/ Programmable voice CPaaS

Outbound calls at $0.05/min.Agents at $0.06.

Per-second billing. Prepaid wallet. Hard $50/day fraud cap on day one. Card-on-file = $5 credit, never a charge.

Start with $5 credit Read the API →

$~/projects/your-app — curl

Four products. One platform.

Pick what you need. Pay by the second.

Full pricing & carrier fees →

AI Voice Agent

Hosted voice agent, AI compute included.

$0.06per minute

STT + LLM + TTS + telephony. One bill. Sub-second time-to-first-audio.

SIP Trunk

BYO carrier voice, in and out.

$0.05per minute

Plug your own Asterisk / FreeSWITCH / LiveKit / Pipecat into our SIP edge.

Phone Numbers

Buy and route US DIDs in seconds.

$1.50per number / month

Search by area code, attach to a trunk or AI agent, port-out anytime.

[ early access ]

SMS Outbound

Programmable A2P messaging.

$0.012per segment

US 10DLC and Toll-Free, pass-through carrier fees published transparently.

REST + Webhooks

One API for the whole call.

POST a call. Pass an agent_id and we run STT, model, and voice — billed per second. Pass a trunk_id and bridge to your own SIP endpoint instead.

POST /v1/calls
POST /v1/agents
POST /v1/sip-trunks
POST /v1/phone-numbers/buy
POST /v1/verifications

// Node.js (server-side)
import Pstn from 'pstn-node';

const pstn = new Pstn(process.env.PSTN_API_KEY);

const call = await pstn.calls.create({
  to:    '+15558675309',
  from:  '+14155552671',
  agent: 'agent_01HX4P5Q9KZ2',
  metadata: { lead_id: 'lead_2912' },
});

console.log(call.id, call.status);
// → call_01HX4PKQX9V2T6HMEWFYZGTX21 queued

Latency budget

Where the 530ms goes.

Every voice agent is a stack of vendors with their own clocks. Here's ours, broken out so you can audit it.

Carrier ingress → STT first partial

Deepgram Nova-3 streaming, Hillsboro edge.

~180ms p50

STT final → LLM first token

Groq Llama 3.3 70B. No caching tricks.

~140ms p50

LLM first token → TTS first audio out

Cartesia Sonic Turbo, streaming chunks.

~210ms p50

Time-to-first-audio target: ≤ 640ms p50 · ≤ 900ms p95 on a real PSTN handset. Measured weekly. Status published at status.pstn.dev.

$5 on signup

Add a card. Get $5. We don't charge it.

Card-on-file is how we keep burner-email farms out — not how we sneak a first charge in. Auto-recharge is off by default. Hard $0 cutoff when the wallet hits zero.

Place a phone call with one POST.

REST, webhooks, HMAC-signed CDRs. No carrier negotiation. No 60-day net-terms. Just an API key.

Start with $5 credit Read the docs →