API testing,
without
the bloat.
Postbox is a keyboard-driven HTTP client that lives in your browser. Collections, environment variables, curl import, and a server-side proxy — everything you need, nothing you don't.
Zero
config needed
100%
browser-based
MIT
licensed
What you get
Built for developers who move fast.
Collections & Routes
Organize every API endpoint into named collections. Create, rename, delete — full control with instant feedback.
Environment Variables
Define <<KEY>> vars per collection. Switch between dev, staging, and prod without touching your requests.
CORS-Free Proxy
Requests route through a Next.js server-side proxy. No more CORS errors blocking your flow in the browser.
curl Import
Paste any curl command into the URL bar. Method, headers, and body auto-parse instantly.
Persistent Storage
Collections save to localStorage automatically. Close the tab, come back later — everything is still there.
Keyboard Driven
Ctrl+Enter to send, Ctrl+S to save. Every action has a shortcut — your mouse is optional.
How it works
From collection to response in seconds.
Create a collection
Group related API routes under a named collection.
›Set env vars
Define <<token>>, <<host>>, or any variable your routes need.
›Add your request
Set method, URL, headers, body — or paste a curl command.
›Send & inspect
Hit Ctrl+Enter. View the response status, headers, and body.
Shortcuts
Stay in the flow.
Every action is a keystroke away. No clicking through menus — just code and send.
Open Source
Built in public. Free forever.
Postbox is MIT licensed. Fork it, modify it, self-host it. PRs welcome — check the roadmap for what's next.