Extension Architecture

Hone has two extension systems that coexist: V1 built-in extensions for language support that ships with the IDE, and V2 plugins for third-party and community extensions distributed via the marketplace.

V1 Built-in Extensions (hone-extensions/)

Language Packs

11 built-in language extensions ship with the IDE binary:

Manifest Format

Each V1 extension declares a hone-extension.json manifest:

{
  "name": "typescript",
  "displayName": "TypeScript Language",
  "version": "1.0.0",
  "activationEvents": [
    "onLanguage:typescript",
    "onLanguage:javascript"
  ],
  "contributes": {
    "languages": [
      {
        "id": "typescript",
        "extensions": [".ts", ".tsx"],
        "aliases": ["TypeScript"]
      }
    ],
    "lspServer": {
      "command": "typescript-language-server",
      "args": ["--stdio"],
      "languages": ["typescript", "javascript"]
    },
    "commands": [],
    "snippets": [
      {
        "language": "typescript",
        "path": "./snippets/typescript.json"
      }
    ]
  }
}

Loading

V1 extensions are loaded by ExtensionRegistry in hone-core:

1. Scan hone-extensions/ directory for hone-extension.json manifests
2. Parse manifests and register language contributions
3. Activate extensions lazily based on activation events (e.g., when a TypeScript file is opened)
4. Start LSP servers as needed

V2 Plugin SDK (hone-extension/)

Overview

V2 plugins are independent packages compiled to native binaries via Perry. They use the @hone/sdk package for the plugin API.

Plugin Structure

import { HonePlugin, HoneHost } from '@hone/sdk';

class MyPlugin extends HonePlugin {
  activate(host: HoneHost): void {
    host.commands.registerCommand('myPlugin.hello', () => {
      host.window.showInformationMessage('Hello from my plugin!');
    });
  }

  deactivate(): void {
    // cleanup
  }
}

HoneHost Interface

HoneHost provides 80+ types covering:

• commands – register and execute commands
• window – show messages, create output channels, status bar items
• workspace – access files, folders, settings
• editor – manipulate the active editor (selections, decorations, edits)
• languages – register language features (completions, hover, diagnostics)
• debug – register debug adapters
• terminal – create and manage terminal instances

Execution Tiers

Plugins run in one of three tiers based on their declared permissions:

The tier is declared in the plugin’s package.json:

{
  "hone": {
    "tier": "PluginHost",
    "permissions": ["fs.read", "editor"]
  }
}

Distribution

V2 plugins are distributed via the Hone marketplace (marketplace.hone.codes):

1. Build – hone-build submits the plugin source to perry-hub workers for cross-platform compilation
2. Publish – compiled binaries are uploaded to the marketplace
3. Install – IDE downloads the platform-appropriate binary from the marketplace
4. Update – marketplace notifies IDE of available updates

CLI

The hone-extension package includes a CLI for plugin development:

• hone ext init – scaffold a new plugin project
• hone ext build – compile the plugin
• hone ext publish – publish to the marketplace
• hone ext test – run plugin tests

Coexistence

Both systems can:

• Register commands in the command registry
• Contribute UI elements (sidebar views, status bar items, decorations)
• Interact with the editor (read/write documents, manage cursors)
• Respond to lifecycle events

V1 extensions handle core language support and ship bundled with the IDE. V2 plugins extend the IDE with third-party functionality and are installed independently by users. Both register with the same underlying command and contribution systems, so they interoperate seamlessly.