AppsFlyer

Build a self-hosted first-party mobile attribution tracker. TypeScript, Fastify, SQLite via better-sqlite3, Vite plus React for the dashboard, Docker Compose for deployment. No accounts, no cloud services, no telemetry. What it does: 1. Link service: POST /api/links creates a tracked link with campaign, source, medium, and an optional destination path in my app. Each link gets a short id served at GET /l/:id. 2. On click, /l/:id records a click row: timestamp, short id, user agent, platform guess from UA, referrer, IP truncated to /24 for IPv4 and /48 for IPv6, and a random click token set as a cookie. Then 302 to a universal link if the platform is iOS or Android, otherwise to a configured web fallback. 3. Serve /.well-known/apple-app-site-association and /.well-known/assetlinks.json from files in ./public so real deep links work. 4. Ingest endpoint: POST /api/events accepts { deviceId, eventName, clickToken?, platform, appVersion, ts, value? } authenticated by a shared secret in APP_INGEST_KEY. Store raw events untouched in an events table. 5. Attribution job: for each first_open event, attribute deterministically if clickToken matches a click. Otherwise do a probabilistic match against clicks in the last 24 hours on the same truncated IP and platform, and mark it as probabilistic with a confidence field. Never overwrite a deterministic match. Store results in an attributions table so the logic can be re-run idempotently. 6. Dashboard at /: table of campaigns with clicks, installs, deterministic versus probabilistic split, and any named post-install events. Date range picker. CSV export. 7. CLI script: npm run import-spend that loads a CSV of campaign,date,spend so the dashboard can show cost per install for channels I bought myself. Explicitly out of scope, and say so in the README: SKAdNetwork and AdAttributionKit postbacks, any integration with Meta, Google, TikTok or Apple Search Ads, fraud detection, audience syncing, and a native SDK. The client side is a documented HTTP contract only. Secrets in .env: APP_INGEST_KEY, PUBLIC_BASE_URL, WEB_FALLBACK_URL. Include a seed script with fake clicks and installs, and vitest tests covering deterministic match, probabilistic match, and the no-double-attribution rule.