Initial commit of n8n MCP Server

A Model Context Protocol (MCP) server that integrates with n8n, providing tools for workflow and execution management via the n8n API.

src/resources/index.ts

@@ -0,0 +1,177 @@
+/**
+ * Resources Module
+ * 
+ * This module provides MCP resource handlers for n8n workflows and executions.
+ */
+
+import { Server } from '@modelcontextprotocol/sdk/server/index.js';
+import {
+  ListResourcesRequestSchema,
+  ListResourceTemplatesRequestSchema,
+  ReadResourceRequestSchema,
+} from '@modelcontextprotocol/sdk/types.js';
+import { EnvConfig } from '../config/environment.js';
+import { createApiService } from '../api/n8n-client.js';
+import { McpError, ErrorCode } from '../errors/index.js';
+
+// Import static resource handlers
+import { 
+  getWorkflowsResource,
+  getWorkflowsResourceMetadata,
+  getWorkflowsResourceUri,
+} from './static/workflows.js';
+import {
+  getExecutionStatsResource,
+  getExecutionStatsResourceMetadata,
+  getExecutionStatsResourceUri,
+} from './static/execution-stats.js';
+
+// Import dynamic resource handlers
+import {
+  getWorkflowResource,
+  getWorkflowResourceTemplateMetadata,
+  getWorkflowResourceTemplateUri,
+  extractWorkflowIdFromUri,
+} from './dynamic/workflow.js';
+import {
+  getExecutionResource,
+  getExecutionResourceTemplateMetadata,
+  getExecutionResourceTemplateUri,
+  extractExecutionIdFromUri,
+} from './dynamic/execution.js';
+
+/**
+ * Set up resource handlers for the MCP server
+ * 
+ * @param server MCP server instance
+ * @param envConfig Environment configuration
+ */
+export function setupResourceHandlers(server: Server, envConfig: EnvConfig): void {
+  // Set up static resources
+  setupStaticResources(server, envConfig);
+
+  // Set up dynamic resources
+  setupDynamicResources(server, envConfig);
+}
+
+/**
+ * Set up static resource handlers
+ * 
+ * @param server MCP server instance
+ * @param envConfig Environment configuration
+ */
+function setupStaticResources(server: Server, envConfig: EnvConfig): void {
+  const apiService = createApiService(envConfig);
+  
+  server.setRequestHandler(ListResourcesRequestSchema, async () => {
+    // Return all available static resources
+    return {
+      resources: [
+        getWorkflowsResourceMetadata(),
+        getExecutionStatsResourceMetadata(),
+      ],
+    };
+  });
+}
+
+/**
+ * Set up dynamic resource handlers
+ * 
+ * @param server MCP server instance
+ * @param envConfig Environment configuration
+ */
+function setupDynamicResources(server: Server, envConfig: EnvConfig): void {
+  const apiService = createApiService(envConfig);
+  
+  server.setRequestHandler(ListResourceTemplatesRequestSchema, async () => {
+    // Return all available dynamic resource templates
+    return {
+      resourceTemplates: [
+        getWorkflowResourceTemplateMetadata(),
+        getExecutionResourceTemplateMetadata(),
+      ],
+    };
+  });
+
+  server.setRequestHandler(ReadResourceRequestSchema, async (request) => {
+    const uri = request.params.uri;
+    console.log(`Resource requested: ${uri}`);
+    
+    try {
+      // Handle static resources
+      if (uri === getWorkflowsResourceUri()) {
+        const content = await getWorkflowsResource(apiService);
+        return {
+          contents: [
+            {
+              uri,
+              mimeType: 'application/json',
+              text: content,
+            },
+          ],
+        };
+      }
+      
+      if (uri === getExecutionStatsResourceUri()) {
+        const content = await getExecutionStatsResource(apiService);
+        return {
+          contents: [
+            {
+              uri,
+              mimeType: 'application/json',
+              text: content,
+            },
+          ],
+        };
+      }
+      
+      // Handle dynamic resources
+      const workflowId = extractWorkflowIdFromUri(uri);
+      if (workflowId) {
+        const content = await getWorkflowResource(apiService, workflowId);
+        return {
+          contents: [
+            {
+              uri,
+              mimeType: 'application/json',
+              text: content,
+            },
+          ],
+        };
+      }
+      
+      const executionId = extractExecutionIdFromUri(uri);
+      if (executionId) {
+        const content = await getExecutionResource(apiService, executionId);
+        return {
+          contents: [
+            {
+              uri,
+              mimeType: 'application/json',
+              text: content,
+            },
+          ],
+        };
+      }
+      
+      // If we get here, the URI isn't recognized
+      throw new McpError(
+        ErrorCode.NotFoundError,
+        `Resource not found: ${uri}`
+      );
+    } catch (error) {
+      console.error(`Error retrieving resource (${uri}):`, error);
+      
+      // Pass through McpErrors
+      if (error instanceof McpError) {
+        throw error;
+      }
+      
+      // Convert other errors to McpError
+      throw new McpError(
+        ErrorCode.InternalError,
+        `Error retrieving resource: ${error instanceof Error ? error.message : 'Unknown error'}`
+      );
+    }
+  });
+}