An entry's name opens its live demo. Sizes are the plain files you copy, before minifying. Module docs list limits and the closest existing open-source project.
Modules & Tools (38)
Small pieces for single-file games and apps, and the tools that build and test them. Tools are not shipped inside a game.
Device and browser adaptation
Make a game behave on slow phones, privacy-focused browsers and power-saving screens.
env-probes 1.1.0 · API 1: Detects privacy modes that round timers (including Firefox's 16.67 ms clock), scramble canvas read-back or block storage, and says what it found in plain words. global EnvProbes · 16.2 KB · docs
frame-kit 1.2.1 · API 1: Frame pacing for canvas games: even-dt smooths the frame time, quality-governor steps effects down and back up, job-pump spreads heavy jobs across frames, frame-meter shows frames a second, hitches and tap delay in plain words. global EvenDt, QualityGovernor, JobPump, FrameMeter · 38.9 KB · docs
fx-governor 1.1.1 · API 1: Steps visual effects down when the device cannot keep up; never back up behind the player. global FxGovernor · 6.2 KB · docs
slow-note 1.0.0 · API 1: Keeps a short note, only on the device, of the errors, slow taps and long frames a page had; copyable as plain text, nothing is sent anywhere. global SlowNote · 9.7 KB · docs
Saving and data safety
Keep a player's progress safe and let them move it between devices.
save-kit 1.2.1 · API 1: Safe localStorage saves, backup slot, checksummed copy-paste save codes with a size limit on what a paste may unpack to. global SaveKit · 26.5 KB · docs
tab-guard 1.1.0 · API 1: Keeps one open copy of a page in charge (Web Locks), so two tabs do not overwrite each other's saved data, and tells the game when the other copy closes. global TabGuard · 9.6 KB · docs
Games - Looks and effects
Curtains, flying elements, lettering and 3D-looking sprites.
cartoon-3d-kit 1.2.0 · API 1: A written style guide plus demo for the soft, glossy cartoon 3D look done in plain CSS and SVG. no script, a style guide · docs
fly-to-mini 1.2.0 · API 1: A big element scrolls away and a copy flies to its sticky mini version (and back). global FlyToMini · 18.1 KB · docs
sprite-baker 1.7.0 · API 1: Tiny software 3D rasterizer that bakes shaded sprites to canvases once at load, or one frame per tick; also makes silhouette masks and packs sprite sheets. global SpriteBaker · 54.5 KB · docs
stage-curtains 1.2.0 · API 1: Velvet stage curtains that slide shut over a page, then fly open. global StageCurtains · 36.1 KB · docs
sticker-text 1.1.0 · API 1: Die-cut sticker lettering in plain CSS text-shadow rings, no images. global StickerText · 5.0 KB · docs
Games - Controls
Let players hold a button, or play with a gamepad.
back-close 1.2.0 · API 1: Makes the phone back swipe or back button close the top panel instead of leaving the page (CloseWatcher, with an opt-in history fallback for browsers without it). global BackClose · 9.1 KB · docs
hold-press 1.1.0 · API 1: Hold-to-repeat for buttons that survives Android Chrome pointercancel. global HoldPress · 13.0 KB · docs
pad-nav 1.1.0 · API 1: Gamepad API to DOM focus: move through buttons, menus, sliders and drop-downs with a controller, no game code. global PadNav · 29.2 KB · docs
wake-keeper 1.1.0 · API 1: Keeps the screen awake only while a game wants it: released on pause, hidden tab and idle, asked again when allowed. global WakeKeeper · 8.2 KB · docs
Games - Assist
Show a new player around, and keep small children away from the buttons that matter.
grown-ups-door 1.0.0 · API 1: A hold-then-drag task a young child will not finish, in front of the buttons and links a grown-up should press (a speed bump, not security). global GrownUpsDoor · 14.8 KB · docs
spotlight-tour 1.1.0 · API 1: A first-time tour: one dimmed layer, a bright window over the current part, Skip and Back, remembers who saw it and gives a finishing gift once. global SpotlightTour · 12.3 KB · docs
Games - Math
The numbers behind idle and clicker games.
idle-core 1.2.0 · API 1: Tested maths for idle/clicker games: costs, buy-many and buy-max, milestones, away income, boost queue, number format. global IdleCore · 22.8 KB · docs
Games - Testing
Test a game by playing it at random, shrinking any failure to a short replay, counting what it draws and driving real browsers.
canvas-probe 1.1.0 · API 1: Test-build counter for canvas 2D games: calls per frame, save/restore leaks, overhanging drawImage sources, draws below half size, style-write repeats, painted area.
firefox-stand-in 1.0.0 · API 1: Runs a Playwright-for-Python test in stock Firefox (through Selenium and geckodriver) without rewriting it; says plainly which calls it supports and stops with a clear message on the rest.
fuzz-kit 1.1.0 · API 1: Seeded, reproducible random-input fuzzer engine with weighted operations, invariants, liveness checks and failure shrinking; Playwright and Puppeteer runners with real input and CPU throttling; stock-Firefox recipe; test-hook stripper.
speed-lab 1.1.1 · API 1: One-button speed test run on the device: compares your page with parts switched off, keeps the scene in view and uncovered, and says the answer in plain sentences with a copyable table.
storage-probe 1.1.0 · API 1: Page that tells you in plain words whether copies of a page saved in different folders share their saved data, see each other's writes and locks; one button, copyable report.
test-isolation 1.1.0 · API 1: Puts a prefix in front of every localStorage key on a test page, so a speed test or random-play run never touches the real saved game.
webkit-driver 1.3.0 · API 1: Drives WebKitGTK or GNOME Web from Node with no dependencies, using the call names of Playwright and Puppeteer (goto, evaluate, waitForFunction, mouse, keyboard, screenshot, console errors), so a test written for them can also run in WebKit.
App - Efficiency
Keep a one-file app small and light: smaller data in memory, smaller pages on the wire.
memory-compression 2.0.3 · API 2: Keeps big data packed in memory and brings it back exactly, in one file with one pack/unpack: bytes and typed arrays (a 120 MB scene shrinks to 52%, 41% in small mode, and restores in about 175 ms, against 525 ms with lz4js and 1.2 s with fflate) and big lists of plain JavaScript objects (300,000 link objects shrink to 14% of their JSON text, 35% for msgpackr with records). Picks the right layer by itself; MemoryCompressionJSO stays as an alias. global MemoryCompression · 274.3 KB · docs
single-file-tools 1.1.0 · API 1: Font subsetting, safe inline-SVG tightening and a Zopfli self-extracting packer for one-file games.
Model simulation
Simulate random walkers over a graph.
walker-sim 2.2.0 · API 2: Simulates random walkers on a network with seeded, repeatable runs, 16 random-number distributions, 95% ranges and the exact odds to check against (about 6 million walkers a second). global WalkerSim · 64.9 KB · docs
Visualization
Draw maps, flow charts and animated pictures from data.
gif-writer 1.2.0 · API 1: Writes animated GIFs from canvas pictures with one shared palette, storing only the pixels that changed (about 6.8 times smaller than gifenc on a mostly still animation). global GifWriter · 40.0 KB · docs
netflow-engine 2.1.0 · API 2: The engine of Netflow Map as a module you can copy and adapt: nine views of a map and eleven network layouts, no two items on top of each other, WebAssembly twins for Force and Distances, and a use() hand-over for the layers and Sankey add-ons; a 30,000-item network lays out in about 0.8 s. global NetflowEngine · 200.3 KB · docs
netflow-layers 1.3.0 · API 1: Lays out a graph in rows (top to bottom or left to right) with story order, tags instead of very long links, a column for the pages every route passes, and tall maps cut into columns; 20,000-page maps draw in about 0.4 s. global NetflowLayers · 29.1 KB · docs
netflow-sankey 2.3.0 · API 2: Lays out a flow chart (Sankey) from a plain list of links, with about half the weighted crossings of d3-sankey on the charts measured, backward links drawn instead of crashing, and an SVG drawer. global NetflowSankey · 48.2 KB · docs
Size and packaging
Open zip and Excel files safely, and pack a finished page into a smaller file that unpacks itself.
lzma-decode 1.3.0 · API 1: Small readable LZMA1 decoder (ES5), tested against Python's lzma. Browsers can only unpack gzip and deflate natively. global lzmaDecode · 22.2 KB · docs
lzma-pack 2.0.0 · API 2: Packs one HTML file into a smaller self-unpacking file with LZMA and a hash check (Python 3 standard library).
pcodec-js 1.1.0 · API 1: Pcodec for web pages: unpacks (and optionally packs) big lists of numbers in a browser, one file, same bytes as any other Pcodec. The unpack-only file is 68 KB gzipped (the other JavaScript build of Pcodec is 324 KB), streams a 4,000,000-number file in 6.8 MB of memory, and WebAssembly is required (no plain-JavaScript backup). global PcodecJS · 171.9 KB · docs
ppmd-decode 1.3.0 · API 1: A PPMd (7-Zip PPMd7) decoder in one ES5 function, about 6.6 KB packed. It unpacks web-page data about 10% smaller than LZMA, but about 4 times slower. PPMd is by Dmitry Shkarin; the public-domain code it follows is Igor Pavlov's, from 7-Zip. global ppmd7Decode · 45.3 KB · docs
ppmd-pack 2.0.0 · API 2: Packs one HTML file into a self-unpacking file with PPMd, the 7-Zip text compressor (PPMd by Dmitry Shkarin; public-domain code by Igor Pavlov, 7-Zip). Pure Python; pays off above about 60 KB of compressed data.
zip-open 1.2.0 · API 1: Opens .zip and Excel .xlsx files safely: limits counted on what really unpacks, so a zip bomb stops at the limit with a plain-words note. global ZipOpen · 30.7 KB · docs
Story editor packages (10)
Packages for interactive stories, kept with the Story Editor they are cut from (source). Each is MIT-licensed, has no dependencies, and runs in Node 18+ or a browser.
Story data
Create, clean, import and save stories in one shared file format.
story-diff: Says in plain words what one edit did to a story, such as "Add page “The Cellar”".
story-format: Create, clean, search, import and export interactive stories as JSON, with a JSON Schema. Twine import lives in twine-import.
story-outline: Turns an indented outline into pages and choices, or into a whole branching story.
twine-import: Reads Twine stories (Twine 2 HTML, Twee 3, Twine 1) and turns SugarCube and Harlowe code into rules, with a plain-words report.
Story validation
Find dead ends and endings nobody can reach before a reader does.
story-check: Exact checker for branching stories with items, numbers and dice: dead ends and endings no player can reach.
Story flow
See a story's shape: maps of its pages and simulated readers.
story-map: Layered, arc and matrix drawings of a story graph (SVG) and seeded simulated players.
Story build and distribute
Turn a story into a game, or play it from code or a terminal.
story-player: Build one offline HTML game from a story, or play a story from code or a terminal.
Story packaging
Pack a finished story page into a smaller page.
zip-page: Wrap a finished HTML page into a smaller page that unzips itself, with a pure-JS inflater fallback.
Story testing
Run tests on stock Firefox, generate random stories and keep two implementations in step.
contract-kit: A guide and a helper (about 7.2 KB minified) for keeping two implementations of one rule set from drifting apart: seeded random inputs, a side-by-side comparison (also for async functions), shrinking a failing input to a small one, a field table and a time limit; runs in browsers too.
qa-kit: Tiered test runner and a Playwright-style API over WebDriver BiDi for stock Firefox; seeded random-story generator.
AI knowledge base (1)
Written processes for working with an AI helper, kept with the Story Editor.
Working with an AI helper
A written process for a person and an AI assistant building software together.
ai-collab-kit: A written process and templates for a person and an AI assistant building software together.