AuthProof

You'd reach for this when you need Claude to interact with APIs that require cryptographic proof of identity rather than traditional API keys. Agents self-register and sign each request using ERC-8128, an Ethereum standard for verifiable credentials, which prevents replay attacks where someone could reuse a captured request. This is useful when building AI agents that need to authenticate against blockchain-based services or any API that supports signed request verification. Instead of hardcoding secrets or managing key rotation, the agent generates its own keypair and proves its identity mathematically with each call.