Wallet Verify SIWE API — Pay Per Call with USDC on Base

wallet_verify_siwe API

Verify a Sign-In-With-Ethereum (EIP-4361) signature. Stateless paid oracle: checks the signature against the message and returns the wallet address + chainId. Never mints sessions or consumes nonces. Get a checksummed address first via wallet_checksum. Part of the x402 Gateway — $0.001 per call, settled in USDC on Base. No accounts, no API keys: agents pay per request via the x402 protocol.

How payment works

Send a POST to https://x402.freeq.one/tools/wallet_verify_siwe without a payment header and the API replies 402 Payment Required with an x402 challenge (payTo address, USDC amount, Base network). A paying agent signs the USDC payment and retries with the X-PAYMENT header — settlement is verified on-chain in seconds and the API response returns with an X-PAYMENT-RESPONSE receipt.

Example call

curl -X POST https://x402.freeq.one/tools/wallet_verify_siwe \
  -H "Content-Type: application/json" \
  -d '{"items":[{"proof":{"merkleTreeDepth":20,"merkleTreeRoot":"0x1","nullifier":"0x1","message":"0x1","scope":"0x1","points":["0x1","0x1","0x1","0x1","0x1","0x1","0x1","0x1"]}}]}'

Browse every pay-per-call API on the all APIs page, or inspect the machine-readable service card and OpenAPI spec.