PipRail
Live · running in your browser right now

See it work.
No install required.

This page loaded @piprail/sdk from a CDN — nothing installed. Build a real 402 Payment Required challenge below and watch an agent price it. The same one line runs on any server.

⏳ loading @piprail/sdk from jsDelivr…

402 what the merchant serves — built in-browser 
click “Run the 402 loop” →
🤖 what the paying agent sees — read from the 402
…then the agent prices it here.

No keys, no server, no network calls — the gate builds the challenge from your address and the client prices it, both in your browser. EVM, Solana, Sui & NEAR run live here; the full 29 chains run the same one line on a server.

Live on Base mainnet

That was a simulation. Here's a real one.

piprail.com/x402/demo is a real 402 Payment Required endpoint — pay $0.01 USDC on Base to unlock it. It speaks both rails, so any x402 client can pay: PipRail's backendless onchain-proof, or the standard exact scheme (settled gaslessly via a facilitator we don't run). Listed on x402scan and 402 Index.

402 see the live challenge 
curl -i https://piprail.com/x402/demo
Using Claude Desktop, Cursor, or Windsurf? The same payment logic runs via @piprail/mcp — no code, just an env block. Set it up →

One SDK. Everywhere it runs.

The merchant side needs only a wallet address — no key — so it gates a route anywhere. The payer side signs with a wallet. The same one line runs on a server and in the browser.

Take payments

requirePayment / createPaymentGate — address only, no key

Server ✓ works
Browser ✓ works

Make payments

PipRailClient — quote, estimate, pay

Server ✓ works
Browser ✓ works

Settle a real on-chain payment

sign → broadcast → confirm → verify

Server ✓ works
Browser ✓ works

The easiest universal payment rail for the agent economy.

Ten chain families, one line, no backend, no fee. Drop it into a server, an edge function, or a plain HTML page.

29 chains, one word

EVM ×20 + Solana, TON, Tron, NEAR, Sui, Aptos, Algorand, Stellar, XRPL. Native coin or stablecoin, everywhere.

No backend, no fee

Self-custodial — payments settle straight to your wallet, verified against your own RPC. We never touch the funds.

Server or browser

Runs headless or client-side from a CDN. A single HTML page can take or make payments.

Built for agents

Spend budgets, an approval hook, and LLM tools. Point an agent at a paid URL — it pays itself, within budget.

Read the docs Copy the HTML example Partner or fund a chain