Built because Datadog was too expensive for my side project
APILens started as a personal tool. Now it's free for every Node.js developer.
The problem I kept hitting
Every time I shipped a Node.js API — whether a freelance project or a side product — I'd immediately lose visibility the moment it hit production. I could see that something was slow, but not which route, not which database query, and definitely not the N+1 patterns hiding in my Mongoose code.
The “right” answer was Datadog or New Relic. Both require a full agent install, 15–30 minutes of config, and cost $23/host/month before you've seen a single metric. For a project making $0, that math doesn't work.
So I built the tool I wanted: one app.use() call, zero infrastructure, zero config — and a real-time dashboard that shows latency, errors, slow routes, and database queries the moment your first request lands.
What APILens actually does
Request / response logging
Every route, status code, duration — aggregated per endpoint, not per request.
Database query profiling
Auto-instruments pg, mysql2, mongoose, prisma, knex, sequelize, ioredis, better-sqlite3. Zero code changes.
N+1 detection
Flags routes that fire the same query pattern 3+ times in a single request cycle.
Distributed tracing
Propagates traceId headers across microservices so you can follow a request end-to-end.
Real-time dashboard
Charts, live tail, error breakdown, slow endpoint list — hosted at apilens.rest/dashboard.
Alerts
Email alerts when error rate or p95 latency crosses your threshold.
The person behind it
I'm Rahul Patel, a full-stack developer focused on Node.js backends and developer tooling. I've been building APIs professionally for several years and have run into the same observability pain across every project — freelance clients, internal tools, and personal products alike.
APILens is an indie project. That means fast decisions, direct support, and no enterprise sales process. If something is broken or confusing, open a GitHub issue and I'll look at it.
The npm package (auto-api-observe) is MIT-licensed. Use it however you like.
Tech stack
The middleware is zero-dependency TypeScript. The cloud pipeline is Node.js + PostgreSQL + Redis. The dashboard is Next.js 14 with Clerk auth. Nothing exotic — the goal is something you can trust in production without reading 10 pages of documentation.