Agentic Commerce
The protocol for machine-to-machine money.
x402 is an open standard for autonomous AI agent payments — fractions of a penny per transaction, settled in stablecoins, no card network required.
Protocol
Payments without accounts.
AI agents pay APIs directly. No API keys, no OAuth, no human in the loop.
An agent hits an endpoint, gets back 402 Payment Required with a machine-readable header,
signs a USDC transfer on Base, and retries. Done.
// 1. Standard GET — no auth headers
const res = await fetch('https://api.stable402.com/gate');
// 2. Decode the 402's PAYMENT-REQUIRED header
if (res.status === 402) {
const header = res.headers.get('PAYMENT-REQUIRED');
const { accepts } = JSON.parse(atob(header));
// → scheme, network, amount, payTo, asset
}
// 3. Sign EIP-3009 transfer, retry with PAYMENT-SIGNATUREReference architecture
Protocol deep dives.
Interactive visualizations mapping each protocol across the payment lifecycle — from intent through on-chain finality.
x402 Lifecycle
How x402 maps to the payment lifecycle.
Stage-by-stage walkthrough with code snippets, compliance stack diagram, and protocol comparison.
Protocol Matrix
Four protocols. Eight stages. One map.
Compare x402, ACP, AP2, and ACK across the full lifecycle — see where they converge and diverge.
ACK Journey
How autonomous agents pay.
Agent identity, negotiation, and settlement — ACK extends x402 for agentic commerce.
Build sequence
Demos.
Every POC ships on Cloudflare Workers, documented as a newsletter issue. Engineering, product, and compliance teams shipping agentic commerce.
The platform
Three sites. One infrastructure.
Stable402 is the implementation layer. StablecoinAtlas maps it. StableKYA handles compliance.
StablecoinAtlas
Physical, logical, and visual diagrams of the stablecoin infrastructure layer. The transit map.
Stable402
This site. Live x402 implementations on Cloudflare Workers. Reference code for agentic payments.
StableKYA
KYA framework, credential architecture, regulatory calendar. Know Your Agent.