> Fun how it goes the opposite compared to the real security implications.

You're spot on, it is pretty interesting. I suggested the extension purely to bridge that trust gap, especially if it's verified by the Chrome Web Store. If the extension is designed to strictly avoid calling any external APIs (other than leetcode graphql), it makes exfiltration impossible, ensuring the cookie never leaves the user's browser

> The OPs seems to be more cumulative lifetime stats rather than just this past year, for a lot of the slides.

I disclose that the last 5 slides are lifetime stats in my readme:

"Note: The last 5 slides are not necessarily specific to 2025 because of leetcode's graphql api only allows querying up to 20 of the latest submissions from an unauthenticated user.

However, if you pass a LEETCODE_SESSION cookie (obtained from leetcode.com, open dev tools -> application -> cookies) with your request you can query all of your accounts submissions. You could also use the calendar endpoint query all of your submissions in the past year, and thus create a much more nuanced leetcode wrapped. (ex: You struggled with this problem the most in 2025.)"

I may try to tackle this via an extension with no server side logic if I have some free time later this week, would certainly be a cooler final product. Only caveat is users would have to manually install the extension from a github repo (too scary for most people) or the chrome web store, which may add too much friction for most people.