NEWRealtime voice API, now with barge-in

Give your product a voice people trust.

Murmur is the realtime API for voice agents that listen, think and speak like people. Ship one in an afternoon.

Start building free

Hear the voices

ReadyLIVE DEMO

Hi, can you move my delivery to Friday?

Of course. Would you like Friday morning or afternoon?

Platform

From hello to done in under a second.

One streaming pipeline handles the whole turn, so your agent answers while the caller is still finishing their thought.

Listen

Streaming STT

Hears every word as it's spoken, through accents and background noise.

Understand

Any LLM

Bring your own model or use ours, with your instructions and knowledge.

Act

Tool calls

Books, looks up and updates your systems mid-sentence.

Speak

Expressive TTS

Replies in a natural voice that pauses, laughs and changes pace.

Full turn · Fast enough to feel human

Voice library

Pick a voice. Or design your own.

Every voice is tuned for live conversation, not narration. Press play to hear how each one handles a real line.

Nova

Warm · conversational

Hi there, thanks for calling. How can I help you today?

AmericanSupport

Atlas

Calm · assured

I can see the payment came through this morning. You're all set.

BritishFinance

Iris

Bright · upbeat

Great news, your order shipped today and arrives Thursday.

AustralianRetail

Kai

Easygoing · friendly

Table for four at eight? Easy. I'll see you then.

AmericanHospitality

Sage

Soft · reassuring

No need to worry. Let's find a time that works for you.

CanadianHealthcare

Rhea

Crisp · professional

I've forwarded the contract and booked a call with your account lead.

Indian EnglishB2B

Capabilities

Everything it takes to sound human.

Barge-in that feels natural

Callers can cut in any time. The agent stops, listens and picks up where it makes sense.

Agent

Caller

The agent yields the moment the caller speaks.AGENT YIELDED · 40MS

Speaks 30+ languages

Detects the caller's language and switches mid-call.

Calls your tools

Define functions once. The agent calls them while it talks.

CALLING…

Guardrails built in

Keep every call on-brand and on-policy.

Redact card numbers
Stay on topic
Escalate to a human

See every conversation

Transcripts, outcomes and trends in one dashboard.

0+%calls resolved without a human

Developers

Ten lines to a phone agent.

SDKs for Node and Python, plus a WebSocket API
Phone, web and in-app calls from one agent
Bring your own LLM, voice or telephony

Get an API key

1import { Murmur } from "murmur";23const murmur = new Murmur();4const agent = await murmur.agents.create({5  voice: "nova",6  instructions: "You are the front desk for Bright Dental.",7  tools: [bookSlot, findPatient],8  interruptions: true,9});1011// Answer calls on a real number12await agent.phone.connect("+1 555 0100");

Pricing

Pay per minute. Nothing else.

Drag to estimate your monthly bill. Volume discounts apply automatically.

Minutes of conversation per month20,000

$1,400/ month

Rate: $0.07 / min
Talk time: 333 hrs

Every plan includes

All voices and languages
Phone numbers and web calling
Tool calls and guardrails
Transcripts and analytics

Start with 60 free minutes

FAQ

Good questions.

Yes. Point Murmur at any model endpoint, or use the built-in model. Listening, speaking and turn-taking stay the same either way.

Yes. Buy a number in the dashboard, port your own, or connect your existing SIP provider.

The agent listens while it speaks. When the caller starts talking it stops, keeps what it already said in context and responds to the new input.

Audio and transcripts are encrypted in transit and at rest. You choose the retention period, and can turn recording off entirely.

Say hello.

Your first voice agent is ten lines and one afternoon away.

Start building free

Read the docs

murmur

The realtime API for voice agents.

Product