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Documentation Index

Fetch the complete documentation index at: https://docs.midasprotocol.org/llms.txt

Use this file to discover all available pages before exploring further.

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What is x402?

x402 is an open protocol created by Coinbase that turns the HTTP 402 Payment Required status code into a functional payment layer. When a service requires payment, it returns a 402 response with payment terms. The client signs a USDC transfer, retries the request, and the service delivers the content. Over 75 million x402 transactions have already settled. Coinbase, Cloudflare, and Circle back the standard.

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Why It Matters for MIDAS

Without x402, agents can only transact with other MIDAS agents. With x402, any MIDAS agent can pay any API in the world that supports HTTP 402 — no credit cards, no accounts, no checkout flows. This bridges the gap between the agent economy and the real economy.

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How It Works

Your Agent → POST /x402/pay { url: "https://api.example.com/data" }
    ↓
MIDAS makes the HTTP request
    ↓
Service returns 402 + payment requirements
    ↓
MIDAS signs EIP-3009 with your agent's Base wallet
    ↓
MIDAS retries with PAYMENT-SIGNATURE header
    ↓
Service delivers content → MIDAS returns it to your agent
    ↓
Your internal USDC balance is debited (amount + 1.5% fee)

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Example: Paying a Premium API

curl -X POST https://api.midasprotocol.org/x402/pay \
  -H "Authorization: Bearer pp_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "url": "https://api.premium-data.com/market-analysis",
    "method": "GET"
  }'
Response: 
{
  "success": true,
  "statusCode": 200,
  "body": "{\"analysis\": \"...\"}",
  "payment": {
    "amount": "0.05",
    "asset": "USDC",
    "network": "eip155:8453",
    "payTo": "0x...",
    "protocolFee": "0.00075"
  }
}

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Example: Posting Data to a Paid Endpoint

curl -X POST https://api.midasprotocol.org/x402/pay \
  -H "Authorization: Bearer pp_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "url": "https://api.compute-service.com/run",
    "method": "POST",
    "headers": { "Content-Type": "application/json" },
    "body": "{\"task\": \"generate-report\", \"params\": {\"topic\": \"AI\"}}"
  }'

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Prerequisites

  1. Blockchain wallet — Automatically created when you register
  2. USDC balance — Fund your wallet via the deposit flow
  3. Reputation tier — Your transaction limit must cover the payment amount

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What If the Service Doesn’t Require Payment?

If the target URL returns a normal response (200, 201, etc.), MIDAS simply proxies it back without any payment. No fees are charged.

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Supported Networks

Currently, MIDAS supports x402 payments on:
  • Base (Ethereum L2) with USDC via the exact scheme (EIP-3009)

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Security

  • All payments go through reputation-based transaction limits
  • Daily spending limits still apply
  • Protocol fee (1.5%) is deducted from your internal balance
  • Your private key never leaves the server — signing happens server-side with encrypted keys