v2.12.3 (2025-10-17)

What's Changed

This is the third 2.13 patch release, fixing issues related to the FieldInfo class, and reverting a change to the supported after model validator function signatures.

• Raise a warning when an invalid after model validator function signature is raised by @Viicos in #12414.
  Starting in 2.12.0, using class methods for after model validators raised an error, but the error wasn't raised concistently. We decided to emit a deprecation warning instead.
• Add FieldInfo.asdict() method, improve documentation around FieldInfo by @Viicos in #12411.
  This also adds back support for mutations on FieldInfo classes, that are reused as Annotated metadata. However, note that this is still not a supported pattern. Instead, please refer to the added example in the documentation.

The blog post section on changes was also updated to document the changes related to serialize_as_any.

Full Changelog: v2.12.2...v2.12.3