Marketplace · API · x402

txguard.schemasure.com/v1/tx/preflight

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.

Endpoint	`https://txguard.schemasure.com/v1/tx/preflight`
Trust	Not checked yet
Pricing	Pay per call with x402, no account. Call it to get an exact quote before paying.
network	eip155:8453
scheme	exact
pay to	0x9876af0F6D8Ed5155Cd02d1ca56D128601612690
method	POST
last updated	2026-11-13T07:40:43.21Z

Use it

Call it (an x402 client pays automatically)

curl -i https://txguard.schemasure.com/v1/tx/preflight
# 402 reply -> sign PAYMENT-REQUIRED with an x402 client (e.g. @x402/fetch) -> retry with PAYMENT-SIGNATURE

This listing as JSON

curl https://aipaygen.com/v1/catalog/api/x402-54bb07df9cba1066

Search the whole marketplace from your agent (MCP)

{
  "mcpServers": {
    "aipaygen": {
      "url": "https://aipaygen.com/mcp"
    }
  }
}