x402 Skill - Agent Payments Protocol

Native HTTP payments for AI agents using the x402 protocol.

Triggers

•/x402 - Check status, balances
•x402 pay - Pay for a resource
•x402 status - Check payment status
•agent payment, pay agent, micropayment

Overview

x402 is Coinbase's open protocol for HTTP-native payments. When a server returns 402 Payment Required, the client automatically pays and retries.

Flow:

•Request resource → Server returns 402 + payment requirements
•Client creates signed payment payload
•Client retries with PAYMENT-SIGNATURE header
•Server verifies payment via facilitator, returns resource

Client Commands

bash

# Check status
node skills/x402/scripts/x402.js status --keystore <path>

# Pay for a resource (auto-handles 402)
node skills/x402/scripts/x402.js fetch --url <url> --keystore <path>

# Quote a payment (without executing)
node skills/x402/scripts/x402.js quote <url>

# Check payment history
node skills/x402/scripts/x402.js history

Flare Facilitator 🔥

We run a Flare-native x402 facilitator for agent payments using USD₮0.

Starting the Facilitator

bash

# Set facilitator wallet (pays gas)
export FACILITATOR_PRIVATE_KEY=0x...

# Or create key file
echo '{"privateKey":"0x..."}' > skills/x402/facilitator/facilitator-key.json

# Start server
cd skills/x402/facilitator && ./start.sh

# Or with custom port
X402_PORT=3402 node skills/x402/facilitator/server.js

Facilitator Endpoints

Endpoint	Method	Description
`/`	GET	Health check + status
`/requirements`	GET	Payment requirements
`/verify`	POST	Verify payment signature
`/settle`	POST	Execute payment on-chain

Why Flare?

•EIP-3009 native: USD₮0 supports transferWithAuthorization
•Fast finality: ~3 second blocks
•Cheap gas: Fractions of a cent per tx
•Stablecoin ready: USD₮0 is native Tether

Supported Networks

Network	Chain ID	Token	Method
Flare 🔥	14	USD₮0	EIP-3009
Base	8453	USDC	EIP-3009
Ethereum	1	USDC	EIP-3009

Integration Example

javascript

import { wrapFetchWithPaymentFromConfig } from '@x402/fetch';
import { ExactEvmScheme } from '@x402/evm';
import { privateKeyToAccount } from 'viem/accounts';

const account = privateKeyToAccount('0x...');

const x402Fetch = wrapFetchWithPaymentFromConfig(fetch, {
  schemes: [{
    network: 'eip155:14', // Flare
    client: new ExactEvmScheme(account)
  }]
});

// Auto-pays if 402
const response = await x402Fetch('https://api.example.com/paid-endpoint');

Architecture

code

Agent A (payer)
    │ Signs EIP-3009 authorization
    ▼
Resource Server (API)
    │ Verifies via facilitator
    ▼
Flare Facilitator ← We run this!
    │ Settles on-chain (pays gas)
    ▼
Flare Network
    └── USD₮0 transfer

Wallet Gen (for Agents)

Generate EVM wallets for AI agents to participate in x402 payments.

bash

# Generate new wallet
node skills/x402/wallet-gen/scripts/wallet.js gen --name my-agent

# Show wallet address + balance
node skills/x402/wallet-gen/scripts/wallet.js show --name my-agent

# List all wallets
node skills/x402/wallet-gen/scripts/wallet.js list

# Export private key (careful!)
node skills/x402/wallet-gen/scripts/wallet.js export --name my-agent --confirm

See wallet-gen/SKILL.md for full documentation.

Agent Tips (m/payments)

Fee-sharing widget for AI agents. Tip your favorite agents on Moltbook, X, or GitHub.

Location: apps/agent-tips/

Features:

•Multi-chain (Flare + HyperEVM)
•RainbowKit wallet connect
•Pool-funded or wallet-funded tips
•Leaderboard

bash

cd skills/x402/apps/agent-tips
npm install
npm run dev  # http://localhost:3456

References

•x402 Spec: https://github.com/coinbase/x402
•x402.org: https://x402.org
•EIP-3009: https://eips.ethereum.org/EIPS/eip-3009