Plugin Development

Plugins extend OpenWriter with custom MCP tools, HTTP routes, context menu items, and sidebar actions.

Plugin Interface

interface OpenWriterPlugin {
  name: string;
  version: string;
  description: string;
  category: 'writing' | 'social-media' | 'image-generation';
  configSchema?: JSONSchemaObject;
  registerRoutes?: (app, config) => void;
  mcpTools?: ToolDefinition[];
  contextMenuItems?: ContextMenuItem[];
  sidebarMenuItems?: SidebarMenuItem[];
}

Extension Points

1. MCP Tools

Register tools that any MCP agent can call. Define with JSON Schema for input validation.

2. HTTP Routes

Add custom API endpoints to the local server. Access editor state and document data.

3. Context Menu Items

Add right-click actions on text selection. Three conditions:

• has-selection — only when text is selected
• empty-node — only on empty nodes
• always — always visible

4. Sidebar Menu Items

Add right-click actions on documents in the sidebar.

Bundled Plugins

Plugin	Category	What It Does
Author’s Voice	Writing	Voice profiling + rewrite in your voice
Image Generator	Image Generation	AI image generation via Gemini
X API	Social Media	Tweet/article posting and threading
Publish	Social Media	Newsletter, scheduler, subscriber management

Configuration

Plugins define a configSchema (JSON Schema) for user-configurable settings. Users set values through the plugin settings panel.

Distribution

• First-party: @openwriter/plugin-*
• Community: openwriter-plugin-*