Two things broke in web analytics at the same time.

Measurement broke. AI assistants send real visitors, and most analytics tools file roughly 70% of them as "direct" because those assistants attach no campaign tag. Meanwhile AI crawlers read your pages every day, and most tools either discard that or count it as people.

Trust broke. Analytics products now write summaries. A sentence like "conversion fell 12% because of the theme release" makes two claims you cannot check: a number the model may have computed itself, and a cause it cannot possibly know.

vitrus — the open-source core. Apache-2.0, zero runtime dependencies, an embedded database, and a 2.4 KB tracker.

• Every metric travels as { id, sql, params, window, value }. Click a number, read the query that produced it.
• Numbers are computed by deterministic SQL. The optional AI layer may rephrase them and may not invent them — a numeric guard drops any sentence it cannot support.
• AI referrals and AI crawlers are separate channels, never summed.
• No cookies, no stored identifier, no consent banner. Do Not Track is honoured by default.

Deliberately absent: session replay and ad-platform attribution.

bun install -g @vitrus/cli
vitrus init && vitrus site add "My site" example.com && vitrus start

Or use the hosted version at app.vitrus.dev — the same engine, with no feature held back from the open source build.