A local git diff viewer that opens a GitHub-style UI in the browser.

go install github.com/yasaricli/bak@latest

Requires Go 1.21+ and git in your PATH.

bak              # working tree (unstaged changes)
bak --staged     # staged changes
bak HEAD         # last commit
bak HEAD~2       # two commits ago
bak HEAD~3..HEAD # range between commits

Prerequisites: Go 1.21+ and git in your PATH.

Clone and build locally:

git clone https://github.com/yasaricli/bak.git
cd bak
go build -o bak .
./bak              # run from the project directory

Run without building:

go run . --staged

Run tests:

go test ./...

To install your local build into $GOPATH/bin:

go install .

1. Runs git diff with the given arguments
2. Parses the unified diff output
3. Starts a local HTTP server on a random available port
4. Opens the browser automatically (open on macOS)
5. Serves a single self-contained HTML page
6. Shuts down once the browser loads the page (or on Ctrl-C)

• Dark theme (GitHub dark style)
• Left sidebar listing changed files with +/- counts
• Clicking a file jumps to that section; active file tracks scroll
• Unified diff with old/new line numbers
• Added lines in green, removed lines in red
• File type icons
• Zero external dependencies — pure HTML/CSS/JS embedded in the binary

bak/
├── main.go               # CLI entry point, arg parsing
└── internal/
    ├── diff/
    │   └── diff.go       # unified diff parser
    ├── render/
    │   └── render.go     # HTML/CSS/JS page builder
    └── server/
        └── server.go     # one-shot HTTP server

MIT