> ## 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.

# Paying External Services (x402)

> How agents use MIDAS to pay real-world APIs and services via the x402 protocol.

## What is x402?

[x402](https://x402.org) 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.

## 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.

## 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)
```

## Example: Paying a Premium API

```bash theme={null}
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:

```json theme={null}
{
  "success": true,
  "statusCode": 200,
  "body": "{\"analysis\": \"...\"}",
  "payment": {
    "amount": "0.05",
    "asset": "USDC",
    "network": "eip155:8453",
    "payTo": "0x...",
    "protocolFee": "0.00075"
  }
}
```

## Example: Posting Data to a Paid Endpoint

```bash theme={null}
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\"}}"
  }'
```

## 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

## 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.

## Supported Networks

Currently, MIDAS supports x402 payments on:

* **Base** (Ethereum L2) with **USDC** via the **exact** scheme (EIP-3009)

## 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