Why I Built Yet Another API Client (and Made It Open Source)

#postman #rust #opensource #tauri

I spend most of my day job writing backend services in Go, wiring up gRPC/Protobuf between microservices at a fintech company in Jakarta. Which means I spend a stupid amount of time in an API client, poking endpoints, checking responses, debugging auth headers.

For years that meant Postman. Then Postman started feeling like it was actively working against me: forced cloud login just to save a collection locally, a UI that got heavier every release, and a memory footprint that made my laptop fan spin up just for sending a GET request. I tried Insomnia, better for a while, then Kong bought it and the trajectory started looking familiar. I also spent a good while with Electron-based alternatives that get the git-native storage idea right, but the RAM usage problem never actually went away, it just moved to a different logo.

At some point I stopped complaining and just started building the thing I actually wanted.

What I Actually Wanted

Nothing fancy. Just:

Fast, native networking. Not a browser sandbox pretending to be a native app.
Collections as plain files, not one giant JSON blob you can't diff or merge.
Something that doesn't eat hundreds of MBs of RAM to show me a response body. So I built Relay, a desktop API client built on Tauri v2, Rust, and React.

The Native Networking Part

Requests run through actual Rust (reqwest/tonic), not a webview's fetch(). No CORS restrictions, real gRPC support, and no Electron/Chromium runtime bundled in, so the installer size and memory footprint are a fraction of the usual.

Relay also has a built-in Performance tab, so you can watch memory and request timing yourself instead of taking my word for it.

The Git-Native Part

This is the part I'm most opinionated about. Every request, folder, and environment is a plain-text .relay file, not one giant JSON blob.

That means:

git diff actually shows what changed
Merge conflicts are readable
Secrets auto-split into a .gitignored file, so they never end up in your commit history