JWT Token Exchange — Exchanging JWTs for Service-Specific Tokens

In this tutorial, you will learn about JWT Token Exchange. We cover key concepts, practical examples, and best practices to help you master this topic.

JWT token exchange converts a broad-scoped user JWT into a service-specific JWT with narrower scope, audience, and claims, ensuring each downstream service receives only the privileges it needs.

sequenceDiagram
    participant Client
    participant Gateway as API Gateway
    participant Auth as Auth Server
    participant Svc as Downstream Service

    Client->>Gateway: Request with broad user JWT
    Gateway->>Auth: Exchange for service-specific JWT
    Auth->>Auth: Validate original, issue scoped JWT
    Auth-->>Gateway: Narrow-scoped JWT
    Gateway->>Svc: Forward with narrow JWT
    Note over Svc: JWT has aud=service-specific
scoped to required actions only

What's Next

Combine with {{< ilink "JWT" "JWT Token Forwarding" }} for propagation and {{< ilink "JWT" "JWT Audience Validation" }} for service specificity.