How would you implement a JWT refresh token mechanism?

Question

Discuss the process of implementing refresh tokens alongside access tokens in a full stack application using JWT.

Accepted Answer

1. Generate short-lived access tokens and longer-lived refresh tokens.
2. Store refresh tokens securely (e.g., HttpOnly cookies).
3. On access token expiration, the client requests a new access token using the refresh token.
4. Validate the refresh token on the server; if valid, issue a new access token and possibly a new refresh token.
5. Handle scenarios of refresh token invalidation (e.g., logout, token rotation).
6. Trade-offs: improved security by limiting access token lifetime but requires careful management of refresh tokens.

How would you implement a JWT refresh token mechanism?

Answer