Build on it, or help build it

Everything above this point answers how do I use this. This part answers how is it built, and what may I build on — and there are two doors, both open.

Build on it. nexus-flow is a library first. An app links nexus-flow-facade, holds one Engine, and reads exactly the lanes the CLI reads — in-process, with no subprocess and no daemon in between. That is not a claim the repository leaves to prose: examples/tauri-board/ is a small, real desktop app that does it in about 120 lines of Rust and one HTML file. Its window lists the work and re-renders on its own whenever anything else writes to the same workspace, because it subscribes to the engine's change stream instead of polling. If you are here to put your own interface on top, that example is the shortest way in.

Help build it. The project takes contributions. The engine, the CLIs, the guides you are reading and the tests that keep them honest all live in one Cargo workspace, and the whole quality bar is four commands you can run on your own machine — the next page lists them, and says which of them CI runs when. The seams are documented rather than guessed at, which is what the pages below are for.

The two doors share a first step: get the source, build it, and run something. Getting started is that step, for both cases.

Where to go from here

• Getting started — the source on your machine, the gates, and the example app.
• Architecture — the map: five layers, which way the arrows point, and which seams are contracts.
• The journey of one operation — one nxf close, followed from the verb to a derived answer nobody wrote — and then the same trip across two machines.