difr

A platform-independent, local code review tool that visualizes Git diffs in a GitHub-style UI with commenting and Claude Code integration.

Features

• GitHub-style Diff Viewer — Split / Unified view with syntax highlighting
• Comments — File-level and line-level comments with review category (MUST/IMO/Q/FYI) and severity (Critical/High/Middle/Low)
• Export — Markdown / JSON / CSV / Excel (.xlsx) export with category and severity metadata
• Claude Code Integration — Real-time WebSocket chat and automated code review
• File Browser — Browse all tracked files with syntax highlighting
• Single Binary — Frontend embedded via Go embed, no separate install required

Installation

GitHub Releases

Download the latest binary for your platform from GitHub Releases:

Platform	File
Linux (x64)	difr-linux-amd64
Linux (ARM64)	difr-linux-arm64
macOS (Intel)	difr-darwin-amd64
macOS (Apple Silicon)	difr-darwin-arm64
Windows (x64)	difr-windows-amd64.exe

On Linux / macOS, make the binary executable after downloading:

chmod +x difr-*

go install

go install github.com/shimasan0x00/difr/cmd/difr@latest

Build from Source

Prerequisites: Go 1.25+, Node.js 22+, Task

git clone https://github.com/shimasan0x00/difr.git
cd difr
task install
task build
# ./difr binary is generated

Usage

difr [flags] [commit | from to | staged | working]

Command	Description
difr	Latest commit diff (HEAD~1..HEAD)
difr <commit>	Diff of a specific commit (<commit>~1..<commit>)
difr <base> <compare>	Diff between two refs (branches, tags, or commits)
difr staged	Staged changes (git diff --cached)
difr working	Unstaged working tree changes
git diff | difr	Read diff from stdin pipe

Examples

# Compare two branches
difr main feature/new-api

# Review staged changes before committing
difr staged

# View a specific commit
difr abc1234

# Pipe from git diff with custom options
git diff --ignore-all-space main | difr

Options

Flag	Default	Description
--port, -p	3333	Server port
--host	127.0.0.1	Bind address
--mode, -m	split	Display mode (split / unified)
--no-open	false	Don't open browser automatically
--no-claude	false	Disable Claude Code integration
--watch, -w	false	Watch for file changes (experimental)
--claude-timeout	5m	Timeout for Claude CLI operations (e.g. 10m, 300s)

Tech Stack

Area	Technology
Backend	Go 1.25 / Chi v5 / cobra
Frontend	React 19 / TypeScript 5.9 / Vite 7
Styling	Tailwind CSS v4
State Management	Zustand v5
Syntax Highlighting	Shiki (github-dark theme)
WebSocket	coder/websocket
Testing	testify / Vitest / React Testing Library / Playwright

Development

Prerequisites: Go 1.25+, Node.js 22+, Task

task install           # Install dependencies (go mod tidy + npm install)

# Development
task dev               # Start Go (:3333) + Vite (:5173) dev servers

# Testing
task test              # All tests (Go + Frontend)
task test:backend      # Go tests only (-race enabled)
task test:frontend     # Vitest only
task test:e2e          # Playwright E2E tests
task test:coverage     # Tests with coverage report

# Quality
task lint              # Run all linters (go vet + eslint)

# Build
task build             # Production binary (single binary with embedded frontend)
task clean             # Clean build artifacts

License

MIT