Is it safe to sign this?
check_signatureRead-onlyIdempotent
Call BEFORE your agent signs or sends anything from a wallet. Decodes a transaction, an EIP-712 typed-data request (Permit, Permit2, EIP-3009 USDC authorizations, Seaport orders), an EIP-7702 delegation or an x402 payment (402 terms + payload) into plain English and returns SAFE / CAUTION / DANGER with risk flags (unlimited approvals, setApprovalForAll, fake USDC domains, x402 overpay or wrong payTo, OFAC SDN counterparties). Free preview tier (offline). The paid x402 endpoint /v1/check adds reasons, on-chain facts (spender is a wallet or contract, token metadata) and an eth_call simulation.
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| tx | No | Transaction to send: {"to":"0x…","data":"0x…","value":"0","from":"0x…"} (from enables simulation) | |
| chain | No | base (default), ethereum, base-sepolia or a chain id | |
| typed_data | No | EIP-712 request {domain, types, primaryType, message} as passed to eth_signTypedData_v4 | |
| authorization | No | EIP-7702 authorization {address (delegate contract), chainId, nonce} | |
| payment_payload | No | x402 payment you are about to send: PAYMENT-SIGNATURE / X-PAYMENT (base64) or JSON | |
| payment_required | No | x402 402 terms: the PAYMENT-REQUIRED header (base64) or JSON {accepts:[…]} |