whydatApp (why?)

Ever install something, then months later wonder why it's on your machine?

why? catches every package manager install (and supported uninstalls) (brew, npm, pip, cargo, apt, …) right as it happens via a lightweight shell hook, then prompts you to jot down what the tool is for, which project needed it, whether it's worth keeping, and what to do with it later. It also captures a short command-history snippet for context (redacted for secrets) so you can reconstruct what led up to an install. Everything stays in a local SQLite database — nothing is sent anywhere. Browse, search, filter, and export your install history through a built-in web UI, or right from the terminal.

What you can answer with why?:

• What do I have installed? — Full inventory across all package managers in one place
• Why did I install this? — Context captured at install time, while you remember
• Which project needed it? — Auto-inferred from your working directory
• Is this still useful? — Mark tools as experimental, for removal, or permanent docs
• What's taking up space? — See resolved install paths and identify candidates to uninstall
• Did I ever install X? — Search by name, command, or description — find it instantly
• Did I ever remove X? — Uninstalls are captured too; removed entries stay in your history
• What led up to this install? — See the recent commands that ran before it (with secret redaction)
• What should I clean up? — Review queue surfaces incomplete entries and stale experimental installs
• How do I set up this project elsewhere? — Export your setup dependencies to Markdown or JSON
• Which managers do I use most? — Dashboard shows install trends by manager, project, and month

Screenshots

Browse and filter your full install history in the web UI:

The dashboard shows installs by purpose, manager, project, and trend over time:

Install

From PyPI (recommended):

uv tool install 'why-cli[web]'   # or: pipx install 'why-cli[web]'
why init                          # interactive setup; edits your shell rc

With Homebrew (macOS/Linux):

brew tap nostoi/why
brew trust --tap nostoi/why      # Homebrew 6 requires this for any third-party tap
brew install why-cli
why init

The formula includes the web UI. Tap source: Nostoi/homebrew-why.

From source (for development or pre-release):

git clone https://github.com/Nostoi/whydatapp.git
cd whydatapp
uv tool install --editable '.[web]'
why init

Restart your shell, then try brew install ripgrep (or any tracked manager).

To upgrade:

uv tool upgrade why-cli          # or: pipx upgrade why-cli

That's it. Schema migrations, new config keys, and the shell hook in ~/.why/ all catch up on their own the next time you run any why command. If the hook was refreshed you'll be told to start a new shell — nothing is restarted for you.

Full install instructions, including building from a wheel: Install guide.

Quick reference

Detailed usage with examples: Usage guide.

Documentation

• Install — Requirements, install paths (PyPI / source / wheel), what why init does, uninstall.
• Usage — Every CLI subcommand with examples.
• Web UI — Walkthrough of the local web interface.
• Configuration — ~/.why/*.toml files, env vars, ignore rules.
• Troubleshooting — Hook not firing, prompt missed, address-in-use, restoring data, filing bugs.
• Development — Clone, set up, run tests, build the wheel, project layout, contribute.
• Changelog — Release history.
• Roadmap — What's shipped and what's next, in priority order with the reasoning.

Privacy

• All data lives in ~/.why/data.db unless you explicitly run why sessions summarize or click Summarize in the web UI. Both surfaces enforce confirm_before_send: with the default remote policy, anything leaving the machine is confirmed first, and the web UI names the endpoint, model, and command count before you approve.
• Recorded transcripts can be removed — why sessions delete <id> hides one, --purge erases it and its commands and summaries.
• The web UI binds to 127.0.0.1 only.
• All static assets vendored locally — no CDN, no Google Fonts, no analytics.
• The shell hook ignores any install triggered by another tracked installer (no false positives from brew resolving deps).
• LLM summaries are opt-in. Command text is redacted on a best-effort basis before storage and before LLM submission, but review payloads with why sessions summarize <id> --print-payload when privacy matters.

License

MIT