orbit (Offline Review Board In Terminal)

A terminal-based code review tool. Browse git diffs, leave comments on specific lines, then export everything as a prompt you can paste into Claude Code or any other AI tool.

Why

Inspired by difit, a great browser-based local diff viewer. Commenting on lines works in the browser, but not yet in the TUI. I wanted a fully terminal-native diff reviewer with line-level comments, a customizable syntax highlighting theme, split view, and a prompt export workflow for AI coding assistants -- so I built orbit.

The key trick is the prompt export. Your review comments become a structured prompt that an AI coding assistant can act on directly. Review a diff, jot down what needs fixing, copy the prompt, paste it, done.

Screenshots

Home screen -- file tree with diff preview

Unified view -- unified diff with syntax highlighting, fold/unfold

Split view -- side-by-side comparison

Comment -- add review comments on any line

Prompt preview -- export comments as a structured prompt

Install

Requires Bun v1.2+.

git clone https://github.com/Hoshock/orbit.git
cd orbit
bun install
bun run register   # symlinks bin/orbit to ~/.local/bin/orbit

Make sure ~/.local/bin is in your PATH.

Usage

orbit                     # unstaged changes (git diff)
orbit .                   # same as above
orbit --staged            # staged changes (git diff --staged)
orbit HEAD                # last commit (HEAD~1..HEAD)
orbit HEAD~3..HEAD        # commit range
orbit feature main        # branch comparison
orbit --root SHA~1..SHA   # diff against empty tree if base is unresolvable

Lazygit integration

Add the following to your lazygit config (~/.config/lazygit/config.yml) to launch orbit directly from lazygit with a single key:

customCommands:
  - key: "o"
    description: "Review uncommitted changes"
    command: "orbit ."
    context: "files"
    output: terminal
  - key: "o"
    description: "Review branch diff"
    command: "orbit {{.SelectedLocalBranch.Name}} {{.CheckedOutBranch.Name}}"
    context: "localBranches"
    output: terminal
  - key: "o"
    description: "Review commit(s)"
    command: "orbit --root {{.SelectedCommitRange.From}}~1..{{.SelectedCommitRange.To}}"
    context: "commits"
    output: terminal

Press o in any of these panels to open orbit:

Panel	What it reviews
Files	Unstaged changes
Branches	Diff between selected branch and current branch
Commits	Selected commit, or range if multiple are selected

For commit ranges, select multiple commits with v (visual mode) or shift+up/down in lazygit, then press o. The ~1 ensures the first selected commit is included in the diff. The --root flag handles the case where the selection includes the initial commit by diffing against an empty tree.

Keybindings

The following are default keybindings. You can override them in config.toml.

File list

Key	Action
Esc/q	Quit
Up/Down	Move cursor
Left/Right	Collapse/expand directory
[/]	Shrink/grow tree panel (10%-50%)
Enter	Open diff or toggle directory
c	Comment list
p	Prompt preview
t	Toggle split/unified
v	Toggle viewed

Diff view

Key	Action
Esc/q	Back to file list
Up/Down	Move by line
Left/Right	Switch side (split mode)
Shift+Up/Down	Select range
c	Comment on current line or selection
d	Delete comment at cursor
e	Edit comment at cursor
f	File-level comment
t	Toggle split/unified
v	Toggle viewed
z	Fold/unfold (incremental, 20 lines at a time)

Comment input

Key	Action
Esc	Cancel
Ctrl+Enter	Submit

Comment list

Key	Action
Esc/q	Back to file list
Up/Down	Move cursor
Enter	Jump to comment
d	Delete comment
e	Edit comment

Prompt preview

Key	Action
Esc/q	Back
y	Copy prompt to clipboard

How the prompt works

Each comment you leave records the file path, line number, which side of the diff (old/new), and the code at that line. When you press p to preview and y to copy, orbit formats all of this into a single text block:

src/app.tsx:L42 (a1b2c3d)
This function should handle the edge case where files is empty.
==========
src/utils/git.ts:L15-L20 (a1b2c3d)
Extract this into a helper, it's duplicated in three places.

Paste that into Claude Code (or any LLM) and it has enough context to act on each comment.

Persistence

Comments, viewed status, and tree panel width are automatically saved and restored across sessions.

Data	Cache file
Comments, viewed, tree width	/tmp/orbit-<repo>-<hash>.json

The hash is derived from the diff range (e.g., HEAD~1..HEAD), so different ranges get separate caches. Cache files live in /tmp and are cleared on OS restart.

Configuration

orbit reads custom settings from ${XDG_CONFIG_HOME:-~/.config}/orbit/config.toml. If the file (or a specific key) is missing, default values are used.

file_tree_initial_width = 0.2
initial_view = "unified" # or "split"

[keybindings.file-tree]
quit = "q"
tree_shrink = "["
tree_grow = "]"
comment_list = "c"
prompt_preview = "p"
toggle_view_mode = "t"
toggle_viewed = "v"

[keybindings.diff-view]
quit = "q"
comment = "c"
delete_comment = "d"
edit_comment = "e"
file_comment = "f"
toggle_view_mode = "t"
toggle_viewed = "v"
fold = "z"

# comment-input has no configurable keybindings (Esc / Ctrl+Enter fixed)

[keybindings.comment-list]
quit = "q"
delete_comment = "d"
edit_comment = "e"

[keybindings.prompt-preview]
quit = "q"
copy_prompt = "y"

Stack

• Bun - runtime and test runner
• OpenTUI - terminal UI framework (React-based)
• React - component model
• Biome - linter and formatter

Development

bun run start             # run from source
bun test                  # run tests
bun run check             # lint + build check
bun run lint              # auto-fix lint issues

Syntax highlighting

orbit uses tree-sitter for syntax highlighting. The following languages are currently supported:

Language	Source
JavaScript	OpenTUI built-in
TypeScript	OpenTUI built-in
Markdown	OpenTUI built-in
Zig	OpenTUI built-in
Python	Bundled grammar (assets/tree-sitter/python/)

Adding a new language

1. Get the .wasm grammar and highlights.scm

   mkdir -p assets/tree-sitter/<language>
   
   # Prebuilt wasm from unpkg
   curl -L "https://unpkg.com/tree-sitter-wasms@latest/out/tree-sitter-<language>.wasm" \
     -o assets/tree-sitter/<language>/tree-sitter-<language>.wasm
   
   # Highlight queries from the official tree-sitter grammar repo
   curl -L "https://raw.githubusercontent.com/tree-sitter/tree-sitter-<language>/master/queries/highlights.scm" \
     -o assets/tree-sitter/<language>/highlights.scm

   Verify the .wasm starts with \0asm (not a 404 page): xxd ... | head -1

2. Register the parser in src/index.tsx

   import langWasm from "../assets/tree-sitter/<language>/tree-sitter-<language>.wasm" with { type: "file" };
   import langHighlights from "../assets/tree-sitter/<language>/highlights.scm" with { type: "file" };

   Then add an entry to the addDefaultParsers() call:

   addDefaultParsers([
     // ... existing entries
     {
       filetype: "<language>",
       wasm: resolve(__dir, langWasm),
       queries: { highlights: [resolve(__dir, langHighlights)] },
     },
   ]);

3. Ensure filetype.ts has the mapping — src/utils/filetype.ts maps file extensions to language names. Add an entry if it doesn't exist yet.

4. Add a LICENSE file — Place a LICENSE in assets/tree-sitter/<language>/ with the MIT notice from the grammar repo. See assets/tree-sitter/python/LICENSE for the format.

5. Verify — bun run check should show the new .wasm and .scm in the build output.

License

MIT