---
title: What is Agent Number — Concepts
description: A persistent US mobile number for an AI agent, issued by REALLY. Same number for SMS and voice.
url: https://agentnumber.really.com/docs/concepts/what-is-agent-number
doc_version: "1.0.0"
last_updated: "2026-05-15"
---

> ## Documentation index
> Fetch the complete documentation index at: https://agentnumber.really.com/llms.txt
> Use this file to discover all available pages before exploring further.

# What is Agent Number

> A persistent US mobile phone number for an AI agent, issued by REALLY (a real wireless carrier). Same number for SMS and voice. Pay once in USDC; your wallet is the account.

## What you actually get

- A real cellular phone number on US wireless spectrum — not VOIP, not Twilio-resold.
- Inbound + outbound SMS via REST or MCP.
- Inbound + outbound voice via WebSocket (16 kHz mono PCM).
- A bearer token, recoverable any time by signing a nonce with the paying wallet.
- One year of unlimited use. Renew with the same wallet to keep the number.

## Why "real cellular" matters

Most "phone number for an AI" services are VOIP wrappers. Two-factor codes don't deliver. Carriers downstream block or rate-limit them. Agent Number issues genuine US mobile numbers — the kind a person carries — so two-factor codes deliver, voice calls work end-to-end, and downstream services treat them like real consumer lines, because they are.

## Pricing

**$1800 USDC per year.** Unlimited SMS + voice. No per-message or per-minute charges. Pay via x402 (Coinbase-verified, Base) or MPP (Tempo) — see [Payment](/docs/payment).

## Where to go next

- [Data model](/docs/concepts/data-model) — the words we use (numbers, subscriptions, tokens) and what they mean
- [SMS vs voice](/docs/concepts/sms-vs-voice) — which channel does what
- [Quickstart](/docs/quickstart) — zero to a working number in four `curl` calls

---

## Sitemap

- [Overview](/docs/)
- [Quickstart](/docs/quickstart)
- [Authentication](/docs/auth)
- [SMS](/docs/sms)
- [Voice](/docs/voice)
- [MCP](/docs/mcp)
- [Payment](/docs/payment)

See the full [sitemap.md](/sitemap.md) for the complete index of docs pages.