CurlIt

A fast, modern, open-source API testing tool built as an alternative to Postman. Test REST APIs, manage collections, configure environments, and import/export cURL commands -- all from your browser.

Features

• Full HTTP Client -- GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS with color-coded method badges
• Request Builder -- Query params, headers, body (JSON/Text/XML/Form Data/URL Encoded), and auth (Basic, Bearer, API Key)
• Response Viewer -- Syntax-highlighted body (JSON, XML, HTML), headers table, cookies table, status/time/size metrics
• Collections -- Organize, save, and reuse requests; import/export as JSON; import Postman collections (v2.1)
• Environment Variables -- Define {{variable}} placeholders substituted at send time across URL, headers, params, body, and auth
• Request History -- Automatically records the last 100 requests, searchable and grouped by date
• Multi-Tab Interface -- Work on multiple requests simultaneously with independent state per tab; double-click tab to rename
• cURL Import/Export -- Paste a cURL command to create a request, or export any request as cURL
• Save Workflow -- Ctrl+S saves changes back to the source collection in-place, or prompts to pick a collection for new requests
• Keyboard Shortcuts -- Ctrl+S save, Ctrl+N new tab, Ctrl+I import cURL, Ctrl+E export cURL, Ctrl+B toggle sidebar
• Resizable Panels -- Drag to resize the sidebar and request/response split
• Dark Theme -- Purpose-built dark UI designed for long sessions
• Local Persistence -- Collections, environments, and history are saved to localStorage

Quick Start

# Clone the repository
git clone https://github.com/abhimanyusinghal/curlit.git
cd curlit

# Install dependencies
npm install

# Start the dev server (frontend + proxy)
npm run dev

Open http://localhost:5173 in your browser.

Tech Stack

Layer	Technology
Frontend	React 19, TypeScript, Tailwind CSS 4
State	Zustand
Editor	CodeMirror 6
Icons	Lucide React
Build	Vite 5
Proxy	Express.js

Project Structure

curlit/
├── docs/                  # Documentation
│   ├── ROADMAP.md
│   ├── ARCHITECTURE.md
│   └── USER_GUIDE.md
├── e2e/                   # Playwright end-to-end tests
├── server/
│   ├── proxy.js           # Express proxy to bypass CORS
│   └── __tests__/         # Proxy server tests
├── src/
│   ├── components/        # React components
│   │   └── __tests__/     # Component integration tests
│   ├── hooks/             # Custom hooks (resizable panels)
│   ├── store/             # Zustand state management
│   │   └── __tests__/     # Store unit tests
│   ├── test/              # Test setup and utilities
│   ├── types/             # TypeScript type definitions
│   │   └── __tests__/     # Type factory tests
│   ├── utils/             # HTTP client, cURL parser, formatters
│   │   └── __tests__/     # Utility unit tests
│   ├── App.tsx            # Root layout
│   ├── index.css          # Tailwind config & global styles
│   └── main.tsx           # Entry point
├── index.html
├── package.json
├── tsconfig.json
├── vite.config.ts
├── vitest.config.ts       # Vitest test configuration
└── playwright.config.ts   # Playwright E2E configuration

Scripts

Command	Description
npm run dev	Start frontend + proxy server
npm run dev:frontend	Start Vite dev server only
npm run dev:server	Start proxy server only
npm run build	TypeScript check + production build
npm run preview	Preview production build
npm test	Run all unit and integration tests
npm run test:watch	Run tests in watch mode
npm run test:coverage	Run tests with V8 coverage report
npm run test:e2e	Run Playwright end-to-end tests

Testing

CurlIt has a comprehensive test suite with 138 automated tests across five layers:

Layer	Tool	Tests	What it covers
Unit	Vitest	63	Pure utility functions (URL building, header construction, body serialization, variable substitution, cURL parsing/generation, formatters) and type factory functions
Store	Vitest	37	Zustand store actions (tabs, requests, collections, history, environments, localStorage persistence)
Component	Vitest + React Testing Library	24	All 9 React components rendered with real store state
Server	Vitest + Supertest	7	Express proxy server (request forwarding, error handling, body types)
E2E	Playwright	12	Full browser workflows (send request, collections, cURL import/export, environments, keyboard shortcuts)

# Run unit + integration tests
npm test

# Run with coverage
npm run test:coverage

# Run E2E tests (requires Chromium -- install with: npx playwright install chromium)
npm run test:e2e

How It Works

CurlIt runs a lightweight Express proxy server alongside the Vite dev server. When you send a request, the frontend POSTs the request configuration to /api/proxy, which forwards it to the target API using Node.js fetch. This avoids browser CORS restrictions and returns the full response (status, headers, body, cookies) back to the UI.

All data (collections, environments, history, panel sizes) is persisted in localStorage -- no database or account required.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Write your code and add tests for new functionality
4. Run npm test and npm run test:e2e to ensure all tests pass
5. Commit your changes (git commit -m 'Add amazing feature')
6. Push to the branch (git push origin feature/amazing-feature)
7. Open a Pull Request

License

This project is licensed under the MIT License -- see the LICENSE file for details.