Address Toolkit

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Paste any EVM address to get it normalized, EIP-55 checksummed, and described — is it a wallet or a contract, lowercase or checksummed, and a Basescan link. Pure in-browser validation plus an optional live type check.

How to use

  1. Paste an address into the field.
  2. Click Inspect to normalize, checksum and (optionally) classify it.
  3. Copy the checksum form or open Basescan.
  4. Agents can use the paid POST /api/address-toolkit endpoint.

Where it applies

  • Catching checksum errors before a payment is signed.
  • Converting between lowercase and EIP-55 forms.
  • Checking whether an address is a contract before interacting.
  • Building tools that consume x402 payTo addresses safely.