Minimal Plugin

A user plugin = package.json + main.js (plain JS, no build step). Put it in .obsidian/harness-like-plugins/my-plugin/.

package.json

{
  "name": "my-plugin",
  "version": "0.0.1",
  "description": "One-line description",
  "dsh": { "id": "my-plugin", "version": "0.0.1", "entry": "main.js" }
}

main.js (one tool + one command)

module.exports = {
  name: 'my-plugin',
  inject: ['toolsCompat', 'commands', 'notice'],
  apply(ctx) {
    ctx.effect(() => [
      ctx.toolsCompat.register({
        name: 'my_tool',
        description: 'What the tool does',
        input: { type: 'object', properties: { x: { type: 'string' } }, required: ['x'] },
        execute(input) { return { ok: true, x: input.x } },
      }),
      ctx.commands.addCommand({
        id: 'hello',
        name: 'Example command',
        callback: () => ctx.notice.notice('Hello'),
      }),
    ])
  },
}

Command ids/names get prefixed automatically (Harness Like: Example command (my-plugin)).

Loading

Plugin Manager → "Authorize & Load" (single = this version / double = trust future) → status becomes running.

Rules

1. inject must declare every service used in apply.
2. Never touch Obsidian DOM directly — use ctx.* services.
3. Wrap all registrations in ctx.effect(() => [disposer...]) so stopping the plugin cleans up.

Full signatures: ctx.* services.