Plugin Developer Docs

Build extensions for Projelli. Ship them via npm or the in-app marketplace.

Projelli has a real plugin system. You can add commands, toolbar buttons, sidebar panels, and settings pages. You can read and write workspace files, talk to the user's configured AI provider, and call out to the network. Plugins run in a sandboxed Web Worker, so a misbehaving plugin can't crash the app or read data it didn't ask permission for.

This docs hub is for plugin authors. If you just want to install plugins, open Settings, then Plugins, inside Projelli.

Get started in 5 minutes →

Sections

Getting Started

Install Node, scaffold a project with create-projelli-plugin, build, and sideload. End to end in 5 minutes.

Manifest Reference

Every field in manifest.json: types, defaults, validation rules, and a complete example.

Permissions

The 6 permissions a plugin can request, what each one grants, and when to declare it.

API Reference

Every method on the PluginAPI object: signatures, return types, and short examples.

Publishing

How to submit a plugin to the in-app marketplace. Fork, add an entry, open a PR.

Examples

Annotated walkthrough of 4 working plugins: word counter, translator, pomodoro, mermaid preview.

What you can build

Editor enhancers, like word counters, grammar checkers, and live diagram previews.
AI workflows, like translation, tone shifting, summarization, and structured rewrites that use the user's own API key.
Productivity tools, like timers, focus modes, and context capture.
External integrations, like sending the current note to a project tracker or pulling research into a workspace.

What's in the box

@projelli/plugin-api, a tiny types-only npm package. Install it as a dev dependency and you get full IntelliSense.
create-projelli-plugin, an npx-runnable scaffolder. One command and you have a working TypeScript project with manifest, sample plugin, build script, and README.
Four reference plugins, each open source under MIT. Read them, fork them, ship your own.
An in-app marketplace, served from a public GitHub repo. Submit your plugin via PR and users can install it with one click.

Status

Plugin API v1.0.0 ships with Projelli v2.0. The shape is stable for the v1.x line. Breaking changes will bump to v2.0 of the API and earlier plugins keep working until you update them.

Next: Getting started →