MCP Memory Server

Instructions

Implementation Reference

• src/memory-manager.ts:162-181 (handler)

  Core implementation of add_decision tool: stores decision in current session's importantDecisions and appends structured Decision to globalDecisions, then persists project memory

  async addImportantDecision(key: string, value: any, reasoning: string): Promise<void> {
    const memory = await this.getProjectMemory();
    
    memory.currentSession.importantDecisions[key] = value;
    
    const decision: Decision = {
      id: this.generateId(),
      decision: `${key}: ${JSON.stringify(value)}`,
      reasoning,
      impact: [],
      timestamp: new Date().toISOString(),
      approvedBy: 'system',
      relatedFiles: []
    };
  
    memory.globalDecisions.push(decision);
    await this.saveProjectMemory(memory);
    
    console.log(chalk.yellow(`💡 Decision recorded: ${key} = ${value}`));
  }

• src/index.ts:803-809 (handler)

  MCP CallToolRequestSchema handler case for 'add_decision': extracts args and delegates to MemoryManager.addImportantDecision

  case 'add_decision': {
    const key = args.key as string;
    const value = args.value as any;
    const reasoning = args.reasoning as string;
    await this.memoryManager.addImportantDecision(key, value, reasoning);
    return { content: [{ type: 'text', text: 'Decision recorded successfully' }] };
  }

• src/index.ts:579-591 (registration)

  Tool registration in ListToolsResponse: defines name, description, and inputSchema for validation

  {
    name: 'add_decision',
    description: 'Record an important technical decision',
    inputSchema: {
      type: 'object',
      properties: {
        key: { type: 'string', description: 'Decision key/name' },
        value: { type: 'string', description: 'Decision value' },
        reasoning: { type: 'string', description: 'Reasoning behind the decision' }
      },
      required: ['key', 'value', 'reasoning']
    }
  },

• src/index.ts:579-591 (schema)

  Input schema definition for add_decision tool parameters: key (string), value (string), reasoning (string)

  {
    name: 'add_decision',
    description: 'Record an important technical decision',
    inputSchema: {
      type: 'object',
      properties: {
        key: { type: 'string', description: 'Decision key/name' },
        value: { type: 'string', description: 'Decision value' },
        reasoning: { type: 'string', description: 'Reasoning behind the decision' }
      },
      required: ['key', 'value', 'reasoning']
    }
  },