aws-serverless

# AWS Serverless ## Patterns ### Lambda Handler Pattern Proper Lambda function structure with error handling **When to use**: ['Any Lambda function implementation', 'API handlers, event processors, scheduled tasks'] ```python ```javascript // Node.js Lambda Handler // handler.js // Initialize outside handler (reused across invocations) const { DynamoDBClient } = require('@aws-sdk/client-dynamodb'); const { DynamoDBDocumentClient, GetCommand } = require('@aws-sdk/lib-dynamodb'); const client = new DynamoDBClient({}); const docClient = DynamoDBDocumentClient.from(client); // Handler function exports.handler = async (event, context) => { // Optional: Don't wait for event loop to clear (Node.js) context.callbackWaitsForEmptyEventLoop = false; try { // Parse input based on event source const body = typeof event.body === 'string' ? JSON.parse(event.body) : event.body; // Business logic const result = await processRequest(body); // Return API Gateway compatible response return { statusCode: 200, headers: { 'Content-Type': 'application/json', 'Access-Control-Allow-Origin': '*' }, body: JSON.stringify(result) }; } catch (error) { console.error('Error:', JSON.stringify({ error: error.message, stack: error.stack, requestId: context.awsRequestId })); return { statusCode: error.statusCode || 500, headers: { 'Content-Type': 'application/json' }, ...