MinIO Has a Free API — S3-Compatible Object Storage You Can Self-Host

#devops #api #tutorial #opensource

AWS S3 API, But Free and On Your Server

MinIO is S3-compatible object storage you can run anywhere. Same API as AWS S3, but free and open-source.

Setup (Docker)

docker run -p 9000:9000 -p 9001:9001 \
  -e MINIO_ROOT_USER=admin \
  -e MINIO_ROOT_PASSWORD=password123 \
  minio/minio server /data --console-address ":9001"

Dashboard at localhost:9001. API at localhost:9000.

Python (boto3 — Same as AWS S3!)

import boto3

s3 = boto3.client("s3",
    endpoint_url="http://localhost:9000",
    aws_access_key_id="admin",
    aws_secret_access_key="password123")

# Create bucket
s3.create_bucket(Bucket="my-files")

# Upload
s3.upload_file("report.pdf", "my-files", "reports/2026/report.pdf")

# Download
s3.download_file("my-files", "reports/2026/report.pdf", "downloaded.pdf")

# List objects
for obj in s3.list_objects_v2(Bucket="my-files")["Contents"]:
    print(f"{obj[Key]}: {obj[Size]} bytes")

Same code works with AWS S3 — just change the endpoint_url.

JavaScript

import { S3Client, PutObjectCommand, ListObjectsV2Command } from "@aws-sdk/client-s3";

const s3 = new S3Client({
  endpoint: "http://localhost:9000",
  region: "us-east-1",
  credentials: { accessKeyId: "admin", secretAccessKey: "password123" },
  forcePathStyle: true
});

await s3.send(new PutObjectCommand({
  Bucket: "my-files",
  Key: "hello.txt",
  Body: "Hello World"
}));