Identity Assertion JWT Authorization Grant (ID-JAG)

The Identity Assertion JWT Authorization Grant (ID-JAG) is a signed JWT, issued by an enterprise identity provider through OAuth 2.0 Token Exchange (RFC 8693), that a client presents as a JWT authorization grant (RFC 7523) to a third-party authorization server to get an access token for that server's API without a user consent prompt. It is defined in draft-ietf-oauth-identity-assertion-authz-grant, an active IETF OAuth Working Group draft that is not yet an RFC as of October 2026.

The flow has three steps: the user signs in to the requesting app through the IdP with OpenID Connect or SAML, the app exchanges that ID token (or a refresh token) at the IdP for an ID-JAG naming the target resource, and the app redeems the ID-JAG at the resource's authorization server. The token carries the typ header oauth-id-jag+jwt and its own token type URN, so it cannot be confused with an ID token. What changes for security teams is where the decision sits: the IdP, not each end user, decides which app may reach which API, and the IdP can refuse or log every connection. ID-JAG is the mechanism behind Cross App Access and the Model Context Protocol's Enterprise-Managed Authorization extension.

See also: Cross App Access, identity chaining, token exchange, MCP authorization, agentic identity, Aaron Parecki, agent identity standards map 2026