Extension Lab

Extension Lab has five small, working tools built only with the public extension API. Try them, then copy their code when you build your own.

Example	Resources	Features
Scribble	Documents	Editable Markdown, page search, favorites, new pages, saved edits
Boombox	Tracks	Playlist, player controls, likes, queue
Zipline	Issues	Kanban board, status changes, issue inspector
Pigeon	Mail threads	Search, folders, stars, archive, compose, sent mail
Kiln	Scene objects	Three.js viewport, selection, visibility, transforms, animated timeline

Each example adds its own page, mode, resource kind, views, sample data, and theme. A mode is a workbench layout with its own navigation, panels, and theme. A resource kind is a type of item, such as a document or a track, that the workbench can open and link to.

Install

Extension Lab is not in the built-in extension catalog. Install it from a copy of the Prompt Studio repository. Use the release tag that matches pst --version, then run the install from inside a linked project folder:

git clone --depth 1 --branch pstdio@<version> https://github.com/pufflyai/prompt-studio.git
pst extensions add <path-to>/prompt-studio/extensions/extension-lab
pst extensions check

Open an example from the project’s Examples group. You do not need a setup command or an external account. Boombox and Pigeon use local sample data. They do not play audio or send email.

State and resources

The samples are ready right away. Your changes are saved in the extension’s storage for the project. Each changed field is saved on its own, so edits in different views do not overwrite each other. When a command finishes, the other views refresh. Navigation uses public page targets and resource references. No view reads the host’s database or internal registries.

Read an example’s data from a terminal:

pst extension-lab resources list --name scribble
pst extension-lab state read --name kiln

Mode defaults

defineMode({ defaultTheme: theme.ref }) gives a mode its theme. The theme applies while the user has not picked another theme for that mode. A user’s pick applies only to that mode. Leaving the mode brings back the global theme.

chrome places views in the mode’s nav, sidenav, activity bar, or status bar. Set a region to false to hide it. Leave a region out to keep the host’s default. Put sizes and collapsing in regionSettings. Set showHeader: false on a docked panel when the example draws its own controls, as Boombox does for its player.

Start with the example definitions, view mounting, and state commands. See Modes and layout for the host API.

Contributing

Inside the Prompt Studio repository, watch the extension while you change it:

pst extensions dev ./extensions/extension-lab

The dev command copies the extension and installs its own dependencies. To check the dashboard, follow the repository’s Docker development workflow.

The examples’ layouts, data, and themes come from the workbench Showcase stories. Lab (faulty) is an example that fails on purpose, to show how the host handles a broken webview. Host contract fixtures, including the fake agent, live in packages/workbench-fixture.