The chat controller (written in TypeScript) coordinates retrieval and generation through separate Web Workers, while the DOM rendering and Zustand state updates run on the main thread.

Both collections use DuckDB’s FTS extension. Query normalization uses the saved index’s analyzer and stopword table before a prepared statement binds the query to match_bm25.

Retrieval returns up to 10 documents in descending score order, with document ID as a deterministic tie-breaker (See SQL). For the two indexes available: NFCorpus indexes concatenated titles and article text, while MS MARCO indexes passage contents.

SELECT id, title, text,
       fts_main_nfcorpus.match_bm25(id, ?) AS score
FROM nfcorpus
WHERE score IS NOT NULL
ORDER BY score DESC, id
LIMIT 10;