--- title: aws-sdk-js description: Configure the AWS SDK for JavaScript v2 to work with Cloudflare R2. image: https://developers.cloudflare.com/dev-products-preview.png --- > 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. [Skip to content](#%5Ftop) # aws-sdk-js You must [generate an Access Key](https://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. If you are interested in the newer version of the AWS JavaScript SDK visit this [dedicated aws-sdk-js-v3 example page](https://developers.cloudflare.com/r2/examples/aws/aws-sdk-js-v3/). JavaScript or TypeScript users may continue to use the [aws-sdk ↗](https://www.npmjs.com/package/aws-sdk) npm package as per normal. You must pass in the R2 configuration credentials when instantiating your `S3` service client: TypeScript ``` import S3 from "aws-sdk/clients/s3.js"; const s3 = new S3({ // Provide your Cloudflare account ID endpoint: `https://${ACCOUNT_ID}.r2.cloudflarestorage.com`, // Retrieve your S3 API credentials for your R2 bucket via API tokens (see: https://developers.cloudflare.com/r2/api/tokens) accessKeyId: `${ACCESS_KEY_ID}`, secretAccessKey: `${SECRET_ACCESS_KEY}`, signatureVersion: "v4",}); console.log(await s3.listBuckets().promise());//=> {//=> Buckets: [//=> { Name: 'user-uploads', CreationDate: 2022-04-13T21:23:47.102Z },//=> { Name: 'my-bucket', CreationDate: 2022-05-07T02:46:49.218Z }//=> ],//=> Owner: {//=> DisplayName: '...',//=> ID: '...'//=> }//=> } console.log(await s3.listObjects({ Bucket: "my-bucket" }).promise());//=> {//=> IsTruncated: false,//=> Name: 'my-bucket',//=> CommonPrefixes: [],//=> MaxKeys: 1000,//=> Contents: [//=> {//=> Key: 'cat.png',//=> LastModified: 2022-05-07T02:50:45.616Z,//=> ETag: '"c4da329b38467509049e615c11b0c48a"',//=> ChecksumAlgorithm: [],//=> Size: 751832,//=> Owner: [Object]//=> },//=> {//=> Key: 'todos.txt',//=> LastModified: 2022-05-07T21:37:17.150Z,//=> ETag: '"29d911f495d1ba7cb3a4d7d15e63236a"',//=> ChecksumAlgorithm: [],//=> Size: 279,//=> Owner: [Object]//=> }//=> ]//=> } ``` ## Generate presigned URLs You can also generate presigned links that can be used to share public read or write access to a bucket temporarily. TypeScript ``` // Use the expires property to determine how long the presigned link is valid.console.log(await s3.getSignedUrlPromise("getObject", { Bucket: "my-bucket", Key: "dog.png", Expires: 3600,}),);// You can also create links for operations such as putObject to allow temporary write access to a specific key.// Specify ContentType to restrict uploads to a specific file type.console.log( await s3.getSignedUrlPromise("putObject", { Bucket: "my-bucket", Key: "dog.png", Expires: 3600, ContentType: "image/png", }),); ``` ``` https://my-bucket..r2.cloudflarestorage.com/dog.png?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=&X-Amz-Date=&X-Amz-Expires=3600&X-Amz-SignedHeaders=host&X-Amz-Signature=https://my-bucket..r2.cloudflarestorage.com/dog.png?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=&X-Amz-Date=&X-Amz-Expires=3600&X-Amz-SignedHeaders=content-type%3Bhost&X-Amz-Signature= ``` You can use the link generated by the `putObject` example to upload to the specified bucket and key, until the presigned link expires. When using a presigned URL with `ContentType`, the client must include a matching `Content-Type` header in the request. Terminal window ``` curl -X PUT "https://my-bucket..r2.cloudflarestorage.com/dog.png?X-Amz-Algorithm=..." \ -H "Content-Type: image/png" \ --data-binary @dog.png ``` ## Restrict uploads with CORS and Content-Type When generating presigned URLs for uploads, you can limit abuse and misuse by: 1. **Restricting Content-Type**: Specify the allowed content type in the presigned URL parameters. The upload will fail if the client sends a different `Content-Type` header. 2. **Configuring CORS**: Set up [CORS rules](https://developers.cloudflare.com/r2/buckets/cors/#add-cors-policies-from-the-dashboard) on your bucket to control which origins can upload files. Configure CORS via the [Cloudflare dashboard ↗](https://dash.cloudflare.com/?to=/:account/r2/overview) by adding a JSON policy to your bucket settings: ``` [ { "AllowedOrigins": ["https://example.com"], "AllowedMethods": ["PUT"], "AllowedHeaders": ["Content-Type"], "ExposeHeaders": ["ETag"], "MaxAgeSeconds": 3600 }] ``` Then generate a presigned URL with a Content-Type restriction: TypeScript ``` const putUrl = await s3.getSignedUrlPromise("putObject", { Bucket: "my-bucket", Key: "user-upload.png", Expires: 3600, ContentType: "image/png",}); ``` When a client uses this presigned URL, they must: * Make the request from an allowed origin (enforced by CORS) * Include the `Content-Type: image/png` header (enforced by the signature) ```json {"@context":"https://schema.org","@type":"TechArticle","@id":"https://developers.cloudflare.com/r2/examples/aws/aws-sdk-js/#page","headline":"aws-sdk-js · Cloudflare R2 docs","description":"Configure the AWS SDK for JavaScript v2 to work with Cloudflare R2.","url":"https://developers.cloudflare.com/r2/examples/aws/aws-sdk-js/","inLanguage":"en","image":"https://developers.cloudflare.com/dev-products-preview.png","dateModified":"2026-04-21","publisher":{"@type":"Organization","name":"Cloudflare","url":"https://www.cloudflare.com/"},"isPartOf":{"@type":"WebSite","@id":"https://developers.cloudflare.com/#website","name":"Cloudflare Docs","url":"https://developers.cloudflare.com/"}} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/directory/","name":"Directory"}},{"@type":"ListItem","position":2,"item":{"@id":"/r2/","name":"R2"}},{"@type":"ListItem","position":3,"item":{"@id":"/r2/examples/","name":"Examples"}},{"@type":"ListItem","position":4,"item":{"@id":"/r2/examples/aws/","name":"S3 SDKs"}},{"@type":"ListItem","position":5,"item":{"@id":"/r2/examples/aws/aws-sdk-js/","name":"aws-sdk-js"}}]} ```