release: 0.21.0

[stainless-app]

Automated Release PR

0.21.0 (2025-11-28)

Full Changelog: v0.20.0...v0.21.0

Features

• Mason/agent auth api (b872928)

Bug Fixes

• ensure streams are always closed (c82f496)

Chores

• add Python 3.14 classifier and testing (9a1e7bf)
• deps: mypy 1.18.1 has a regression, pin to 1.17 (038b10d)

---

This pull request is managed by Stainless's GitHub App.

The semver version number is based on included commit messages. Alternatively, you can manually set the version number in the title of this pull request.

For a better experience, it is recommended to use either rebase-merge or squash-merge when merging this pull request.

🔗 Stainless website
📚 Read the docs
🙋 Reach out for help or questions

[stainless-app]

🧪 Testing

    To try out this version of the SDK, run:
    ```
    pip install 'https://pkg.stainless.com/s/kernel-python/038b10d52935961c37ebb0806e9b0754b4d53a20/kernel-0.20.0-py3-none-any.whl'
    ```

    _Expires: Sun, 28 Dec 2025 03:14:03 GMT_

[mesa-dot-dev]

Mesa Description

Automated Release PR

0.21.0 (2025-11-28)

Full Changelog: v0.20.0...v0.21.0

Features

• Mason/agent auth api (b872928)

Bug Fixes

• ensure streams are always closed (c82f496)

Chores

• add Python 3.14 classifier and testing (9a1e7bf)
• deps: mypy 1.18.1 has a regression, pin to 1.17 (038b10d)

---

This pull request is managed by Stainless's GitHub App.

The semver version number is based on included commit messages. Alternatively, you can manually set the version number in the title of this pull request.

For a better experience, it is recommended to use either rebase-merge or squash-merge when merging this pull request.

🔗 Stainless website
📚 Read the docs
🙋 Reach out for help or questions

^{Description generated by Mesa. Update settings}

[mesa-dot-dev]

Performed full review of bce9faa...1410b95

Analysis

1. Incomplete Python 3.14 Support - The PR adds the Python 3.14 classifier to pyproject.toml but lacks actual testing infrastructure updates in CI workflow files or noxfile.py test sessions.

2. Misleading Changelog - Claims to "add Python 3.14 classifier and testing" but only implements the classifier addition, creating a discrepancy between documentation and implementation.

3. Potential Versioning Issue - Using a patch version (0.20.1) may be questionable if adding Python 3.14 support is considered a new feature, which typically warrants a minor version bump (0.21.0) according to SemVer.

4. Premature Python Version Support - Needs verification that Python 3.14 is stable enough for production use, as it may still be in pre-release.

Tip

Help

Slash Commands:

• /review - Request a full code review
• /review latest - Review only changes since the last review
• /describe - Generate PR description. This will update the PR body or issue comment depending on your configuration
• /help - Get help with Mesa commands and configuration options

^{4 files reviewed | 0 comments | Edit Agent Settings • Read Docs}

[mesa-dot-dev]

Performed full review of bce9faa...1410b95

Analysis

1. The addition of Python 3.14 classifier is premature as Python 3.14 won't be released until approximately October 2026, which could mislead users, cause PyPI rejection, or break CI/CD pipelines.

2. Adding support for an unreleased Python version without testing against it introduces potential compatibility risks.

3. Version references have been updated across multiple files, but the classifier change doesn't align with the nature of a patch release (0.20.0 to 0.20.1) which should only contain bug fixes.

4. The release should either remain at 0.20.0 or the Python 3.14 classifier addition should be reverted until proper testing can be performed.

Tip

Help

Slash Commands:

• /review - Request a full code review
• /review latest - Review only changes since the last review
• /describe - Generate PR description. This will update the PR body or issue comment depending on your configuration
• /help - Get help with Mesa commands and configuration options

^{4 files reviewed | 0 comments | Edit Agent Settings • Read Docs}