Memory Bank MCP

Implementation Reference

• src/mcp/memoryBankMcp.ts:378-423 (handler)

  Main handler function for the 'query_memory_bank' tool. Validates memory bank initialization, reads all documents using readAllDocuments, performs advanced search, formats relevant snippets from top matching documents, and returns structured text response.

  async ({ query }) => {
    try {
      // Check if Memory Bank has been initialized
      if (!MEMORY_BANK_DIR) {
        return {
          content: [{ type: 'text', text: `ℹ️ Memory Bank not initialized. Please use 'initialize_memory_bank' tool first.` }]
        };
      }
  
      // Check if Memory Bank directory exists on disk
      if (!await fs.pathExists(MEMORY_BANK_DIR)) {
        return {
          content: [{ type: 'text', text: `ℹ️ Memory Bank directory (${MEMORY_BANK_DIR}) not found on disk. Please use 'initialize_memory_bank' tool first.` }]
        };
      }
  
      // Read all documents
      const documents = await readAllDocuments(MEMORY_BANK_DIR);
      
      // Advanced search function
      const searchResults = performAdvancedSearch(query, documents);
      
      if (searchResults.length === 0) {
        return {
          content: [{ type: 'text', text: `ℹ️ No results found for query "${query}".` }]
        };
      }
      
      // Format results
      const formattedResults = searchResults.map(result => {
        return `📄 **${result.documentType}**:\n${result.snippet}\n`;
      }).join('\n');
      
      return {
        content: [{ 
          type: 'text', 
          text: `🔍 Results for query "${query}":\n\n${formattedResults}` 
        }]
      };
    } catch (error) {
      console.error('Error querying Memory Bank:', error);
      return {
        content: [{ type: 'text', text: `❌ Error: ${error instanceof Error ? error.message : String(error)}` }],
        isError: true
      };
    }

• src/mcp/memoryBankMcp.ts:375-377 (schema)

  Zod input schema for the query_memory_bank tool, requiring a 'query' string parameter with minimum length of 5 characters.

  {
    query: z.string().min(5, 'Query must be at least 5 characters')
  },

• src/mcp/memoryBankMcp.ts:373-425 (registration)

  MCP server.tool registration for 'query_memory_bank', specifying tool name, input schema, and handler function reference.

  server.tool(
    'query_memory_bank',
    {
      query: z.string().min(5, 'Query must be at least 5 characters')
    },
    async ({ query }) => {
      try {
        // Check if Memory Bank has been initialized
        if (!MEMORY_BANK_DIR) {
          return {
            content: [{ type: 'text', text: `ℹ️ Memory Bank not initialized. Please use 'initialize_memory_bank' tool first.` }]
          };
        }
  
        // Check if Memory Bank directory exists on disk
        if (!await fs.pathExists(MEMORY_BANK_DIR)) {
          return {
            content: [{ type: 'text', text: `ℹ️ Memory Bank directory (${MEMORY_BANK_DIR}) not found on disk. Please use 'initialize_memory_bank' tool first.` }]
          };
        }
  
        // Read all documents
        const documents = await readAllDocuments(MEMORY_BANK_DIR);
        
        // Advanced search function
        const searchResults = performAdvancedSearch(query, documents);
        
        if (searchResults.length === 0) {
          return {
            content: [{ type: 'text', text: `ℹ️ No results found for query "${query}".` }]
          };
        }
        
        // Format results
        const formattedResults = searchResults.map(result => {
          return `📄 **${result.documentType}**:\n${result.snippet}\n`;
        }).join('\n');
        
        return {
          content: [{ 
            type: 'text', 
            text: `🔍 Results for query "${query}":\n\n${formattedResults}` 
          }]
        };
      } catch (error) {
        console.error('Error querying Memory Bank:', error);
        return {
          content: [{ type: 'text', text: `❌ Error: ${error instanceof Error ? error.message : String(error)}` }],
          isError: true
        };
      }
    }
  );

• src/mcp/memoryBankMcp.ts:434-474 (helper)

  performAdvancedSearch helper: implements semantic search by splitting documents into sections and paragraphs, computing relevance scores for query terms, extracting snippets, sorting by score, and limiting to top 5 results.

  function performAdvancedSearch(query: string, documents: Record<string, string>): SearchResult[] {
    const results: SearchResult[] = [];
    const queryTerms = query.toLowerCase().split(/\s+/).filter(term => term.length > 2);
    
    // Search in each document
    for (const [docType, content] of Object.entries(documents)) {
      // Split document into sections and paragraphs
      const sections = content.split(/\n#{2,3}\s+/).filter(Boolean);
      
      for (const section of sections) {
        // Extract title and content
        const titleMatch = section.match(/^([^\n]+)/);
        const title = titleMatch ? titleMatch[1].trim() : '';
        
        // Evaluate each paragraph
        const paragraphs = section.split(/\n\n+/);
        
        for (const paragraph of paragraphs) {
          // Calculate relevance score
          const relevanceScore = calculateRelevanceScore(query, queryTerms, paragraph);
          
          // Add results above threshold
          if (relevanceScore > 0.3) {
            // Extract relevant snippet
            const snippet = extractRelevantSnippet(paragraph, queryTerms, title);
            
            results.push({
              documentType: docType,
              relevanceScore,
              snippet
            });
          }
        }
      }
    }
    
    // Sort results by relevance and return top 5
    return results
      .sort((a, b) => b.relevanceScore - a.relevanceScore)
      .slice(0, 5);
  }

• src/utils/fileManager.ts:113-143 (helper)

  readAllDocuments utility function called by the handler to load all .md documents from the memory bank directory into a Record<string, string> for search processing.

  export async function readAllDocuments(directoryPath: string): Promise<Record<string, string>> {
    try {
      // Check if directory exists
      if (!await fs.pathExists(directoryPath)) {
        throw new Error(`Directory not found: ${directoryPath}`);
      }
      
      // List all files
      const files = await fs.readdir(directoryPath);
      
      // Filter only markdown files
      const markdownFiles = files.filter(file => file.endsWith('.md'));
      
      // Read each file
      const results: Record<string, string> = {};
      
      for (const file of markdownFiles) {
        const filePath = path.join(directoryPath, file);
        const content = await fs.readFile(filePath, 'utf-8');
        
        // Use filename as key (without extension)
        const fileName = path.basename(file, path.extname(file));
        results[fileName] = content;
      }
      
      return results;
    } catch (error) {
      console.error('Error reading documents:', error);
      throw new Error(`Failed to read documents: ${error}`);
    }
  }