Frontend / Backend Contract

The frontend communicates with the Julia backend over /api.

The main endpoints are:

• POST /api/streams: build a HEN from stream and interval payloads
• POST /api/solve: solve the currently built HEN
• GET /api/results/match: fetch the detail matrix for a hot/cold match
• GET /api/results/stream: fetch a stream detail view
• POST /api/streamsets: save a streamset snapshot

The frontend also supports optional API-key-based access control through the X-API-Key header or query parameter.

The frontend stores the active hen_id in UI state and uses it when loading detail views and solve results.