digi-pet

A Digimon V-Pet that lives above the Claude Code prompt. It eats your session's prompt cache, fights while Claude works, and digivolves by the Digital Monster Color's rules from what you actually do: turns, tests, commits and how well you look after it.

Every Digimon and evolution chart of the five versions: Digitama Hatchery, Digital Monster Color.

Install

/plugin marketplace add trongtaiz/digi-pet
/plugin install digi-pet@digi-pet

Then /reload-plugins, or start a new session. Your pet hatches from a random egg (one of the five DMC versions).

digi-pet is a hooks-module plugin: it needs a Claude Code build that loads plugin hook modules. Notifications use osascript, so they are macOS only; everything else runs anywhere.

How it works

The screen

The pet sits in a small Digivice in the band above the prompt. What the band shows follows what Claude is doing:

• Idle: the pet walks around its screen, with its name, stage, hunger hearts and progress to the next stage beside it.
• Working: while a turn runs, the band becomes a fight (see Battles). With ten rows or more, the tool running gets a row of its own under the pet: the command, file or task it runs, and for how long (⏵ Bash npm test 12s).
• Needs you: when it is hungry, starving, sick or digivolving, the Digivice shell takes that state's colour (orange, red, purple, gold) and the pet says why.

With little room (a long draft in the prompt) the band shrinks to the bare screen, then a half-size one, then a single line. /digi pane opens a side pane with the full picture: the Digivice, its six stats as bars, the branches its stage can take and its evolution so far.

Hunger is the prompt cache

Claude Code caches the conversation for a while after each request (60 minutes on a 1-hour cache, 5 on the default one). Coming back before it expires is cheap; after, the whole context is sent again at full price. The pet's hunger is that clock:

Since the last request (60 min cache)	The pet
under 30 min	full
30 to 45 min	peckish
45 to 55 min	hungry: a toast and a macOS notification
55 to 60 min	starving: another warning, with the minutes left
60 min and over	the cache is cold

Any prompt feeds it. The thresholds scale with ttlMinutes. The pet does not get hungry when the cache is not worth keeping warm:

• in rest hours (restHours, lunch and evenings by default), unless you /digi wake it, which keeps it up until that window ends;
• on a break (/digi break 90m, /digi break until 15:30) or after /digi sleep, until your next prompt;
• in a side session (/digi side, or a folder listed in sidePaths), where it still shows when the cache goes cold (cache 42m left (cold at 10:00));
• when the context is under minContextTokens, since a small cache is cheap to rebuild.

It also does not warn you about a cache that will expire during rest hours anyway: feeding it then would only move the expiry into the break.

Care mistakes

A cache that goes cold, and is then picked up again the same day, is a care mistake: the pet is sick for the next three turns, and the mistake counts against it when it digivolves. Like evolution, the pane counts this stage's only; /digi stats also gives the total. To keep this fair:

• it is at most one care mistake per session per day;
• coming back the next day is never one (the day starts at dayStartsHour, so a late night belongs to the evening before);
• a cache that went cold in rest hours or on a break is never one.

A context over 85% full is an overfeed, which also counts at evolution time. Turns sent in rest hours are sleep disturbances.

Battles

While a turn runs, monsters run in from the left and the pet shoots them down. That part is for show. The real battles are your checks: tests, builds, type-checks and linters (npm test, pytest, tsc, cargo test, eslint and the like).

• When a check fails, a red boss appears with "1 check red" and stays.
• When the same check passes again, the boss blows up: a win. A run of one file wins only the failures in that file; a run of everything wins them all.
• If a turn ends with it still red, it is a loss, once. Still red at the next turn's end, it is the same battle, not another loss.
• An interrupted turn is neither.

A check is red	It goes green in the same turn

Failures are read from the check's output as well as its exit code, since most runs are piped through tail. When the output names what failed (FAIL tests/a.test.js, src/a.ts(3,1): error TS…), the battle goes by those names, so the same broken test seen through another command is the same battle. A failure another session already lost this week is a known one, and costs no loss again. A test that was broken before you started costs you one loss, not one every turn.

Only a check run as a command counts: grep jest or a script in a heredoc is not one. With several checks in one call (npx jest; npx eslint src), each is judged by the failures it prints itself. A run against other code than your work (after git stash, on an old commit or a remote branch checked out, or in a worktree made in the same command) is no battle.

Wins this stage show top right. The win ratio counts this stage's battles only, starts clean at each digivolution, and decides its later evolutions.

Allies

Each subagent Claude runs joins the fight as a small Digimon in front of the pet, its task written above it: Koromon for a general-purpose agent, Tokomon for Explore, Tsunomon for Plan, Tanemon or Pagumon for any other type. Up to three stand on the field, and +n counts the rest. When the subagent is done the ally cheers and leaves; if it failed, it lies grey a moment first. One still running between turns waits on the pet's own screen.

Allies are for show. What counts toward growth is the summon: each Agent call that returns without an error, whether or not an ally was drawn for it.

Stats

Six stats grow from your work. Past 20 points in a day a stat grows a quarter as fast, so no single marathon day makes the pet.

Stat	Grows from
STA	time Claude spends working
INT	research: reads, searches, web lookups
ATK	lines written (Edit and Write)
DEF	checks that pass
SPD	parallel tool calls and quick turns
SYN	your prompts, pats (/digi pet, three a day) and a streak of active days

Growing up

The pet hatches from an egg, then goes Baby I, Baby II, Rookie, Champion, Ultimate and Mega. Each stage lasts a while before it can digivolve (at normal pace; an active day is one with at least five turns):

Stage	Before it can digivolve
Egg	3 turns
Baby I	25 turns
Baby II	2 active days and 100 turns
Rookie	5 active days
Champion	10 active days and 30 trophies
Ultimate	21 active days, 60 trophies and 10 summons
Mega	14 active days, then a jogress

A trophy is a commit or an opened pull request; a summon is a subagent. Pull requests count on any forge whose CLI or MCP server opens them: GitHub (gh), GitLab (glab, or git push -o merge_request.create), Gitea and Forgejo (tea, fj), Azure DevOps (az repos pr create) and Gerrit (a push to refs/for/). pace makes every stage last a quarter as long (fast) or twice as long (slow).

Which Digimon it becomes is the Digital Monster Color's own chart. The counts since the pet entered its stage pick the branch: care mistakes, training (turns where Claude used tools, up to 12 a day), overfeeds, sleep disturbances, battles and win ratio. Becoming an Ultimate or a Mega takes an 80% win ratio. Under 40% it never happens; between 40% and 80% there is a chance that rises with the ratio, rolled once a day.

Two house rules sit on top of the chart:

• Chaos. Risky commands (git push --force, --no-verify, git reset --hard, rm -rf of anything but temp or build folders) and interrupted turns are chaos. Five or more per day of a stage sends the pet down the Virus branch where there is one.
• A Rookie always digivolves. If no branch fits, it takes the chart's catch-all, as the device does.

/digi shows the counts and what the next stage still needs. /digi pane lists the branches: each Digimon the stage can become, the counts its rule asks for (ticked when met), ▸ on the one the counts lead to now, and the chaos that would send it down the Virus branch. /digi log lists every digivolution so far.

Jogress and eggs

A Mega with 15 battles this stage and an 80% win ratio can fuse with the partner its chart names: /digi jogress. A few Ultimates (Kimeramon) can too, once their stage has lasted, besides digivolving by their own rule. When both ways are open, the pet does not pick for you: it waits out that day for /digi evolve or /digi jogress, and with no pick it digivolves on its own the next day. Each new pet hatches from one of the five DMC version eggs at random, and each egg leads to a different chart.

Commands

Command
/digi or /digi stats	Stats, hunger, and what the next evolution needs
/digi pane	Open the side pane: the Digivice, stats, branches and evolution log
/digi log	Evolution history
/digi pet	Pat it (the first three a day raise SYN)
/digi evolve	Digivolve now, when a jogress is also open and the pet waits for a pick
/digi jogress	Fuse with a partner, where the chart allows
/digi sleep	Sleep until your next prompt
/digi wake	Wake it: ends a sleep or a break, and keeps it up through the rest window it is in
/digi break 90m / until 15:30 / off	A one-off rest window
/digi side [off]	Mark this session as side work: no hunger
/digi sim <species> [state] / sim off	Preview any species and state
/digi debug ttl <min> / off	Shorten the cache TTL to watch hunger play out

Options

Set them with claude plugin configure digi-pet@digi-pet:

Option	Default
ttlMinutes	60	Your cache TTL: 60 on a 1-hour cache, 5 on the default one
restHours	12:00-14:00,18:00-08:00	Nap windows, local time
dayStartsHour	4	A late night counts as the evening before
sidePaths		Globs whose sessions are side sessions
minContextTokens	20000	Below this the cache is cheap to rebuild; no hunger
notify	true	macOS notifications when hungry or starving
pace	normal	fast, normal or slow growth
reducedMotion	false	Draw everything still

In the desktop app the band and the pane are drawn as pictures, redrawn as the pet changes: a web page sets rows of text apart and draws block glyphs at other widths, so the pixels would not meet. The pet's screen, the fight and the pane play their loops as the terminal's do; the tool row under the pet is still, and so is a picture too big for the desktop to take, such as a wide field of allies.

Development

bun install
claude plugin test plugin       # tests
claude plugin validate plugin
bun run preview                 # preview/index.html: every state, rendered
bun scripts/preview.ts --html --readme   # redraw the images in docs/images

To run your working copy, add the folder as a marketplace: /plugin marketplace add /path/to/digi-pet.

License

The code is MIT (see LICENSE). The Digimon sprites, names and evolution data are not: they belong to Bandai / Toei, and digi-pet is an unofficial fan project. See NOTICE.md.