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, with no code, just an env block. Set it up →

One SDK. Everywhere it runs.

The merchant side needs only a wallet address, never a 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 and it pays itself, within budget.

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