Hi, I want to do A/B test on my page, but don't want to store any session identifiers in cookies or local storage. I made a script that hashes the user IP and user-agent and returns a number from 0-7 (group_id), which I send with events to my data store. The issue is that now GrowthBook only sees 7 users (it probably ignores 0, but I can shift the ids by 1), but what is worse is that it has assigned 6 of those values to Control and only 1 to Variation 1 (I have configured 50% split). What would be the best way to fix this, or is Growth Book unsuitable for this case? I don't want to track individual users or their sessions because of GDPR.

We don't really support custom hashing / forced variations in the way you're imagining. Our notion of forced variation is for testing/QA purposes and bypasses the normal experiment flow, skips tracking callbacks, etc. Can you use the IP directly as your hash attribute instead of trying to force a bucket? Also should note that bucketing on IP can lead to bias because its very common for many users to have the same IP address.

Thanks, skipping the SDK is a great idea, I have just a single experiment with a single flag, so it will be only a few lines of code.