Token Introspection

OAuth 2.0 Token Introspection is a mechanism that allows resource servers to query the authorization server to determine the active state and metadata of an access token in real-time. This is essential for validating tokens and enforcing fine-grained access control. What Is Token Introspection? Token introspection is defined in RFC 7662. It provides a standardized way for a resource server to ask the authorization server whether an access token is valid and to retrieve associated metadata such as scopes, expiration, and client info. ...

When building secure APIs, validating tokens is critical. But not all tokens are self-contained (like JWTs). That’s where OAuth 2.0 Token Introspection comes in — a mechanism to verify token status, scope, and expiration in real time via the authorization server. What Is Token Introspection? Token introspection is defined in RFC 7662. It allows a protected resource (like your API server) to ask the authorization server: “Is this token valid? What does it contain?” ...