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

1. cr <ref> parses the git diff and renders it side-by-side with syntax highlighting
2. You navigate with vim motions and leave inline comments
3. Comments are auto-saved to .crit/reviews/ as YAML — the exact same format crit uses
4. cr status outputs all comments as JSON for Claude (or any tool) to consume
5. Claude reads the comments, edits your code, and you can re-review with cr

Better Together: cr + crit

cr was built to complement crit, not replace it. They cover different parts of the review workflow and share the same .crit/ storage format:

Tool	Reviews	Think of it as
crit	Markdown documents (plans, specs, designs)	"Review what Claude writes"
cr	Git diffs (code changes across files)	"Review what Claude changes"

Shared storage

Both tools read and write to .crit/reviews/ using the same YAML schema:

• Comments left in cr show up in crit status <file>
• Comments left in crit are visible in cr
• The session manifest at .crit/code-review.yaml is readable by both

The full ecosystem

# Install both
go install github.com/kevindutra/crit/cmd/crit@latest
go install github.com/adilp/crit-diff@latest

# Claude writes a plan → review the document with crit
crit review docs/plan.md

# Claude implements the plan → review the code changes with cr
cr main

# Both leave comments in .crit/ → Claude addresses them
claude "address the comments in .crit/"

In Claude Code

/crit:review docs/plan.md   → crit opens to review the document
/cr-review main              → cr opens to review the diff

Both skills follow the same pattern: open TUI in a tmux pane, user reviews and comments, Claude reads the comments and acts on them.

Configuration

~/.config/cr/config.toml — only override what you need:

[keys]
leader = "Space"

[keys.normal]
scroll_down = "j"
scroll_up = "k"
quit = "q"
# ... see cr --help or press ? in the TUI for all bindings

[display]
theme = "auto"       # auto | dark | light
word_diff = true     # word-level diff on by default
wrap = false         # line wrapping off by default
tab_width = 4
min_width = 100      # below this, show "too narrow" message

[colors]
add_bg = "#0d2818"           # line background for added lines
delete_bg = "#2d1117"        # line background for deleted lines
emphasis_add = "#1a4d2e"     # word-level add highlight
emphasis_delete = "#5c1a1a"  # word-level delete highlight
cursor_active = "237"        # cursor on active pane
cursor_inactive = "235"      # cursor on inactive pane

Development

go test ./...
go build ./...
go vet ./...

License

MIT