[GitHub release](https://github.com/pydantic/pydantic/releases/tag/v2.8.0)
The code released in v2.8.0 is functionally identical to that of v2.8.0b1.
What's Changed
Packaging
* Update citation version automatically with new releases by sydney-runkle in [9673](https://github.com/pydantic/pydantic/pull/9673)
* Bump pyright to `v1.1.367` and add type checking tests for pipeline API by adriangb in [9674](https://github.com/pydantic/pydantic/pull/9674)
* Update `pydantic.v1` stub to `v1.10.17` by sydney-runkle in [9707](https://github.com/pydantic/pydantic/pull/9707)
* General package updates to prep for `v2.8.0b1` by sydney-runkle in [9741](https://github.com/pydantic/pydantic/pull/9741)
* Bump `pydantic-core` to `v2.20.0` by sydney-runkle in [9745](https://github.com/pydantic/pydantic/pull/9745)
* Add support for Python 3.13 by sydney-runkle in [9743](https://github.com/pydantic/pydantic/pull/9743)
* Update `pdm` version used for `pdm.lock` to v2.16.1 by sydney-runkle in [9761](https://github.com/pydantic/pydantic/pull/9761)
* Update to `ruff` `v0.4.8` by Viicos in [9585](https://github.com/pydantic/pydantic/pull/9585)
New Features
* Experimental: support `defer_build` for `TypeAdapter` by MarkusSintonen in [8939](https://github.com/pydantic/pydantic/pull/8939)
* Implement `deprecated` field in json schema by NeevCohen in [9298](https://github.com/pydantic/pydantic/pull/9298)
* Experimental: Add pipeline API by adriangb in [9459](https://github.com/pydantic/pydantic/pull/9459)
* Add support for programmatic title generation by NeevCohen in [9183](https://github.com/pydantic/pydantic/pull/9183)
* Implement `fail_fast` feature by uriyyo in [9708](https://github.com/pydantic/pydantic/pull/9708)
* Add `ser_json_inf_nan='strings'` mode to produce valid JSON by josh-newman in [pydantic/pydantic-core1307](https://github.com/pydantic/pydantic-core/pull/1307)
Changes
* Add warning when "alias" is set in ignored `Annotated` field by nix010 in [9170](https://github.com/pydantic/pydantic/pull/9170)
* Support serialization of some serializable defaults in JSON schema by sydney-runkle in [9624](https://github.com/pydantic/pydantic/pull/9624)
* Relax type specification for `__validators__` values in `create_model` by sydney-runkle in [9697](https://github.com/pydantic/pydantic/pull/9697)
* **Breaking Change:** Improve `smart` union matching logic by sydney-runkle in [pydantic/pydantic-core1322](https://github.com/pydantic/pydantic-core/pull/1322)
You can read more about our `smart` union matching logic [here](https://docs.pydantic.dev/dev/concepts/unions/#smart-mode). In some cases, if the old behavior
is desired, you can switch to `left-to-right` mode and change the order of your `Union` members.
Performance
Internal Improvements
* ⚡️ Speed up `_display_error_loc()` by 25% in `pydantic/v1/error_wrappers.py` by misrasaurabh1 in [9653](https://github.com/pydantic/pydantic/pull/9653)
* ⚡️ Speed up `_get_all_json_refs()` by 34% in `pydantic/json_schema.py` by misrasaurabh1 in [9650](https://github.com/pydantic/pydantic/pull/9650)
* ⚡️ Speed up `is_pydantic_dataclass()` by 41% in `pydantic/dataclasses.py` by misrasaurabh1 in [9652](https://github.com/pydantic/pydantic/pull/9652)
* ⚡️ Speed up `to_snake()` by 27% in `pydantic/alias_generators.py` by misrasaurabh1 in [9747](https://github.com/pydantic/pydantic/pull/9747)
* ⚡️ Speed up `unwrap_wrapped_function()` by 93% in `pydantic/_internal/_decorators.py` by misrasaurabh1 in [9727](https://github.com/pydantic/pydantic/pull/9727)
Fixes
* Replace `__spec__.parent` with `__package__` by hramezani in [9331](https://github.com/pydantic/pydantic/pull/9331)
* Fix Outputted Model JSON Schema for `Sequence` type by anesmemisevic in [9303](https://github.com/pydantic/pydantic/pull/9303)
* Fix typing of `_frame_depth` by Viicos in [9353](https://github.com/pydantic/pydantic/pull/9353)
* Make `ImportString` json schema compatible by amitschang in [9344](https://github.com/pydantic/pydantic/pull/9344)
* Hide private attributes (`PrivateAttr`) from `__init__` signature in type checkers by idan22moral in [9293](https://github.com/pydantic/pydantic/pull/9293)
* Make detection of `TypeVar` defaults robust to the CPython `PEP-696` implementation by AlexWaygood in [9426](https://github.com/pydantic/pydantic/pull/9426)
* Fix usage of `PlainSerializer` with builtin types by Viicos in [9450](https://github.com/pydantic/pydantic/pull/9450)
* Add more robust custom validation examples by ChrisPappalardo in [9468](https://github.com/pydantic/pydantic/pull/9468)
* Fix ignored `strict` specification for `StringConstraint(strict=False)` by vbmendes in [9476](https://github.com/pydantic/pydantic/pull/9476)
* **Breaking Change:** Use PEP 570 syntax by Viicos in [9479](https://github.com/pydantic/pydantic/pull/9479)
* Use `Self` where possible by Viicos in [9479](https://github.com/pydantic/pydantic/pull/9479)
* Do not alter `RootModel.model_construct` signature in the `mypy` plugin by Viicos in [9480](https://github.com/pydantic/pydantic/pull/9480)
* Fixed type hint of `validation_context` by OhioDschungel6 in [9508](https://github.com/pydantic/pydantic/pull/9508)
* Support context being passed to TypeAdapter's `dump_json`/`dump_python` by alexcouper in [9495](https://github.com/pydantic/pydantic/pull/9495)
* Updates type signature for `Field()` constructor by bjmc in [9484](https://github.com/pydantic/pydantic/pull/9484)
* Improve builtin alias generators by sydney-runkle in [9561](https://github.com/pydantic/pydantic/pull/9561)
* Fix typing of `TypeAdapter` by Viicos in [9570](https://github.com/pydantic/pydantic/pull/9570)
* Add fallback default value for private fields in `__setstate__` of BaseModel by anhpham1509 in [9584](https://github.com/pydantic/pydantic/pull/9584)
* Support `PEP 746` by adriangb in [9587](https://github.com/pydantic/pydantic/pull/9587)
* Allow validator and serializer functions to have default values by Viicos in [9478](https://github.com/pydantic/pydantic/pull/9478)
* Fix bug with mypy plugin's handling of covariant `TypeVar` fields by dmontagu in [9606](https://github.com/pydantic/pydantic/pull/9606)
* Fix multiple annotation / constraint application logic by sydney-runkle in [9623](https://github.com/pydantic/pydantic/pull/9623)
* Respect `regex` flags in validation and json schema by sydney-runkle in [9591](https://github.com/pydantic/pydantic/pull/9591)
* Fix type hint on `IpvAnyAddress` by sydney-runkle in [9640](https://github.com/pydantic/pydantic/pull/9640)
* Allow a field specifier on `__pydantic_extra__` by dmontagu in [9659](https://github.com/pydantic/pydantic/pull/9659)
* Use normalized case for file path comparison by sydney-runkle in [9737](https://github.com/pydantic/pydantic/pull/9737)
* Modify constraint application logic to allow field constraints on `Optional[Decimal]` by lazyhope in [9754](https://github.com/pydantic/pydantic/pull/9754)
* `validate_call` type params fix by sydney-runkle in [9760](https://github.com/pydantic/pydantic/pull/9760)
* Check all warnings returned by pytest.warns() by s-t-e-v-e-n-k in [9702](https://github.com/pydantic/pydantic/pull/9702)
* Reuse `re.Pattern` object in regex patterns to allow for regex flags by sydney-runkle in [pydantic/pydantic-core1318](https://github.com/pydantic/pydantic-core/pull/1318)
New Contributors
* idan22moral made their first contribution in [9294](https://github.com/pydantic/pydantic/pull/9294)
* anesmemisevic made their first contribution in [9303](https://github.com/pydantic/pydantic/pull/9303)
* max-muoto made their first contribution in [9338](https://github.com/pydantic/pydantic/pull/9338)
* amitschang made their first contribution in [9344](https://github.com/pydantic/pydantic/pull/9344)
* paulmartin91 made their first contribution in [9410](https://github.com/pydantic/pydantic/pull/9410)
* OhioDschungel6 made their first contribution in [9405](https://github.com/pydantic/pydantic/pull/9405)
* AlexWaygood made their first contribution in [9426](https://github.com/pydantic/pydantic/pull/9426)
* kinuax made their first contribution in [9433](https://github.com/pydantic/pydantic/pull/9433)
* antoni-jamiolkowski made their first contribution in [9431](https://github.com/pydantic/pydantic/pull/9431)
* candleindark made their first contribution in [9448](https://github.com/pydantic/pydantic/pull/9448)
* nix010 made their first contribution in [9170](https://github.com/pydantic/pydantic/pull/9170)
* tomy0000000 made their first contribution in [9457](https://github.com/pydantic/pydantic/pull/9457)
* vbmendes made their first contribution in [9470](https://github.com/pydantic/pydantic/pull/9470)
* micheleAlberto made their first contribution in [9471](https://github.com/pydantic/pydantic/pull/9471)
* ChrisPappalardo made their first contribution in [9468](https://github.com/pydantic/pydantic/pull/9468)
* blueTurtz made their first contribution in [9475](https://github.com/pydantic/pydantic/pull/9475)
* WinterBlue16 made their first contribution in [9477](https://github.com/pydantic/pydantic/pull/9477)
* bittner made their first contribution in [9500](https://github.com/pydantic/pydantic/pull/9500)
* alexcouper made their first contribution in [9495](https://github.com/pydantic/pydantic/pull/9495)
* bjmc made their first contribution in [9484](https://github.com/pydantic/pydantic/pull/9484)
* pjvv made their first contribution in [9529](https://github.com/pydantic/pydantic/pull/9529)
* nedbat made their first contribution in [9530](https://github.com/pydantic/pydantic/pull/9530)
* gunnellEvan made their first contribution in [9469](https://github.com/pydantic/pydantic/pull/9469)
* jaymbans made their first contribution in [9531](https://github.com/pydantic/pydantic/pull/9531)
* MarcBresson made their first contribution in [9534](https://github.com/pydantic/pydantic/pull/9534)
* anhpham1509 made their first contribution in [9584](https://github.com/pydantic/pydantic/pull/9584)
* K-dash made their first contribution in [9595](https://github.com/pydantic/pydantic/pull/9595)
* s-t-e-v-e-n-k made their first contribution in [9527](https://github.com/pydantic/pydantic/pull/9527)
* airwoodix made their first contribution in [9506](https://github.com/pydantic/pydantic/pull/9506)
* misrasaurabh1 made their first contribution in [9653](https://github.com/pydantic/pydantic/pull/9653)
* AlessandroMiola made their first contribution in [9740](https://github.com/pydantic/pydantic/pull/9740)
* mylapallilavanyaa made their first contribution in [9746](https://github.com/pydantic/pydantic/pull/9746)
* lazyhope made their first contribution in [9754](https://github.com/pydantic/pydantic/pull/9754)
* YassinNouh21 made their first contribution in [9759](https://github.com/pydantic/pydantic/pull/9759)