Here are a list of all the changes from the latest 5.x.x version to 6.0.0

Major Release Changes

• Preparing for implementing Sendable conformance (make classes final, set some member variables to private). PR #493
• Add Sendable Conformance to all relevant objects/protocols. This includes AWSClient, AWSService, CredentialProvider, AWSShape and others.
• Add support for automatic HTTP checksum calculation (md5, crc32, crc32c, sha1 and sha256) where checksum tests are supported (S3). PR #499
• AWSHTTPClient, AWSHTTPRequest, AWSHTTPResponse are no longer public symbols.
• Move _payloadOptions to AWSShape and rename to _options.
• AWSResponse.headers type is now HTTPHeaders instead of [String: Any].
• AWSPayload.stream has byteBufferAllocator parameter removed as it is no longer used.
• Removed ConfigFile
• DictionaryDecoder is no longer public
• Removed version of SotoSignerV4.signHeaders/signURL that don't include omitSecurityToken parameter.
• Removed version of AWSClient.init that doesn' include options parameter.
• Removed version of AWSService.with that doesn't include region parameter.
• Removed deprecated AWSClient.paginate functions

Minor Release Changes

• Added async version of AWSClient.shutdown
• Added AWSBase64Data to store base64 encoded data. This is to replace all instances of Data in AWS service API input/output shapes.
• Add xmlNamespace to AWSServiceConfig.
• Add AWSShape option .checksumRequired which calculates a checksum (md5, crc32, crc32c, sha1 and sha256) of the payload and places it in the headers.
• Add AWSShape option .md5ChecksumHeader which indicates the shape has a MD5-Content header which will be calculated if the service config has option .calculateMD5 set to true.
• Add Location.hostname which is used for placing content in the hostname.
• Add Location.headerPrefix which is used for placing a dictionary into multiple headers with the keys prefixed by a string. This was part of the S3 middleware but has now been generalised.

Patch changes

• Remove retry on NIOConnectionError as AsyncHTTPClient does this for us.
• Only retry on HTTPClient.remoteConnectionClosed in debug builds as this could retry non-idempotent calls even when they have been successful.
• Set user-agent header to "Soto/6.0".
• Fix empty query protocol requests. Queries with no body should still include the API version and operation name in the body. PR #494
• Fix V4 Signing bug where sequential spaces have to be removed from header values when building canonical request. PR #498
• Require at least version 1.9.0 of AsyncHTTPClient

Other changes

• Use endpoints.json file from aws-sdk-go-v2 when generating region file
• Renamed sanity scripts to validate
• Add GitHub action to test for API breaking changes to run on all PRs
• Use docc to generate documentation https://soto-project.github.io/soto-core/6.x.x/documentation/sotocore