Mechanics you can change

A recipe copies TypeScript into your game. Read it, import it, and change it. Installation does not start a timer or activate behavior.

You want to	Recipe	Files to edit
Move, jump, collide with terrain	movement-2d	src/game/systems/movement/platformer.ts, collision.ts, tile-grid.ts
Follow a character	camera-2d	src/game/systems/camera/follow-camera.ts
Flash, shake, emit particles	feedback-2d	src/game/systems/feedback/feedback.ts
Health, inventory, cooldowns, turns	gameplay-state	src/game/systems/gameplay/
Change the world over a day	day-and-night-system	src/game/systems/day-night/day-night-clock.ts

Keep every recipe’s license and integration notes with its source. Advance a mechanic from your scene’s update callback. It shares the game’s existing loop.

Choose where the rule belongs

Change a setting when the rule stays the same, such as movement speed. Change the source when the rule changes, such as letting a player jump again in the air. Do not patch a dependency under .hopkit/vendor/ to change your game’s rules.

The guide’s buffered jump is a small readable example. Its jump buffer remembers a recent press until the character lands. Increasing that duration gives players more forgiveness without changing jump height.

Install and review

The generated project includes a local recipe command. It reads the bundled snapshot under .hopkit/registry/ and requires no registry server:

node scripts/recipes.mjs add day-and-night-system --apply
node scripts/recipes.mjs diff day-and-night-system

Read the printed file changes before applying an update:

node scripts/recipes.mjs update day-and-night-system --apply

An update can replace unchanged installed source. Modified source produces a conflict instead of silently discarding your changes. Merge the desired upstream changes manually, check the game, and play the affected behavior. Reinstalling the same bundled snapshot does not fetch a newer Hopkit release.

The registry JSON is also compatible with the installed shadcn CLI. Its overwrite prompt is replacement, not a source merge. Inspect its actual targets and integration notes before accepting a replacement.