---
description: Configure s3mini, a lightweight TypeScript S3 client, to work with Cloudflare R2.
title: s3mini
image: https://developers.cloudflare.com/og-docs.png
---

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# s3mini

Last updated Aug 25, 2026|Copy as Markdown|[View as Markdown](https://66f4ea29.previews.developers.cloudflare.com/r2/examples/aws/s3mini/index.md)|[Agent setup](https://66f4ea29.previews.developers.cloudflare.com/agent-setup/)

You must [generate an Access Key](https://66f4ea29.previews.developers.cloudflare.com/r2/api/tokens/) before getting started. All examples will utilize `access_key_id` and `access_key_secret` variables which represent the **Access Key ID** and **Secret Access Key** values you generated.

  
[s3mini ↗](https://www.npmjs.com/package/s3mini) is a zero-dependency, lightweight (\~20 KB minified) TypeScript S3 client that uses AWS SigV4 signing. It runs natively on Node.js, Bun, and Cloudflare Workers without polyfills.

Unlike the AWS SDKs, s3mini expects a **bucket-scoped endpoint** — the bucket name is part of the endpoint URL, so you do not pass a separate `bucket` parameter to each operation.

## Install

```sh
npm install s3mini
```

## Node.js / Bun

```ts
import { S3mini } from "s3mini";

const s3 = new S3mini({
	accessKeyId: process.env.R2_ACCESS_KEY_ID!,
	secretAccessKey: process.env.R2_SECRET_ACCESS_KEY!,
	// Bucket-scoped endpoint — include your bucket name in the path
	endpoint: `https://${process.env.ACCOUNT_ID}.r2.cloudflarestorage.com/my-bucket`,
	region: "auto",
});

// Upload an object
await s3.putObject("hello.txt", "Hello from s3mini!");

// Download an object as a string
const text = await s3.getObject("hello.txt");
console.log(text);

// List objects with a prefix
const objects = await s3.listObjects("/", "hello");
console.log(objects);

// Delete an object
await s3.deleteObject("hello.txt");
```

## Cloudflare Workers

Prefer R2 bindings inside Workers

When your Worker and R2 bucket live in the same Cloudflare account, [R2 bindings](https://66f4ea29.previews.developers.cloudflare.com/r2/api/workers/workers-api-reference/) give you zero-latency access without managing API credentials. Use the S3 API when you need cross-account access or interoperability with S3-compatible tooling.

s3mini works natively in Workers without the `nodejs_compat` compatibility flag.

```ts
import { S3mini } from "s3mini";

interface Env {
	R2_ACCESS_KEY_ID: string;
	R2_SECRET_ACCESS_KEY: string;
	ACCOUNT_ID: string;
}

export default {
	async fetch(request: Request, env: Env): Promise<Response> {
		const s3 = new S3mini({
			accessKeyId: env.R2_ACCESS_KEY_ID,
			secretAccessKey: env.R2_SECRET_ACCESS_KEY,
			endpoint: `https://${env.ACCOUNT_ID}.r2.cloudflarestorage.com/my-bucket`,
			region: "auto",
		});

		const url = new URL(request.url);
		const key = url.pathname.slice(1); // strip leading "/"

		if (!key) {
			return new Response("Missing object key", { status: 400 });
		}

		switch (request.method) {
			case "PUT": {
				const data = await request.arrayBuffer();
				const contentType =
					request.headers.get("content-type") ?? "application/octet-stream";
				await s3.putObject(key, new Uint8Array(data), contentType);
				return new Response("Created", { status: 201 });
			}

			case "GET": {
				const response = await s3.getObjectResponse(key);
				if (!response) {
					return new Response("Not Found", { status: 404 });
				}
				return new Response(response.body, {
					headers: {
						"content-type":
							response.headers.get("content-type") ??
							"application/octet-stream",
						etag: response.headers.get("etag") ?? "",
					},
				});
			}

			case "DELETE": {
				await s3.deleteObject(key);
				return new Response(null, { status: 204 });
			}

			default:
				return new Response("Method Not Allowed", { status: 405 });
		}
	},
};
```

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