Excalidraw MCP Server

Instructions

Implementation Reference

• src/operations/drawings.ts:48-72 (handler)

  The core handler function that implements the create_drawing tool logic: generates a unique ID, saves the drawing content and metadata to JSON files in storage directory, and returns the ID and name.

  export async function createDrawing(name: string, content: string): Promise<{ id: string, name: string }> {
    await ensureStorageDir();
    
    // Generate a unique ID for the drawing
    const id = `${Date.now()}-${Math.random().toString(36).substring(2, 9)}`;
    
    // Create the drawing file
    const filePath = path.join(STORAGE_DIR, `${id}.json`);
    
    // Save the drawing content
    await fs.writeFile(filePath, content, 'utf-8');
    
    // Create a metadata file for the drawing
    const metadataPath = path.join(STORAGE_DIR, `${id}.meta.json`);
    const metadata = {
      id,
      name,
      createdAt: new Date().toISOString(),
      updatedAt: new Date().toISOString(),
    };
    
    await fs.writeFile(metadataPath, JSON.stringify(metadata, null, 2), 'utf-8');
    
    return { id, name };
  }

• src/operations/drawings.ts:20-23 (schema)

  Zod schema defining the input for create_drawing: name and content strings.

  export const CreateDrawingSchema = z.object({
    name: z.string().min(1),
    content: z.string().min(1),
  });

• index.ts:63-66 (registration)

  Registration of the create_drawing tool in the MCP server's tool list, including name, description, and input schema.

    name: "create_drawing",
    description: "Create a new Excalidraw drawing",
    inputSchema: zodToJsonSchema(drawings.CreateDrawingSchema),
  },

• index.ts:113-119 (handler)

  MCP server dispatch handler for create_drawing: parses arguments using the schema and delegates to the createDrawing implementation.

  case "create_drawing": {
    const args = drawings.CreateDrawingSchema.parse(request.params.arguments);
    const result = await drawings.createDrawing(args.name, args.content);
    return {
      content: [{ type: "text", text: JSON.stringify(result, null, 2) }],
    };
  }