Agent Fuel — Autonomous Payment & Gas Management

Keep your agent running by automatically managing wallet balances, topping up via MoonPay, and paying for x402-enabled APIs.

Prerequisites

1. MoonPay CLI installed and authenticated:

npm install -g @moonpay/cli
mp login

1. A funded wallet (can be created via mp wallet create)

Quick Start

Check Balance

mp wallet balance

Auto Top-Up When Low

When the agent detects low balance (configurable threshold), trigger:

mp buy --amount 20 --currency USDC --chain base

Swap Tokens

mp swap --from ETH --to USDC --amount 0.01 --chain base

x402 Payments

For APIs that return HTTP 402, the agent should:

1. Parse the PAYMENT-REQUIRED header for amount and payment address
2. Sign the payment using the agent wallet
3. Retry the request with PAYMENT-SIGNATURE header
4. Log the transaction

Balance Monitoring

The agent should periodically check balance and act:

IF balance < minBalance:
  IF dailySpend < maxDailySpend:
    mp buy --amount {topUpAmount} --currency USDC
    notify human "⛽ Auto top-up: ${topUpAmount} USDC"
  ELSE:
    notify human "⚠️ Daily spend limit reached. Manual top-up needed."

Configuration

Store in ~/clawd/.secrets/agent-fuel.json:

{
  "chain": "base",
  "currency": "USDC",
  "minBalance": 5.0,
  "topUpAmount": 20.0,
  "maxDailySpend": 100.0,
  "alertThreshold": 2.0,
  "x402Enabled": true,
  "x402MaxPerRequest": 0.10
}

Safety Rules

• NEVER exceed maxDailySpend without human approval
• ALWAYS log transactions with reason
• ALERT human when balance drops below alertThreshold
• PAUSE spending if 3+ top-ups in 1 hour (possible loop)

MoonPay CLI Reference