Excalidraw MCP Server

Instructions

Implementation Reference

• src/operations/drawings.ts:63-90 (handler)

  The core handler function that implements the create_drawing tool logic: generates a unique ID, saves the drawing content to a JSON file, creates metadata, 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:35-38 (schema)

  Zod schema for input validation of the create_drawing tool, requiring 'name' and 'content' as non-empty strings.

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

• src/index.ts:66-69 (registration)

  Tool registration in the MCP server's listTools response, defining name, description, and input schema.

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

• src/index.ts:116-124 (handler)

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

  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) }],
    };
  }