Pydantic Release Notes

What's Changed

Performance

• Avoid Python tuple allocation during model fields validation by @Viicos in #13955
• Avoid unnecessary extra dict allocation in model validation by @Viicos in #13956

Fixes

• Fix arguments-v3 schema with variadic keywords by @Viicos in #13954
• Fix TypeError on ForwardRef on Python 3.10.0 by @Viicos in #13964
• Support closed and extra_items via inheritance in TypedDict by @Viicos in #13967
• Enforce the max_digits whole-digits limit in the Python Decimal validator by @Viicos in #13972
• Reject out-of-range int inputs for timedelta by @Viicos in #13973
• Support named tuples in Sequence validation by @Viicos in #13978

Full Changelog: v2.14.0...v2.14.1

What's Changed

The highlights of the v2.14 release are available in the blog post.

Several minor changes (considered non-breaking changes according to our versioning policy) are also included in this release. Make sure to look into them before upgrading.

This release drops support for Python 3.9 and adds support for Python 3.15.

New Features

• Add support for multiple_of constraint in fraction and timedelta core schemas by @Viicos in #13873
• Add namespace parameter to create_model() by @Viicos in #13895

Changes

• Add an ordered-dict core schema by @Viicos in #13796
• Add a counter core schema by @Viicos in #13824
• Do not mutate model_config attribute by @Viicos in #13825
• Reject newlines in NameEmail validation by @Viicos in #13897

Fixes

• Call enum constructors in both validation modes by @Viicos in #13792
• Fix documentation examples not raising and remove unused string_sub_type unused error code by @Viicos in #13821
• Catch OverflowError during ByteSize validation by @Viicos in #13850
• Require multiple_of constraints to be positive by @Viicos in #13862
• Always pop field name and model type stacks during schema generation by @saquibjawedbit in #13859
• Handle TypeError gracefully during docstring extraction by @Viicos in #13874
• Fix config propagation of stdlib dataclasses and TypedDicts in JSON Schema by @Viicos in #13891
• Don't apply ser_json_timedelta to all datetime types in serialization inference by @Viicos in #13892
• Encode JSON Schema defaults with a consistent configuration by @Viicos in #13893
• Propagate init and kw_only=False from Field() to stdlib dataclass fields by @Viicos in #13898
• Respect propagated extra config in the JSON Schema of stdlib dataclasses by @Viicos in #13899
• Handle OS errors during ZoneInfo validation by @Viicos in #13912
• Handle exceptions during Decimal validation by @Viicos in #13940
• Rebuild incomplete types during serialization inference by @Viicos in #13922
• Reject large exponents in Fraction validation by @Viicos in #13944
• Avoid validating URL prefix multiple times in multi host URLs by @Viicos in #13945

Full Changelog: v2.13.0...v2.14.0

What's Changed

This pre-release adds full support for Python 3.15 specific features, such as support for frozendict, making use of TypeForm and stabilizing the MISSING sentinel type.

New Features

• Allow any CoreSchema to be used as serialization by @Viicos in #13680
• Add support for frozendict type by @Viicos in #13634
• Allow dict, frozendict and frozenset as defaultdict default factories by @Viicos in #13623
• Add support for TypeForm by @Viicos in #13459.

This adds support for static type checking where a type form is expected. For instance, type adapters:

from pydantic import TypeAdapter
ta = TypeAdapter(int | str)
assert_type(ta.validate_python(1), int | str)

• Add support for lazy imports by @Viicos in #13776
• Stabilize MISSING sentinel by @Viicos in #13782.

The MISSING sentinel is no longer experimental, and can be imported as from pydantic import MISSING.

Changes

• Take ser_json_temporal into account when generating JSON Schema by @shashiKundur1 in #13665
• Use the field name in signature when validate_by_alias isFalse by @jaideeppyne in #13730
• Add a deque core schema by @Viicos in #13757
• Do not mention MISSING as a valid value in validation errors by @Viicos in #13779
• Refactor Decimal JSON Schema pattern constraint by @Viicos in #13672

Performance

• Refactor type references logic by @Viicos in #13643
• Improve performance of GenerateSchema.generate_schema() dispatching by @Viicos in #13614
• Move schema gathering logic to pydantic-core by @Viicos in #13725
• Improve performance of FieldInfo construction by @Viicos in #13726

Fixes

• Fix support for callable discriminators with PEP 695 type aliases by @Viicos in #13604
• Preserve re.Pattern instance for compiled patterns in the experimental pipeline by @soma0212 in #13611
• Fix missing GC traversal on some pydantic-core struct fields by @Viicos in #13624
• Fix missing GC traversal in pydantic-core for GeneralFieldsSerializer by @Viicos in #13629
• Fix JSON schema discriminator mapping keys for bool discriminators by @remi-fongaufier in #13632
• Fix application of other constraints in the pipeline API by @Viicos in #13659
• Support bare None annotation for discriminated unions by @Viicos in #13667
• Respect runtime alias validation configuration when wrap validators are present by @Viicos in #13668
• Exclude computed fields with exclude_if from JSON Schema required fields by @Bishwas-py in #13563
• Use config of TypeAdapter in JSON Schema generation by @Viicos in #13676
• Support populate_by_name in @validate_call by @Viicos in #13691
• Allow None to serialize against secret fields by @Viicos in #13699
• Do not drop include/exclude if serializer wasn't called by @Viicos in #13702
• Don't apply serialization temporal formats to validation JSON schemas by @MLuc24 in #13711
• Reflect str_min_length and str_max_length config in the JSON schema by @MLuc24 in #13714
• Treat a class attribute set to None as existing when assigning with extra='allow' by @Kropiunig in #13718
• Use the field name in validation JSON schemas when validate_by_alias is False by @MLuc24 in #13717
• Do not rely on normalization to validate decimals by @Viicos in #13742
• Handle any exception when trying to compute JSON Schema default by @Viicos in #13741
• Fix Mypy plugin crash with import cycle by @Viicos in #13767
• Fix supported constraints for types of datetime module by @Viicos in #13768
• Fix inconsistencies between constraints and core schemas allowed values by @Viicos in #13772
• Allow self to be used as a parameter with @validate_call by @Viicos in #13773
• Fix race conditions in freethreaded build by @Viicos in #13785

New Contributors

• @soma0212 made their first contribution in #13611
• @remi-fongaufier made their first contribution in #13632
• @shashiKundur1 made their first contribution in #13665
• @MLuc24 made their first contribution in #13711
• @jaideeppyne made their first contribution in #13730

Full Changelog: v2.14.0a1...v2.14.0b2

What's Changed

This is the first beta release of the 2.14 version, providing some new features and performance improvements for model builds.

This release is the first to provide initial support for Python 3.15, although not all 3.15 specific features are supported yet.

Packaging

• Add agent skills by @Viicos in #13193

New Features

• Add support for EllipsisType by @Viicos in #13484
• Add initial support for Python 3.15 by @Viicos in #13587

Changes

• Populate slots from generic class during parameterization by @Viicos in #13243
• Avoid using explicit Any in the Mypy plugin by @Viicos in #13196
• Support Fraction type in pydantic-core by @Viicos in #13339
• Use constant-time comparison for SecretStr and SecretBytes types by @Viicos in #13518
• Fix application of constraints in pipeline API by @Viicos in #13516
• Optimize type lookup logic in core schema generation by @Viicos in #13573
• Add a named-tuple core schema by @Viicos in #13505
• Raise explicit TypeError on invalid index_key serialization wrap handler by @Viicos in #13506

Performance

• Cache ModelPrivateAttr.default_factory_takes_validated_data property by @Viicos in #13390
• Introduce micro-optimizations for model class building by @dmontagu in #13540
• Try Format.VALUE before FORWARDREF when evaluating annotations in ModelMetaclass by @Viicos in #13584
• Optimize type lookup logic in core schema generation by @Viicos in #13573
• Avoid exponential core schema traversal in gather_schemas_for_cleaning() by @dmontagu in #13523

Fixes

• Validate falsy AliasGenerator outputs by @jiyujie2006 in #13248
• Do not resolve recursive 'definitions-ref' schemas in schema cleaning by @Viicos in #13276
• Fix missing max_length check on lazy iteration validation by @davidhewitt in #13278
• Handle missing errors with default factories taking validated data by @Viicos in #13291
• Recognise WindowsPath as a schema type by @davidhewitt in #13326
• Fix application of nested operators in pipeline API by @Viicos in #13363
• Fix type variable substitution in pydantic_extra by @Viicos in #13391
• Fix json_schema_extra dict being dropped when a callable follows it in Annotated by @Srivatsa03 in #13374
• Skip RootModel.init() in Mypy plugin by @Viicos in #13441
• Defer placeholders in Mypy plugin by @Viicos in #13442
• Do not ignore timezone offset when using 'seconds'/'milliseconds' temporal_mode by @Viicos in #13436
• Make model rebuilding logic thread safe by @Viicos in #13438
• Fix Interval zero bounds silently dropped in pipeline API by @pctablet505 in #13452
• Sync RootModel.model_dump() signature with its parent by @Viicos in #13456
• Return NotImplemented from URL ordering comparisons with foreign types by @chinesepowered in #13495
• Don't error on unhashable generic arguments on generic Pydantic models by @Viicos in #13515
• Fix population of SerializationInfo.exclude_computed_fields by @Viicos in #13560
• Fix serialization of ValidateAs by @Viicos in #13487
• Allow reuse of validators when plugins are set by @Viicos in #13535
• Avoid double-wrapping polymorphism trampoline for model serializers by @davidhewitt in #13552
• Add AllowInfNan type to the field metadata gathering by @mberdyshev in #13586

New Contributors

• @jiyujie2006 made their first contribution in #13248
• @pctablet505 made their first contribution in #13452
• @LuShadowX made their first contribution in #13503
• @mberdyshev made their first contribution in #13586

Full Changelog: v2.14.0a1...v2.14.0b1

v2.14.0a1 (2026-05-22)

What's Changed

Packaging

Add PyEmscripten platform tag support by @Viicos, @greateggsgreg and @sinaatalay in #13199:

pydantic-core now has a 3.14 wheel published with the pyemscripten_2026_0 platform tag.

Note that this wheel can only be used with Pyodide 314.0 and greater, still in development.

It is recommended to wait for the final 314.0 release (and for Pydantic to publish a new wheel in a future 2.14 release).

Changes

Accept None in MultiHostUrl.build()'s hosts parameter by @Viicos in #13068

Drop support for Python 3.9 by @Viicos in #13070

Remove support for eval_type_backport() by @Viicos in #13133

Only deepcopy non-updated fields in model_copy() by @connorcarpenter15 in #13087

Fixes

Add Mypy plugin workaround for dynamic models defined in functions by @ilevkivskyi in #13177

Fallback to create_model() overload definition when base is set to a type variable in the Mypy plugin by @cyphercodes in #13146

New Contributors

@ilevkivskyi made their first contribution in #13177

@cyphercodes made their first contribution in #13146

@connorcarpenter15 made their first contribution in #13087

Full Changelog: v2.13.4...v2.14.0a1