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txguard.schemasure.com tx preflight
https://txguard.schemasure.com/v1/tx/preflight
answers 402
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
We sent a real
POST request to this endpoint and it
answered 402 with payment requirements we could parse.
- Price
- $0.01
- Network
- base
- Pay to
- 0x9876af0F6D8Ed5155Cd02d1ca56D128601612690
- Spec dialect
- v2 (declares x402Version 2)
- Transport
- PAYMENT-REQUIRED header
- HTTP method
- POST
- Response latency
- 191 ms
- Payment options
- 1 usable of 1
- Last checked
- 2026-08-15T14:23:25.001Z (18h ago)
- Category
- finance-crypto
Re-check it yourself:
curl "https://api.the402.dev/validate?url=https%3A%2F%2Ftxguard.schemasure.com%2Fv1%2Ftx%2Fpreflight"