v2.12.0b1 (2025-10-03)

This is the first beta release of the upcoming 2.12 release.

What's Changed

Packaging

• Bump pydantic-core to v2.40.1 by @Viicos in #12314

New Features

• Add support for exclude_if at the field level by @andresliszt in #12141
• Add ValidateAs annotation helper by @Viicos in #11942
• Add configuration options for validation and JSON serialization of temporal types by @ollz272 in #12068
• Add support for PEP 728 by @Viicos in #12179
• Add field name in serialization error by @NicolasPllr1 in pydantic-core#1799
• Add option to preserve empty URL paths by @davidhewitt in pydantic-core#1789

Changes

• Raise error if an incompatible pydantic-core version is installed by @Viicos in #12196
• Remove runtime warning for experimental features by @Viicos in #12265
• Warn if registering virtual subclasses on Pydantic models by @Viicos in #11669

Fixes

• Fix __getattr__() behavior on Pydantic models when a property raised an AttributeError and extra values are present by @raspuchin in #12106
• Add test to prevent regression with Pydantic models used as annotated metadata by @Viicos in #12133
• Allow to use property setters on Pydantic dataclasses with validate_assignment set by @Viicos in #12173
• Fix mypy v2 plugin for upcoming mypy release by @cdce8p in #12209
• Respect custom title in functions JSON Schema by @Viicos in #11892
• Fix ImportString JSON serialization for objects with a name attribute by @chr1sj0nes in #12219
• Do not error on fields overridden by methods in the mypy plugin by @Viicos in #12290

New Contributors

• @raspuchin made their first contribution in #12106
• @chr1sj0nes made their first contribution in #12219