diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPythonCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPythonCodegen.java
index c3d95ec1e93e..6518cd7869e2 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPythonCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPythonCodegen.java
@@ -50,6 +50,7 @@
 import org.openapitools.codegen.CodegenOperation;
 import org.openapitools.codegen.CodegenParameter;
 import org.openapitools.codegen.CodegenProperty;
+import org.openapitools.codegen.CodegenResponse;
 import org.openapitools.codegen.DefaultCodegen;
 import org.openapitools.codegen.GeneratorLanguage;
 import org.openapitools.codegen.IJsonSchemaValidationProperties;
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonFastAPIServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonFastAPIServerCodegen.java
index d219a8c48a6e..ea1fb0ba315f 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonFastAPIServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonFastAPIServerCodegen.java
@@ -219,6 +219,8 @@ public String getTypeDeclaration(Schema p) {
 
     @Override
     public OperationsMap postProcessOperationsWithModels(OperationsMap objs, List<ModelMap> allModels) {
+        super.postProcessOperationsWithModels(objs, allModels);
+
         OperationMap operations = objs.getOperations();
         // Set will make sure that no duplicated items are used.
         Set<String> securityImports = new HashSet<>();
diff --git a/modules/openapi-generator/src/main/resources/python-fastapi/param_type.mustache b/modules/openapi-generator/src/main/resources/python-fastapi/param_type.mustache
index d97c018015fa..0fd1f7fd9cad 100644
--- a/modules/openapi-generator/src/main/resources/python-fastapi/param_type.mustache
+++ b/modules/openapi-generator/src/main/resources/python-fastapi/param_type.mustache
@@ -1 +1 @@
-{{#isString}}str{{/isString}}{{#isInteger}}int{{/isInteger}}{{#isLong}}int{{/isLong}}{{#isFloat}}float{{/isFloat}}{{#isDouble}}float{{/isDouble}}{{#isByteArray}}str{{/isByteArray}}{{#isBinary}}str{{/isBinary}}{{#isBoolean}}bool{{/isBoolean}}{{#isDate}}str{{/isDate}}{{#isDateTime}}str{{/isDateTime}}{{#isModel}}{{dataType}}{{/isModel}}{{#isContainer}}{{dataType}}{{/isContainer}}
\ No newline at end of file
+{{{vendorExtensions.x-py-typing}}}
\ No newline at end of file
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/python/PythonFastAPIServerCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/python/PythonFastAPIServerCodegenTest.java
new file mode 100644
index 000000000000..52a6789ca154
--- /dev/null
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/python/PythonFastAPIServerCodegenTest.java
@@ -0,0 +1,60 @@
+package org.openapitools.codegen.python;
+
+import com.google.common.collect.Sets;
+import io.swagger.parser.OpenAPIParser;
+import io.swagger.v3.oas.models.OpenAPI;
+import io.swagger.v3.oas.models.Operation;
+import io.swagger.v3.oas.models.media.ArraySchema;
+import io.swagger.v3.oas.models.media.Schema;
+import io.swagger.v3.parser.core.models.ParseOptions;
+import org.openapitools.codegen.*;
+import org.openapitools.codegen.languages.PythonClientCodegen;
+import org.openapitools.codegen.languages.PythonFastAPIServerCodegen;
+import org.openapitools.codegen.languages.features.CXFServerFeatures;
+import org.testng.Assert;
+import org.testng.annotations.Test;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.List;
+
+import static org.openapitools.codegen.TestUtils.assertFileContains;
+import static org.openapitools.codegen.TestUtils.assertFileExists;
+
+public class PythonFastAPIServerCodegenTest {
+
+    // Helper function, intended to reduce boilerplate
+    static private String generateFiles(DefaultCodegen codegen, String filePath) throws IOException {
+        final File output = Files.createTempDirectory("test").toFile().getCanonicalFile();
+        output.deleteOnExit();
+        final String outputPath = output.getAbsolutePath().replace('\\', '/');
+
+        codegen.setOutputDir(output.getAbsolutePath());
+        codegen.additionalProperties().put(CXFServerFeatures.LOAD_TEST_DATA_FROM_FILE, "true");
+
+        final ClientOptInput input = new ClientOptInput();
+        final OpenAPI openAPI = new OpenAPIParser().readLocation(filePath, null, new ParseOptions()).getOpenAPI();
+        input.openAPI(openAPI);
+        input.config(codegen);
+
+        final DefaultGenerator generator = new DefaultGenerator();
+        final List<File> files = generator.opts(input).generate();
+
+        Assert.assertTrue(files.size() > 0);
+        return outputPath + "/";
+    }
+
+
+    @Test(description = "test containerType in parameters")
+    public void testContainerType() throws IOException {
+        final DefaultCodegen codegen = new PythonFastAPIServerCodegen();
+        final String outputPath = generateFiles(codegen, "src/test/resources/bugs/pr_18691.json");
+        final Path p = Paths.get(outputPath + "src/openapi_server/apis/default_api.py");
+
+        assertFileExists(p);
+        assertFileContains(p, "body: Optional[Dict[str, Any]] = Body(None, description=\"\"),");
+    }
+}
diff --git a/modules/openapi-generator/src/test/resources/bugs/pr_18691.json b/modules/openapi-generator/src/test/resources/bugs/pr_18691.json
new file mode 100644
index 000000000000..ed2b0664d954
--- /dev/null
+++ b/modules/openapi-generator/src/test/resources/bugs/pr_18691.json
@@ -0,0 +1,24 @@
+{
+  "openapi": "3.0.1",
+  "info": {
+    "title": "OpenAPI definition",
+    "version": "v0"
+  },
+  "paths": {
+    "/licensing/token/renew": {
+      "post": {
+        "description": "Manually ask license issuer for a new token. Available in Grafana Enterprise v7.4+.\n\nYou need to have a permission with action `licensing:update`.",
+        "operationId": "postRenewLicenseToken",
+        "requestBody": {
+          "content": {
+            "application/json": {
+              "schema": {
+                "type": "object"
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+}
\ No newline at end of file
diff --git a/samples/server/petstore/python-fastapi/src/openapi_server/apis/fake_api.py b/samples/server/petstore/python-fastapi/src/openapi_server/apis/fake_api.py
index d9ee44de6900..30ea703d9084 100644
--- a/samples/server/petstore/python-fastapi/src/openapi_server/apis/fake_api.py
+++ b/samples/server/petstore/python-fastapi/src/openapi_server/apis/fake_api.py
@@ -23,6 +23,9 @@
 )
 
 from openapi_server.models.extra_models import TokenModel  # noqa: F401
+from pydantic import Field, StrictStr
+from typing import Optional
+from typing_extensions import Annotated
 
 
 router = APIRouter()
@@ -43,8 +46,8 @@
     response_model_by_alias=True,
 )
 async def fake_query_param_default(
-    has_default: str = Query('Hello World', description="has default value", alias="hasDefault"),
-    no_default: str = Query(None, description="no default value", alias="noDefault"),
+    has_default: Annotated[Optional[StrictStr], Field(description="has default value")] = Query('Hello World', description="has default value", alias="hasDefault"),
+    no_default: Annotated[Optional[StrictStr], Field(description="no default value")] = Query(None, description="no default value", alias="noDefault"),
 ) -> None:
     """"""
     if not BaseFakeApi.subclasses:
diff --git a/samples/server/petstore/python-fastapi/src/openapi_server/apis/fake_api_base.py b/samples/server/petstore/python-fastapi/src/openapi_server/apis/fake_api_base.py
index 5af08fcbd8e9..e42ac8cbe228 100644
--- a/samples/server/petstore/python-fastapi/src/openapi_server/apis/fake_api_base.py
+++ b/samples/server/petstore/python-fastapi/src/openapi_server/apis/fake_api_base.py
@@ -2,6 +2,9 @@
 
 from typing import ClassVar, Dict, List, Tuple  # noqa: F401
 
+from pydantic import Field, StrictStr
+from typing import Optional
+from typing_extensions import Annotated
 
 
 class BaseFakeApi:
@@ -12,8 +15,8 @@ def __init_subclass__(cls, **kwargs):
         BaseFakeApi.subclasses = BaseFakeApi.subclasses + (cls,)
     async def fake_query_param_default(
         self,
-        has_default: str,
-        no_default: str,
+        has_default: Annotated[Optional[StrictStr], Field(description="has default value")],
+        no_default: Annotated[Optional[StrictStr], Field(description="no default value")],
     ) -> None:
         """"""
         ...
diff --git a/samples/server/petstore/python-fastapi/src/openapi_server/apis/pet_api.py b/samples/server/petstore/python-fastapi/src/openapi_server/apis/pet_api.py
index 70feda075f28..b95032de33d5 100644
--- a/samples/server/petstore/python-fastapi/src/openapi_server/apis/pet_api.py
+++ b/samples/server/petstore/python-fastapi/src/openapi_server/apis/pet_api.py
@@ -23,6 +23,9 @@
 )
 
 from openapi_server.models.extra_models import TokenModel  # noqa: F401
+from pydantic import Field, StrictBytes, StrictInt, StrictStr, field_validator
+from typing import List, Optional, Tuple, Union
+from typing_extensions import Annotated
 from openapi_server.models.api_response import ApiResponse
 from openapi_server.models.pet import Pet
 from openapi_server.security_api import get_token_petstore_auth, get_token_api_key
@@ -45,7 +48,7 @@
     response_model_by_alias=True,
 )
 async def add_pet(
-    pet: Pet = Body(None, description="Pet object that needs to be added to the store"),
+    pet: Annotated[Pet, Field(description="Pet object that needs to be added to the store")] = Body(None, description="Pet object that needs to be added to the store"),
     token_petstore_auth: TokenModel = Security(
         get_token_petstore_auth, scopes=["write:pets", "read:pets"]
     ),
@@ -66,8 +69,8 @@ async def add_pet(
     response_model_by_alias=True,
 )
 async def delete_pet(
-    petId: int = Path(..., description="Pet id to delete"),
-    api_key: str = Header(None, description=""),
+    petId: Annotated[StrictInt, Field(description="Pet id to delete")] = Path(..., description="Pet id to delete"),
+    api_key: Optional[StrictStr] = Header(None, description=""),
     token_petstore_auth: TokenModel = Security(
         get_token_petstore_auth, scopes=["write:pets", "read:pets"]
     ),
@@ -89,7 +92,7 @@ async def delete_pet(
     response_model_by_alias=True,
 )
 async def find_pets_by_status(
-    status: List[str] = Query(None, description="Status values that need to be considered for filter", alias="status"),
+    status: Annotated[List[StrictStr], Field(description="Status values that need to be considered for filter")] = Query(None, description="Status values that need to be considered for filter", alias="status"),
     token_petstore_auth: TokenModel = Security(
         get_token_petstore_auth, scopes=["read:pets"]
     ),
@@ -111,7 +114,7 @@ async def find_pets_by_status(
     response_model_by_alias=True,
 )
 async def find_pets_by_tags(
-    tags: List[str] = Query(None, description="Tags to filter by", alias="tags"),
+    tags: Annotated[List[StrictStr], Field(description="Tags to filter by")] = Query(None, description="Tags to filter by", alias="tags"),
     token_petstore_auth: TokenModel = Security(
         get_token_petstore_auth, scopes=["read:pets"]
     ),
@@ -134,7 +137,7 @@ async def find_pets_by_tags(
     response_model_by_alias=True,
 )
 async def get_pet_by_id(
-    petId: int = Path(..., description="ID of pet to return"),
+    petId: Annotated[StrictInt, Field(description="ID of pet to return")] = Path(..., description="ID of pet to return"),
     token_api_key: TokenModel = Security(
         get_token_api_key
     ),
@@ -158,7 +161,7 @@ async def get_pet_by_id(
     response_model_by_alias=True,
 )
 async def update_pet(
-    pet: Pet = Body(None, description="Pet object that needs to be added to the store"),
+    pet: Annotated[Pet, Field(description="Pet object that needs to be added to the store")] = Body(None, description="Pet object that needs to be added to the store"),
     token_petstore_auth: TokenModel = Security(
         get_token_petstore_auth, scopes=["write:pets", "read:pets"]
     ),
@@ -179,9 +182,9 @@ async def update_pet(
     response_model_by_alias=True,
 )
 async def update_pet_with_form(
-    petId: int = Path(..., description="ID of pet that needs to be updated"),
-    name: str = Form(None, description="Updated name of the pet"),
-    status: str = Form(None, description="Updated status of the pet"),
+    petId: Annotated[StrictInt, Field(description="ID of pet that needs to be updated")] = Path(..., description="ID of pet that needs to be updated"),
+    name: Annotated[Optional[StrictStr], Field(description="Updated name of the pet")] = Form(None, description="Updated name of the pet"),
+    status: Annotated[Optional[StrictStr], Field(description="Updated status of the pet")] = Form(None, description="Updated status of the pet"),
     token_petstore_auth: TokenModel = Security(
         get_token_petstore_auth, scopes=["write:pets", "read:pets"]
     ),
@@ -202,9 +205,9 @@ async def update_pet_with_form(
     response_model_by_alias=True,
 )
 async def upload_file(
-    petId: int = Path(..., description="ID of pet to update"),
-    additional_metadata: str = Form(None, description="Additional data to pass to server"),
-    file: str = Form(None, description="file to upload"),
+    petId: Annotated[StrictInt, Field(description="ID of pet to update")] = Path(..., description="ID of pet to update"),
+    additional_metadata: Annotated[Optional[StrictStr], Field(description="Additional data to pass to server")] = Form(None, description="Additional data to pass to server"),
+    file: Annotated[Optional[Union[StrictBytes, StrictStr, Tuple[StrictStr, StrictBytes]]], Field(description="file to upload")] = Form(None, description="file to upload"),
     token_petstore_auth: TokenModel = Security(
         get_token_petstore_auth, scopes=["write:pets", "read:pets"]
     ),
diff --git a/samples/server/petstore/python-fastapi/src/openapi_server/apis/pet_api_base.py b/samples/server/petstore/python-fastapi/src/openapi_server/apis/pet_api_base.py
index db77ff6c6a36..872fd4172642 100644
--- a/samples/server/petstore/python-fastapi/src/openapi_server/apis/pet_api_base.py
+++ b/samples/server/petstore/python-fastapi/src/openapi_server/apis/pet_api_base.py
@@ -2,6 +2,9 @@
 
 from typing import ClassVar, Dict, List, Tuple  # noqa: F401
 
+from pydantic import Field, StrictBytes, StrictInt, StrictStr, field_validator
+from typing import List, Optional, Tuple, Union
+from typing_extensions import Annotated
 from openapi_server.models.api_response import ApiResponse
 from openapi_server.models.pet import Pet
 from openapi_server.security_api import get_token_petstore_auth, get_token_api_key
@@ -14,7 +17,7 @@ def __init_subclass__(cls, **kwargs):
         BasePetApi.subclasses = BasePetApi.subclasses + (cls,)
     async def add_pet(
         self,
-        pet: Pet,
+        pet: Annotated[Pet, Field(description="Pet object that needs to be added to the store")],
     ) -> Pet:
         """"""
         ...
@@ -22,8 +25,8 @@ async def add_pet(
 
     async def delete_pet(
         self,
-        petId: int,
-        api_key: str,
+        petId: Annotated[StrictInt, Field(description="Pet id to delete")],
+        api_key: Optional[StrictStr],
     ) -> None:
         """"""
         ...
@@ -31,7 +34,7 @@ async def delete_pet(
 
     async def find_pets_by_status(
         self,
-        status: List[str],
+        status: Annotated[List[StrictStr], Field(description="Status values that need to be considered for filter")],
     ) -> List[Pet]:
         """Multiple status values can be provided with comma separated strings"""
         ...
@@ -39,7 +42,7 @@ async def find_pets_by_status(
 
     async def find_pets_by_tags(
         self,
-        tags: List[str],
+        tags: Annotated[List[StrictStr], Field(description="Tags to filter by")],
     ) -> List[Pet]:
         """Multiple tags can be provided with comma separated strings. Use tag1, tag2, tag3 for testing."""
         ...
@@ -47,7 +50,7 @@ async def find_pets_by_tags(
 
     async def get_pet_by_id(
         self,
-        petId: int,
+        petId: Annotated[StrictInt, Field(description="ID of pet to return")],
     ) -> Pet:
         """Returns a single pet"""
         ...
@@ -55,7 +58,7 @@ async def get_pet_by_id(
 
     async def update_pet(
         self,
-        pet: Pet,
+        pet: Annotated[Pet, Field(description="Pet object that needs to be added to the store")],
     ) -> Pet:
         """"""
         ...
@@ -63,9 +66,9 @@ async def update_pet(
 
     async def update_pet_with_form(
         self,
-        petId: int,
-        name: str,
-        status: str,
+        petId: Annotated[StrictInt, Field(description="ID of pet that needs to be updated")],
+        name: Annotated[Optional[StrictStr], Field(description="Updated name of the pet")],
+        status: Annotated[Optional[StrictStr], Field(description="Updated status of the pet")],
     ) -> None:
         """"""
         ...
@@ -73,9 +76,9 @@ async def update_pet_with_form(
 
     async def upload_file(
         self,
-        petId: int,
-        additional_metadata: str,
-        file: str,
+        petId: Annotated[StrictInt, Field(description="ID of pet to update")],
+        additional_metadata: Annotated[Optional[StrictStr], Field(description="Additional data to pass to server")],
+        file: Annotated[Optional[Union[StrictBytes, StrictStr, Tuple[StrictStr, StrictBytes]]], Field(description="file to upload")],
     ) -> ApiResponse:
         """"""
         ...
diff --git a/samples/server/petstore/python-fastapi/src/openapi_server/apis/store_api.py b/samples/server/petstore/python-fastapi/src/openapi_server/apis/store_api.py
index 8f492e32ceff..5204ab3ec5b2 100644
--- a/samples/server/petstore/python-fastapi/src/openapi_server/apis/store_api.py
+++ b/samples/server/petstore/python-fastapi/src/openapi_server/apis/store_api.py
@@ -23,6 +23,9 @@
 )
 
 from openapi_server.models.extra_models import TokenModel  # noqa: F401
+from pydantic import Field, StrictInt, StrictStr
+from typing import Dict
+from typing_extensions import Annotated
 from openapi_server.models.order import Order
 from openapi_server.security_api import get_token_api_key
 
@@ -44,7 +47,7 @@
     response_model_by_alias=True,
 )
 async def delete_order(
-    orderId: str = Path(..., description="ID of the order that needs to be deleted"),
+    orderId: Annotated[StrictStr, Field(description="ID of the order that needs to be deleted")] = Path(..., description="ID of the order that needs to be deleted"),
 ) -> None:
     """For valid response try integer IDs with value &lt; 1000. Anything above 1000 or nonintegers will generate API errors"""
     if not BaseStoreApi.subclasses:
@@ -84,7 +87,7 @@ async def get_inventory(
     response_model_by_alias=True,
 )
 async def get_order_by_id(
-    orderId: int = Path(..., description="ID of pet that needs to be fetched", ge=1, le=5),
+    orderId: Annotated[int, Field(le=5, strict=True, ge=1, description="ID of pet that needs to be fetched")] = Path(..., description="ID of pet that needs to be fetched", ge=1, le=5),
 ) -> Order:
     """For valid response try integer IDs with value &lt;&#x3D; 5 or &gt; 10. Other values will generate exceptions"""
     if not BaseStoreApi.subclasses:
@@ -103,7 +106,7 @@ async def get_order_by_id(
     response_model_by_alias=True,
 )
 async def place_order(
-    order: Order = Body(None, description="order placed for purchasing the pet"),
+    order: Annotated[Order, Field(description="order placed for purchasing the pet")] = Body(None, description="order placed for purchasing the pet"),
 ) -> Order:
     """"""
     if not BaseStoreApi.subclasses:
diff --git a/samples/server/petstore/python-fastapi/src/openapi_server/apis/store_api_base.py b/samples/server/petstore/python-fastapi/src/openapi_server/apis/store_api_base.py
index 40c01de8b941..4539841d2df7 100644
--- a/samples/server/petstore/python-fastapi/src/openapi_server/apis/store_api_base.py
+++ b/samples/server/petstore/python-fastapi/src/openapi_server/apis/store_api_base.py
@@ -2,6 +2,9 @@
 
 from typing import ClassVar, Dict, List, Tuple  # noqa: F401
 
+from pydantic import Field, StrictInt, StrictStr
+from typing import Dict
+from typing_extensions import Annotated
 from openapi_server.models.order import Order
 from openapi_server.security_api import get_token_api_key
 
@@ -13,7 +16,7 @@ def __init_subclass__(cls, **kwargs):
         BaseStoreApi.subclasses = BaseStoreApi.subclasses + (cls,)
     async def delete_order(
         self,
-        orderId: str,
+        orderId: Annotated[StrictStr, Field(description="ID of the order that needs to be deleted")],
     ) -> None:
         """For valid response try integer IDs with value &lt; 1000. Anything above 1000 or nonintegers will generate API errors"""
         ...
@@ -28,7 +31,7 @@ async def get_inventory(
 
     async def get_order_by_id(
         self,
-        orderId: int,
+        orderId: Annotated[int, Field(le=5, strict=True, ge=1, description="ID of pet that needs to be fetched")],
     ) -> Order:
         """For valid response try integer IDs with value &lt;&#x3D; 5 or &gt; 10. Other values will generate exceptions"""
         ...
@@ -36,7 +39,7 @@ async def get_order_by_id(
 
     async def place_order(
         self,
-        order: Order,
+        order: Annotated[Order, Field(description="order placed for purchasing the pet")],
     ) -> Order:
         """"""
         ...
diff --git a/samples/server/petstore/python-fastapi/src/openapi_server/apis/user_api.py b/samples/server/petstore/python-fastapi/src/openapi_server/apis/user_api.py
index f09f127ba51a..4bf9265c9c20 100644
--- a/samples/server/petstore/python-fastapi/src/openapi_server/apis/user_api.py
+++ b/samples/server/petstore/python-fastapi/src/openapi_server/apis/user_api.py
@@ -23,6 +23,9 @@
 )
 
 from openapi_server.models.extra_models import TokenModel  # noqa: F401
+from pydantic import Field, StrictStr, field_validator
+from typing import List
+from typing_extensions import Annotated
 from openapi_server.models.user import User
 from openapi_server.security_api import get_token_api_key
 
@@ -43,7 +46,7 @@
     response_model_by_alias=True,
 )
 async def create_user(
-    user: User = Body(None, description="Created user object"),
+    user: Annotated[User, Field(description="Created user object")] = Body(None, description="Created user object"),
     token_api_key: TokenModel = Security(
         get_token_api_key
     ),
@@ -64,7 +67,7 @@ async def create_user(
     response_model_by_alias=True,
 )
 async def create_users_with_array_input(
-    user: List[User] = Body(None, description="List of user object"),
+    user: Annotated[List[User], Field(description="List of user object")] = Body(None, description="List of user object"),
     token_api_key: TokenModel = Security(
         get_token_api_key
     ),
@@ -85,7 +88,7 @@ async def create_users_with_array_input(
     response_model_by_alias=True,
 )
 async def create_users_with_list_input(
-    user: List[User] = Body(None, description="List of user object"),
+    user: Annotated[List[User], Field(description="List of user object")] = Body(None, description="List of user object"),
     token_api_key: TokenModel = Security(
         get_token_api_key
     ),
@@ -107,7 +110,7 @@ async def create_users_with_list_input(
     response_model_by_alias=True,
 )
 async def delete_user(
-    username: str = Path(..., description="The name that needs to be deleted"),
+    username: Annotated[StrictStr, Field(description="The name that needs to be deleted")] = Path(..., description="The name that needs to be deleted"),
     token_api_key: TokenModel = Security(
         get_token_api_key
     ),
@@ -130,7 +133,7 @@ async def delete_user(
     response_model_by_alias=True,
 )
 async def get_user_by_name(
-    username: str = Path(..., description="The name that needs to be fetched. Use user1 for testing."),
+    username: Annotated[StrictStr, Field(description="The name that needs to be fetched. Use user1 for testing.")] = Path(..., description="The name that needs to be fetched. Use user1 for testing."),
 ) -> User:
     """"""
     if not BaseUserApi.subclasses:
@@ -149,8 +152,8 @@ async def get_user_by_name(
     response_model_by_alias=True,
 )
 async def login_user(
-    username: str = Query(None, description="The user name for login", alias="username", regex=r"/^[a-zA-Z0-9]+[a-zA-Z0-9\.\-_]*[a-zA-Z0-9]+$/"),
-    password: str = Query(None, description="The password for login in clear text", alias="password"),
+    username: Annotated[str, Field(strict=True, description="The user name for login")] = Query(None, description="The user name for login", alias="username", regex=r"/^[a-zA-Z0-9]+[a-zA-Z0-9\.\-_]*[a-zA-Z0-9]+$/"),
+    password: Annotated[StrictStr, Field(description="The password for login in clear text")] = Query(None, description="The password for login in clear text", alias="password"),
 ) -> str:
     """"""
     if not BaseUserApi.subclasses:
@@ -189,8 +192,8 @@ async def logout_user(
     response_model_by_alias=True,
 )
 async def update_user(
-    username: str = Path(..., description="name that need to be deleted"),
-    user: User = Body(None, description="Updated user object"),
+    username: Annotated[StrictStr, Field(description="name that need to be deleted")] = Path(..., description="name that need to be deleted"),
+    user: Annotated[User, Field(description="Updated user object")] = Body(None, description="Updated user object"),
     token_api_key: TokenModel = Security(
         get_token_api_key
     ),
diff --git a/samples/server/petstore/python-fastapi/src/openapi_server/apis/user_api_base.py b/samples/server/petstore/python-fastapi/src/openapi_server/apis/user_api_base.py
index b260864f1ca6..3b10dbdb8766 100644
--- a/samples/server/petstore/python-fastapi/src/openapi_server/apis/user_api_base.py
+++ b/samples/server/petstore/python-fastapi/src/openapi_server/apis/user_api_base.py
@@ -2,6 +2,9 @@
 
 from typing import ClassVar, Dict, List, Tuple  # noqa: F401
 
+from pydantic import Field, StrictStr, field_validator
+from typing import List
+from typing_extensions import Annotated
 from openapi_server.models.user import User
 from openapi_server.security_api import get_token_api_key
 
@@ -13,7 +16,7 @@ def __init_subclass__(cls, **kwargs):
         BaseUserApi.subclasses = BaseUserApi.subclasses + (cls,)
     async def create_user(
         self,
-        user: User,
+        user: Annotated[User, Field(description="Created user object")],
     ) -> None:
         """This can only be done by the logged in user."""
         ...
@@ -21,7 +24,7 @@ async def create_user(
 
     async def create_users_with_array_input(
         self,
-        user: List[User],
+        user: Annotated[List[User], Field(description="List of user object")],
     ) -> None:
         """"""
         ...
@@ -29,7 +32,7 @@ async def create_users_with_array_input(
 
     async def create_users_with_list_input(
         self,
-        user: List[User],
+        user: Annotated[List[User], Field(description="List of user object")],
     ) -> None:
         """"""
         ...
@@ -37,7 +40,7 @@ async def create_users_with_list_input(
 
     async def delete_user(
         self,
-        username: str,
+        username: Annotated[StrictStr, Field(description="The name that needs to be deleted")],
     ) -> None:
         """This can only be done by the logged in user."""
         ...
@@ -45,7 +48,7 @@ async def delete_user(
 
     async def get_user_by_name(
         self,
-        username: str,
+        username: Annotated[StrictStr, Field(description="The name that needs to be fetched. Use user1 for testing.")],
     ) -> User:
         """"""
         ...
@@ -53,8 +56,8 @@ async def get_user_by_name(
 
     async def login_user(
         self,
-        username: str,
-        password: str,
+        username: Annotated[str, Field(strict=True, description="The user name for login")],
+        password: Annotated[StrictStr, Field(description="The password for login in clear text")],
     ) -> str:
         """"""
         ...
@@ -69,8 +72,8 @@ async def logout_user(
 
     async def update_user(
         self,
-        username: str,
-        user: User,
+        username: Annotated[StrictStr, Field(description="name that need to be deleted")],
+        user: Annotated[User, Field(description="Updated user object")],
     ) -> None:
         """This can only be done by the logged in user."""
         ...