Callstack

A desktop REST API testing tool built with Tauri 2 and React. Runs as a native OS window with a Rust HTTP client — no browser CORS or Origin restrictions.

Features

• Full HTTP method support: GET, POST, PUT, DELETE, PATCH
• Projects and folders: Organize requests into projects with nested folders; drag-and-drop reordering
• Environments: Per-project variable sets; template syntax ({{variable}}) resolved at send time
• Request builder:
  • URL params editor (key-value, auto-appended to URL)
  • Headers editor with enable/disable toggle per row
  • Body editor with JSON/XML validation and auto Content-Type insertion
  • File attachments for multipart requests
  • Pinnable tabs (persist visible alongside others)
• Response viewer:
  • Body tab: JSON syntax highlighting, XML/HTML pretty-printing, plain text
  • Headers tab
  • Preview tab: rendered HTML, images, video, and audio (base64)
  • Copy body, save to file, clear response actions
  • Status code, response time (ms), and size (bytes) in the toolbar
• Request log panel: Collapsible footer showing all requests sent in the session; expands each entry to show the equivalent curl command (with copy button)
• Resizable layout: Sidebar width and request/response split are both draggable and persisted
• Theming: Dark, light, or system preference — toggled in the header
• Google Sign-In: Optional; scopes requests to the signed-in user's email so multiple users share one local database
• Offline, local-first: All data lives in a SQLite file on disk — no network required after install

Getting Started

Prerequisites

• Rust (stable)
• Node.js 18+
• Tauri CLI v2

Run in development

make dev

This starts Vite (HMR) and the Tauri native window together. The Rust backend recompiles on changes.

Build a distributable

make build

Produces a platform-native bundle (.app + .dmg on macOS, .msi on Windows, .AppImage on Linux) in src-tauri/target/release/bundle/.

Other commands

make web-dev    # Vite dev server only (no Rust backend, useful for pure UI work)
make clean      # Remove web/dist and src-tauri/target
make icons      # Regenerate app icons from source (requires Pillow)
make help       # List all targets

Architecture

callstack/
├── src-tauri/          # Rust / Tauri 2 backend
│   ├── src/
│   │   ├── lib.rs          # App setup, command registration
│   │   ├── http_client.rs  # send_request — reqwest-based HTTP proxy
│   │   └── database.rs     # All SQLite CRUD (rusqlite)
│   └── tauri.conf.json
└── web/                # React 19 + Vite + TypeScript frontend
    └── src/
        ├── components/     # Feature-grouped UI components
        ├── context/        # AppContext (useReducer global state)
        ├── hooks/          # useHttpClient, useDatabase, useAuth
        └── lib/            # types.ts, template.ts

IPC: The frontend calls Rust commands via invoke() from @tauri-apps/api/core. There is no HTTP server or REST API between frontend and backend.

Data flow: React state (Context + useReducer) drives the UI. Every mutation is also persisted to SQLite via debounced invoke() calls (300 ms). On startup, all projects, requests, folders, and environments are loaded from SQLite into React state.

HTTP client: All requests are sent by reqwest in Rust. This means no browser-imposed CORS restrictions, no forced Origin header, and full control over every header sent.

Database

SQLite file location: ~/Library/Application Support/callstack/callstack.db (macOS).

projects    (id, user_email, name, description, created_at, updated_at)
folders     (id, project_id, name, created_at, updated_at)
requests    (id, project_id, folder_id, user_email, name, method, url,
             params, headers, body, attachments, position, created_at, updated_at)
responses   (id, request_id, status, status_text, headers, body,
             time_ms, size, timestamp_ms, created_at)
environments (id, project_id, name, variables, created_at, updated_at)

params, headers, attachments, and variables are stored as JSON strings. responses captures the full last response per request (overwritten on each send).

Design Conventions

Accent colors by HTTP method:

Method	Token	Color
GET	--accent-get	#10b981 teal
POST	--accent-post	#3b82f6 blue
PUT	--accent-put	#f59e0b amber
DELETE	--accent-delete	#ef4444 red
PATCH	--accent-patch	#a855f7 purple

Typography: JetBrains Mono for code, URLs, and response bodies. Outfit for UI chrome. Both fonts are self-hosted in web/public/fonts/ — no external font requests.

Spacing: 8 px base grid — --space-half (4 px), --space-1 (8 px), --space-2 (16 px), --space-3 (24 px), --space-4 (32 px).

Theming: CSS custom properties scoped to [data-theme="light"] / [data-theme="dark"]. Defaults to prefers-color-scheme.

License

Apache License Version 2.0