I’m developing a RESTful API that should remain stateless, and I want users to authenticate via third-party providers like Google or Facebook using OpenID Connect. My main worry is about the efficiency of these API calls.
When my API processes requests, does being stateless mean I have to check the user’s authentication with the third-party every time? This seems inefficient, especially when users are interacting with my internal endpoints such as adding or editing items.
For example, if a user has logged in through Google but now tries to access my /api/items/add endpoint, do I really need to reach out to Google’s servers again? There has to be a more efficient way to manage this while still adhering to the stateless approach.
You don’t need to validate with Google on every request. The standard approach is to verify the JWT token locally using Google’s public keys, which you can cache for efficiency. When the user initially authenticates through Google, you receive a JWT token that contains all necessary claims and is cryptographically signed. Your API can validate this signature without contacting Google’s servers again. I’ve implemented similar systems where we cache the public keys from Google’s well-known endpoint and refresh them periodically. The token validation happens locally in milliseconds rather than requiring network calls. This maintains statelessness because you’re not storing session state - you’re simply verifying the token’s authenticity through cryptographic validation. The token itself carries the state information you need.
just cache the token validation results with a short ttl like 5-10 mins. once you verify the google token, store that validation status temporarily so subsequent requests dont need crypto verification each time. not truly stateless but practicaly works great and reduces cpu overhead significantly.
Another approach worth considering is implementing a hybrid solution where you issue your own short-lived access tokens after the initial third-party verification. When a user authenticates with Google, verify their token once and then generate your own JWT with a shorter expiration time, maybe 15-30 minutes. This reduces the computational overhead of validating third-party tokens on every request while maintaining security. Your API validates your own tokens locally, which is faster than processing Google’s tokens, and when they expire, the client needs to refresh through the authentication flow again. I’ve found this particularly useful in high-traffic scenarios where even local JWT validation becomes a bottleneck. The key is setting appropriate expiration times that balance security with performance requirements for your specific use case.