Give your agent a phone line in one POST

Onboard yourself — no key from us

There is no waiting list and no sales call. The agent walks the whole path on its own: it proves who it is, its operator passes KYC once, and from then on it pays for its own calls in USDC. We never hand out credentials by hand.

The whole path in code

from voicegate import VoiceGate, AgentKey

vg  = VoiceGate()                       # no api_key anywhere
key = AgentKey.generate()               # persist key.seed_b64() somewhere safe

reg = vg.kya_register(key, operator_email="ops@example.com", domain="example.com")
# → the operator passes KYC once (Stripe), then:

vc = vg.kya_get_credential(key, reg["agent_id"])
vg.kya_login(key, vc["credential"])     # session token, held by the client

vg.link_wallet(reg["agent_id"], "0x…")  # then send USDC on Base
vg.call(
    to="+14155550123",
    greeting="Hi, this is Ada calling on behalf of Nordwind Studio.",
    prompt="Confirm tomorrow's 3pm appointment.",
)

Quickstart

Install the SDK and place a call. The SDK is open source under MIT and wraps the same REST API documented below.

pip install voicegate        # Python
npm i voicegate              # Node

Python

from voicegate import VoiceGate

vg = VoiceGate(
    api_key="vg_live_...",
    base_url="https://aivoicegate.com",
)

call = vg.call(
    to="+14155550123",
    greeting="Hi, this is Ada calling on behalf of Nordwind Studio.",
    prompt=(
        "You are booking a table for four at 7pm on Friday. "
        "If 7pm is unavailable, accept anything between 6:30pm and 8pm. "
        "Confirm the name Nordwind and thank them."
    ),
    language="en",
    voice="female",
)

print(call["call_uuid"], call["rate_micros_per_min"])

Node

import { VoiceGate } from "voicegate";

const vg = new VoiceGate({
  apiKey: process.env.VOICEGATE_API_KEY,
  baseUrl: "https://aivoicegate.com",
});

const call = await vg.call({
  to: "+14155550123",
  greeting: "Hi, this is Ada calling on behalf of Nordwind Studio.",
  prompt: "You are booking a table for four at 7pm on Friday.",
  language: "en",
  voice: "female",
});

console.log(call.call_uuid, call.rate_micros_per_min);

Plain HTTP

curl -X POST https://aivoicegate.com/v1/agent-call \
  -H "x-api-key: vg_live_..." \
  -H "content-type: application/json" \
  -d '{
    "to": "+14155550123",
    "greeting": "Hi, this is Ada calling on behalf of Nordwind Studio.",
    "prompt": "You are booking a table for four at 7pm on Friday.",
    "language": "en",
    "voice": "female"
  }'

Authentication

Every endpoint except discovery, registration and public identity lookups requires an API key in the x-api-key header. Base URL:

https://aivoicegate.com/v1

Place a call

Places a real outbound call over our own telephony. The greeting is spoken as soon as the line connects; from then on VoiceGate transcribes the other side, feeds it to the agent brain, and speaks the reply — turn by turn, until either side hangs up.

Body

Response 200

{
  "status": "calling",
  "call_uuid": "8f3c1e6a-...",
  "channel": "single",
  "billed": "per-minute",
  "hold_micros": 600000,
  "rate_micros_per_min": 60000,
  "destination_region": "US/Canada (NANP)"
}

hold_micros is what was reserved for the maximum call length, not what you will pay. rate_micros_per_min is in millionths of a USDC: 60000 means $0.06 per minute. The final charge lands on the balance when the call ends.

Discovery and x402

A GET on the paid resource returns 402 Payment Required with x402 v2 payment requirements — the price, the asset, the chain and the address to pay. An agent that has never seen VoiceGate can discover the cost and settle without a human, and x402 indexes can list the resource without holding a key.

{
  "x402Version": 1,
  "error": "payment required",
  "accepts": [{
    "scheme": "exact",
    "network": "eip155:8453",
    "amount": "60000",
    "asset": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913",
    "payTo": "0x...",
    "resource": "https://aivoicegate.com/v1/agent-call",
    "description": "VoiceGate outbound call, prepaid per minute",
    "maxTimeoutSeconds": 120,
    "extra": { "name": "USD Coin", "version": "2" }
  }],
  "resource": { "url": "...", "description": "...", "mimeType": "application/json" }
}

The asset is native USDC on Base (6 decimals) and amount is in atomic units, so 60000 is $0.06. A 402 from the POST endpoint carries the same structure with the amount needed for that specific call.

Balance, wallet and history

Current balance, what is on hold, and the terms the account is charged under.

{
  "agent_id": "…",
  "balance_micros": 970000,
  "held_micros": 0,
  "available_micros": 970000,
  "balance_usdc": 0.97,
  "daily_cap_micros": 5000000,
  "daily_spent_micros": 30000,
  "rate_micros_per_min": 60000,
  "max_call_seconds": 600,
  "pay_to": "0x…"
}

available_micros is balance minus holds — that is what a new call is checked against. pay_to is where to send USDC to top up.

Links a Base address to the agent. Incoming USDC from that address credits this agent's balance automatically. Body: {"wallet_address": "0x…"} — a 40-hex-digit address. Without this link a transfer still arrives at our address but cannot be attributed to you, so link the wallet before sending anything.

Append-only ledger for the account: topup, hold, release, charge, refund, adjust. Every entry carries an amount in micro-USDC, a timestamp and a reference — for a top-up, the on-chain transaction hash.

Agent identity (KYA)

Registers an agent and its operator. Returns an agent_id with kyc_status: "pending". All fields are optional, but an agent with a public key and a registration URI can later prove who it is instead of just holding a secret.

curl -X POST https://aivoicegate.com/v1/agents/register \
  -H "content-type: application/json" \
  -d '{
    "operator_email": "ops@example.com",
    "operator_kind": "business",
    "domain": "example.com",
    "public_key": "z6Mk…",
    "registration_uri": "https://example.com/.well-known/agent.json",
    "erc8004_agent_id": "…"
  }'

Public trust lookup: KYC status, reputation and whether the agent is banned. Anyone can call it — that is the point. The party on the other end of a call should be able to check who is calling.

How billing actually works

Money is held in micro-USDC — millionths of a dollar — because per-second billing at $0.06 a minute produces fractions of a cent, and a two-decimal column loses them.

The lifecycle of one call

A daily spending cap applies per agent (default $5/day during beta) as a blast radius limit: a looping agent burns its cap, not your whole balance.

Coverage and rates

VoiceGate is deny-by-default. A destination that is not explicitly allowed is refused with 403 before any money moves or any line opens.

More countries open as carrier verification completes. If you need a specific destination, ask — the list is a policy table, not a technical limit.

Errors

Errors are JSON with a stable error code. Read the code, not the prose.

Rate limits

Every 429 carries a Retry-After header. Respect it; retrying into a limit only extends it.

Acceptable use

VoiceGate is a narrow, clean service and stays that way on purpose.

Allowed: consented task calls, bookings and scheduling, status and availability checks, expected callbacks.

Not allowed: cold mass-calling without consent, deceptive impersonation of a person or company, fraud or pressure scenarios, calls to purchased lists. Agents doing this lose the line and carry the record on their portable reputation.

Need a destination that is not open yet, or an integrator key for many agents? Tell us what you need →. For anything else: support@aivoicegate.com.