Excalidraw MCP Server

import { z } from "zod"; import fs from "fs/promises"; import path from "path"; import { ExcalidrawResourceNotFoundError, ExcalidrawValidationError, } from "../common/errors.js"; import { validateFileId, safeJsonParse, sanitizeErrorMessage, } from "../common/security.js"; // Define the storage directory for drawings const STORAGE_DIR = path.join(process.cwd(), "storage"); // Ensure storage directory exists async function ensureStorageDir() { try { await fs.mkdir(STORAGE_DIR, { recursive: true }); } catch (error) { console.error( "Failed to create storage directory:", sanitizeErrorMessage(error) ); throw new ExcalidrawValidationError( sanitizeErrorMessage(error, "Storage directory creation failed") ); } } // Schema for creating a drawing export const CreateDrawingSchema = z.object({ name: z.string().min(1), content: z.string().min(1), }); // Schema for getting a drawing export const GetDrawingSchema = z.object({ id: z.string().min(1), }); // Schema for updating a drawing export const UpdateDrawingSchema = z.object({ id: z.string().min(1), content: z.string().min(1), }); // Schema for deleting a drawing export const DeleteDrawingSchema = z.object({ id: z.string().min(1), }); // Schema for listing drawings export const ListDrawingsSchema = z.object({ page: z.number().int().min(1).optional().default(1), perPage: z.number().int().min(1).max(100).optional().default(10), }); // Create a new drawing 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 }; } // Get a drawing by ID export async function getDrawing( id: string ): Promise<{ id: string; name: string; content: string; metadata: any }> { // Validate the ID for security validateFileId(id); await ensureStorageDir(); // Get the drawing file path const filePath = path.join(STORAGE_DIR, `${id}.json`); const metadataPath = path.join(STORAGE_DIR, `${id}.meta.json`); try { // Read the drawing content const content = await fs.readFile(filePath, "utf-8"); // Read the metadata const metadataStr = await fs.readFile(metadataPath, "utf-8"); const metadata = safeJsonParse(metadataStr, "drawing metadata"); return { id, name: metadata.name, content, metadata, }; } catch (error) { if (error instanceof ExcalidrawValidationError) { throw error; // Re-throw validation errors as-is } throw new ExcalidrawResourceNotFoundError( sanitizeErrorMessage(error, `Drawing with ID ${id} not found`) ); } } // Update a drawing by ID export async function updateDrawing( id: string, content: string ): Promise<{ id: string; name: string }> { // Validate the ID for security validateFileId(id); await ensureStorageDir(); // Get the drawing file path const filePath = path.join(STORAGE_DIR, `${id}.json`); const metadataPath = path.join(STORAGE_DIR, `${id}.meta.json`); try { // Check if the drawing exists await fs.access(filePath); // Read the metadata const metadataStr = await fs.readFile(metadataPath, "utf-8"); const metadata = safeJsonParse(metadataStr, "drawing metadata"); // Update the drawing content await fs.writeFile(filePath, content, "utf-8"); // Update the metadata metadata.updatedAt = new Date().toISOString(); await fs.writeFile( metadataPath, JSON.stringify(metadata, null, 2), "utf-8" ); return { id, name: metadata.name }; } catch (error) { if (error instanceof ExcalidrawValidationError) { throw error; // Re-throw validation errors as-is } throw new ExcalidrawResourceNotFoundError( sanitizeErrorMessage(error, `Drawing with ID ${id} not found`) ); } } // Delete a drawing by ID export async function deleteDrawing(id: string): Promise<void> { // Validate the ID for security validateFileId(id); await ensureStorageDir(); // Get the drawing file path const filePath = path.join(STORAGE_DIR, `${id}.json`); const metadataPath = path.join(STORAGE_DIR, `${id}.meta.json`); try { // Check if the drawing exists await fs.access(filePath); // Delete the drawing file await fs.unlink(filePath); // Delete the metadata file await fs.unlink(metadataPath); } catch (error) { throw new ExcalidrawResourceNotFoundError( sanitizeErrorMessage(error, `Drawing with ID ${id} not found`) ); } } // List all drawings export async function listDrawings( page: number = 1, perPage: number = 10 ): Promise<{ drawings: any[]; total: number }> { await ensureStorageDir(); try { // Get all files in the storage directory const files = await fs.readdir(STORAGE_DIR); // Filter metadata files const metadataFiles = files.filter((file) => file.endsWith(".meta.json")); // Calculate pagination const start = (page - 1) * perPage; const end = start + perPage; const paginatedFiles = metadataFiles.slice(start, end); // Read metadata for each drawing const drawings = await Promise.all( paginatedFiles.map(async (file) => { const metadataPath = path.join(STORAGE_DIR, file); const metadataStr = await fs.readFile(metadataPath, "utf-8"); return safeJsonParse(metadataStr, "drawing metadata"); }) ); return { drawings, total: metadataFiles.length, }; } catch (error) { console.error("Failed to list drawings:", sanitizeErrorMessage(error)); return { drawings: [], total: 0, }; } }