Recovers the ECDSA signer address from an EIP-712 digest (e.g. the sibling x402-eip712-digest-recomputer's output) and a signature in (r, s, v) or (r, s, yParity) form. Normalizes the recovery-id across the raw bit (0/1), legacy Ethereum v (27/28), and EIP-155 v (chainId*2+35/36) conventions, each a well-known transcription trap. Reports the recovered address as a fact, plus a separate boolean comparing it to any claimed signer.
This node recovers the address whose private key produced the supplied signature over the supplied digest: "this address signed this specific EIP-712 typed-data structure, under this specific domain." It does not prove the recovered address is who the payload claims signed it beyond the match check below, that funds moved, that a transfer settled, or that the authorization was ever submitted on-chain. An authorization is not a settlement. This node never fetches chain state, never calls a facilitator, and is never a party to a payment.
signature (full hex blob) OR the split r/s fields, plus a recovery marker: yParity takes priority, else v, else the byte embedded in a 65-byte signature. A wrong recovery-id conversion silently recovers the wrong address rather than crashing (SPEC-X402-CRYPTO-CORE-1-2026-08-09.md Β§5.2).