Agent API Authentication

When an agent requests access to a payment API or sensitive endpoint, how does the API verify the agent's identity?

Traditional API authentication uses API keys, OAuth tokens, or mTLS certificates — all designed for human users or service accounts. But agents are different: they restart frequently, spawn sub-agents, and migrate between environments.

Stripe has proposed an x-agent-trust header for agent payment authentication. MetaMask requires trust verification for x402 payments. The pattern is clear: services want to verify not just that a request is authorized, but that it comes from a specific, known agent.

AIdent makes this possible. An agent's Ed25519 public key serves as its identity credential. Services can verify request signatures against the registered public key, confirming both authorization and agent identity in one step.