auth-md

# auth-md Generate, validate, and explain the **auth.md** protocol — the open standard that lets AI agents register for services on behalf of users, without signup forms. --- ## Protocol Context auth.md is a Markdown file published at a service's root (typically `https://service.com/auth.md`) that instructs agents on how to register. It works simultaneously as human-readable documentation and as a discoverable runtime artifact for agents. The protocol extends RFC 9728 (OAuth 2.0 Protected Resource Metadata) with an `agent_auth` block in the Authorization Server metadata. Registration returns an `identity_assertion` (service-signed JWT) that the agent exchanges at `/oauth2/token` for an `access_token`. Three registration methods are supported: | Flow | Mechanism | When to use | |------|-----------|-------------| | **identity_assertion** | Provider signs an ID-JAG (with `auth_time`) asserting user identity. Service verifies JWKS, returns `identity_assertion`. Agent exchanges at `/oauth2/token`. | Service does JIT provisioning from OIDC/SAML; wants zero-friction registration. | | **service_auth** | Email hint + browser-based ceremony. Agent receives `user_code` + `verification_uri`; user signs in and types code. Agent polls `/oauth2/token`. | Agents on platforms that can't mint ID-JAGs; self-serve without trust list. | | **anonymous** | No identity upfront. Immediate `identity_assertion` with pre-claim scopes. Optional deferred claim for scope upgrade. | Agent needs basic ...