pi-file-watcher

Aider-style watch mode for pi. Watch any folder for source file saves — when a line ending with #pi! is detected, it's automatically sent to the LLM as a prompt.

Install

pi install npm:pi-file-watcher

Usage

Start watching a directory (defaults to . if no path given):

/watch start
/watch start ./src

Then in any source file, add #pi! at the end of a comment line and save:

// refactor this function to use async/await  #pi!

# rename this variable to something descriptive  #pi!

-- optimise this query  #pi!

Pi picks it up instantly and starts working. The marker is automatically removed from the file when the task is complete.

Deferred execution

Add a time annotation after #pi! to schedule the prompt instead of firing immediately:

// refactor this to use async/await    #pi! @5m
// review this file for edge cases     #pi! @2h
// clean up before standup             #pi! @09:30
// come back to this tonight           #pi! @18:00

Relative formats: 30s, 5m, 2h, 1h30m Absolute format: HH:MM local time (schedules next day if already past)

If you save again before the timer fires, the old job is cancelled and re-evaluated from the new file content. Use /watch cancel to cancel manually.

Configuration

Auto-start watching (recommended)

Launch pi and start watching immediately with --watch:

pi --watch ./src
pi --watch ./src --marker "#go!"

Or persist it in your settings file (~/.pi/agent/settings.json for global, .pi/settings.json for project):

{ "flags": { "--watch": "./src", "--marker": "#go!" } }

Extra ignored directories

By default the watcher skips node_modules, .git, dist, build, and a handful of other common output dirs. Add more with --ignore (comma-separated, merged with the defaults):

pi --ignore "tmp,fixtures,__snapshots__"

Or in settings:

{ "flags": { "--ignore": "tmp,fixtures" } }

Persistent marker

Set your preferred marker once via CLI flag — pi remembers it across sessions:

pi --marker "#go!"

Or add it to your settings file:

{ "flags": { "--marker": "#go!" } }

Runtime marker change

Change the marker for the current session only:

/watch marker #go!

Commands

| Command | Description | |---|---| | /watch start [path] | Start watching a directory (defaults to .) | | /watch stop [path] | Stop watching one or all directories | | /watch status | Show watched paths, marker, and pending deferred jobs | | /watch marker <marker> | Change the trigger marker for this session | | /watch cancel [path] | Cancel pending deferred job(s) |

How it works

When a trigger fires, the file watcher closes immediately — the OS drops any events that arrive while the LLM is processing. After the LLM finishes its turn, the watcher restarts fresh. This means no storage, no seen-set, no extra files — the OS kernel provides the deduplication guarantee. The same approach used by aider.

The LLM is also instructed to remove the #pi! marker from the file as part of completing the task, preventing accidental re-triggers on subsequent saves.

License

MIT