Installation

The @atomic-rail/usage-gate package is a lightweight, framework-agnostic library for protecting and metering your APIs.

1. Install Package

npm install @atomic-rail/usage-gate

2. Dependencies

The package handles all standard x402 payment logic internally. You do not need to install @x402/core or @x402/next unless you are building custom payment schemes.

3. Environment Variables

You must provide your project credentials to the gate. These are found in the Settings → Security tab of your dashboard.

# .env.local
METER_PROJECT_ID=proj_...
METER_HMAC_SECRET=...

4. Initialization

Create a singleton instance of the gate to share across your app.

import { AtomicGate } from "@atomic-rail/usage-gate";

export const gate = new AtomicGate({
projectId: process.env.METER_PROJECT_ID,
hmacSecret: process.env.METER_HMAC_SECRET,
sellerWallet: "0x...",
debug: process.env.NODE_ENV === "development",
});

5. Troubleshooting

"Invalid Signature"

This means the METER_HMAC_SECRET in your code does not match the one in your dashboard. Rotate the secret in the dashboard and update your environment variables.

"Module not found"

Ensure you are using a Node.js version that supports the standard fetch API (v18+) or a modern runtime like Bun or Deno.