See every trace.
Debug any flow.

An Electron desktop tool that captures every UI event, network call, console log, and error — zero code changes required. Correlates frontend and backend in a unified trace timeline.

// do not proceed

Caution. Use FlowLens at your own risk. You might actually start shipping faster.

You enjoy debugging at 3 AM

Who needs sleep when you can grep through 47 log files?

console.log is your best friend

20 hours of adding logs, 5 minutes of actual fixing. Peak productivity.

You think bugs add character

That random crash in production? It's a feature. Users love surprises.

You love context-switching

Browser, terminal, editor, repeat. Great cardio for your fingers.

Guesswork is your methodology

"It works on my machine" is a valid deployment strategy, right?

Stack traces are bedtime stories

Nothing puts you to sleep faster than 200 lines of minified errors.

You enjoy debugging at 3 AM

Who needs sleep when you can grep through 47 log files?

console.log is your best friend

20 hours of adding logs, 5 minutes of actual fixing. Peak productivity.

You think bugs add character

That random crash in production? It's a feature. Users love surprises.

You love context-switching

Browser, terminal, editor, repeat. Great cardio for your fingers.

Guesswork is your methodology

"It works on my machine" is a valid deployment strategy, right?

Stack traces are bedtime stories

Nothing puts you to sleep faster than 200 lines of minified errors.

Everything you need to trace full-stack behavior

Up and running in minutes

Follow these steps to start tracing your full-stack app.

1

Paste your URL

Paste your app's URL into FlowLens. It loads in an embedded browser with auto-injected instrumentation.

flowlens
URL: http://localhost:3000
2

Add backend tracing

Install @nihal/flowlens-node to correlate server-side spans with frontend traces.

$ npm i @nihal/flowlens-node
3

Wire up middleware

Add the middleware to your Express, Fastify, or raw HTTP server. CORS must allow the trace header.

backend
import cors from "cors";
import { flowlens } from "@nihal/flowlens-node";

app.use(flowlens({ serviceName: "my-api" });
Full SDK reference

Ready to debug?

Get started in under a minute.

Read the Docs