--- title: Direct Fetch for Fastly Object Storage summary: null url: >- https://www.fastly.com/documentation/guides/platform/object-storage/direct-fetch-for-object-storage --- Direct Fetch for Fastly Object Storage lets you transfer data from a remote source directly into Fastly Object Storage without first downloading it to the client. When a client sends a Direct Fetch request: 1. It sends a `PutObject` or `UploadPart` request with the remote object's URL in the `fastly-object-storage-source-url` header. 2. Fastly Object Storage fetches the data from the provided URL. If the request includes a `Range` header, the same range is requested from the source. 3. Fastly Object Storage writes the fetched data to the destination object or multipart upload part and returns a standard `PutObject` or `UploadPart` response for the requested operation. Direct Fetch reduces transfer time and client bandwidth when copying objects from another storage provider or assembling a multipart upload from ranges of an existing object. ## Before you begin Make sure you review the [prerequisites](https://www.fastly.com/documentation/guides/platform/object-storage/about-object-storage/#prerequisites) for using Fastly Object Storage. ## Limitations and considerations Note the following limitations and considerations when using Direct Fetch for Fastly Object Storage. Direct Fetch requests have the following requirements: - Direct Fetch supports the `PutObject` and `UploadPart` operations. - The `fastly-object-storage-source-url` header must be included in the set of signed headers when generating the [AWS Sigv4 signature](https://docs.aws.amazon.com/AmazonS3/latest/API/sigv4-auth-using-authorization-header.html). If the request includes a `Range` header, it must be included in the signature as well. - A single Direct Fetch source response body cannot be greater than 5 GB. Use the multipart upload API to transfer a larger object in parts. The remote source must meet the following conditions: - The source URL must be reachable by Fastly Object Storage. For an object that isn't publicly accessible, use a pre-signed URL that grants temporary access to the object. - For a request without a `Range` header, the source must return `HTTP 200 OK`. Direct Fetch rejects an unsolicited `HTTP 206 Partial Content` response. - For a ranged request, the source must return either `HTTP 206 Partial Content` with a valid `Content-Range` header or `HTTP 200 OK`. - Multipart ranges are not allowed. - The source must not require more than one redirect. Direct Fetch handles transferred data differently than a standard upload: - The client request must have an empty body and a `Content-Length` header with a value of `0`. Fastly Object Storage obtains the object data from the source URL. - Custom metadata headers returned from the source in `x-amz-meta-` prefixed headers will not be written to Fastly Object Storage. To include custom metadata, include the `x-amz-meta-` prefixed metadata headers on the `PutObject` or `CreateMultipartUpload` request. The same metadata restrictions apply to Direct Fetch requests as on standard `PutObject` or `CreateMultipartUpload` requests. - Object metadata such as `ETag` and `Last-Modified` for data migrated via Direct Fetch will not match the source `ETag` or `Last-Modified`. ## Using Direct Fetch with `PutObject` and `UploadPart` To use Direct Fetch for Fastly Object Storage, set the `fastly-object-storage-source-url` header on a standard `PutObject` or `UploadPart` request. Set the header to the URL of the object you want Fastly Object Storage to fetch, typically from a non-Fastly storage provider like AWS S3. If the object is in a private bucket, use a pre-signed URL to grant temporary, time-limited access without sharing the source account's credentials. > **IMPORTANT:** The `fastly-object-storage-source-url` header must be included in the set of signed headers when generating the [AWS Sigv4 signature](https://docs.aws.amazon.com/AmazonS3/latest/API/sigv4-auth-using-authorization-header.html). The `Range` header must also be signed when requesting a range from the source. Then, create a `PutObject` request to `https://fos-region.object.fastlystorage.app/my-fos-bucket/object-key` with an empty body and `Content-Length: 0`, where: - `fos-region.object.fastlystorage.app` is the [regional Object Storage endpoint](https://www.fastly.com/documentation/guides/platform/object-storage/working-with-object-storage/#managing-object-storage-buckets-and-objects) where you want to send the request. - `my-fos-bucket` is the name of your Object Storage bucket. - `object-key` is the name of the destination object in your Object Storage bucket. To store only part of the source object, add one supported HTTP byte `Range` header to the request. The resulting destination object contains only the selected bytes. ## Using Direct Fetch with multipart uploads To transfer an object through multipart upload, first send a standard `CreateMultipartUpload` request. For each part, send an `UploadPart` request with the upload ID, part number, `fastly-object-storage-source-url` header, an empty body, and `Content-Length: 0`. > **IMPORTANT:** The `fastly-object-storage-source-url` header must be included in the set of signed headers when generating the [AWS Sigv4 signature](https://docs.aws.amazon.com/AmazonS3/latest/API/sigv4-auth-using-authorization-header.html). The `Range` header must also be signed when requesting a range from the source. You can add a different `Range` header to each `UploadPart` request to fetch specific sections of the source object. After all parts have been uploaded, send a standard `CompleteMultipartUpload` request with the part numbers and ETags returned by the `UploadPart` responses. ## Validating a transfer After a successful Direct Fetch `PutObject` request, send a `HeadObject` or `GetObject` request to the same region, bucket, and object key to confirm that the object exists. For multipart uploads, validate the object after the `CompleteMultipartUpload` request succeeds. ## Error handling Direct Fetch reports feature-specific errors through both an XML response body and a `fastly-object-storage-df-error` header, which contains a description of the error that occurred. For example, if the source server responds with an unsupported `HTTP 503 Service Unavailable` status code, the `fastly-object-storage-df-error` header will report `DirectFetchSourceStatus 503` and the response status itself will be `HTTP 400 Invalid Request`.