Aws Lambda Download S3 File High Quality May 2026

Downloading files from Amazon S3 to an AWS Lambda function is a core task for serverless workflows like image processing, data transformation, or log analysis. Depending on your needs, you can download files directly to local storage, process them in memory, or stream them to stay within Lambda's resource limits. Prerequisites

import boto3 import os def lambda_handler(event, context): s3 = boto3.client('s3') bucket = 'your-bucket-name' key = 'data/example.csv' download_path = '/tmp/example.csv' s3.download_file(bucket, key, download_path) # Process the file from /tmp with open(download_path, 'r') as f: print(f.read()) Use code with caution. Node.js (AWS SDK v3) javascript aws lambda download s3 file

const { S3Client, GetObjectCommand } = require("@aws-sdk/client-s3"); const fs = require('fs'); const { pipeline } = require('stream/promises'); exports.handler = async (event) => { const client = new S3Client({}); const command = new GetObjectCommand({ Bucket: "your-bucket-name", Key: "data/example.csv", }); const response = await client.send(command); await pipeline(response.Body, fs.createWriteStream('/tmp/example.csv')); }; Use code with caution. Method 2: Process In-Memory (No Local File) Downloading files from Amazon S3 to an AWS