# aiobotocore 3.9.1

- Product: aiobotocore (https://whatsnew.fyi/product/aiobotocore)
- Vendor: aiobotocore
- Date: 2026-08-22
- Version: 3.9.1
- Original notes: https://github.com/aio-libs/aiobotocore/releases/tag/3.9.1
- Permalink: https://whatsnew.fyi/product/aiobotocore/releases/3.9.1

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

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- **changed** — Update botocore dependency specification to support botocore >= 1.43.66, < 1.43.76
- **changed** — Seed the amz-sdk-request header's max token on the initial request attempt instead of only after a retry occurs
- **changed** — Honor a per-request read_timeout override when computing retry timing to match botocore 1.43.66 and 1.43.72
- **fixed** — Fix login credential refreshes by calling the generated create_oauth2_token method directly instead of botocore's sync-only create_o_auth2_token compatibility alias
- **fixed** — Fix a concurrency-safety issue in HTTPSession session management

* bump botocore dependency specification to support
  ``"botocore >= 1.43.66, < 1.43.76"`` (#1693, #1709)
* seed the ``amz-sdk-request`` header's ``max`` token on the initial request
  attempt (previously only appeared once a retry occurred) and honour a
  per-request ``read_timeout`` override when computing retry timing, matching
  botocore 1.43.66 and 1.43.72 (#1709)
* fix login credential refreshes calling botocore's sync-only
  ``create_o_auth2_token`` compatibility alias, which aiobotocore cannot
  resolve asynchronously, by calling the generated ``create_oauth2_token``
  method directly (closes #1697) (#1704)
* fix a concurrency-safety issue in ``HTTPSession`` session management
  (closes #1695) (#1696)