keep your carrier

Use your numbers, or buy one on your carrier account. No markup.

3-min call · classicExample
  • stt180 s$0.0323
  • llm7.2k tok in$0.0015
  • llm1.4k tok out$0.0012
  • tts2.7k chars$0.1890
  • platform3 min$0.0360
total$0.2601

See what each call cost

Billed per second, with every stage itemized.

Frequently asked questions

How do I get started?

Sign up, describe your agent, pick a voice and talk to it in your browser. Then put it live in one of three ways. Connect your carrier and pick or buy a number, add it to your website or app with an API key, or let Claude Code, Codex or Cursor set it up through the MCP server. Going live needs $5 of credit. Get started

Do I need a SIP trunk?

Only for phone calls. Calls to and from real numbers run over a trunk from your own carrier, and your carrier bills you directly with no markup. For Twilio, Telnyx, Plivo, Vobiz, Vonage and Exotel the console sets the trunk up for you from your carrier's API keys. To put an agent in your website or mobile app instead, there is nothing to connect: your app talks to the agent over a WebSocket. Connecting a trunk

Can I buy a phone number through Wixzel Voice?

Yes, on your own carrier account. Connect Twilio, Telnyx, Plivo, Vobiz or Vonage, then search for a number on the Phone numbers page and buy it there. Your carrier bills you at its own price. Wixzel Voice adds nothing and does not sell numbers itself. The same is in the API as POST /v1/phone-numbers/purchase and in the MCP server. Numbers that need regulatory approval, like Indian ones, use the approved documents already on your carrier account. Buying a number

Can I put an agent in my website or mobile app?

Yes. Your server calls POST /v1/realtime/sessions and gets a one-minute, single-use client secret; your page or app opens wss://api.voice.wixzel.com/v1/realtime with it and streams audio. The TypeScript SDK has a drop-in browser client (wixzel-voice/realtime) and the Dart SDK a protocol client for Flutter. Your API key never reaches the client. Realtime: web and mobile

How are web and app sessions billed?

Exactly like a phone call on the same engine: the same per-minute price, from the same balance, per second. A session counts toward your concurrent-call limit, appears in your call log with channel: "web" and ends with the same callCompleted webhook. There is no telephony cost, because there is no phone line. Billing and records

Do I need accounts with Deepgram, ElevenLabs or OpenRouter?

No. The provider accounts are ours. One wv_live_… key and a credit balance cover every engine, and there is nothing to bring. API keys

How am I billed?

Prepaid. You add credit, calls spend it per second of speech, per token and per character, and you cannot be billed for more than you put in. The minimum top-up is $5. Credits

What happens when credit runs out?

A call that cannot fund its first 15 seconds is refused with a 402 before anything is allocated. Mid-call, at about a minute of runway, the agent warns your caller, then speaks a closing line and hangs up. It does not drop the line mid-sentence. Running out

Can I retry a request safely?

Send an Idempotency-Key. It is required on POST /v1/calls, POST /v1/agents/{id}/test-call and POST /v1/billing/topups, and a replay with the same key and body returns the original response instead of dialling twice. Keys are kept for 24 hours. POST /v1/campaigns/{id}/start takes no key, and starting a stopped campaign dials every lead on it again. Idempotency

Which engines are available?

Today: classic, sarvam, gemini-live, deepgram-agent. GET /v1/engines is the source of truth: an engine whose provider is degraded disappears from that list before your calls start failing. Voice engines

Is there an SDK?

Yes, two official ones: a TypeScript SDK (wixzel-voice on npm) for TypeScript, JavaScript, browsers and edge runtimes, and a Dart SDK (wixzel_voice on pub.dev) for Dart and Flutter. Both cover every endpoint and include a realtime client for talking to an agent from a browser or app, retry rate limits, page through lists and send an idempotency key on the requests that require one. Every other language works against the plain HTTP API and the OpenAPI document, and the integration guide has a fifteen-line client to start from. If you are building with an AI agent, there is also an official MCP server for Claude Code, Codex and Cursor. SDKs

What stage is the product at?

Alpha, and deployed. Behavioural changes ship behind a dated Wixzel-Version header, and an existing key keeps the behaviour it was created with until you pin a newer date. Versioning

Build your first voice agent

Add $5 of credit to start. No subscription, billed per second.