Welcome

API-first, privacy-respecting analytics for vibe coders, small startups, and AI agents.

Millimetric is a hosted analytics product where the HTTP API is the source of truth. You call it from your server, your browser, or an AI agent — every client speaks the same protocol.

What you get

• One HTTP API, three first-class clients (browser SDK, Node SDK, MCP server for AI agents).
• No cookies — anonymous_id lives in localStorage and only when you call track().
• No raw IPs at rest — IPs are HMAC'd with a daily-rotating salt; only country survives.
• Smart attribution — a server-side classifier separates Facebook social from Facebook paid, Google organic from Google Ads, and every other common combination, with a confidence label and an audit trail.
• First-class MCP — agents emit events with track_event and query their own data with top_sources, get_stats, query_events.

Pick your path

If you want to…	Go here
See a working example in 60 seconds	Quickstart
Understand what an event is	Events
Understand what to put in properties	Properties
Stitch anonymous → known users	Identities
Know how Facebook social vs paid gets decided	Attribution
See exactly what gets stored	Privacy
Reference every endpoint	API overview
Drop the SDK into React / Next / Vue / Svelte	Framework recipes
Connect an AI agent	MCP server
Build a signup funnel, e-commerce dashboard, attribution model	Recipes

Three keys you'll meet everywhere

Key prefix	Where it lives	What it can do
pk_live_…	Browsers	Ingest only — origin-allowlisted
sk_live_…	Servers, scripts, anywhere private	Ingest only — full powers
rk_live_…	Servers, MCP clients, dashboards	Read only

Mint them in the dashboard (apps/web). You'll see the secret exactly once.

Send your first event

curl -X POST https://api.millimetric.ai/v1/track \
  -H "Authorization: Bearer sk_live_..." \
  -H "Content-Type: application/json" \
  -d '{
    "event": "signup",
    "anonymous_id": "u_abc",
    "user_id": "user_42",
    "properties": { "plan": "free" }
  }'

That's the whole API surface for ingest. Add url + referrer and the classifier gives you source / medium / campaign for free.

The next thing to read is the Quickstart, then Events and Properties for the conceptual ground floor.