boto/s3transfer

Recent updates

• 0.18.0

  2026-05-28

  No release notes were provided for version 0.18.0. The code diff indicates a functional change in multipart copy behavior, plus internal refactoring and a version bump.

• 0.17.1

  2026-05-26

  Version 0.17.1 introduces a new S3 download execution path intended to reduce latency by avoiding a HEAD request under specific checksum-validation configuration. The core logic changes live in the download submission flow and introduce a new internal “first chunk” ranged-GET callback to drive metadata and subsequent chunk scheduling.

  Breaking

• 0.17.0

  2026-04-29

  Release 0.17.0 primarily updates supported Python versions, ending support for Python 3.9 and shifting the project and CI to Python 3.10+. The code diff also changes network timeout exception handling and updates developer tooling and CI action pin versions.

  Breaking

• 0.16.1

  2026-04-22

  Release 0.16.1 primarily adds support in TransferManager for customer-provided full-object checksums using additional algorithms (SHA512, MD5, and XXHASH variants). The code diff also includes several CI and development-environment changes (workflows, test helpers, and dependency lock updates) that are not reflected in any published release notes.

  SecurityFeatures

• 0.16.0

  2025-12-01

  Release 0.16.0 was published, but no release notes were provided, so changes cannot be assessed from documentation alone. Developers should review the diff between the previous version and 0.16.0 to identify API compatibility, behavior changes, and any required migrations.

• 0.15.0

  2025-11-20

  Version 0.15.0 introduces ETag validation for stored objects during multipart copy operations by passing an additional precondition to each UploadPartCopy call. The code also adds a new exception type to represent ETag mismatches, and updates CI Python matrix to use Python 3.14 instead of 3.14-dev.

  Features

• 0.14.0

  2025-09-09

  This release introduces new validation for multipart download responses, ensuring that the requested HTTP Range aligns with the ContentRange returned by the service. It also adds a new exception type used when this validation fails, and updates CI workflow pinned commit SHAs.

• 0.13.1

  2025-07-18

  Release 0.13.1 adds provisional support for Python 3.14, plus a small set of internal maintenance changes. The provided release notes are empty, but the CHANGELOG documents the Python 3.14 support. The code diff also includes several undocumented internal behavioral changes around how S3 clients are created (via a new create_nested_client helper).

  Features

• 0.13.0

  2025-05-22

  This release (0.13.0) adds ETag validation during multipart (ranged) downloads by capturing the stored object ETag from HeadObject and using it to protect subsequent GetObject part requests. The implementation injects an IfMatch precondition into ranged GetObject calls and converts ETag mismatches into a dedicated download failure exception.

  Features

• 0.12.0

  2025-04-22

  Release 0.12.0 primarily updates supported Python versions by removing Python 3.8 from packaging and CI/test configurations. It also updates linting/CI runner and tooling targets to align with the new minimum Python version.

  Breaking

• 0.11.5

  2025-04-17

  Release 0.11.5 adds an S3 enhancement described as memory performance fixes for downloads to non-seekable streams. The only functional code change shown is within the S3 download buffering logic (DeferQueue), plus version and changelog updates. Release notes provided by the publisher are effectively missing, so the behavioral impact of the download queue changes is not documented.

• 0.11.4

  2025-03-04

  Release 0.11.4 was published on 2025-03-04, but the publisher did not provide any release notes. No changes, fixes, or compatibility information can be determined from the release notes text.