x402-agent-suite-preflight

Drop-in preflight guard for AI agents. One function call to the x402 Trust Layer — spend-policy + identity + URL risk + security grade (+ optional signed attestation) — before your agent pays any external x402 endpoint. Works with any framework (LangChain, CrewAI, Coinbase AgentKit, custom).

No API keys. The agent pays per call in USDC with its own wallet via the Dexter / CDP facilitator.

The 3-line rule

1. proxyPreflight() or guardPreflight()   ← this package
2. x402_check → x402_fetch (external API)
3. POST /api/receipt-auditor/verify       ← confirm settlement

These are advisory signals — responses include securityGrade and a summary. You keep control of the final pay/deny decision.

Install

npm install x402-agent-suite-preflight @dexterai/x402

Usage

import { proxyPreflight } from "x402-agent-suite-preflight";

const result = await proxyPreflight({
  wallet: { solanaPrivateKey: process.env.SOLANA_PRIVATE_KEY! }, // or { evmPrivateKey }
  agentId: "my-agent-1",
  walletAddress: "YourWalletAddress",
  targetUrl: "https://api.example.com/paid-endpoint",
  estimatedCostUsdc: 0.05,
  policy: { dailyCapUsdc: 10, perCallCapUsdc: 1, allowedHosts: ["api.example.com"] },
});

if (!result.allowed) throw new Error(`Blocked: ${result.summary}`);
// result.securityGrade === "A".."F", result.attestationId for the receipt trail

Wrap every payment (drop-in pattern)

Gate any agent's outbound payment behind one guard call so a scam/over-budget URL never gets paid:

import { guardPreflight } from "x402-agent-suite-preflight";

async function safePay(url: string, estCostUsdc: number) {
  const check = await guardPreflight({
    wallet: { evmPrivateKey: process.env.EVM_PRIVATE_KEY! },
    agentId: "fleet-agent",
    walletAddress: process.env.AGENT_WALLET!,
    targetUrl: url,
    estimatedCostUsdc: estCostUsdc,
    policy: { dailyCapUsdc: 25, perCallCapUsdc: 2 },
  });
  if (!check.allowed) throw new Error(`Guard blocked ${url}: ${check.summary}`);
  return yourX402Fetch(url); // only runs once guard approves
}

API

• proxyPreflight() — POST /api/x402/proxy ($0.08) — default: guard + probe + optional attestation.
• guardPreflight() — POST /api/guard/pre-x402 ($0.05) — lightweight allow/deny (spend + identity + risk).
• TrustedSolanaAgent — convenience class wrapping a Solana agent wallet with built-in preflight (see trusted-agent.ts).

Links

• Live API & dashboard: https://x402trustlayer.xyz/dashboard
• OpenAPI: https://x402trustlayer.xyz/openapi.json
• Source: https://github.com/mimranchohan/x402-trust-layer

MIT © Mimran Chohan