cr

crit-diff

A full-screen, side-by-side diff viewer with vim-native navigation. A companion to crit — the excellent terminal review tool for markdown documents.

Where crit handles document review (plans, specs, markdown), cr handles git diff review (code changes across files) with a GitHub-style side-by-side TUI. Both tools share the same .crit/ comment format, so they work together seamlessly as part of the same review ecosystem.

We recommend installing both for the full workflow — crit for reviewing what Claude writes, cr for reviewing what Claude changes.

Install

Claude Code Plugin Marketplace (recommended)

cr is available as a Claude Code plugin. Add the marketplace and install:

/plugin marketplace add adilp/crit-diff
/plugin install cr

Then use /cr:review <ref> to open the TUI. After you close it, Claude reads your comments and edits the code to address them.

From source

go install github.com/adilp/crit-diff@latest

Make sure $GOPATH/bin (defaults to ~/go/bin) is in your PATH:

export PATH="$PATH:$(go env GOPATH)/bin"

Manual skill install

If you prefer not to use the plugin, you can install the Claude Code skill directly:

cr setup-claude            # Install globally (~/.claude/skills/)
cr setup-claude --project  # Install for current project only
cr setup-claude --force    # Overwrite existing installation

Then use /cr-review <ref> in Claude Code.

Requirements

• Go 1.21+ for building from source
• git — cr is a git tool, it reads diffs from your repo
• tmux — required for the Claude Code integration. cr opens the review TUI in a tmux split pane next to Claude Code.
• fzf (optional) — for fuzzy file/content search. Falls back to a built-in filter if not installed.

Starting a tmux session

If you're not already in tmux, start one before launching Claude Code:

tmux new -s work
# Now launch Claude Code inside this tmux session
claude

If you forget, cr will tell you — but the split-pane review won't work outside of tmux.

Usage

# Review working tree changes (staged + unstaged)
cr

# Review changes against a branch
cr main

# Review last N commits
cr -1
cr -3

# Review a commit range
cr HEAD~5..HEAD
cr v1.0..v1.1

# Review only staged changes
cr --staged

# Filter to specific paths
cr main -- src/services/

# Output review comments as JSON
cr status

Claude Code Integration

/cr-review main            # review changes against main
/cr-review -3              # review last 3 commits
/cr-review --staged        # review staged changes

Workflow:

1. Claude opens cr in a tmux pane alongside your conversation
2. You review the diff side-by-side, leave comments with c, quit with q
3. Claude reads your comments via cr status and addresses them automatically
4. Claude offers to re-open cr for you to verify the changes

tmux split pane mode

When running inside tmux, you can open the TUI in a side-by-side split pane:

# Open review in a tmux split and return immediately
cr --detach main

# Open review in a tmux split and block until it closes
cr --detach --wait main

This is how the Claude Code skill invokes cr — --detach --wait is a single blocking call that opens the TUI next to Claude Code and waits for you to finish reviewing.

Keybindings

All keybindings are configurable via ~/.config/cr/config.toml.

Navigation

Key	Action
j / k	Scroll down / up
h / l	Switch to left (old) / right (new) pane
Ctrl-d / Ctrl-u	Half page down / up
gg / G	Jump to top / bottom of file
]c / [c	Next / prev hunk
]f / [f	Next / prev file
]m / [m	Next / prev comment
]e / [e	Expand context below / above (10 lines)

File switching

Key	Action
Tab	Toggle file tree sidebar
Space f	Fuzzy file search
Space s	Fuzzy content search

Comments

Key	Action
c	Comment on current line
V	Visual select mode (then j/k to extend, c to comment on range)
e	Edit comment (cursor must be on comment row)
dc	Delete comment (cursor must be on comment row)

View

Key	Action
w	Toggle word-level diff highlighting
z	Toggle line wrapping
/	Search within current file
?	Help overlay
q	Quit (comments are auto-saved)

How It Works

git repo ──git diff──> cr (TUI) ──.crit/ YAML──> crit / Claude