---
features:
  - |
    S3 API

    * Added support for aws-chunked transfers. Recent AWS clients recently
      began defaulting to this mode. See also:
      `Transferring Payload in Multiple Chunks (Chunked Upload)
      <https://docs.aws.amazon.com/AmazonS3/latest/API/sigv4-streaming.html>`__.

    * Added support for verifying additional checksums during upload. All
      algorithms currently supported by AWS are supported: CRC64NVME,
      CRC32, CRC32C, SHA1, and SHA256. See also: `Checking object integrity
      in Amazon S3
      <https://docs.aws.amazon.com/AmazonS3/latest/userguide/checking-object-integrity.html>`__.
      Note that some algorithms require the availability of additional
      libraries: ISA-L or anycrc.

    * Added support for create-without-overwrite conditional writes.

  - |
    Let clients request heartbeats during COPYs by including
    the query parameter ``heartbeat=on``.

    With heartbeating turned on, the proxy will start its response
    immediately with 202 Accepted then send a single whitespace
    character periodically until the request completes. At that
    point, a final summary chunk will be sent which includes a
    ``Response Status`` key indicating success or failure.

  - |
    Labeled metrics

    * Added support for emitting labeled statsd metrics in a variety of
      formats. Middleware authors should see `the LabeledStatsdClient documentation
      <https://docs.openstack.org/swift/latest/misc.html#swift.common.statsd_client.LabeledStatsdClient>`__
      for more information.

    * Instrumented proxy-logging with labeled metrics. See
      ``proxy-server.conf-sample`` for more information.

    * Instrumented the object-server with labeled metrics. See
      ``object-server.conf-sample`` for more information.

  - |
    Added ``access_user_id`` logging field; out-of-tree auth middlewares should
    use ``environ['swift.access_logging']['user_id']`` to populate this field.

  - |
    Introduced an extensible ring format. This allows both more than 65,536
    devices and more data structures to be in a ring. For more information,
    see `Ring File Formats -- Ring v2
    <https://docs.openstack.org/swift/latest/overview_ring_format.html#ring-v2>`__.

  - |
    Python 3.13 (with the GIL enabled) is now supported. Free-threaded
    builds remain untested.
upgrade:
  - |
    Removed support for Python 3.6.

  - |
    Removed support for pickled ring files. These have not been written
    since Swift 1.7.0.
deprecations:
  - |
    Flamingo (2025.2) will be the final stable release to support Python 3.7 and 3.8.
fixes:
  - |
    S3 API

    * Fixed HTTP framing issues when returning errors for a request with
      ``Expect: 100-continue``.

    * Improved various error messages to better imitate AWS responses.

  - |
    SSYNC connections are now promptly terminated when subrequests timeout.

  - |
    Fixed a recursion error in the account-quota middleware.

  - |
    Fixed an error in ``invalidate_hash`` when the partition is deleted while
    waiting for the partition lock.

  - |
    Various other minor bug fixes and improvements.