The short authoring guide for Perch mods: package shape, the Lua declarations (settings/widgets), handlers, scopes, style. Read this first.

The canonical vocabulary (api-spec.json): display components and their props, shared props, color roles, host functions, handlers, scopes, contexts. Pass part to fetch one section.

The modding and API documentation. Without page, lists pages (id, title, description); with page (e.g. "modding/your-first-widget", "api/host"), returns that page. search finds pages whose text mentions a term.

The builtin Perch packages (media, clock, weather, launcher, …) are complete worked examples of the vocabulary. Without id, lists them; with id, returns every file of that package.

Checks a package folder: mod.json against the manifest schema (id = folder name, no legacy widgets/settings keys, known scopes), the entry exists, every .lua parses, the entry declares a widget, and display types exist in the vocabulary. The definitive check is Perch's own loader — run the package (perch_run) and read Settings → Installed mods for the loader's verdict.

Launches Perch with PERCH_MOD_DEV pointed at the folder that contains this package, so the widget appears in Settings → Layout → Widgets and on the notch. Windows only. Set PERCH_EXE if Perch is not installed through Steam.