debuff

Install

Works with Claude Code, Codex, VS Code, Cursor, Windsurf, Claude Desktop. Read the repository before you give any tool access to your data.

npx agentmarket install connector/debuff-jp-debuff

About

Use cases: testing, debugging

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Permissions

What this server can do and what it asks for, from its tool list and install config. Checked Oct 25, 2026.

Tools

9 read · 14 write · 0 delete

Secrets

None asked for

Install scripts

None found

Runs as

Node.js package

Tools (23)

Read from the source code; the running server may differ. Descriptions are the server’s own words; hidden characters are shown as [U+…].

• buildProduction build

  Build for production and return the size report (raw, gzip, brotli per file). `leaks` lists dev-only code found in the output; it must be empty. `saves` compares the game's saves with saves.json: an error means players would lose saved progress. Don't accept save changes yourself; tell the human (they run `debuff build --accept-saves`).

• fuzzFuzz playtest

  Play the game headlessly with random but plausible input (movement keys held, action keys tapped) to find runtime errors, stuck states and back-and-forth loops. Each finding includes the explained error (kind, source-mapped file:line, hint) and `repro`: a scenario file that replays it exactly. Pass that file to run_scenarios to reproduce, then again after fixing to verify. The same seed gives the same inputs.

• game_captureCapture frame

  Screenshot of the current frame as a PNG image. With `path`, also saves it to that file in the project.

• game_commandRun a game command

  Run a command the game registered with devTools({ commands }) (warp to a level, grant an item, select a cell), like a scenario's { command, args } step; recorded in replays. Prefer it over computing screen coordinates for game_input. An unknown name lists the registered ones. Returns the command's result and the new state.

• game_errorsRuntime errorsread-only

  Runtime errors since the game started, explained: kind (your-code, debuff-usage, debuff-bug, outside), where (source file:line, source-mapped), a hint, the loop phase and tick, and a repeat count. A loop error stops the game; fix it, then game_pause false to resume. For debuff-bug, tell the human and share reportUrl rather than working around it. Type errors aren't runtime errors: use typecheck.

• game_framesFrame breakdownread-only

  Recent frames, oldest first: intervalMs (what the player feels), updateMs, renderMs, steps (>1 means catching up), quads, drawCalls and longTaskMs (browser-reported main-thread stalls). Use it to explain stutter; in headless mode times reflect stepping, not real play. summary: true returns percentiles and the 3 slowest frames instead of every frame.

• game_inputSend input

  Keyboard or pointer input. press/release take a KeyboardEvent.code (e.g. Space, ArrowLeft, KeyZ). tap/pointer_down/pointer_move take logical x, y. Input takes effect on the next game_step.

• game_notesHuman notesread-only

  Moments the human flagged in the overlay (live mode): their words, the tick, the scene's inspect() state then, and the frames leading up to it.

• game_paramsList paramsread-only

  Every tunable param group: schema (type, default, min, max, units, description) and current values.

• game_pausePause or resume

  Pause or resume a live game (headless games are always paused). game_step also pauses first.

• game_profileFrame profileread-only

  Why the game stutters, from myaku: frame-time percentiles (p50/p95/p99), hitches per minute, and the worst hitches explained. Each has a cause (script, gc, upload, compile, layout, throttled, hidden, unknown), a confidence, the script and function to look at when known, and a hint. Spans show time in debuff's update and render. Prefer this over game_frames to explain stutter; measure in live mode, since headless stepping doesn't reflect real play.

• game_replaySave a replay

  Everything played since the game loaded (keys, pointer, param changes) up to `toTick` (default: now), saved as a scenario in .debuff/replays/ that replays it exactly. Use a note's `tick` to reproduce what the human saw when they flagged it, then run_scenarios with the returned file. `warnings` lists anything a replay can't reproduce (for example slow motion).

• game_rewindRewind the live game

  Live mode only. Take the human's game back (or forward, within the known session) to `tick`: the page reloads, replays the session's inputs to that tick and stays paused, so the state is exactly what it was then. Use a note's `tick` to look at the moment the human flagged. The page needs a second to reload; then use game_state or game_capture.

• game_set_paramSet param

  Set a tunable param live. Values are validated against the param's type and range. Changes last until game_start or a reload.

• game_startStart game

  Connect to the game. auto (default): attach to the human's live game if `debuff dev` has it open in a browser, else start a private headless copy, paused. Returns the mode, state and how many notes the human has flagged. Replaces any running session.

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Stars

3

Forks

1

Open issues

0

Weekly downloads

2,558

Last commit (this folder)

Oct 23, 2026 (5 days ago)

Last release

Oct 23, 2026 (5 days ago)

Last package publish

Oct 23, 2026 (5 days ago)

From GitHub (fetched Oct 24, 2026) and the package registry.

Details

Registry name

jp.debuff/debuff

Version

0.15.0

Auth

No auth

Packages

npm @debuffjp/mcp

License

MIT

Repository

github.com/debuffjp/debuff

Website

debuff.jp/docs/agents

First seen

Oct 24, 2026

Last checked

Oct 25, 2026

Source

Official MCP Registrygithub-graphql