Applications

Everything else in the lake is an open-source program we install (server apps). These three are ours, in the apps repository.

App	Language	Runs where	Page
API	Node 24, Express 5, plain SQL (pg), jose for tokens	Anywhere with network access to the servers (today: a developer machine)	API
Web app	React 19, Vite, Tailwind, CodeMirror	Built to static files; needs the API	Web app
Worker	Python 3 (standard library + psycopg2) and Spark jobs	The processing host, as the lake-worker service	Worker

How they cooperate: the web app talks only to the API. The API writes uploads to storage and the registry. The worker reads the registry, runs Spark, and writes progress back to the same registry rows, which the API then shows. The API and the worker never call each other over HTTP; the registry database is their shared mailbox.

Installation status

The worker has an install script (step 15). The API and the web app do not have server install scripts yet: they run with npm run dev on a developer machine against the staging server. Their production install is planned work.