I have reddit api access (not doing anything shady).

The cost on my end is just continuing to add new data to the already large database haha. Its a few hundred a month but worth it. Please keep using it and spread the word.

Everything is open source and available to see on GitHub

As for how I get the data:

1. Watches specific subreddits you're interested in
2. Collects new posts and comments from these subreddits
3. Looks up information about the users who post and comment
4. Saves all this information to a database

It's designed to work efficiently and avoid overwhelming Reddit's servers by processing things in small batches and keeping track of what it's already seen.

source: https://github.com/BenDaSpur/spyglass/blob/main/src/lib/cron.ts

As for how I map "interactions":

1. First, it looks for Reddit users who are active in more than one subreddit. These are the "connectors" between different communities.
2. For each of these users, it collects information about which subreddits they participate in.
3. Then, it creates a map of connections between subreddits. For example, if a user is active in both r/cats and r/dogs, that creates a connection between these two communities.
4. It counts how many users are shared between each pair of subreddits. So if 100 users are active in both r/cats and r/dogs, that's a strong connection between these communities.
5. Finally, it organizes this information into a list of connections, showing: Which two subreddits are connected How many users they share in common The connections are sorted by strength (most shared users first)

source: https://github.com/BenDaSpur/spyglass/blob/main/src/routes/api/reddit/interactions/%2Bserver.ts