s3mini

Last updated Apr 21, 2026 You must generate an Access Key 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 ↗︎ 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

npm install s3mini

Node.js / Bun

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 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.

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 });
        }
    },
};

Was this helpful?

YesNo

On this page

s3mini - 图1Docs

{"@context":"https://schema.org","@type":"TechArticle","@id":"https://developers.cloudflare.com/r2/examples/aws/s3mini/#page","headline":"s3mini","description":"Configure s3mini, a lightweight TypeScript S3 client, to work with Cloudflare R2.","url":"https://developers.cloudflare.com/r2/examples/aws/s3mini/","inLanguage":"en","image":"https://developers.cloudflare.com/r2/examples/aws/s3mini/og.png?v=3f76ec3166510ff7","dateModified":"2026-04-21","publisher":{"@type":"Organization","name":"Cloudflare","description":"One platform for your apps, agents, and workforce. Build, secure, and scale without managing infrastructure","url":"https://www.cloudflare.com/","sameAs":["https://github.com/cloudflare","https://www.linkedin.com/company/cloudflare","https://x.com/cloudflare"],"logo":{"@type":"ImageObject","url":"https://developers.cloudflare.com/logo.svg"},"address":{"@type":"PostalAddress","streetAddress":"101 Townsend St","addressLocality":"San Francisco","addressRegion":"CA","postalCode":"94107","addressCountry":"US"},"contactPoint":[{"@type":"ContactPoint","contactType":"Customer Support","url":"https://support.cloudflare.com/","availableLanguage":["English"]},{"@type":"ContactPoint","contactType":"Sales","url":"https://www.cloudflare.com/contact/","availableLanguage":["English"]}]},"isPartOf":{"@type":"WebSite","@id":"https://developers.cloudflare.com/#website","name":"Cloudflare Docs","url":"https://developers.cloudflare.com/"}}

description: Store R2 objects in Cloudflare's cache using the Workers Cache API for faster retrieval. title: Use the Cache API image: https://developers.cloudflare.com/r2/examples/cache-api/og.png?v=105d9b206a7f65dd

Skip to content

Documentation Index
Fetch the complete documentation index at: https://developers.cloudflare.com/r2/llms.txt
Use this file to discover all available pages before exploring further.