Storage provider

s3nd with AWS S3

The original. Credentials come from the provider chain, so a Lambda or an ECS task needs no keys at all.

createBucket()

import { createBucket } from 's3nd'

// Credentials from the AWS provider chain: env, shared config, or the role.
const store = createBucket({
  bucket: process.env.S3_BUCKET,
  region: 'eu-west-3',
  prefix: 'transfers',
  maxSize: 4 * 1024 * 1024,
})

Why this one

AWS S3

On AWS, s3nd is the AWS SDK v3 with the transfer semantics on top. Omit credentials and the default provider chain applies: environment variables, the shared config file, or the role attached to the instance, task or function. Nothing to store, nothing to rotate.

From the command line

A starter configuration, and what is left to do.

init writes the file with ${VAR} references rather than secrets, so it is meant to be committed; the env file it points at is not.

$s3nd init --provider aws --bucket transfers

s3nd.config.json

{
  "bucket": "transfers",
  "region": "eu-west-3",
  "prefix": "transfers",
  "expiresIn": "24h"
}

Then

01Give the machine credentials the usual way: AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY, a profile, or a role.
02Add a lifecycle rule on the transfers/ prefix that expires objects after a day or two.
03Run s3nd doctor. It performs the operations s3nd needs and reports what happened.

Worth knowing

Notes on S3.

Virtual-hosted addressing

Without an endpoint, s3nd leaves path-style addressing off, which is what S3 proper expects. Set forcePathStyle yourself only if a gateway in front demands it.

ACLs are off by default

Buckets created after 2023 have "bucket owner enforced" on. Make objects public with a bucket policy or a CDN, and leave the acl option alone.

Expiry cleanup

expiresIn stops a transfer being handed over; only a lifecycle rule deletes the object. Give the prefix a rule that expires objects after a day or two, and s3nd doctor turns green.

The full guide

Other providers

The endpoint is the only difference.

Cloudflare R2

No egress fees, which is exactly what moving a 2 GB file between two laptops wants.

MinIO

One Docker command, and the real code path runs on your laptop and in CI.

Scaleway Object Storage

European regions, S3-compatible, and the region actually means something.

Wasabi

Flat-rate storage with no egress charge, on a regional endpoint.

Put a file. Hand over the code.

Point it at the bucket you already pay for. Nothing to deploy, nothing to sign up for, nothing in the middle.

Install the CLI Put it in your app GitHub

$npm install -g @s3nd/cli$s3nd init --provider r2 --bucket drop$s3nd put ./anything.zip