fix: normalize node type prefixes for n8n workflow exports (#71)

- Add centralized normalizeNodeType utility to handle prefix conversion
  - n8n-nodes-base.* → nodes-base.*
  - @n8n/n8n-nodes-langchain.* → nodes-langchain.*
- Update all 9 affected MCP tools to use normalized node types
- AI agents can now use node types directly from n8n workflow exports
- Maintains backward compatibility with existing shortened prefixes
- Add comprehensive test coverage for all affected methods

Fixes #71

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

docs/CHANGELOG.md

@@ -5,6 +5,25 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [2.7.18] - 2025-07-18
+
+### Fixed
+- **Node type prefix normalization for AI agents** (Issue #71)
+  - AI agents can now use node types directly from n8n workflow exports without manual conversion
+  - Added automatic normalization: `n8n-nodes-base.httpRequest` → `nodes-base.httpRequest`
+  - Added automatic normalization: `@n8n/n8n-nodes-langchain.agent` → `nodes-langchain.agent`
+  - Fixed 9 MCP tools that were failing with full package names:
+    - `get_node_info`, `get_node_essentials`, `get_node_as_tool_info`
+    - `search_node_properties`, `validate_node_minimal`, `validate_node_config`
+    - `get_property_dependencies`, `search_nodes`, `get_node_documentation`
+  - Maintains backward compatibility - existing short prefixes continue to work
+  - Created centralized `normalizeNodeType` utility for consistent handling across all tools
+
+### Added
+- **Node type utilities** in `src/utils/node-utils.ts`
+  - `normalizeNodeType()` - Converts full package names to database format
+  - `getNodeTypeAlternatives()` - Provides fallback options for edge cases
+
 ## [2.7.17] - 2025-07-17
 
 ### Fixed
@@ -664,6 +683,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Basic n8n and MCP integration
 - Core workflow automation features
 
+[2.7.18]: https://github.com/czlonkowski/n8n-mcp/compare/v2.7.17...v2.7.18
 [2.7.17]: https://github.com/czlonkowski/n8n-mcp/compare/v2.7.16...v2.7.17
 [2.7.16]: https://github.com/czlonkowski/n8n-mcp/compare/v2.7.15...v2.7.16
 [2.7.15]: https://github.com/czlonkowski/n8n-mcp/compare/v2.7.13...v2.7.15

package.json

@@ -1,6 +1,6 @@
 {
   "name": "n8n-mcp",
-  "version": "2.7.17",
+  "version": "2.7.18",
   "description": "Integration between n8n workflow automation and Model Context Protocol (MCP)",
   "main": "dist/index.js",
   "bin": {

package.runtime.json

@@ -1,6 +1,6 @@
 {
   "name": "n8n-mcp-runtime",
-  "version": "2.7.13",
+  "version": "2.7.18",
   "description": "n8n MCP Server Runtime Dependencies Only",
   "private": true,
   "dependencies": {

src/mcp/server.ts

@@ -25,6 +25,7 @@ import * as n8nHandlers from './handlers-n8n-manager';
 import { handleUpdatePartialWorkflow } from './handlers-workflow-diff';
 import { getToolDocumentation, getToolsOverview } from './tools-documentation';
 import { PROJECT_VERSION } from '../utils/version';
+import { normalizeNodeType, getNodeTypeAlternatives } from '../utils/node-utils';
 
 interface NodeRow {
   node_type: string;
@@ -341,16 +342,19 @@ export class N8NDocumentationMCPServer {
   private async getNodeInfo(nodeType: string): Promise<any> {
     await this.ensureInitialized();
     if (!this.repository) throw new Error('Repository not initialized');
-    let node = this.repository.getNode(nodeType);
+    
+    // First try with normalized type
+    const normalizedType = normalizeNodeType(nodeType);
+    let node = this.repository.getNode(normalizedType);
+    
+    if (!node && normalizedType !== nodeType) {
+      // Try original if normalization changed it
+      node = this.repository.getNode(nodeType);
+    }
     
     if (!node) {
-      // Try alternative formats
-      const alternatives = [
-        nodeType,
-        nodeType.replace('n8n-nodes-base.', ''),
-        `n8n-nodes-base.${nodeType}`,
-        nodeType.toLowerCase()
-      ];
+      // Fallback to other alternatives for edge cases
+      const alternatives = getNodeTypeAlternatives(nodeType);
       
       for (const alt of alternatives) {
         const found = this.repository!.getNode(alt);
@@ -359,10 +363,10 @@ export class N8NDocumentationMCPServer {
           break;
         }
       }
-      
-      if (!node) {
-        throw new Error(`Node ${nodeType} not found`);
-      }
+    }
+    
+    if (!node) {
+      throw new Error(`Node ${nodeType} not found`);
     }
     
     // Add AI tool capabilities information
@@ -394,6 +398,16 @@ export class N8NDocumentationMCPServer {
     await this.ensureInitialized();
     if (!this.db) throw new Error('Database not initialized');
     
+    // Normalize the query if it looks like a full node type
+    let normalizedQuery = query;
+    
+    // Check if query contains node type patterns and normalize them
+    if (query.includes('n8n-nodes-base.') || query.includes('@n8n/n8n-nodes-langchain.')) {
+      normalizedQuery = query
+        .replace(/n8n-nodes-base\./g, 'nodes-base.')
+        .replace(/@n8n\/n8n-nodes-langchain\./g, 'nodes-langchain.');
+    }
+    
     const searchMode = options?.mode || 'OR';
     
     // Check if FTS5 table exists
@@ -403,11 +417,11 @@ export class N8NDocumentationMCPServer {
     `).get();
     
     if (ftsExists) {
-      // Use FTS5 search
-      return this.searchNodesFTS(query, limit, searchMode);
+      // Use FTS5 search with normalized query
+      return this.searchNodesFTS(normalizedQuery, limit, searchMode);
     } else {
-      // Fallback to LIKE search (existing implementation)
-      return this.searchNodesLIKE(query, limit);
+      // Fallback to LIKE search with normalized query
+      return this.searchNodesLIKE(normalizedQuery, limit);
     }
   }
   
@@ -938,11 +952,23 @@ export class N8NDocumentationMCPServer {
   private async getNodeDocumentation(nodeType: string): Promise<any> {
     await this.ensureInitialized();
     if (!this.db) throw new Error('Database not initialized');
-    const node = this.db!.prepare(`
+    
+    // First try with normalized type
+    const normalizedType = normalizeNodeType(nodeType);
+    let node = this.db!.prepare(`
       SELECT node_type, display_name, documentation, description 
       FROM nodes 
       WHERE node_type = ?
-    `).get(nodeType) as NodeRow | undefined;
+    `).get(normalizedType) as NodeRow | undefined;
+    
+    // If not found and normalization changed the type, try original
+    if (!node && normalizedType !== nodeType) {
+      node = this.db!.prepare(`
+        SELECT node_type, display_name, documentation, description 
+        FROM nodes 
+        WHERE node_type = ?
+      `).get(nodeType) as NodeRow | undefined;
+    }
     
     if (!node) {
       throw new Error(`Node ${nodeType} not found`);
@@ -1030,16 +1056,18 @@ Full documentation is being prepared. For now, use get_node_essentials for confi
     if (cached) return cached;
     
     // Get the full node information
-    let node = this.repository.getNode(nodeType);
+    // First try with normalized type
+    const normalizedType = normalizeNodeType(nodeType);
+    let node = this.repository.getNode(normalizedType);
+    
+    if (!node && normalizedType !== nodeType) {
+      // Try original if normalization changed it
+      node = this.repository.getNode(nodeType);
+    }
     
     if (!node) {
-      // Try alternative formats
-      const alternatives = [
-        nodeType,
-        nodeType.replace('n8n-nodes-base.', ''),
-        `n8n-nodes-base.${nodeType}`,
-        nodeType.toLowerCase()
-      ];
+      // Fallback to other alternatives for edge cases
+      const alternatives = getNodeTypeAlternatives(nodeType);
       
       for (const alt of alternatives) {
         const found = this.repository!.getNode(alt);
@@ -1048,10 +1076,10 @@ Full documentation is being prepared. For now, use get_node_essentials for confi
           break;
         }
       }
-      
-      if (!node) {
-        throw new Error(`Node ${nodeType} not found`);
-      }
+    }
+    
+    if (!node) {
+      throw new Error(`Node ${nodeType} not found`);
     }
     
     // Get properties (already parsed by repository)
@@ -1101,16 +1129,18 @@ Full documentation is being prepared. For now, use get_node_essentials for confi
     if (!this.repository) throw new Error('Repository not initialized');
     
     // Get the node
-    let node = this.repository.getNode(nodeType);
+    // First try with normalized type
+    const normalizedType = normalizeNodeType(nodeType);
+    let node = this.repository.getNode(normalizedType);
+    
+    if (!node && normalizedType !== nodeType) {
+      // Try original if normalization changed it
+      node = this.repository.getNode(nodeType);
+    }
     
     if (!node) {
-      // Try alternative formats
-      const alternatives = [
-        nodeType,
-        nodeType.replace('n8n-nodes-base.', ''),
-        `n8n-nodes-base.${nodeType}`,
-        nodeType.toLowerCase()
-      ];
+      // Fallback to other alternatives for edge cases
+      const alternatives = getNodeTypeAlternatives(nodeType);
       
       for (const alt of alternatives) {
         const found = this.repository!.getNode(alt);
@@ -1119,10 +1149,10 @@ Full documentation is being prepared. For now, use get_node_essentials for confi
           break;
         }
       }
-      
-      if (!node) {
-        throw new Error(`Node ${nodeType} not found`);
-      }
+    }
+    
+    if (!node) {
+      throw new Error(`Node ${nodeType} not found`);
     }
     
     // Get properties and search (already parsed by repository)
@@ -1257,16 +1287,18 @@ Full documentation is being prepared. For now, use get_node_essentials for confi
     if (!this.repository) throw new Error('Repository not initialized');
     
     // Get node info to access properties
-    let node = this.repository.getNode(nodeType);
+    // First try with normalized type
+    const normalizedType = normalizeNodeType(nodeType);
+    let node = this.repository.getNode(normalizedType);
+    
+    if (!node && normalizedType !== nodeType) {
+      // Try original if normalization changed it
+      node = this.repository.getNode(nodeType);
+    }
     
     if (!node) {
-      // Try alternative formats
-      const alternatives = [
-        nodeType,
-        nodeType.replace('n8n-nodes-base.', ''),
-        `n8n-nodes-base.${nodeType}`,
-        nodeType.toLowerCase()
-      ];
+      // Fallback to other alternatives for edge cases
+      const alternatives = getNodeTypeAlternatives(nodeType);
       
       for (const alt of alternatives) {
         const found = this.repository!.getNode(alt);
@@ -1275,10 +1307,10 @@ Full documentation is being prepared. For now, use get_node_essentials for confi
           break;
         }
       }
-      
-      if (!node) {
-        throw new Error(`Node ${nodeType} not found`);
-      }
+    }
+    
+    if (!node) {
+      throw new Error(`Node ${nodeType} not found`);
     }
     
     // Get properties
@@ -1312,16 +1344,18 @@ Full documentation is being prepared. For now, use get_node_essentials for confi
     if (!this.repository) throw new Error('Repository not initialized');
     
     // Get node info to access properties
-    let node = this.repository.getNode(nodeType);
+    // First try with normalized type
+    const normalizedType = normalizeNodeType(nodeType);
+    let node = this.repository.getNode(normalizedType);
+    
+    if (!node && normalizedType !== nodeType) {
+      // Try original if normalization changed it
+      node = this.repository.getNode(nodeType);
+    }
     
     if (!node) {
-      // Try alternative formats
-      const alternatives = [
-        nodeType,
-        nodeType.replace('n8n-nodes-base.', ''),
-        `n8n-nodes-base.${nodeType}`,
-        nodeType.toLowerCase()
-      ];
+      // Fallback to other alternatives for edge cases
+      const alternatives = getNodeTypeAlternatives(nodeType);
       
       for (const alt of alternatives) {
         const found = this.repository!.getNode(alt);
@@ -1330,10 +1364,10 @@ Full documentation is being prepared. For now, use get_node_essentials for confi
           break;
         }
       }
-      
-      if (!node) {
-        throw new Error(`Node ${nodeType} not found`);
-      }
+    }
+    
+    if (!node) {
+      throw new Error(`Node ${nodeType} not found`);
     }
     
     // Get properties
@@ -1364,16 +1398,18 @@ Full documentation is being prepared. For now, use get_node_essentials for confi
     if (!this.repository) throw new Error('Repository not initialized');
     
     // Get node info
-    let node = this.repository.getNode(nodeType);
+    // First try with normalized type
+    const normalizedType = normalizeNodeType(nodeType);
+    let node = this.repository.getNode(normalizedType);
+    
+    if (!node && normalizedType !== nodeType) {
+      // Try original if normalization changed it
+      node = this.repository.getNode(nodeType);
+    }
     
     if (!node) {
-      // Try alternative formats
-      const alternatives = [
-        nodeType,
-        nodeType.replace('n8n-nodes-base.', ''),
-        `n8n-nodes-base.${nodeType}`,
-        nodeType.toLowerCase()
-      ];
+      // Fallback to other alternatives for edge cases
+      const alternatives = getNodeTypeAlternatives(nodeType);
       
       for (const alt of alternatives) {
         const found = this.repository!.getNode(alt);
@@ -1382,10 +1418,10 @@ Full documentation is being prepared. For now, use get_node_essentials for confi
           break;
         }
       }
-      
-      if (!node) {
-        throw new Error(`Node ${nodeType} not found`);
-      }
+    }
+    
+    if (!node) {
+      throw new Error(`Node ${nodeType} not found`);
     }
     
     // Determine common AI tool use cases based on node type
@@ -1538,16 +1574,18 @@ Full documentation is being prepared. For now, use get_node_essentials for confi
     if (!this.repository) throw new Error('Repository not initialized');
     
     // Get node info
-    let node = this.repository.getNode(nodeType);
+    // First try with normalized type
+    const normalizedType = normalizeNodeType(nodeType);
+    let node = this.repository.getNode(normalizedType);
+    
+    if (!node && normalizedType !== nodeType) {
+      // Try original if normalization changed it
+      node = this.repository.getNode(nodeType);
+    }
     
     if (!node) {
-      // Try alternative formats
-      const alternatives = [
-        nodeType,
-        nodeType.replace('n8n-nodes-base.', ''),
-        `n8n-nodes-base.${nodeType}`,
-        nodeType.toLowerCase()
-      ];
+      // Fallback to other alternatives for edge cases
+      const alternatives = getNodeTypeAlternatives(nodeType);
       
       for (const alt of alternatives) {
         const found = this.repository!.getNode(alt);
@@ -1556,10 +1594,10 @@ Full documentation is being prepared. For now, use get_node_essentials for confi
           break;
         }
       }
-      
-      if (!node) {
-        throw new Error(`Node ${nodeType} not found`);
-      }
+    }
+    
+    if (!node) {
+      throw new Error(`Node ${nodeType} not found`);
     }
     
     // Get properties  

src/utils/node-utils.ts

@@ -0,0 +1,46 @@
+/**
+ * Normalizes node type from n8n export format to database format
+ * 
+ * Examples:
+ * - 'n8n-nodes-base.httpRequest' → 'nodes-base.httpRequest'
+ * - '@n8n/n8n-nodes-langchain.agent' → 'nodes-langchain.agent'
+ * - 'nodes-base.slack' → 'nodes-base.slack' (unchanged)
+ * 
+ * @param nodeType The node type to normalize
+ * @returns The normalized node type
+ */
+export function normalizeNodeType(nodeType: string): string {
+  // Handle n8n-nodes-base -> nodes-base
+  if (nodeType.startsWith('n8n-nodes-base.')) {
+    return nodeType.replace('n8n-nodes-base.', 'nodes-base.');
+  }
+  
+  // Handle @n8n/n8n-nodes-langchain -> nodes-langchain
+  if (nodeType.startsWith('@n8n/n8n-nodes-langchain.')) {
+    return nodeType.replace('@n8n/n8n-nodes-langchain.', 'nodes-langchain.');
+  }
+  
+  // Return unchanged if already normalized or unknown format
+  return nodeType;
+}
+
+/**
+ * Gets alternative node type formats to try for lookups
+ * 
+ * @param nodeType The original node type
+ * @returns Array of alternative formats to try
+ */
+export function getNodeTypeAlternatives(nodeType: string): string[] {
+  const alternatives: string[] = [];
+  
+  // Add lowercase version
+  alternatives.push(nodeType.toLowerCase());
+  
+  // If it's just a bare node name, try with common prefixes
+  if (!nodeType.includes('.')) {
+    alternatives.push(`nodes-base.${nodeType}`);
+    alternatives.push(`nodes-langchain.${nodeType}`);
+  }
+  
+  return alternatives;
+}