# mutuals index: hubble-sync tutorial

TODO: link to tutorial post

**heads up!** hubble-sync is very new! there will be breaking changes! but it works and runs in production.

**heads up!** `hubble-sync-rocksdb` is recommended for now! `hubble-sync-fjall` *should work*, but doesn't have counters implemented yet, so a lot of system-status insight will be missing.

## [Step 0](./moots-0-counts): Sync the Atmosphere


## [Step 1](./moots-1-mutuals): Compute mutuals! (WIP)


## [Step 2](./moots-2-fast-reads): Maintain an index for faster reads (WIP)


## postscript: where to go from here:

- record blocks to exclude from mutuals (both sides)
  - resolve block lists?
- counts: eliminate reads by using hyper-log-log sketches for unique followers
- generic follow-like mutuals
- roaring bitmaps!


## hacking: codegen for lexicons

```bash
cargo run -p lexgen
```