WriteGetObjectResponse - Amazon Simple Storage Service
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Passes transformed objects to a GetObject operation when using Object Lambda access points. For information about Object Lambda access points, see Transforming objects with Object Lambda access points in the Amazon S3 User Guide.

This operation supports metadata that can be returned by GetObject, in addition to RequestRoute, RequestToken, StatusCode, ErrorCode, and ErrorMessage. The GetObject response metadata is supported so that the WriteGetObjectResponse caller, typically an Amazon Lambda function, can provide the same metadata when it internally invokes GetObject. When WriteGetObjectResponse is called by a customer-owned Lambda function, the metadata returned to the end user GetObject call might differ from what Amazon S3 would normally return.

You can include any number of metadata headers. When including a metadata header, it should be prefaced with x-amz-meta. For example, x-amz-meta-my-custom-header: MyCustomValue. The primary use case for this is to forward GetObject metadata.

Amazon provides some prebuilt Lambda functions that you can use with S3 Object Lambda to detect and redact personally identifiable information (PII) and decompress S3 objects. These Lambda functions are available in the Amazon Serverless Application Repository, and can be selected through the Amazon Management Console when you create your Object Lambda access point.

Example 1: PII Access Control - This Lambda function uses Amazon Comprehend, a natural language processing (NLP) service using machine learning to find insights and relationships in text. It automatically detects personally identifiable information (PII) such as names, addresses, dates, credit card numbers, and social security numbers from documents in your Amazon S3 bucket.

Example 2: PII Redaction - This Lambda function uses Amazon Comprehend, a natural language processing (NLP) service using machine learning to find insights and relationships in text. It automatically redacts personally identifiable information (PII) such as names, addresses, dates, credit card numbers, and social security numbers from documents in your Amazon S3 bucket.

Example 3: Decompression - The Lambda function S3ObjectLambdaDecompression, is equipped to decompress objects stored in S3 in one of six compressed file formats including bzip2, gzip, snappy, zlib, zstandard and ZIP.

For information on how to view and use these functions, see Using Amazon built Lambda functions in the Amazon S3 User Guide.

Request Syntax

POST /WriteGetObjectResponse HTTP/1.1 x-amz-request-route: RequestRoute x-amz-request-token: RequestToken x-amz-fwd-status: StatusCode x-amz-fwd-error-code: ErrorCode x-amz-fwd-error-message: ErrorMessage x-amz-fwd-header-accept-ranges: AcceptRanges x-amz-fwd-header-Cache-Control: CacheControl x-amz-fwd-header-Content-Disposition: ContentDisposition x-amz-fwd-header-Content-Encoding: ContentEncoding x-amz-fwd-header-Content-Language: ContentLanguage Content-Length: ContentLength x-amz-fwd-header-Content-Range: ContentRange x-amz-fwd-header-Content-Type: ContentType x-amz-fwd-header-x-amz-delete-marker: DeleteMarker x-amz-fwd-header-ETag: ETag x-amz-fwd-header-Expires: Expires x-amz-fwd-header-x-amz-expiration: Expiration x-amz-fwd-header-Last-Modified: LastModified x-amz-fwd-header-x-amz-missing-meta: MissingMeta x-amz-fwd-header-x-amz-object-lock-mode: ObjectLockMode x-amz-fwd-header-x-amz-object-lock-legal-hold: ObjectLockLegalHoldStatus x-amz-fwd-header-x-amz-object-lock-retain-until-date: ObjectLockRetainUntilDate x-amz-fwd-header-x-amz-mp-parts-count: PartsCount x-amz-fwd-header-x-amz-replication-status: ReplicationStatus x-amz-fwd-header-x-amz-request-charged: RequestCharged x-amz-fwd-header-x-amz-restore: Restore x-amz-fwd-header-x-amz-server-side-encryption: ServerSideEncryption x-amz-fwd-header-x-amz-server-side-encryption-customer-algorithm: SSECustomerAlgorithm x-amz-fwd-header-x-amz-server-side-encryption-aws-kms-key-id: SSEKMSKeyId x-amz-fwd-header-x-amz-server-side-encryption-customer-key-MD5: SSECustomerKeyMD5 x-amz-fwd-header-x-amz-storage-class: StorageClass x-amz-fwd-header-x-amz-tagging-count: TagCount x-amz-fwd-header-x-amz-version-id: VersionId x-amz-fwd-header-x-amz-server-side-encryption-bucket-key-enabled: BucketKeyEnabled Body

URI Request Parameters

The request uses the following URI parameters.


The size of the content body in bytes.


A string that uniquely identifies an error condition. Returned in the <Code> tag of the error XML response for a corresponding GetObject call. Cannot be used with a successful StatusCode header or when the transformed object is provided in the body. All error codes from S3 are sentence-cased. Regex value is "^[A-Z][a-zA-Z]+$".


Contains a generic description of the error condition. Returned in the <Message> tag of the error XML response for a corresponding GetObject call. Cannot be used with a successful StatusCode header or when the transformed object is provided in body.


Indicates that a range of bytes was specified.


Specifies caching behavior along the request/reply chain.


Specifies presentational information for the object.


Specifies what content encodings have been applied to the object and thus what decoding mechanisms must be applied to obtain the media-type referenced by the Content-Type header field.


The language the content is in.


The portion of the object returned in the response.


A standard MIME type describing the format of the object data.


An opaque identifier assigned by a web server to a specific version of a resource found at a URL.


The date and time at which the object is no longer cacheable.


The date and time that the object was last modified.


Specifies whether an object stored in Amazon S3 is (true) or is not (false) a delete marker.


If object stored in Amazon S3 expiration is configured (see PUT Bucket lifecycle) it includes expiry-date and rule-id key-value pairs providing object expiration information. The value of the rule-id is URL encoded.


Set to the number of metadata entries not returned in x-amz-meta headers. This can happen if you create metadata using an API like SOAP that supports more flexible metadata than the REST API. For example, using SOAP, you can create metadata whose values are not legal HTTP headers.


The count of parts this object has.


Indicates whether an object stored in Amazon S3 has an active legal hold.

Valid Values: ON | OFF


Indicates whether an object stored in Amazon S3 has Object Lock enabled. For more information about S3 Object Lock, see Object Lock.



The date and time when Object Lock is configured to expire.


Indicates if request involves bucket that is either a source or destination in a Replication rule. For more information about S3 Replication, see Replication.



If present, indicates that the requester was successfully charged for the request.

Valid Values: requester


Provides information about object restoration operation and expiration time of the restored object copy.


The server-side encryption algorithm used when storing requested object in Amazon S3 (for example, AES256, aws:kms).

Valid Values: AES256 | aws:kms


If present, specifies the ID of the Amazon Key Management Service (Amazon KMS) symmetric customer managed key that was used for stored in Amazon S3 object.


Indicates whether the object stored in Amazon S3 uses an S3 bucket key for server-side encryption with Amazon KMS (SSE-KMS).


Encryption algorithm used if server-side encryption with a customer-provided encryption key was specified for object stored in Amazon S3.


128-bit MD5 digest of customer-provided encryption key used in Amazon S3 to encrypt data stored in S3. For more information, see Protecting data using server-side encryption with customer-provided encryption keys (SSE-C).


The class of storage used to store object in Amazon S3.



The number of tags, if any, on the object.


An ID used to reference a specific version of the object.


The integer status code for an HTTP response of a corresponding GetObject request.

Status Codes

  • 200 - OK

  • 206 - Partial Content

  • 304 - Not Modified

  • 400 - Bad Request

  • 401 - Unauthorized

  • 403 - Forbidden

  • 404 - Not Found

  • 405 - Method Not Allowed

  • 409 - Conflict

  • 411 - Length Required

  • 412 - Precondition Failed

  • 416 - Range Not Satisfiable

  • 500 - Internal Server Error

  • 503 - Service Unavailable


Route prefix to the HTTP URL generated.

Required: Yes


A single use encrypted token that maps WriteGetObjectResponse to the end user GetObject request.

Required: Yes

Request Body

The request accepts the following binary data.

Response Syntax

HTTP/1.1 200

Response Elements

If the action is successful, the service sends back an HTTP 200 response with an empty HTTP body.


Sample Response

The following illustrates a sample response.

HTTP/1.1 200 OK x-amz-request-id: 19684529-d1aa-413e-9382-9ff490962d12 Date: Wed, 24 Feb 2021 10:57:53 GMT Content-Length: 0

Sample Request

The following illustrates a sample request from a POST.

POST /WriteGetObjectResponse HTTP/1.1 Host: <RequestRoute>.s3-object-lambda.<Region>.amazonaws.com x-amz-request-token: <RequestToken> Authorization: authorization string Content-Type: text/plain Content-Length: 16 [16 bytes of object data]

Sample Error Response

The following response returns a ValidationError error because the RequestToken could not be decrypted.

<?xml version="1.0" encoding="UTF-8"?> <Error xmlns=""> <Code>ValidationError</Code> <Message>Invalid token</Message> <RequestId>fcd2cd5e-def0-4001-8030-1fd1d61d2c9d</RequestId> </Error>

See Also

For more information about using this API in one of the language-specific Amazon SDKs, see the following: