mypet 🐱

A fluffy desktop cat that eats your Claude Code tokens.

Move your mouse near the cat — a wobbly little Claude-cookie follows your cursor. Double-click the cat to feed it. It chomps one claude -p call and bubbles back a Claude Code tip, a prompt to try, a 打油诗 (Chinese quatrain), or a tech-news headline. Then goes back to sleep.

👉 mypet.renlab.ai

Why

You pay for Claude Code anyway. The little cat spends your subscription quota — no separate Anthropic API key, no server, no telemetry. When you're not feeding it, it costs zero CPU and zero network. When you do feed it, you get one cute interruption and one tiny morsel of useful information.

It's a screensaver that pays rent.

How it works

 mouse near + double-click  ─►  chomp animation  ─►  claude -p "<prompt>"  ─►  💬 tip bubble
                                                                                    │
                                           click bubble copies tip + dismisses  ◄──┘

1. Move mouse close to the cat — a wobbly little cookie sticks to your cursor.
2. A single click earns a soft kitten meow (one of three, picked at random).
3. Double-click the cat to trigger a feed; it plays a chomp animation and immediately shows a "let me think…" bubble while it works.
4. mypet shells out to your local claude CLI — same login, same quota.
5. The reply replaces the thinking bubble (with theme badge + token count).
6. Click the bubble to copy the tip; it auto-dismisses after a few seconds.

Cooldown: one feed per minute (the cat tells you when it's still digesting). No interaction for 10 min → the cat gets quietly hungry. All visual — still zero background work.

States

Each state plays its own bundled APNG (3D Pixar-style kitten, generated via Kling and cleaned through BiRefNet). The Mac app overlays subtle procedural micro-motion only when it adds something — most of the time the APNG carries the entire performance.

Feedback cycle (user-triggered)

State	When	Looks like
idle	default	sitting, slow breath + tail-tip twitch
eating	feeding	nibbling a Claude-cookie held in both paws
excited	feed succeeded	sparkly eyes, tail vibrating high
purring	tip showing	eyes closed in crescent smile, head tilted

Sleep progression (passive — silent, never grabs attention)

State	When	Looks like
sleepy	1min idle	heavy eyelids, slow blink, one droop-and-recover
dozing	2.5min idle	sitting upright, head dropped to chest, eyes closed
sleeping	5min idle	curled into a fluffy ball on its side, deep breath

Mood / engagement

State	When	Looks like
hungry	10min no feed	quiet sad sit, glistening eyes, no demand
petting	hover ≥1s on cat	head leans into invisible hand, eyes squint happy

Spatial (drag the window to a screen edge)

State	When	Looks like
clingTop	window near top	kitten hangs upside-down by both front paws
peekRight	window near right edge	half body peeks out from the right, looking back curiously
peekLeft	window near left edge	mirrored peekRight

Personality moments (rare, idle-only, gated to recent activity)

State	When	Looks like
licking	rare ambient	kitten licks its right paw (~5 slow licks)
washing	rare ambient	kitten wipes face with the licked paw

Tip themes

Every feed picks one of six themes (weighted toward the Claude Code niche) so you don't get the same vibe twice in a row:

Badge	Theme	Weight	What you get
☕	claudeTip	30%	Non-obvious Claude Code tip
💡	promptIdea	20%	A specific prompt to type into Claude Code now
📰	techNews	18%	One-line tech-news headline
🤓	til	14%	"Today I learned" fact a senior eng would still find surprising
😆	devJoke	10%	Programmer one-liner
🥟	dayouShi	8%	程序员打油诗 (Chinese punny quatrain)

Click the bubble to copy the tip to your clipboard. The menubar 🐾 dropdown keeps the last 10 tips under Recent tips — click any to copy.

Requirements

• macOS 13 or later
• Claude Code CLI on your PATH (claude --version works)

Install

mypet is built for Claude Code users (it feeds on your CC tokens), so the natural way in is to let Claude Code install it.

Option A — paste a prompt into Claude Code (recommended)

Install mypet — a cute 3D desktop kitten that lives in my screen corner and feeds on Claude Code tokens. Run brew install --cask anzy-renlab-ai/tap/mypet, then launch the mypet app.

Claude Code runs the install and opens the app for you.

No Claude Code yet? mypet needs it — the feed shells out to your local claude CLI. Get it first at claude.com/code.

Option B — Homebrew yourself

brew install --cask anzy-renlab-ai/tap/mypet

Updates later with brew upgrade --cask mypet.

Option C — pre-built .app (manual)

1. Grab the latest mypet-x.y.z-macos.zip from Releases.
2. Unzip → drag mypet.app to /Applications.
3. First launch only: macOS Gatekeeper will say "developer cannot be verified" because the app is ad-hoc signed (no Apple Developer ID). Right-click mypet.app → Open → Open in the dialog. Or:

   xattr -d com.apple.quarantine /Applications/mypet.app

4. Look for the 🐾 paw in your menubar.

Option C — build from source

git clone https://github.com/anzy-renlab-ai/mypet
cd mypet
swift run mypet

After install

First launch shows a tiny onboarding wizard (detects claude, asks about launch-at-login, plays a demo feed).

The cat sits in the bottom-right of your primary display. The menubar 🐾 gives you Feed now, Recent tips, Bring cat to this screen, Snap to edge, Launch at login, and Quit.

Tests

swift test

95 tests cover the claude subprocess wrapper (binary discovery, timeout, cancellation, output normalization including multi-line tips, error classification, concurrency guard, FD-leak check, JSON envelope parsing for token capture), the feed log (corruption recovery, cooldown, hungry detection, max-entries cap), the pet state machine, the feed coordinator (theme rotation + locale-aware prompts + token reporting), and the window configuration (snap-to-edge, expanded/compact sizes).

Layout

Sources/MyPet/
  App/        MyPetApp, AppDelegate, MenubarController
  Window/     PetWindow (borderless, transparent, status-bar level, draggable)
  Scene/      TurtleView + CuteCatFace (all-vector cat, no SF Symbol)
  UI/         OnboardingView, TipBubble, FeedButton
  Domain/     ClaudeSubprocess, FeedCoordinator, PetState, LoginItem
  Storage/    FeedLog (JSON in Application Support)

See CLAUDE.md for the architecture cheat-sheet and invariants that exist to keep mypet stable + cheap (zero-CPU-when-idle, hover-via-Task, single-in-flight feed, etc.).

License

Dual-tracked:

• Source code (LICENSE) — MIT. Fork it, ship it, sell it.
• Cat artwork & audio (Sources/MyPet/Resources/sprites/LICENSE) — All Rights Reserved. The fluffy kitten is © alvin. Personal use of mypet is fine; re-packaging the cat in another product / training AI on the sprites / commercial redistribution requires written permission.

See NOTICE.md for the full attribution.

PRs welcome on the code — especially new tip prompts. Skin contributions welcome but submitted skins are dual-licensed (code MIT, artwork CC-BY-NC by default unless you specify otherwise).