opencode-generative-ui

OpenCode plugin that recreates Claude-style generative UI widgets with two custom tools:

• visualize_read_me
• show_widget

The plugin renders HTML fragments and raw SVG in a native macOS window using Glimpse.

This project is an OpenCode-focused extraction and adaptation of the original Michaelliv/pi-generative-ui work for pi. The original repo did the reverse-engineering work and established the shape of the widget tools and guideline set.

The runtime now uses the same morphdom shell-update approach as the pi implementation: Glimpse loads a stable shell document, widget content is injected via win.send(), and DOM updates are diffed into place instead of replacing the whole page.

What it does

When OpenCode decides a response should be visual, the plugin can:

1. Load Claude-style widget design guidance with visualize_read_me
2. Render the resulting widget with show_widget
3. Return any window.glimpse.send(data) interaction payload back to the model

Typical use cases:

• interactive explainers
• charts and dashboards
• SVG diagrams
• mockups
• calculators

Widget windows include built-in viewport controls:

• pinch or Cmd/Ctrl + wheel to zoom
• middle-mouse drag to pan
• Space + drag to pan with a regular mouse or trackpad
• keyboard shortcuts: +, -, 0, F, and arrow keys

Install

From npm in OpenCode

OpenCode does not auto-discover this repo or install it just because it exists on GitHub.

For npm installation, all of the following must be true:

1. This package has been published to npm
2. The package name is listed in your OpenCode config
3. OpenCode is restarted so it can install the plugin

After publishing, add the package name to your OpenCode config:

{
  "$schema": "https://opencode.ai/config.json",
  "plugin": ["opencode-generative-ui"]
}

OpenCode installs npm plugins listed in opencode.json automatically with Bun on startup.

You do not need to run npm install or bun install inside the repo where you want to use the plugin. Just add the plugin name to your OpenCode config and restart OpenCode.

You can add it either:

1. Globally in ~/.config/opencode/opencode.json
2. Per project in opencode.json

Example global config:

{
  "$schema": "https://opencode.ai/config.json",
  "plugin": ["opencode-generative-ui"]
}

You can verify that OpenCode resolved the plugin with:

opencode debug config

If the package is installed correctly, you should see opencode-generative-ui in the resolved plugin list.

Runtime requirements

• macOS
• Bun
• OpenCode
• a working Swift/Xcode toolchain for glimpseui

This plugin opens widget windows through Glimpse, which builds a small native Swift binary during install.

If glimpseui fails to build, update your Xcode Command Line Tools or full Xcode install, then rerun:

bun pm trust glimpseui

Depending on how OpenCode installed the plugin, you may need to run that in the OpenCode cache/config directory rather than inside your app repo.

Local plugin development

If you are developing this plugin itself, install dependencies in this plugin repo:

bun install

If Bun blocks the native build:

bun pm trust glimpseui

Use from a local checkout before publishing

Clone this repo, then copy the plugin entry file into your OpenCode plugin directory if you want to run it before publishing to npm.

For project-local use today:

1. Copy src/index.ts to .opencode/plugins/generative-ui.ts
2. Copy src/lib/ into .opencode/plugins/lib/
3. Copy glimpseui.d.ts into .opencode/
4. Copy this package.json into .opencode/package.json or merge the dependencies into your existing one
5. Run bun install
6. If Bun blocks lifecycle scripts, run bun pm trust glimpseui

Development

Install dependencies in this repo:

bun install

Typecheck:

bun run typecheck

Build publishable output:

bun run build

Current limitation

This plugin now uses morphdom for in-window DOM updates, but it still does not reproduce pi's token-by-token widget streaming. OpenCode does not currently expose the same tool-argument delta hooks, so widgets still render when the tool executes rather than progressively during argument streaming.

Credits

• Original reverse-engineering and pi implementation: Michaelliv/pi-generative-ui
• Native widget window runtime: Glimpse

License

MIT