Payment infrastructure for
autonomous agents.
A settlement rail built for software that needs to transact on its own — HTTP 402-native micropayments, instant cross-chain settlement, and zero key custody. No signup standing between an agent and the API it just discovered.
Built as one rail.
Same chain coverage, same compliance layer, same SDKs — whether you're publishing an API for agents to discover, settling x402 calls from your backend, or moving funds privately between accounts.
Monetize your API in
one line of code.
List endpoints, charge per call, accept USDC across every chain x402 supports. No subscriptions, no API keys to manage, no billing logic in your stack — the client signs each call and the facilitator settles instantly.
- Pay-per-call with native USDC settlement
- Solana, Base, SKALE, Avalanche, Polygon, SEI, peaq
- AI agent-native: x402 client + Anthropic SDK plug-in
relai:quote:eyJ2IjoxLCJxIjoicV9tb2tqMnpiMV9WSXZPSk43Y2hKY01OM3FiIi…Pay privately.
Settle on chain.
Shielded links for buyer-initiated push. Shielded payment requests for seller-initiated invoicing. Stealth recipients, end-to-end encrypted receipts, atomic clawback prevention — without the wallet-graph leak.
- Privacy Pools + ASP compliance baked in
- Encrypted proof URLs — leak ⇒ ciphertext only
- Stealth recipients on redeem (Solana + EVM)
One line.
Any endpoint paid.
Drop our middleware into any Express / Hono / Fastify app and any route becomes a paid resource. We validate the x402 payment header, settle USDC across every chain we support, and pass the call through to your handler. Zero wallets in your stack.
- 1-line install, framework-agnostic
- Multi-chain settlement out of the box
- Sponsored gas on Solana via fee-payer
server.tsimport { relai } from "@relai-fi/x402"
app.use({
price: "0.01", // $0.01 USDC per call
network: "base-sepolia",
facilitator: relai.facilitator,
})
app.get("/data", (req, res) => {
res.json({ data: "…" })
})X-PAYMENT.Built for the agent economy.
Autonomous agents transact at machine speed. They need micropayments without subscriptions, privacy without losing audit trail, and SDKs that work without a human in the loop. Everything we ship — marketplace, payments, facilitator — answers to that.
Pick a path. Ship in minutes.
List your API, issue a private invoice, or wire x402 into your existing stack. One set of credentials, zero custody, instant cross-chain settlement.