diff
The diff pane as a plugin: /diff opens the session's uncommitted changes
beside the transcript, one row per changed file and every file's hunks
beneath, and closes it again; each toggle leaves Diff panel shown or
Diff panel hidden in the transcript. The header, the file list and its
toggles stay put while the wheel moves the hunks under them three rows a
tick (the plugin answers the pane's ui.scroll itself); a row's click puts
that file's hunks at the top; past eight rows the list scrolls under the
built-in's list keys (ctrl+up/ctrl+down, opt+up/opt+down), and
ctrl+x b moves the comparison base on, as the built-in's chord does: both
through Buttons that declare the engine's own actions. The pane refreshes
as Claude edits, runs shell commands and finishes turns, and while it is
open it polls the repository's HEAD so a commit or checkout made elsewhere
shows too. The first successful edit of a session opens the pane by itself
where the terminal is wide enough (144 columns when the person never chose,
110 when they kept it open before; a person who closed it is left alone).
Under the fullscreen layout a terminal under 110 columns gets the
built-in's line asking for a wider one and nothing opens. Without that
layout (CLAUDE_CODE_NO_FLICKER=0, which /diff learns from the command's
presentation) the pane opens inline at any width, focused, in the
built-in dialog's shape: the title, the count, the file rows, the key
hints; the arrows walk the rows, Enter shows that file's hunks alone,
Escape backs out to the list and then closes, leaving Diff dialog dismissed; toasts are held while it is up. A file's ask button arms that
file: its hunks ride the next prompt as context, once.
The pane compares the working tree against HEAD, split at the session's
start (the default), against HEAD plainly, or against the merge-base with
the default branch; the base line under the header names a base other than
the session's, and the choice is kept per repository in the plugin's store.
A picker shows one earlier turn's edits instead of the working tree, read
from the session's messages. Files that changed before the session started
(by their timestamp, among the paths already dirty at the start), and noise
(lockfiles, generated and test files), are listed apart and folded until
asked for; a rename lists as git prints it. Outside a git repository
/diff says so and does nothing else.
hooks/register.ts is the module; everything under hooks/ is its parts.
What it hooks
| event | what the hook does |
|---|---|
session.start |
Binds the engine once, registers /diff (a session where another /diff is listed leaves the plugin idle), and pins the repository. |
ui.render of PromptHint |
Reads the terminal's width, which decides whether the first edit opens the pane. |
ui.render of Pane |
Draws the pane: docked, the header, base line, source picker, file list and toggles over the window of hunks; inline, the dialog. |
command.run of diff |
Opens or closes the pane (focused and closing on Escape without the fullscreen layout), says which, and remembers the choice. |
ui.close of the pane |
Backs out of the dialog's detail view instead of closing; else remembers the person's close as /diff's. |
ui.scroll of the pane |
Docked, moves the hunks under the pinned header and list (three rows a wheel tick, a page a page key) and keeps the engine's window still. |
command.run of clear, resume |
Closes the pane and forgets the session's state. |
tool.call of Edit, Write, NotebookEdit |
After the edit, refreshes an open pane; the session's first successful edit opens it. |
tool.call of Bash, PowerShell |
After the command, refreshes an open pane. |
turn.complete |
Refreshes an open pane. |
prompt.submit |
Adds the armed file's hunks to the prompt's context and disarms. |
What it calls on $
clock.after, clock.every, clock.now, command.register, fs.list,
fs.read, fs.stat, process.run (git, read-only), session.messages,
store.get, store.set, telemetry.log, telemetry.mark, ui.close,
ui.invalidate, ui.log, ui.open, ui.resolve, ui.status.
$.telemetry is the telemetry plugin's noun; where it is absent the rows
are dropped and nothing else changes.
Try it
claude --plugin-dir /path/to/diff
then /diff inside a git repository with a modified file.