TxGuard /v1/tx/preflight APIPOST /v1/tx/preflight · x402 API by TxGuard
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.
What does this x402 API do?
TxGuard /v1/tx/preflight API. This is an x402-gated POST API resource from TxGuard. TOLL·402 did not invoke this route automatically because doing so was not considered safe. No normalized USD price is recorded; the listing names Base. No settled paid call has been verified.
- Published price
- No normalized USD price is recorded
- Networks
- Base
- Latest evidence
- TOLL·402 did not invoke this route automatically because doing so was not considered safe
- Resource ID
- c6c6b5bb140b5573b4c473d5
Start with a quote-only recipe. Payment signing stays in your project.
const response = await fetch("https://txguard.schemasure.com/v1/tx/preflight", {
method: "POST",
headers: { "content-type": "application/json" },
body: JSON.stringify({
"type": "http",
"method": "POST",
"bodyType": "json",
"bodyFieldNames": [
"expected_quote",
"unsigned_tx"
],
"pathParamNames": [],
"queryParamNames": []
}),
});
console.log(response.status);
console.log(Object.fromEntries(response.headers));
console.log((await response.text()).slice(0, 1000));
// A valid 402 is a quote, not a completed paid call.Review the provider input schema before running this non-read-only method. No payment code is included.
- Exact route checked
not safely testable · potentially-mutating-method:POST
- Origin reachable
HEAD https://txguard.schemasure.com/ returned 200.
- Observed in cdp-bazaar
The registry record was observed and retained with provenance.
What evidence supports this listing?
Each record has an exact-route quote outcome. Unresolved templates and potentially mutating methods are labeled instead of being invoked without provider-specific test input. A quote is still separate from a settled paid call. Read the discovery and verification methodology →
Which networks and payment options does it accept?
The normalized listing price is No normalized USD price is recorded. Raw protocol requirements remain visible below for implementation and audit use.