silverbullet/website/🔌 Plugs.md

SilverBullet at its core is bare bones in terms of functionality, most of its power it gains from plugs.

Plugs are an extension mechanism (implemented using a library called PlugOS that’s part of the silverbullet repo) that runs “plug” code in the browser using web workers.

Plugs can hook into SB in various ways:

• Extend the Markdown parser and its syntax
• Define new commands and keybindings
• Respond to various events triggered either on the server or client-side
• Run recurring and background tasks.
• Define their own extension mechanisms through custom events

Each plug runs in its own sandboxed environment and communicates with SB via syscalls that expose a vast range of functionality. Plugs can be loaded, unloaded, and updated without having to restart SB itself.

Plugs are distributed as self-contained JavaScript bundles (ending with .plug.js). Upon boot, SB will load all core plugs bundled with SB itself (listed below), as well as any additional plugs stored in the _plug folder in your space. Typically, management of plugs in the _plug folder is done using 🔌 Core/Plug Management.

Core plugs

These plugs are distributed with SilverBullet and are automatically enabled:

plug where uri = null order by name render [[template/plug]]

Third-party plugs

These plugs are written either by third parties or distributed separately from the main SB distribution:

plug where uri != null order by name render [[template/plug]]

How to develop your own plug

The easiest way to get started is to click the “Use this template” on the silverbullet-plug-template repo.

Generally, every plug consists of a YAML manifest file named yourplugname.plug.yml. This file defines all functions that form your plug. To be loadable by SilverBullet (or any PlugOS-based system for that matter), it needs to be compiled into a JSON bundle (ending with .plug.json).

Generally, the way to do this is to run silverbullet plug:compile as follows:

silverbullet plug:compile yourplugname.plug.yaml

During development, you may want to compile plugs in debug mode, which will not minify them and generate source maps:

silverbullet plug:compile --debug yourplugname.plug.yaml

If you use the plug template, this command is wrapped in your deno.jsonc file, so you can just run either:

deno task build

to build it once, or

deno task watch

to build it and rebuild it when files are changed. This will write a yourplugname.plug.js file into the same folder.

Once you have a compiled .plug.js file you can load it into SB in a few ways by listing it in your space’s PLUGS page.

For development it’s easiest to simply copy the .plug.js file into your space’s _plug/ folder:

cp myplug.plug.js ~/myspace/_plug/

Within seconds (watch your browser’s JavaScript console), your plug should be picked up, synced to your browser and loaded. No need to even reload the page.

Debugging

Since plugs run in your browser, you can use the usual browser debugging tools. When you console.log things, these logs will appear in your browser’s JavaScript console.

Distribution

Once you’re happy with your plug, you can distribute it in various ways:

• You can put it on github by simply committing the resulting .plug.js file there and instructing users to point to by adding - github:yourgithubuser/yourrepo/yourplugname.plug.js to their PLUGS file
• Add a release in your github repo and instruct users to add the release as - ghr:yourgithubuser/yourrepo or if they need a specific release - ghr:yourgithubuser/yourrepo/release-name
• You can put it on any other web server, and tell people to load it via https, e.g., - https://mydomain.com/mypugname.plug.js.