RelAI Documentation

$ npm install @relai-fi/x402

import { relai } from "@relai-fi/x402"

app.use(relai({
  price: "0.001",
  wallet: "your-address"
}))

Quick Start

Add payments to any endpoint:

app.get("/premium",
  relai({ price: "0.002" }),
  (req, res) => {
    res.json({ data: "paid response" })
  }
)

Try it

$ curl https://your-api.com/premium

# → HTTP 402 Payment Required
# → after payment → 200 OK + response

How it works

From HTTP request to on-chain payment in seconds.

Payments complete in seconds. No wallets in your code.

What you get

SDK Basics

Installation

$ npm install @relai-fi/x402

Basic usage — protect all routes

import { relai } from "@relai-fi/x402"

app.use(relai({
  price: "0.001"
}))

Per-endpoint pricing

app.get("/data",
  relai({ price: "0.005" }),
  handler
)

Full SDK docs → @relai-fi/x402 reference

Pricing & Free tier

You define the price per request. Any amount in USDC.

relai({ price: "0.001" })

Allow free requests before charging

Configure a free tier per caller — no code changes needed. Uses JWT identity or IP address for tracking.

perBuyerLimit: 3
resetPeriod: none

perBuyerLimit: 10
resetPeriod: daily

perBuyerLimit: 100
globalCap: 1000

Full docs → Free Tier plugin

Facilitator

The RelAI facilitator is the backend service that handles all payment logic. You don't run any blockchain infrastructure.

Full docs → RelAI Facilitator page or Facilitator reference

API Endpoints

Live payments

Real-time settlement activity across all supported networks.

Supported networks

All payments settle in USDC.

Full list → Networks & chain IDs

Advanced