feat: Drop python 3.9 support

.claude/settings.local.json

@@ -0,0 +1,8 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(uvx ty:*)"
+    ],
+    "deny": []
+  }
+}

.github/workflows/ci.yml

@@ -18,7 +18,7 @@ jobs:
 
       - uses: actions/setup-python@v6
         with:
-          python-version: "3.9"
+          python-version: "3.10"
 
       - name: Install Pre-Commit
         run: python -m pip install pre-commit
@@ -40,7 +40,7 @@ jobs:
 
       - uses: actions/setup-python@v6
         with:
-          python-version: "3.9"
+          python-version: "3.10"
 
       - name: Install uv
         uses: astral-sh/setup-uv@v6
@@ -57,7 +57,7 @@ jobs:
 
       - uses: actions/setup-python@v6
         with:
-          python-version: "3.9"
+          python-version: "3.10"
 
       - name: Install uv
         uses: astral-sh/setup-uv@v6
@@ -74,7 +74,7 @@ jobs:
 
       - uses: actions/setup-python@v6
         with:
-          python-version: "3.9"
+          python-version: "3.10"
 
       - name: Install uv
         uses: astral-sh/setup-uv@v6
@@ -89,10 +89,10 @@ jobs:
     strategy:
       fail-fast: true
       matrix:
-        python-version: ["3.9", "3.10", "3.11", "3.12", "3.13"]
+        python-version: ["3.10", "3.11", "3.12", "3.13"]
     uses: ./.github/workflows/test.yml
     with:
-      coverage: ${{ (matrix.python-version == '3.12' || matrix.python-version == '3.9') }}
+      coverage: ${{ (matrix.python-version == '3.12' || matrix.python-version == '3.10') }}
       python-version: ${{ matrix.python-version }}
 
   # add an aggregate step here to check if any of the steps of the matrix 'test' job

docs/examples/openapi/customize_openapi_types.py

@@ -1,10 +1,10 @@
-from typing import Literal, Union
+from typing import Literal, Optional
 
 from litestar import Litestar, post
 
 
 @post("/")
-async def query_type_test(param: Union[Literal["1"], None]) -> None:
+async def query_type_test(param: Optional[Literal["1"]]) -> None:
     return None
 
 

docs/examples/parameters/layered_parameters.py

@@ -1,4 +1,4 @@
-from typing import Annotated, Union
+from typing import Annotated
 
 from litestar import Controller, Litestar, Router, get
 from litestar.params import Parameter
@@ -17,7 +17,7 @@ def my_handler(
         local_param: str,
         router_param: str,
         controller_param: Annotated[int, Parameter(int, lt=50)],
-    ) -> dict[str, Union[str, int]]:
+    ) -> dict[str, str | int]:
         return {
             "path_param": path_param,
             "local_param": local_param,

docs/examples/security/jwt/custom_decode_payload.py

@@ -1,6 +1,6 @@
 import dataclasses
 from collections.abc import Sequence
-from typing import Any, Optional, Union
+from typing import Any, Optional
 
 from litestar.security.jwt.token import JWTDecodeOptions, Token
 
@@ -14,7 +14,7 @@ def decode_payload(
         secret: str,
         algorithms: list[str],
         issuer: Optional[list[str]] = None,
-        audience: Union[str, Sequence[str], None] = None,
+        audience: Optional[str | Sequence[str]] = None,
         options: Optional[JWTDecodeOptions] = None,
     ) -> Any:
         payload = super().decode_payload(

docs/examples/todo_app/create/dict.py

@@ -1,12 +1,12 @@
-from typing import Any, Union
+from typing import Any
 
 from litestar import Litestar, post
 
-TODO_LIST: list[dict[str, Union[str, bool]]] = []
+TODO_LIST: list[dict[str, str | bool]] = []
 
 
 @post("/")
-async def add_item(data: dict[str, Any]) -> list[dict[str, Union[str, bool]]]:
+async def add_item(data: dict[str, Any]) -> list[dict[str, str | bool]]:
     TODO_LIST.append(data)
     return TODO_LIST
 

docs/examples/todo_app/get_list/dict.py

@@ -1,16 +1,14 @@
-from typing import Union
-
 from litestar import Litestar, get
 
-TODO_LIST: list[dict[str, Union[str, bool]]] = [
+TODO_LIST: list[dict[str, str | bool]] = [
     {"title": "Start writing TODO list", "done": True},
     {"title": "???", "done": False},
     {"title": "Profit", "done": False},
 ]
 
 
 @get("/")
-async def get_list() -> list[dict[str, Union[str, bool]]]:
+async def get_list() -> list[dict[str, str | bool]]:
     return TODO_LIST
 
 

docs/usage/templating.rst

@@ -105,15 +105,15 @@ argument which should be the template class, and it specifies two methods:
 
 .. code-block:: python
 
-   from typing import Protocol, Union, List
+   from typing import Protocol, List
    from pydantic import DirectoryPath
 
    # the template class of the respective library
    from some_lib import SomeTemplate
 
 
    class TemplateEngineProtocol(Protocol[SomeTemplate]):
-       def __init__(self, directory: Union[DirectoryPath, List[DirectoryPath]]) -> None:
+       def __init__(self, directory: DirectoryPath | List[DirectoryPath]) -> None:
            """Builds a template engine."""
            ...
 

litestar/_openapi/schema_generation/schema.py

@@ -13,7 +13,6 @@
     TYPE_CHECKING,
     Any,
     Literal,
-    Union,
     cast,
 )
 from uuid import UUID
@@ -510,7 +509,7 @@ def for_constrained_field(self, field: FieldDefinition) -> Schema:
         Returns:
             A schema instance.
         """
-        kwarg_definition = cast("Union[ParameterKwarg, BodyKwarg]", field.kwarg_definition)
+        kwarg_definition = cast("ParameterKwarg | BodyKwarg", field.kwarg_definition)
         if any(is_class_and_subclass(field.annotation, t) for t in (int, float, Decimal)):
             return create_numerical_constrained_field_schema(field.annotation, kwarg_definition)
         if any(is_class_and_subclass(field.annotation, t) for t in (str, bytes)):
@@ -529,7 +528,7 @@ def for_collection_constrained_field(self, field_definition: FieldDefinition) ->
             A schema instance.
         """
         schema = Schema(type=OpenAPIType.ARRAY)
-        kwarg_definition = cast("Union[ParameterKwarg, BodyKwarg]", field_definition.kwarg_definition)
+        kwarg_definition = cast("ParameterKwarg | BodyKwarg", field_definition.kwarg_definition)
         if kwarg_definition.min_items:
             schema.min_items = kwarg_definition.min_items
         if kwarg_definition.max_items:

litestar/_signature/model.py

@@ -10,7 +10,6 @@
     Callable,
     ClassVar,
     Literal,
-    Optional,
     TypedDict,
     Union,
     cast,
@@ -312,7 +311,7 @@ def _create_annotation(
                 for inner_type in field_definition.inner_types
                 if not inner_type.is_none_type
             ]
-            return Optional[Union[tuple(types)]] if field_definition.is_optional else Union[tuple(types)]  # pyright: ignore
+            return Union[(*tuple(types), None)] if field_definition.is_optional else Union[tuple(types)]  # type: ignore
 
         if decoder := _get_decoder_for_type(annotation, type_decoders=type_decoders):
             # FIXME: temporary (hopefully) hack, see: https://github.com/jcrist/msgspec/issues/497

litestar/datastructures/headers.py

@@ -10,7 +10,6 @@
     Any,
     ClassVar,
     Optional,
-    Union,
     cast,
 )
 
@@ -46,14 +45,14 @@ def _encode_headers(headers: Iterable[tuple[str, str]]) -> "RawHeadersList":
 class Headers(CIMultiDictProxy[str], MultiMixin[str]):  # pyright: ignore
     """An immutable, case-insensitive multi dict for HTTP headers."""
 
-    def __init__(self, headers: Optional[Union[Mapping[str, str], "RawHeaders", MultiDict[str]]] = None) -> None:  # pyright: ignore
+    def __init__(self, headers: "Optional[Mapping[str, str] | RawHeaders | MultiDict[str]]" = None) -> None:  # pyright: ignore
         """Initialize ``Headers``.
 
         Args:
             headers: Initial value.
         """
         if not isinstance(headers, MultiDict):
-            headers_: Union[Mapping[str, str], list[tuple[str, str]]] = {}
+            headers_: Mapping[str, str] | list[tuple[str, str]] = {}
             if headers:
                 if isinstance(headers, Mapping):
                     headers_ = headers  # pyright: ignore

litestar/dto/_backend.py

@@ -14,7 +14,6 @@
     ClassVar,
     Final,
     Protocol,
-    Union,
     cast,
 )
 
@@ -825,7 +824,7 @@ def _create_struct_for_field_definitions(
 
         field_type = _create_transfer_model_type_annotation(field_definition.transfer_type)
         if field_definition.is_partial:
-            field_type = Union[field_type, UnsetType]
+            field_type = field_type | UnsetType
 
         if field_definition.passthrough_constraints:
             if (field_meta := _create_struct_field_meta_for_field_definition(field_definition)) is not None:

litestar/file_system.py

@@ -6,7 +6,7 @@
 import pathlib
 from datetime import datetime
 from stat import S_ISDIR
-from typing import TYPE_CHECKING, Any, Callable, ClassVar, Final, Union, cast
+from typing import TYPE_CHECKING, Any, Callable, ClassVar, Final, cast
 
 import anyio
 from typing_extensions import NotRequired, TypeAlias, TypedDict
@@ -37,7 +37,7 @@
     from litestar.types import PathType
 
 
-AnyFileSystem: TypeAlias = "Union[BaseFileSystem, FsspecFileSystem, FsspecAsyncFileSystem]"
+AnyFileSystem: TypeAlias = "BaseFileSystem | FsspecFileSystem | FsspecAsyncFileSystem"
 SymlinkResolver: TypeAlias = "Callable[[AnyFileSystem, PathType], Awaitable[str]]"
 
 

litestar/logging/config.py

@@ -5,7 +5,7 @@
 from dataclasses import dataclass, field, fields
 from importlib.util import find_spec
 from logging import INFO
-from typing import TYPE_CHECKING, Any, Callable, Literal, Union, cast
+from typing import TYPE_CHECKING, Any, Callable, Literal, cast
 
 from litestar.exceptions import ImproperlyConfiguredException, MissingDependencyException
 from litestar.serialization.msgspec_hooks import _msgspec_json_encoder
@@ -148,7 +148,7 @@ class BaseLoggingConfig(ABC):
 
     exception_logging_handler: ExceptionLoggingHandler | None
     """Handler function for logging exceptions."""
-    disable_stack_trace: set[Union[int, type[Exception]]]  # noqa: UP007
+    disable_stack_trace: set[int | type[Exception]]
     """Set of http status codes and exceptions to disable stack trace logging for."""
 
     @abstractmethod
@@ -227,7 +227,7 @@ class LoggingConfig(BaseLoggingConfig):
     """Should the root logger be configured, defaults to True for ease of configuration."""
     log_exceptions: Literal["always", "debug", "never"] = field(default="always")
     """Should exceptions be logged, defaults to log exceptions when 'app.debug == True'"""
-    disable_stack_trace: set[Union[int, type[Exception]]] = field(default_factory=set)  # noqa: UP007
+    disable_stack_trace: set[int | type[Exception]] = field(default_factory=set)
     """Set of http status codes and exceptions to disable stack trace logging for."""
     exception_logging_handler: ExceptionLoggingHandler | None = field(default=None)
     """Handler function for logging exceptions."""
@@ -453,7 +453,7 @@ class StructLoggingConfig(BaseLoggingConfig):
     """Whether to cache the logger configuration and reuse."""
     log_exceptions: Literal["always", "debug", "never"] = field(default="always")
     """Should exceptions be logged, defaults to log exceptions when 'app.debug == True'"""
-    disable_stack_trace: set[Union[int, type[Exception]]] = field(default_factory=set)  # noqa: UP007
+    disable_stack_trace: set[int | type[Exception]] = field(default_factory=set)
     """Set of http status codes and exceptions to disable stack trace logging for."""
     exception_logging_handler: ExceptionLoggingHandler | None = field(default=None)
     """Handler function for logging exceptions."""

litestar/middleware/_internal/exceptions/middleware.py

@@ -3,7 +3,7 @@
 from inspect import getmro
 from sys import exc_info
 from traceback import format_exception
-from typing import TYPE_CHECKING, Any, Union, cast
+from typing import TYPE_CHECKING, Any, cast
 
 from litestar.enums import ScopeType
 from litestar.exceptions import HTTPException, LitestarException, WebSocketException
@@ -220,7 +220,7 @@ def handle_exception_logging(self, logger: Logger, logging_config: BaseLoggingCo
             None
         """
         exc = exc_info()
-        exc_detail: set[Union[Exception, int]] = {exc[0], getattr(exc[0], "status_code", None)}  # type: ignore[arg-type]  # noqa: UP007
+        exc_detail: set[Exception | int] = {exc[0], getattr(exc[0], "status_code", None)}  # type: ignore[arg-type]
 
         if (
             (

litestar/middleware/constraints.py

@@ -2,7 +2,7 @@
 import dataclasses
 import functools
 import inspect
-from typing import TYPE_CHECKING, Any, Literal, Optional, Union, cast
+from typing import TYPE_CHECKING, Any, Literal, Optional, cast
 
 from typing_extensions import Self
 
@@ -343,7 +343,7 @@ def check_middleware_constraints(middlewares: tuple[Middleware, ...]) -> None:
     positions: collections.defaultdict[object, list[int]] = collections.defaultdict(list)
 
     for i, middleware in enumerate(middlewares):
-        middleware_type: Union[object, type]
+        middleware_type: object | type
         if inspect.isfunction(middleware):
             positions[middleware].append(i)
             middleware_type = middleware

litestar/openapi/spec/callback.py

@@ -1,13 +1,6 @@
 from __future__ import annotations
 
-from typing import TYPE_CHECKING, Union
-
-if TYPE_CHECKING:
-    from litestar.openapi.spec.path_item import PathItem
-    from litestar.openapi.spec.reference import Reference
-
-
-Callback = dict[str, Union["PathItem", "Reference"]]
+Callback = "dict[str, PathItem | Reference]"
 """A map of possible out-of band callbacks related to the parent operation. Each value in the map is a
 `Path Item Object <https://spec.openapis.org/oas/v3.1.0#pathItemObject>`_ that describes a set of requests that may be
 initiated by the API provider and the expected responses. The key value used to identify the path item object is an

litestar/openapi/spec/responses.py

@@ -1,12 +1,6 @@
 from __future__ import annotations
 
-from typing import TYPE_CHECKING, Union
-
-if TYPE_CHECKING:
-    from litestar.openapi.spec.reference import Reference
-    from litestar.openapi.spec.response import OpenAPIResponse
-
-Responses = dict[str, Union["OpenAPIResponse", "Reference"]]
+Responses = "dict[str, OpenAPIResponse | Reference]"
 """A container for the expected responses of an operation. The container maps a
 HTTP response code to the expected response.
 
@@ -21,7 +15,7 @@
 
 Fixed Fields
 
-default: ``Optional[Union[Response, Reference]]``
+default: ``Optional[Response | Reference]``
 
 The documentation of responses other than the ones declared for specific HTTP response codes. Use this field to cover
 undeclared responses. A `Reference Object <https://spec.openapis.org/oas/v3.1.0#referenceObject>`_ can link to a

litestar/plugins/base.py

@@ -2,7 +2,7 @@
 
 import abc
 from contextlib import contextmanager
-from typing import TYPE_CHECKING, Any, Protocol, TypeVar, Union, cast, runtime_checkable
+from typing import TYPE_CHECKING, Any, Protocol, TypeVar, cast, runtime_checkable
 
 if TYPE_CHECKING:
     from collections.abc import Iterator
@@ -274,14 +274,9 @@ def is_constrained_field(field_definition: FieldDefinition) -> bool:
         return False
 
 
-PluginProtocol = Union[
-    CLIPlugin,
-    InitPluginProtocol,
-    OpenAPISchemaPlugin,
-    ReceiveRoutePlugin,
-    SerializationPlugin,
-    DIPlugin,
-]
+PluginProtocol = (
+    CLIPlugin | InitPluginProtocol | OpenAPISchemaPlugin | ReceiveRoutePlugin | SerializationPlugin | DIPlugin
+)
 
 PluginT = TypeVar("PluginT", bound=PluginProtocol)