Add config parameter to Parser classes

docs/cli-reference/model-customization.md

@@ -1368,11 +1368,15 @@ model types (Pydantic v1/v2, dataclass, TypedDict, msgspec) handle const fields.
 
             from __future__ import annotations
 
+            from typing import Literal
+
             from pydantic import BaseModel, Field
 
 
             class Api(BaseModel):
-                version: str = Field('v1', const=True, description='The version of this API')
+                version: Literal['v1'] = Field(
+                    'v1', const=True, description='The version of this API'
+                )
             ```
 
         === "Pydantic v2"

docs/cli-reference/template-customization.md

@@ -2553,11 +2553,15 @@ helps maintain consistency with codebases that prefer double-quote formatting.
 
     from __future__ import annotations
 
+    from typing import Literal
+
     from pydantic import BaseModel, Field, confloat
 
 
     class MapState1(BaseModel):
-        map_view_mode: str = Field("MODE_2D", alias="mapViewMode", const=True)
+        map_view_mode: Literal["MODE_2D"] = Field(
+            "MODE_2D", alias="mapViewMode", const=True
+        )
 
 
     class MapState2(BaseModel):
@@ -2567,8 +2571,10 @@ helps maintain consistency with codebases that prefer double-quote formatting.
         bearing: Bearing | None = None
         pitch: Pitch
         drag_rotate: DragRotate | None = Field(None, alias="dragRotate")
-        map_split_mode: str = Field("SWIPE_COMPARE", alias="mapSplitMode", const=True)
-        is_split: bool = Field(True, alias="isSplit", const=True)
+        map_split_mode: Literal["SWIPE_COMPARE"] = Field(
+            "SWIPE_COMPARE", alias="mapSplitMode", const=True
+        )
+        is_split: Literal[True] = Field(True, alias="isSplit", const=True)
 
 
     class MapState3(BaseModel):

src/datamodel_code_generator/__init__.py

@@ -469,7 +469,7 @@ def generate(  # noqa: PLR0912, PLR0913, PLR0914, PLR0915
     field_constraints: bool = False,
     snake_case_field: bool = False,
     strip_default_none: bool = False,
-    aliases: Mapping[str, str] | None = None,
+    aliases: Mapping[str, str | list[str]] | None = None,
     disable_timestamp: bool = False,
     enable_version_header: bool = False,
     enable_command_header: bool = False,

src/datamodel_code_generator/_types/generate_config_dict.py

@@ -52,7 +52,7 @@ class GenerateConfigDict(TypedDict):
     field_constraints: NotRequired[bool]
     snake_case_field: NotRequired[bool]
     strip_default_none: NotRequired[bool]
-    aliases: NotRequired[Mapping[str, str] | None]
+    aliases: NotRequired[Mapping[str, str | list[str]] | None]
     disable_timestamp: NotRequired[bool]
     enable_version_header: NotRequired[bool]
     enable_command_header: NotRequired[bool]

src/datamodel_code_generator/_types/parser_config_dict.py

@@ -46,7 +46,7 @@ class ParserConfigDict(TypedDict):
     field_constraints: NotRequired[bool]
     snake_case_field: NotRequired[bool]
     strip_default_none: NotRequired[bool]
-    aliases: NotRequired[Mapping[str, str] | None]
+    aliases: NotRequired[Mapping[str, str | list[str]] | None]
     allow_population_by_field_name: NotRequired[bool]
     apply_default_values_for_required_fields: NotRequired[bool]
     allow_extra_fields: NotRequired[bool]

src/datamodel_code_generator/config.py

@@ -8,6 +8,7 @@
 from typing import TYPE_CHECKING, Annotated, Any
 
 from pydantic import BaseModel, Field
+from typing_extensions import Self
 
 from datamodel_code_generator.enums import (
     DEFAULT_SHARED_MODULE_NAME,
@@ -85,7 +86,7 @@ class Config:
     field_constraints: bool = False
     snake_case_field: bool = False
     strip_default_none: bool = False
-    aliases: Mapping[str, str] | None = None
+    aliases: Mapping[str, str | list[str]] | None = None
     disable_timestamp: bool = False
     enable_version_header: bool = False
     enable_command_header: bool = False
@@ -201,9 +202,36 @@ class ParserConfig(BaseModel):
         class Config:
             """Pydantic v1 model config."""
 
-            extra = "forbid"
+            extra = "allow"
             arbitrary_types_allowed = True
 
+    @classmethod
+    def from_options(cls, options: dict[str, Any]) -> Self:
+        """Create a ParserConfig from options dict with version-compatible validation."""
+        if is_pydantic_v2():
+            from datamodel_code_generator.model.base import (  # noqa: PLC0415
+                DataModel,
+                DataModelFieldBase,
+            )
+            from datamodel_code_generator.types import DataTypeManager, StrictTypes  # noqa: PLC0415
+
+            cls.model_rebuild(
+                _types_namespace={
+                    "DataModel": DataModel,
+                    "DataModelFieldBase": DataModelFieldBase,
+                    "DataTypeManager": DataTypeManager,
+                    "StrictTypes": StrictTypes,
+                }
+            )
+            return cls.model_validate(options)
+        # For Pydantic v1, use construct() to skip validation (forward refs not resolved)
+        defaults: dict[str, Any] = {}
+        for field_name, field in cls.__fields__.items():  # type: ignore[attr-defined]
+            # Note: ParserConfig fields don't use default_factory, so we only handle static defaults
+            defaults[field_name] = field.default
+        defaults.update(options)
+        return cls.construct(**defaults)  # type: ignore[return-value]
+
     data_model_type: type[DataModel] = pydantic_model.BaseModel
     data_model_root_type: type[DataModel] = pydantic_model.CustomRootType
     data_type_manager_type: type[DataTypeManager] = pydantic_model.DataTypeManager
@@ -220,7 +248,7 @@ class Config:
     field_constraints: bool = False
     snake_case_field: bool = False
     strip_default_none: bool = False
-    aliases: Mapping[str, str] | None = None
+    aliases: Mapping[str, str | list[str]] | None = None
     allow_population_by_field_name: bool = False
     apply_default_values_for_required_fields: bool = False
     allow_extra_fields: bool = False
@@ -316,6 +344,21 @@ class Config:
     target_pydantic_version: TargetPydanticVersion | None = None
 
 
+class OpenAPIParserConfig(ParserConfig):
+    """Configuration model for OpenAPIParser.__init__()."""
+
+    openapi_scopes: list[OpenAPIScope] | None = None
+    include_path_parameters: bool = False
+    use_status_code_in_response_name: bool = False
+
+
+class GraphQLParserConfig(ParserConfig):
+    """Configuration model for GraphQLParser.__init__()."""
+
+    data_model_scalar_type: type[DataModel] | None = None
+    data_model_union_type: type[DataModel] | None = None
+
+
 class ParseConfig(BaseModel):
     """Configuration model for Parser.parse()."""