Tenant federation

A federation link declares directional trust from a source tenant to a target tenant. Reverse access requires a separate link.

Federation supports cross-tenant authentication evidence but does not merge tenants. Clients, subjects, signing keys, grants and resource audiences remain isolated. A resource server continues to accept only its configured issuer.

Account access in the target tenant requires an explicit valid link. Revoking federation prevents new use of that trust and invalidates paths that depend on it; it does not rewrite product-owned account bindings.

Use external Google or Apple providers for social identity and tenant federation for Identity-to-Identity trust. Their audience and linking policies are intentionally separate.