list_lambda_functions

Instructions

Implementation Reference

• index.js:380-408 (handler)

  Main MCP tool handler for 'list_lambda_functions'. Parses input args, calls LambdaAnalyzer.listFunctions helper, and returns formatted markdown response with function list and optional metrics.

  async listLambdaFunctions(args) {
    const { runtime, includeMetrics = false } = args;
    
    const functions = await this.lambdaAnalyzer.listFunctions(runtime, includeMetrics);
  
    return {
      content: [
        {
          type: 'text',
          text: `# Lambda Functions\n\n` +
                `## Summary\n` +
                `- **Total Functions**: ${functions.length}\n` +
                `- **Runtimes**: ${[...new Set(functions.map(f => f.runtime))].join(', ')}\n\n` +
                `## Functions List\n` +
                `${functions.map(func => 
                  `### ${func.name}\n` +
                  `- **Runtime**: ${func.runtime}\n` +
                  `- **Memory**: ${func.memory}MB\n` +
                  `- **Timeout**: ${func.timeout}s\n` +
                  `- **Last Modified**: ${func.lastModified}\n` +
                  `${includeMetrics ? 
                    `- **Avg Duration**: ${func.metrics?.avgDuration || 'N/A'}ms\n` +
                    `- **Cold Start Rate**: ${func.metrics?.coldStartRate || 'N/A'}%\n` +
                    `- **Error Rate**: ${func.metrics?.errorRate || 'N/A'}%\n` : ''}\n`
                ).join('')}`
        }
      ]
    };
  }

• index.js:133-145 (schema)

  Input schema defining parameters for the list_lambda_functions tool: optional runtime filter and includeMetrics flag.

  inputSchema: {
    type: 'object',
    properties: {
      runtime: {
        type: 'string',
        description: 'Filter by runtime (e.g., nodejs18.x, python3.9)'
      },
      includeMetrics: {
        type: 'boolean',
        description: 'Include basic performance metrics (default: false)'
      }
    }
  }

• index.js:130-146 (registration)

  Registration of the list_lambda_functions tool in the ListToolsRequest handler response, providing name, description, and schema.

  {
    name: 'list_lambda_functions',
    description: 'List all Lambda functions in the account with basic performance info',
    inputSchema: {
      type: 'object',
      properties: {
        runtime: {
          type: 'string',
          description: 'Filter by runtime (e.g., nodejs18.x, python3.9)'
        },
        includeMetrics: {
          type: 'boolean',
          description: 'Include basic performance metrics (default: false)'
        }
      }
    }
  },

• src/lambda-analyzer.js:127-164 (helper)

  Helper method in LambdaAnalyzer that implements the core logic: lists all Lambda functions via AWS SDK, filters by runtime, enriches with config and optional performance metrics.

  async listFunctions(runtime, includeMetrics) {
    const command = new ListFunctionsCommand({});
    const response = await this.lambdaClient.send(command);
    
    let functions = response.Functions || [];
    
    if (runtime) {
      functions = functions.filter(func => func.Runtime === runtime);
    }
  
    const result = [];
    for (const func of functions) {
      const functionInfo = {
        name: func.FunctionName,
        runtime: func.Runtime,
        memory: func.MemorySize,
        timeout: func.Timeout,
        lastModified: func.LastModified
      };
  
      if (includeMetrics) {
        try {
          const quickAnalysis = await this.analyzeFunction(func.FunctionName, '24h', false);
          functionInfo.metrics = {
            avgDuration: quickAnalysis.avgDuration,
            coldStartRate: quickAnalysis.coldStartRate,
            errorRate: quickAnalysis.errorRate
          };
        } catch (error) {
          functionInfo.metrics = null;
        }
      }
  
      result.push(functionInfo);
    }
  
    return result;
  }