Memory MCP Server

Instructions

Implementation Reference

• src/handlers/ToolHandlers.ts:193-208 (handler)

  MCP tool handler case for 'set_short_term_memory': validates input parameters and delegates storage to MemoryStore.

  case "set_short_term_memory": {
    const { sessionId, key, value, ttlMinutes = 30 } = request.params.arguments as any;
    
    // Validate inputs
    ValidationUtils.validateSessionId(sessionId);
    ValidationUtils.validateMemoryKey(key);
    ValidationUtils.validateTTLMinutes(ttlMinutes);
    
    memoryStore.setShortTermMemory(sessionId, key, value, ttlMinutes);
    return {
      content: [{
        type: "text",
        text: `Stored short-term memory for session ${sessionId}: ${key}`
      }]
    };
  }

• src/handlers/ToolHandlers.ts:22-47 (schema)

  Tool specification including name, description, and input schema for 'set_short_term_memory' returned in ListTools.

  {
    name: "set_short_term_memory",
    description: "Store data in short-term memory for a session",
    inputSchema: {
      type: "object",
      properties: {
        sessionId: {
          type: "string",
          description: "Session identifier"
        },
        key: {
          type: "string",
          description: "Memory key"
        },
        value: {
          description: "Memory value (any JSON-serializable data)"
        },
        ttlMinutes: {
          type: "number",
          description: "Time to live in minutes (default: 30)",
          default: 30
        }
      },
      required: ["sessionId", "key", "value"]
    }
  },

• src/store/MemoryStore.ts:86-102 (helper)

  Core implementation of short-term memory storage with TTL expiration handling in MemoryStore class.

  setShortTermMemory(sessionId: string, key: string, value: any, ttlMinutes?: number): void {
    const ttl = ttlMinutes || this.config.defaultTTLMinutes || 30;
    const expiresAt = Date.now() + (ttl * 60 * 1000);
    const existing = this.shortTermMemory.get(sessionId);
    
    if (existing && existing.expiresAt > Date.now()) {
      existing.data[key] = value;
      existing.expiresAt = expiresAt;
    } else {
      this.shortTermMemory.set(sessionId, {
        sessionId,
        data: { [key]: value },
        timestamp: Date.now(),
        expiresAt
      });
    }
  }