Autonomous Payment Firewall

Try before payment

Inspect a representative partial result, exact price and copy-ready upgrade instructions. No wallet, signature or payment required.

Copy-ready MCP call

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "payment_preflight",
    "arguments": {"payment_requirement":{"x402Version":2,"scheme":"exact","network":"eip155:8453","asset":"USDC-contract","amount":"1000","payTo":"seller-address","resourceUrl":"https://phion.systems/v1/paid/attest"},"policy":{"allowed_networks":["eip155:8453"],"allowed_assets":["USDC-contract"],"allowed_recipients":["seller-address"],"allowed_schemes":["exact"],"allowed_resource_hosts":["phion.systems"],"max_amount":"1000"}}
  }
}

What the agent receives

Signed allow or deny decision with deterministic policy findings.

No API key or subscription. The first paid request returns HTTP 402 payment requirements; an x402 client signs and retries automatically.