S3Service

A lightweight TypeScript wrapper built on top of AWS SDK v3 to simplify common S3 operations such as:

1. Uploading files

2. Generating presigned upload URLs

3. Generating presigned download URLs

This service is ideal for backend APIs that need secure, temporary access to S3 objects.

🚀 Features

1. Direct file upload to S3

2. Generate presigned upload URL (for client-side uploads)

3. Generate presigned download URL (secure controlled downloads)

Customizable URL expiration

Written in TypeScript

📦 Installation npm install @core-services/s3

⚙️ Configuration

Create a config object using the S3ServiceConfig type:

interface S3ServiceConfig { region: string; accessKeyId: string; secretAccessKey: string; bucketName: string; expiresInSeconds?: number; }

🛠️ Usage

1. Initialize the service import { S3Service } from "@core-services/s3";

const s3Service = new S3Service({ region: "ap-south-1", accessKeyId: process.env.AWS_ACCESS_KEY!, secretAccessKey: process.env.AWS_SECRET_KEY!, bucketName: "your-bucket-name", expiresInSeconds: 3600, // optional });

📬 Generate Presigned Upload URL

Useful when frontends/mobile apps upload directly to S3 without passing through your backend.

const { uploadUrl, key } = await s3Service.generateUploadUrl( "uploads/profile.png", "image/png" ); frontend can PUT file to uploadUrl

📥 Generate Presigned Download URL

const { downloadUrl } = await s3Service.generateDownloadUrl( "uploads/profile.png" );

1. downloadUrl is valid only for configured expiration time

📤 Upload File to S3 (Server-Side)

await s3Service.uploadObject( "uploads/image.png", fileBuffer, "image/png" );

generateUploadUrl(key, contentType)

Creates a presigned PUT URL for client uploads. Returns { uploadUrl, key }.

generateDownloadUrl(key)

Creates a presigned GET URL for downloading files. Returns { downloadUrl }.