{
  "aid": "txguard.txguard.schemasure.com",
  "name": "TxGuard",
  "type": "index",
  "description": "TxGuard tells an agent what a Base transaction actually does before it signs one. It decodes calldata against verified ABIs, resolves every known proxy pattern including the legacy slot Base USDC really uses, unwraps multicall wrappers recursively, classifies allowances against the token's own supply rather than a list of sentinel values, and runs the full x402 authorization check table against the quote a payment claims to satisfy. There is no model anywhere in it. When a four-byte selector matches more than one signature it returns unknown and hands back every candidate, because a confident decode of an ambiguous selector is how a preflight API becomes dangerous.",
  "image": "https://txguard.schemasure.com/icon.svg",
  "tags": [
    "base",
    "transaction",
    "preflight",
    "x402",
    "eip3009",
    "approvals",
    "agent-safety",
    "simulation",
    "deterministic"
  ],
  "created": "2026-08-03",
  "modified": "2026-08-05",
  "specificationVersion": "0.18",
  "apis": [
    {
      "aid": "txguard.v1.tx.preflight",
      "name": "TxGuard — Explain and check a Base transaction or x402 payment authorization before signing it",
      "description": "Explain and preflight an unsigned Base transaction, EIP-712 typed data, or an EIP-3009 x402 payment authorization before you sign it. Decodes intent against verified ABIs, resolves proxies, classifies approvals, and checks a payment authorization against the quote it claims to pay: recipient, amount, asset, chain, freshness, and nonce replay. Returns unknown rather than guessing when a selector is ambiguous. Not a guarantee that a transaction is safe or profitable.",
      "humanURL": "https://txguard.schemasure.com/docs",
      "baseURL": "https://txguard.schemasure.com/v1/tx/preflight",
      "tags": [
        "base",
        "transaction",
        "preflight",
        "x402",
        "eip3009",
        "approvals",
        "agent-safety",
        "simulation",
        "deterministic"
      ],
      "properties": [
        {
          "type": "OpenAPI",
          "url": "https://txguard.schemasure.com/openapi.json"
        },
        {
          "type": "x402",
          "url": "https://txguard.schemasure.com/.well-known/x402.json"
        },
        {
          "type": "Pricing",
          "url": "https://txguard.schemasure.com/.well-known/pricing.json"
        },
        {
          "type": "Benchmarks",
          "url": "https://txguard.schemasure.com/.well-known/benchmarks.json"
        },
        {
          "type": "LLMs",
          "url": "https://txguard.schemasure.com/llms.txt"
        }
      ]
    }
  ]
}