FastAPI class

Here’s the reference information for the FastAPI class, with all its parameters, attributes and methods.

You can import the FastAPI class directly from fastapi:

  1. from fastapi import FastAPI

fastapi.FastAPI

  1. FastAPI(
  2.     *,
  3.     debug=False,
  4.     routes=None,
  5.     title="FastAPI",
  6.     summary=None,
  7.     description="",
  8.     version="0.1.0",
  9.     openapi_url="/openapi.json",
  10.     openapi_tags=None,
  11.     servers=None,
  12.     dependencies=None,
  13.     default_response_class=Default(JSONResponse),
  14.     redirect_slashes=True,
  15.     docs_url="/docs",
  16.     redoc_url="/redoc",
  17.     swagger_ui_oauth2_redirect_url="/docs/oauth2-redirect",
  18.     swagger_ui_init_oauth=None,
  19.     middleware=None,
  20.     exception_handlers=None,
  21.     on_startup=None,
  22.     on_shutdown=None,
  23.     lifespan=None,
  24.     terms_of_service=None,
  25.     contact=None,
  26.     license_info=None,
  27.     openapi_prefix="",
  28.     root_path="",
  29.     root_path_in_servers=True,
  30.     responses=None,
  31.     callbacks=None,
  32.     webhooks=None,
  33.     deprecated=None,
  34.     include_in_schema=True,
  35.     swagger_ui_parameters=None,
  36.     generate_unique_id_function=Default(generate_unique_id),
  37.     separate_input_output_schemas=True,
  38.     **extra
  39. )

Bases: Starlette

FastAPI app class, the main entrypoint to use FastAPI.

Read more in the FastAPI docs for First Steps.

Example

  1. from fastapi import FastAPI
  3. app = FastAPI()
PARAMETERDESCRIPTION
debug

Boolean indicating if debug tracebacks should be returned on server errors.

Read more in the Starlette docs for Applications.

TYPE: bool DEFAULT: False

routes

You normally wouldn’t use this parameter with FastAPI, it is inherited from Starlette and supported for compatibility.

In FastAPI, you normally would use the path operation methods, like app.get(), app.post(), etc. Note: you probably shouldn’t use this parameter, it is inherited from Starlette and supported for compatibility.

A list of routes to serve incoming HTTP and WebSocket requests.

TYPE: Optional[List[BaseRoute]] DEFAULT: None

title

The title of the API.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more in the FastAPI docs for Metadata and Docs URLs.

Example

  1. from fastapi import FastAPI
  3. app = FastAPI(title=“ChimichangApp”)

TYPE: str DEFAULT: ‘FastAPI’

summary

A short summary of the API.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more in the FastAPI docs for Metadata and Docs URLs.

Example

  1. from fastapi import FastAPI
  3. app = FastAPI(summary=“Deadpond’s favorite app. Nuff said.”)

TYPE: Optional[str] DEFAULT: None

description

A description of the API. Supports Markdown (using CommonMark syntax).

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more in the FastAPI docs for Metadata and Docs URLs.

Example

  1. from fastapi import FastAPI
  3. app = FastAPI(
  4.     description=“””
  5.                 ChimichangApp API helps you do awesome stuff. 🚀
  7.                 ## Items
  9.                 You can read items.
  11.                 ## Users
  13.                 You will be able to:
  15.                  Create users (not implemented).
  16.                  Read users (not implemented).
  18.                 “””
  19. )

TYPE: str DEFAULT: ‘’

version

The version of the API.

Note This is the version of your application, not the version of the OpenAPI specification nor the version of FastAPI being used.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more in the FastAPI docs for Metadata and Docs URLs.

Example

  1. from fastapi import FastAPI
  3. app = FastAPI(version=“0.0.1”)

TYPE: str DEFAULT: ‘0.1.0’

openapiurl

The URL where the OpenAPI schema will be served from.

If you set it to None, no OpenAPI schema will be served publicly, and the default automatic endpoints /docs and /redoc will also be disabled.

Read more in the FastAPI docs for Metadata and Docs URLs.

Example

  1. from fastapi import FastAPI
  3. app = FastAPI(openapi_url=“/api/v1/openapi.json”)

TYPE: Optional[str] DEFAULT: ‘/openapi.json’

openapi_tags

A list of tags used by OpenAPI, these are the same tags you can set in the path operations, like:

  • @app.get(“/users/“, tags=[“users”])
  • @app.get(“/items/“, tags=[“items”])

The order of the tags can be used to specify the order shown in tools like Swagger UI, used in the automatic path /docs.

It’s not required to specify all the tags used.

The tags that are not declared MAY be organized randomly or based on the tools’ logic. Each tag name in the list MUST be unique.

The value of each item is a dict containing:

  • name: The name of the tag.
  • description: A short description of the tag. CommonMark syntax MAY be used for rich text representation.
  • externalDocs: Additional external documentation for this tag. If provided, it would contain a dict with:
    • description: A short description of the target documentation. CommonMark syntax MAY be used for rich text representation.
    • url: The URL for the target documentation. Value MUST be in the form of a URL.

Read more in the FastAPI docs for Metadata and Docs URLs.

Example

  1. from fastapi import FastAPI
  3. tags_metadata = [
  4.     {
  5.         “name”: “users”,
  6.         “description”: “Operations with users. The login logic is also here.”,
  7.     },
  8.     {
  9.         “name”: “items”,
  10.         “description”: “Manage items. So _fancy they have their own docs.”,
  11.         “externalDocs”: {
  12.             “description”: “Items external docs”,
  13.             “url”: “https://fastapi.tiangolo.com/“,
  14.         },
  15.     },
  16. ]
  18. app = FastAPI(openapi_tags=tags_metadata)

TYPE: Optional[List[Dict[str, Any]]] DEFAULT: None

servers

A list of dicts with connectivity information to a target server.

You would use it, for example, if your application is served from different domains and you want to use the same Swagger UI in the browser to interact with each of them (instead of having multiple browser tabs open). Or if you want to leave fixed the possible URLs.

If the servers list is not provided, or is an empty list, the default value would be a a dict with a url value of /.

Each item in the list is a dict containing:

  • url: A URL to the target host. This URL supports Server Variables and MAY be relative, to indicate that the host location is relative to the location where the OpenAPI document is being served. Variable substitutions will be made when a variable is named in {brackets}.
  • description: An optional string describing the host designated by the URL. CommonMark syntax MAY be used for rich text representation.
  • variables: A dict between a variable name and its value. The value is used for substitution in the server’s URL template.

Read more in the FastAPI docs for Behind a Proxy.

Example

  1. from fastapi import FastAPI
  3. app = FastAPI(
  4.     servers=[
  5.         {“url”: “https://stag.example.com“, “description”: “Staging environment”},
  6.         {“url”: “https://prod.example.com“, “description”: “Production environment”},
  7.     ]
  8. )

TYPE: Optional[List[Dict[str, Union[str, Any]]]] DEFAULT: None

dependencies

A list of global dependencies, they will be applied to each path operation, including in sub-routers.

Read more about it in the FastAPI docs for Global Dependencies.

Example

  1. from fastapi import Depends, FastAPI
  3. from .dependencies import func_dep_1, func_dep_2
  5. app = FastAPI(dependencies=[Depends(func_dep_1), Depends(func_dep_2)])

TYPE: Optional[Sequence[Depends]] DEFAULT: None

default_response_class

The default response class to be used.

Read more in the FastAPI docs for Custom Response - HTML, Stream, File, others.

Example

  1. from fastapi import FastAPI
  2. from fastapi.responses import ORJSONResponse
  4. app = FastAPI(default_response_class=ORJSONResponse)

TYPE: Type[Response] DEFAULT: Default(JSONResponse)

redirect_slashes

Whether to detect and redirect slashes in URLs when the client doesn’t use the same format.

Example

  1. from fastapi import FastAPI
  3. app = FastAPI(redirect_slashes=True)  # the default
  5. @app.get(“/items/“)
  6. async def read_items():
  7.     return [{“item_id”: “Foo”}]

With this app, if a client goes to /items (without a trailing slash), they will be automatically redirected with an HTTP status code of 307 to /items/.

TYPE: bool DEFAULT: True

docs_url

The path to the automatic interactive API documentation. It is handled in the browser by Swagger UI.

The default URL is /docs. You can disable it by setting it to None.

If openapi_url is set to None, this will be automatically disabled.

Read more in the FastAPI docs for Metadata and Docs URLs.

Example

  1. from fastapi import FastAPI
  3. app = FastAPI(docs_url=“/documentation”, redoc_url=None)

TYPE: Optional[str] DEFAULT: ‘/docs’

redoc_url

The path to the alternative automatic interactive API documentation provided by ReDoc.

The default URL is /redoc. You can disable it by setting it to None.

If openapi_url is set to None, this will be automatically disabled.

Read more in the FastAPI docs for Metadata and Docs URLs.

Example

  1. from fastapi import FastAPI
  3. app = FastAPI(docs_url=“/documentation”, redoc_url=“redocumentation”)

TYPE: Optional[str] DEFAULT: ‘/redoc’

swagger_ui_oauth2_redirect_url

The OAuth2 redirect endpoint for the Swagger UI.

By default it is /docs/oauth2-redirect.

This is only used if you use OAuth2 (with the “Authorize” button) with Swagger UI.

TYPE: Optional[str] DEFAULT: ‘/docs/oauth2-redirect’

swagger_ui_init_oauth

OAuth2 configuration for the Swagger UI, by default shown at /docs.

Read more about the available configuration options in the Swagger UI docs.

TYPE: Optional[Dict[str, Any]] DEFAULT: None

middleware

List of middleware to be added when creating the application.

In FastAPI you would normally do this with app.add_middleware() instead.

Read more in the FastAPI docs for Middleware.

TYPE: Optional[Sequence[Middleware]] DEFAULT: None

exception_handlers

A dictionary with handlers for exceptions.

In FastAPI, you would normally use the decorator @app.exception_handler().

Read more in the FastAPI docs for Handling Errors.

TYPE: Optional[Dict[Union[int, Type[Exception]], Callable[[Request, Any], Coroutine[Any, Any, Response]]]] DEFAULT: None

on_startup

A list of startup event handler functions.

You should instead use the lifespan handlers.

Read more in the FastAPI docs for lifespan.

TYPE: Optional[Sequence[Callable[[], Any]]] DEFAULT: None

on_shutdown

A list of shutdown event handler functions.

You should instead use the lifespan handlers.

Read more in the FastAPI docs for lifespan.

TYPE: Optional[Sequence[Callable[[], Any]]] DEFAULT: None

lifespan

A Lifespan context manager handler. This replaces startup and shutdown functions with a single context manager.

Read more in the FastAPI docs for lifespan.

TYPE: Optional[Lifespan[AppType]] DEFAULT: None

terms_of_service

A URL to the Terms of Service for your API.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more at the FastAPI docs for Metadata and Docs URLs.

Example

  1. app = FastAPI(terms_of_service=“http://example.com/terms/“)

TYPE: Optional[str] DEFAULT: None

contact

A dictionary with the contact information for the exposed API.

It can contain several fields.

  • name: (str) The name of the contact person/organization.
  • url: (str) A URL pointing to the contact information. MUST be in the format of a URL.
  • email: (str) The email address of the contact person/organization. MUST be in the format of an email address.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more at the FastAPI docs for Metadata and Docs URLs.

Example

  1. app = FastAPI(
  2.     contact={
  3.         “name”: “Deadpoolio the Amazing”,
  4.         “url”: “http://x-force.example.com/contact/“,
  5.         “email”: “dp@x-force.example.com”,
  6.     }
  7. )

TYPE: Optional[Dict[str, Union[str, Any]]] DEFAULT: None

license_info

A dictionary with the license information for the exposed API.

It can contain several fields.

  • name: (str) REQUIRED (if a license_info is set). The license name used for the API.
  • identifier: (str) An SPDX license expression for the API. The identifier field is mutually exclusive of the url field. Available since OpenAPI 3.1.0, FastAPI 0.99.0.
  • url: (str) A URL to the license used for the API. This MUST be the format of a URL.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more at the FastAPI docs for Metadata and Docs URLs.

Example

  1. app = FastAPI(
  2.     license_info={
  3.         “name”: “Apache 2.0”,
  4.         “url”: “https://www.apache.org/licenses/LICENSE-2.0.html“,
  5.     }
  6. )

TYPE: Optional[Dict[str, Union[str, Any]]] DEFAULT: None

openapi_prefix

“openapi_prefix” has been deprecated in favor of “root_path”, which follows more closely the ASGI standard, is simpler, and more automatic. A URL prefix for the OpenAPI URL.

TYPE: str DEFAULT: ‘’

root_path

A path prefix handled by a proxy that is not seen by the application but is seen by external clients, which affects things like Swagger UI.

Read more about it at the FastAPI docs for Behind a Proxy.

Example

  1. from fastapi import FastAPI
  3. app = FastAPI(root_path=“/api/v1”)

TYPE: str DEFAULT: ‘’

root_path_in_servers

To disable automatically generating the URLs in the servers field in the autogenerated OpenAPI using the root_path.

Read more about it in the FastAPI docs for Behind a Proxy.

Example

  1. from fastapi import FastAPI
  3. app = FastAPI(root_path_in_servers=False)

TYPE: bool DEFAULT: True

responses

Additional responses to be shown in OpenAPI.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Additional Responses in OpenAPI.

And in the FastAPI docs for Bigger Applications.

TYPE: Optional[Dict[Union[int, str], Dict[str, Any]]] DEFAULT: None

callbacks

OpenAPI callbacks that should apply to all path operations.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for OpenAPI Callbacks.

TYPE: Optional[List[BaseRoute]] DEFAULT: None

webhooks

Add OpenAPI webhooks. This is similar to callbacks but it doesn’t depend on specific path operations.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Note: This is available since OpenAPI 3.1.0, FastAPI 0.99.0.

Read more about it in the FastAPI docs for OpenAPI Webhooks.

TYPE: Optional[APIRouter] DEFAULT: None

deprecated

Mark all path operations as deprecated. You probably don’t need it, but it’s available.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[bool] DEFAULT: None

include_in_schema

To include (or not) all the path operations in the generated OpenAPI. You probably don’t need it, but it’s available.

This affects the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Query Parameters and String Validations.

TYPE: bool DEFAULT: True

swagger_ui_parameters

Parameters to configure Swagger UI, the autogenerated interactive API documentation (by default at /docs).

Read more about it in the FastAPI docs about how to Configure Swagger UI.

TYPE: Optional[Dict[str, Any]] DEFAULT: None

generate_unique_id_function

Customize the function used to generate unique IDs for the path operations shown in the generated OpenAPI.

This is particularly useful when automatically generating clients or SDKs for your API.

Read more about it in the FastAPI docs about how to Generate Clients.

TYPE: Callable[[APIRoute], str] DEFAULT: Default(generate_unique_id)

separate_input_output_schemas

Whether to generate separate OpenAPI schemas for request body and response body when the results would be more precise.

This is particularly useful when automatically generating clients.

For example, if you have a model like:

  1. from pydantic import BaseModel
  3. class Item(BaseModel):
  4.     name: str
  5.     tags: list[str] = []

When Item is used for input, a request body, tags is not required, the client doesn’t have to provide it.

But when using Item for output, for a response body, tags is always available because it has a default value, even if it’s just an empty list. So, the client should be able to always expect it.

In this case, there would be two different schemas, one for input and another one for output.

TYPE: bool DEFAULT: True

**extra

Extra keyword arguments to be stored in the app, not used by FastAPI anywhere.

TYPE: Any DEFAULT: {}

Source code in fastapi/applications.py

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def init(
    self: AppType,
    ,
    debug: Annotated[
        bool,
        Doc(
            “””
            Boolean indicating if debug tracebacks should be returned on server
            errors.

            Read more in the
            Starlette docs for Applications.
            “””
        ),
    ] = False,
    routes: Annotated[
        Optional[List[BaseRoute]],
        Doc(
            “””
            Note: you probably shouldn’t use this parameter, it is inherited
            from Starlette and supported for compatibility.

            —-

            A list of routes to serve incoming HTTP and WebSocket requests.
            “””
        ),
        deprecated(
            “””
            You normally wouldn’t use this parameter with FastAPI, it is inherited
            from Starlette and supported for compatibility.

            In FastAPI, you normally would use the path operation methods,
            like app.get(), app.post(), etc.
            “””
        ),
    ] = None,
    title: Annotated[
        str,
        Doc(
            “””
            The title of the API.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more in the
            FastAPI docs for Metadata and Docs URLs.

            Example

            python</span>
<span>            from fastapi import FastAPI</span>

<span>            app = FastAPI(title="ChimichangApp")</span>
<span>
            “””
        ),
    ] = “FastAPI”,
    summary: Annotated[
        Optional[str],
        Doc(
            “””
            A short summary of the API.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more in the
            FastAPI docs for Metadata and Docs URLs.

            Example

            python</span>
<span>            from fastapi import FastAPI</span>

<span>            app = FastAPI(summary="Deadpond's favorite app. Nuff said.")</span>
<span>
            “””
        ),
    ] = None,
    description: Annotated[
        str,
        Doc(
            ‘’’
            A description of the API. Supports Markdown (using
            CommonMark syntax).

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more in the
            FastAPI docs for Metadata and Docs URLs.

            Example

            ```python
            from fastapi import FastAPI

            app = FastAPI(
                description=”””
                            ChimichangApp API helps you do awesome stuff. 🚀

                            ## Items

                            You can read items.

                            ## Users

                            You will be able to:

                             Create users (not implemented).
                             Read users (not implemented).

                            “””
            )
            </span>
<span>            '''</span>
        <span>),</span>
    <span>]</span> <span>=</span> <span>""</span><span>,</span>
    <span>version</span><span>:</span> <span>Annotated</span><span>[</span>
        <span>str</span><span>,</span>
        <span>Doc</span><span>(</span>
<span>            </span><span>"""</span>
<span>            The version of the API.</span>

<span>            **Note** This is the version of your application, not the version of</span>
<span>            the OpenAPI specification nor the version of FastAPI being used.</span>

<span>            It will be added to the generated OpenAPI (e.g. visible at `/docs`).</span>

<span>            Read more in the</span>
<span>            [FastAPI docs for Metadata and Docs URLs](https://fastapi.tiangolo.com/tutorial/metadata/#metadata-for-api).</span>

<span>            **Example**</span>

<span>python
            from fastapi import FastAPI

            app = FastAPI(version=”0.0.1”)
            </span>
<span>            """</span>
        <span>),</span>
    <span>]</span> <span>=</span> <span>"0.1.0"</span><span>,</span>
    <span>openapi_url</span><span>:</span> <span>Annotated</span><span>[</span>
        <span>Optional</span><span>[</span><span>str</span><span>],</span>
        <span>Doc</span><span>(</span>
<span>            </span><span>"""</span>
<span>            The URL where the OpenAPI schema will be served from.</span>

<span>            If you set it to `None`, no OpenAPI schema will be served publicly, and</span>
<span>            the default automatic endpoints `/docs` and `/redoc` will also be</span>
<span>            disabled.</span>

<span>            Read more in the</span>
<span>            [FastAPI docs for Metadata and Docs URLs](https://fastapi.tiangolo.com/tutorial/metadata/#openapi-url).</span>

<span>            **Example**</span>

<span>python
            from fastapi import FastAPI

            app = FastAPI(openapi_url=”/api/v1/openapi.json”)
            ``</span>
<span>            """</span>
        <span>),</span>
    <span>]</span> <span>=</span> <span>"/openapi.json"</span><span>,</span>
    <span>openapi_tags</span><span>:</span> <span>Annotated</span><span>[</span>
        <span>Optional</span><span>[</span><span>List</span><span>[</span><span>Dict</span><span>[</span><span>str</span><span>,</span> <span>Any</span><span>]]],</span>
        <span>Doc</span><span>(</span>
<span>            </span><span>"""</span>
<span>            A list of tags used by OpenAPI, these are the sametags` you can set
            in the path operations, like:

             @app.get("/users/", tags=["users"])
             @app.get("/items/", tags=["items"])

            The order of the tags can be used to specify the order shown in
            tools like Swagger UI, used in the automatic path /docs.

            It’s not required to specify all the tags used.

            The tags that are not declared MAY be organized randomly or based
            on the tools’ logic. Each tag name in the list MUST be unique.

            The value of each item is a dict containing:

             name: The name of the tag.
             description: A short description of the tag.
                CommonMark syntax MAY be used for rich
                text representation.
             externalDocs: Additional external documentation for this tag. If
                provided, it would contain a dict with:
                 description: A short description of the target documentation.
                    CommonMark syntax MAY be used for
                    rich text representation.
                 url: The URL for the target documentation. Value MUST be in
                    the form of a URL.

            Read more in the
            FastAPI docs for Metadata and Docs URLs.

            Example

            python</span>
<span>            from fastapi import FastAPI</span>

<span>            tags_metadata = [</span>
<span>                {</span>
<span>                    "name": "users",</span>
<span>                    "description": "Operations with users. The **login** logic is also here.",</span>
<span>                },</span>
<span>                {</span>
<span>                    "name": "items",</span>
<span>                    "description": "Manage items. So _fancy_ they have their own docs.",</span>
<span>                    "externalDocs": {</span>
<span>                        "description": "Items external docs",</span>
<span>                        "url": "https://fastapi.tiangolo.com/",</span>
<span>                    },</span>
<span>                },</span>
<span>            ]</span>

<span>            app = FastAPI(openapi_tags=tags_metadata)</span>
<span>
            “””
        ),
    ] = None,
    servers: Annotated[
        Optional[List[Dict[str, Union[str, Any]]]],
        Doc(
            “””
            A list of dicts with connectivity information to a target server.

            You would use it, for example, if your application is served from
            different domains and you want to use the same Swagger UI in the
            browser to interact with each of them (instead of having multiple
            browser tabs open). Or if you want to leave fixed the possible URLs.

            If the servers list is not provided, or is an empty list, the
            default value would be a a dict with a url value of /.

            Each item in the list is a dict containing:

             url: A URL to the target host. This URL supports Server Variables
            and MAY be relative, to indicate that the host location is relative
            to the location where the OpenAPI document is being served. Variable
            substitutions will be made when a variable is named in {brackets}.
             description: An optional string describing the host designated by
            the URL. CommonMark syntax MAY be used for
            rich text representation.
             variables: A dict between a variable name and its value. The value
                is used for substitution in the server’s URL template.

            Read more in the
            FastAPI docs for Behind a Proxy.

            Example

            python</span>
<span>            from fastapi import FastAPI</span>

<span>            app = FastAPI(</span>
<span>                servers=[</span>
<span>                    {"url": "https://stag.example.com", "description": "Staging environment"},</span>
<span>                    {"url": "https://prod.example.com", "description": "Production environment"},</span>
<span>                ]</span>
<span>            )</span>
<span>
            “””
        ),
    ] = None,
    dependencies: Annotated[
        Optional[Sequence[Depends]],
        Doc(
            “””
            A list of global dependencies, they will be applied to each
            path operation, including in sub-routers.

            Read more about it in the
            FastAPI docs for Global Dependencies.

            Example

            python</span>
<span>            from fastapi import Depends, FastAPI</span>

<span>            from .dependencies import func_dep_1, func_dep_2</span>

<span>            app = FastAPI(dependencies=[Depends(func_dep_1), Depends(func_dep_2)])</span>
<span>
            “””
        ),
    ] = None,
    default_response_class: Annotated[
        Type[Response],
        Doc(
            “””
            The default response class to be used.

            Read more in the
            FastAPI docs for Custom Response - HTML, Stream, File, others.

            Example

            python</span>
<span>            from fastapi import FastAPI</span>
<span>            from fastapi.responses import ORJSONResponse</span>

<span>            app = FastAPI(default_response_class=ORJSONResponse)</span>
<span>
            “””
        ),
    ] = Default(JSONResponse),
    redirect_slashes: Annotated[
        bool,
        Doc(
            “””
            Whether to detect and redirect slashes in URLs when the client doesn’t
            use the same format.

            Example

            python</span>
<span>            from fastapi import FastAPI</span>

<span>            app = FastAPI(redirect_slashes=True)  # the default</span>

<span>            @app.get("/items/")</span>
<span>            async def read_items():</span>
<span>                return [{"item_id": "Foo"}]</span>
<span>

            With this app, if a client goes to /items (without a trailing slash),
            they will be automatically redirected with an HTTP status code of 307
            to /items/.
            “””
        ),
    ] = True,
    docs_url: Annotated[
        Optional[str],
        Doc(
            “””
            The path to the automatic interactive API documentation.
            It is handled in the browser by Swagger UI.

            The default URL is /docs. You can disable it by setting it to None.

            If openapi_url is set to None, this will be automatically disabled.

            Read more in the
            FastAPI docs for Metadata and Docs URLs.

            Example

            python</span>
<span>            from fastapi import FastAPI</span>

<span>            app = FastAPI(docs_url="/documentation", redoc_url=None)</span>
<span>
            “””
        ),
    ] = “/docs”,
    redoc_url: Annotated[
        Optional[str],
        Doc(
            “””
            The path to the alternative automatic interactive API documentation
            provided by ReDoc.

            The default URL is /redoc. You can disable it by setting it to None.

            If openapi_url is set to None, this will be automatically disabled.

            Read more in the
            FastAPI docs for Metadata and Docs URLs.

            Example

            python</span>
<span>            from fastapi import FastAPI</span>

<span>            app = FastAPI(docs_url="/documentation", redoc_url="redocumentation")</span>
<span>
            “””
        ),
    ] = “/redoc”,
    swagger_ui_oauth2_redirect_url: Annotated[
        Optional[str],
        Doc(
            “””
            The OAuth2 redirect endpoint for the Swagger UI.

            By default it is /docs/oauth2-redirect.

            This is only used if you use OAuth2 (with the “Authorize” button)
            with Swagger UI.
            “””
        ),
    ] = “/docs/oauth2-redirect”,
    swagger_ui_init_oauth: Annotated[
        Optional[Dict[str, Any]],
        Doc(
            “””
            OAuth2 configuration for the Swagger UI, by default shown at /docs.

            Read more about the available configuration options in the
            Swagger UI docs.
            “””
        ),
    ] = None,
    middleware: Annotated[
        Optional[Sequence[Middleware]],
        Doc(
            “””
            List of middleware to be added when creating the application.

            In FastAPI you would normally do this with app.add_middleware()
            instead.

            Read more in the
            FastAPI docs for Middleware.
            “””
        ),
    ] = None,
    exception_handlers: Annotated[
        Optional[
            Dict[
                Union[int, Type[Exception]],
                Callable[[Request, Any], Coroutine[Any, Any, Response]],
            ]
        ],
        Doc(
            “””
            A dictionary with handlers for exceptions.

            In FastAPI, you would normally use the decorator
            @app.exception_handler().

            Read more in the
            FastAPI docs for Handling Errors.
            “””
        ),
    ] = None,
    on_startup: Annotated[
        Optional[Sequence[Callable[[], Any]]],
        Doc(
            “””
            A list of startup event handler functions.

            You should instead use the lifespan handlers.

            Read more in the FastAPI docs for lifespan.
            “””
        ),
    ] = None,
    on_shutdown: Annotated[
        Optional[Sequence[Callable[[], Any]]],
        Doc(
            “””
            A list of shutdown event handler functions.

            You should instead use the lifespan handlers.

            Read more in the
            FastAPI docs for lifespan.
            “””
        ),
    ] = None,
    lifespan: Annotated[
        Optional[Lifespan[AppType]],
        Doc(
            “””
            A Lifespan context manager handler. This replaces startup and
            shutdown functions with a single context manager.

            Read more in the
            FastAPI docs for lifespan.
            “””
        ),
    ] = None,
    terms_of_service: Annotated[
        Optional[str],
        Doc(
            “””
            A URL to the Terms of Service for your API.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more at the
            FastAPI docs for Metadata and Docs URLs.

            Example

            python</span>
<span>            app = FastAPI(terms_of_service="http://example.com/terms/")</span>
<span>
            “””
        ),
    ] = None,
    contact: Annotated[
        Optional[Dict[str, Union[str, Any]]],
        Doc(
            “””
            A dictionary with the contact information for the exposed API.

            It can contain several fields.

             name: (str) The name of the contact person/organization.
             url: (str) A URL pointing to the contact information. MUST be in
                the format of a URL.
             email: (str) The email address of the contact person/organization.
                MUST be in the format of an email address.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more at the
            FastAPI docs for Metadata and Docs URLs.

            Example

            python</span>
<span>            app = FastAPI(</span>
<span>                contact={</span>
<span>                    "name": "Deadpoolio the Amazing",</span>
<span>                    "url": "http://x-force.example.com/contact/",</span>
<span>                    "email": "dp@x-force.example.com",</span>
<span>                }</span>
<span>            )</span>
<span>
            “””
        ),
    ] = None,
    license_info: Annotated[
        Optional[Dict[str, Union[str, Any]]],
        Doc(
            “””
            A dictionary with the license information for the exposed API.

            It can contain several fields.

             name: (str) REQUIRED (if a license_info is set). The
                license name used for the API.
             identifier: (str) An SPDX license expression
                for the API. The identifier field is mutually exclusive of the url
                field. Available since OpenAPI 3.1.0, FastAPI 0.99.0.
             url: (str) A URL to the license used for the API. This MUST be
                the format of a URL.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more at the
            FastAPI docs for Metadata and Docs URLs.

            Example

            python</span>
<span>            app = FastAPI(</span>
<span>                license_info={</span>
<span>                    "name": "Apache 2.0",</span>
<span>                    "url": "https://www.apache.org/licenses/LICENSE-2.0.html",</span>
<span>                }</span>
<span>            )</span>
<span>
            “””
        ),
    ] = None,
    openapi_prefix: Annotated[
        str,
        Doc(
            “””
            A URL prefix for the OpenAPI URL.
            “””
        ),
        deprecated(
            “””
            “openapi_prefix” has been deprecated in favor of “root_path”, which
            follows more closely the ASGI standard, is simpler, and more
            automatic.
            “””
        ),
    ] = “”,
    root_path: Annotated[
        str,
        Doc(
            “””
            A path prefix handled by a proxy that is not seen by the application
            but is seen by external clients, which affects things like Swagger UI.

            Read more about it at the
            FastAPI docs for Behind a Proxy.

            Example

            python</span>
<span>            from fastapi import FastAPI</span>

<span>            app = FastAPI(root_path="/api/v1")</span>
<span>
            “””
        ),
    ] = “”,
    root_path_in_servers: Annotated[
        bool,
        Doc(
            “””
            To disable automatically generating the URLs in the servers field
            in the autogenerated OpenAPI using the root_path.

            Read more about it in the
            FastAPI docs for Behind a Proxy.

            Example

            python</span>
<span>            from fastapi import FastAPI</span>

<span>            app = FastAPI(root_path_in_servers=False)</span>
<span>
            “””
        ),
    ] = True,
    responses: Annotated[
        Optional[Dict[Union[int, str], Dict[str, Any]]],
        Doc(
            “””
            Additional responses to be shown in OpenAPI.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Additional Responses in OpenAPI.

            And in the
            FastAPI docs for Bigger Applications.
            “””
        ),
    ] = None,
    callbacks: Annotated[
        Optional[List[BaseRoute]],
        Doc(
            “””
            OpenAPI callbacks that should apply to all path operations.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for OpenAPI Callbacks.
            “””
        ),
    ] = None,
    webhooks: Annotated[
        Optional[routing.APIRouter],
        Doc(
            “””
            Add OpenAPI webhooks. This is similar to callbacks but it doesn’t
            depend on specific path operations.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Note: This is available since OpenAPI 3.1.0, FastAPI 0.99.0.

            Read more about it in the
            FastAPI docs for OpenAPI Webhooks.
            “””
        ),
    ] = None,
    deprecated: Annotated[
        Optional[bool],
        Doc(
            “””
            Mark all path operations as deprecated. You probably don’t need it,
            but it’s available.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    include_in_schema: Annotated[
        bool,
        Doc(
            “””
            To include (or not) all the path operations in the generated OpenAPI.
            You probably don’t need it, but it’s available.

            This affects the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Query Parameters and String Validations.
            “””
        ),
    ] = True,
    swagger_ui_parameters: Annotated[
        Optional[Dict[str, Any]],
        Doc(
            “””
            Parameters to configure Swagger UI, the autogenerated interactive API
            documentation (by default at /docs).

            Read more about it in the
            FastAPI docs about how to Configure Swagger UI.
            “””
        ),
    ] = None,
    generate_unique_id_function: Annotated[
        Callable[[routing.APIRoute], str],
        Doc(
            “””
            Customize the function used to generate unique IDs for the path
            operations shown in the generated OpenAPI.

            This is particularly useful when automatically generating clients or
            SDKs for your API.

            Read more about it in the
            FastAPI docs about how to Generate Clients.
            “””
        ),
    ] = Default(generate_unique_id),
    separate_input_output_schemas: Annotated[
        bool,
        Doc(
            “””
            Whether to generate separate OpenAPI schemas for request body and
            response body when the results would be more precise.

            This is particularly useful when automatically generating clients.

            For example, if you have a model like:

            python</span>
<span>            from pydantic import BaseModel</span>

<span>            class Item(BaseModel):</span>
<span>                name: str</span>
<span>                tags: list[str] = []</span>
<span>

            When Item is used for input, a request body, tags is not required,
            the client doesn’t have to provide it.

            But when using Item for output, for a response body, tags is always
            available because it has a default value, even if it’s just an empty
            list. So, the client should be able to always expect it.

            In this case, there would be two different schemas, one for input and
            another one for output.
            “””
        ),
    ] = True,
    extra: Annotated[
        Any,
        Doc(
            “””
            Extra keyword arguments to be stored in the app, not used by FastAPI
            anywhere.
            “””
        ),
    ],
) -> None:
    self.debug = debug
    self.title = title
    self.summary = summary
    self.description = description
    self.version = version
    self.terms_of_service = terms_of_service
    self.contact = contact
    self.license_info = license_info
    self.openapi_url = openapi_url
    self.openapi_tags = openapi_tags
    self.root_path_in_servers = root_path_in_servers
    self.docs_url = docs_url
    self.redoc_url = redoc_url
    self.swagger_ui_oauth2_redirect_url = swagger_ui_oauth2_redirect_url
    self.swagger_ui_init_oauth = swagger_ui_init_oauth
    self.swagger_ui_parameters = swagger_ui_parameters
    self.servers = servers or []
    self.separate_input_output_schemas = separate_input_output_schemas
    self.extra = extra
    self.openapi_version: Annotated[
        str,
        Doc(
            “””
            The version string of OpenAPI.

            FastAPI will generate OpenAPI version 3.1.0, and will output that as
            the OpenAPI version. But some tools, even though they might be
            compatible with OpenAPI 3.1.0, might not recognize it as a valid.

            So you could override this value to trick those tools into using
            the generated OpenAPI. Have in mind that this is a hack. But if you
            avoid using features added in OpenAPI 3.1.0, it might work for your
            use case.

            This is not passed as a parameter to the FastAPI class to avoid
            giving the false idea that FastAPI would generate a different OpenAPI
            schema. It is only available as an attribute.

            Example**

            python</span>
<span>            from fastapi import FastAPI</span>

<span>            app = FastAPI()</span>

<span>            app.openapi_version = "3.0.2"</span>
<span>
            “””
        ),
    ] = “3.1.0”
    self.openapi_schema: Optional[Dict[str, Any]] = None
    if self.openapi_url:
        assert self.title, “A title must be provided for OpenAPI, e.g.: ‘My API’”
        assert self.version, “A version must be provided for OpenAPI, e.g.: ‘2.1.0’”
    # TODO: remove when discarding the openapi_prefix parameter
    if openapi_prefix:
        logger.warning(
            ‘“openapi_prefix” has been deprecated in favor of “root_path”, which ‘
            “follows more closely the ASGI standard, is simpler, and more “
            “automatic. Check the docs at “
            “https://fastapi.tiangolo.com/advanced/sub-applications/“
        )
    self.webhooks: Annotated[
        routing.APIRouter,
        Doc(
            “””
            The app.webhooks attribute is an APIRouter with the path
            operations* that will be used just for documentation of webhooks.

            Read more about it in the
            FastAPI docs for OpenAPI Webhooks.
            “””
        ),
    ] = (
        webhooks or routing.APIRouter()
    )
    self.root_path = root_path or openapi_prefix
    self.state: Annotated[
        State,
        Doc(
            “””
            A state object for the application. This is the same object for the
            entire application, it doesn’t change from request to request.

            You normally woudln’t use this in FastAPI, for most of the cases you
            would instead use FastAPI dependencies.

            This is simply inherited from Starlette.

            Read more about it in the
            Starlette docs for Applications.
            “””
        ),
    ] = State()
    self.dependency_overrides: Annotated[
        Dict[Callable[…, Any], Callable[…, Any]],
        Doc(
            “””
            A dictionary with overrides for the dependencies.

            Each key is the original dependency callable, and the value is the
            actual dependency that should be called.

            This is for testing, to replace expensive dependencies with testing
            versions.

            Read more about it in the
            FastAPI docs for Testing Dependencies with Overrides.
            “””
        ),
    ] = {}
    self.router: routing.APIRouter = routing.APIRouter(
        routes=routes,
        redirect_slashes=redirect_slashes,
        dependency_overrides_provider=self,
        on_startup=on_startup,
        on_shutdown=on_shutdown,
        lifespan=lifespan,
        default_response_class=default_response_class,
        dependencies=dependencies,
        callbacks=callbacks,
        deprecated=deprecated,
        include_in_schema=include_in_schema,
        responses=responses,
        generate_unique_id_function=generate_unique_id_function,
    )
    self.exception_handlers: Dict[
        Any, Callable[[Request, Any], Union[Response, Awaitable[Response]]]
    ] = ({} if exception_handlers is None else dict(exception_handlers))
    self.exception_handlers.setdefault(HTTPException, http_exception_handler)
    self.exception_handlers.setdefault(
        RequestValidationError, request_validation_exception_handler
    )
    self.exception_handlers.setdefault(
        WebSocketRequestValidationError,
        # Starlette still has incorrect type specification for the handlers
        websocket_request_validation_exception_handler,  # type: ignore
    )

    self.user_middleware: List[Middleware] = (
        [] if middleware is None else list(middleware)
    )
    self.middleware_stack: Union[ASGIApp, None] = None
    self.setup()

openapi_version instance-attribute

openapi_version = '3.1.0'

The version string of OpenAPI.

FastAPI will generate OpenAPI version 3.1.0, and will output that as the OpenAPI version. But some tools, even though they might be compatible with OpenAPI 3.1.0, might not recognize it as a valid.

So you could override this value to trick those tools into using the generated OpenAPI. Have in mind that this is a hack. But if you avoid using features added in OpenAPI 3.1.0, it might work for your use case.

This is not passed as a parameter to the FastAPI class to avoid giving the false idea that FastAPI would generate a different OpenAPI schema. It is only available as an attribute.

Example

from fastapi import FastAPI

app = FastAPI()

app.openapi_version = "3.0.2"

webhooks instance-attribute

webhooks = webhooks or APIRouter()

The app.webhooks attribute is an APIRouter with the path operations that will be used just for documentation of webhooks.

Read more about it in the FastAPI docs for OpenAPI Webhooks.

state instance-attribute

state = State()

A state object for the application. This is the same object for the entire application, it doesn’t change from request to request.

You normally woudln’t use this in FastAPI, for most of the cases you would instead use FastAPI dependencies.

This is simply inherited from Starlette.

Read more about it in the Starlette docs for Applications.

dependency_overrides instance-attribute

dependency_overrides = {}

A dictionary with overrides for the dependencies.

Each key is the original dependency callable, and the value is the actual dependency that should be called.

This is for testing, to replace expensive dependencies with testing versions.

Read more about it in the FastAPI docs for Testing Dependencies with Overrides.

openapi

openapi()

Generate the OpenAPI schema of the application. This is called by FastAPI internally.

The first time it is called it stores the result in the attribute app.openapi_schema, and next times it is called, it just returns that same result. To avoid the cost of generating the schema every time.

If you need to modify the generated OpenAPI schema, you could modify it.

Read more in the FastAPI docs for OpenAPI.

Source code in fastapi/applications.py

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def openapi(self) -> Dict[str, Any]:
    “””
    Generate the OpenAPI schema of the application. This is called by FastAPI
    internally.

    The first time it is called it stores the result in the attribute
    app.openapi_schema, and next times it is called, it just returns that same
    result. To avoid the cost of generating the schema every time.

    If you need to modify the generated OpenAPI schema, you could modify it.

    Read more in the
    FastAPI docs for OpenAPI.
    “””
    if not self.openapi_schema:
        self.openapi_schema = get_openapi(
            title=self.title,
            version=self.version,
            openapi_version=self.openapi_version,
            summary=self.summary,
            description=self.description,
            terms_of_service=self.terms_of_service,
            contact=self.contact,
            license_info=self.license_info,
            routes=self.routes,
            webhooks=self.webhooks.routes,
            tags=self.openapi_tags,
            servers=self.servers,
            separate_input_output_schemas=self.separate_input_output_schemas,
        )
    return self.openapi_schema

websocket

websocket(path, name=None, *, dependencies=None)

Decorate a WebSocket function.

Read more about it in the FastAPI docs for WebSockets.

Example

from fastapi import FastAPI, WebSocket

app = FastAPI()

@app.websocket("/ws")
async def websocket_endpoint(websocket: WebSocket):
    await websocket.accept()
    while True:
        data = await websocket.receive_text()
        await websocket.send_text(f"Message text was: {data}")
PARAMETERDESCRIPTION
path

WebSocket path.

TYPE: str

name

A name for the WebSocket. Only used internally.

TYPE: Optional[str] DEFAULT: None

dependencies

A list of dependencies (using Depends()) to be used for this WebSocket.

Read more about it in the FastAPI docs for WebSockets.

TYPE: Optional[Sequence[Depends]] DEFAULT: None

Source code in fastapi/applications.py

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def websocket(
    self,
    path: Annotated[
        str,
        Doc(
            “””
            WebSocket path.
            “””
        ),
    ],
    name: Annotated[
        Optional[str],
        Doc(
            “””
            A name for the WebSocket. Only used internally.
            “””
        ),
    ] = None,
    ,
    dependencies: Annotated[
        Optional[Sequence[Depends]],
        Doc(
            “””
            A list of dependencies (using Depends()) to be used for this
            WebSocket.

            Read more about it in the
            FastAPI docs for WebSockets.
            “””
        ),
    ] = None,
) -> Callable[[DecoratedCallable], DecoratedCallable]:
    “””
    Decorate a WebSocket function.

    Read more about it in the
    FastAPI docs for WebSockets.

    *Example

    python</span>
<span>    from fastapi import FastAPI, WebSocket</span>

<span>    app = FastAPI()</span>

<span>    @app.websocket("/ws")</span>
<span>    async def websocket_endpoint(websocket: WebSocket):</span>
<span>        await websocket.accept()</span>
<span>        while True:</span>
<span>            data = await websocket.receive_text()</span>
<span>            await websocket.send_text(f"Message text was: {data}")</span>
<span>
    “””

    def decorator(func: DecoratedCallable) -> DecoratedCallable:
        self.add_api_websocket_route(
            path,
            func,
            name=name,
            dependencies=dependencies,
        )
        return func

    return decorator

include_router

include_router(
    router,
    *,
    prefix="",
    tags=None,
    dependencies=None,
    responses=None,
    deprecated=None,
    include_in_schema=True,
    default_response_class=Default(JSONResponse),
    callbacks=None,
    generate_unique_id_function=Default(generate_unique_id)
)

Include an APIRouter in the same app.

Read more about it in the FastAPI docs for Bigger Applications.

Example
from fastapi import FastAPI

from .users import users_router

app = FastAPI()

app.include_router(users_router)
PARAMETERDESCRIPTION
router

The APIRouter to include.

TYPE: APIRouter

prefix

An optional path prefix for the router.

TYPE: str DEFAULT: ‘’

tags

A list of tags to be applied to all the path operations in this router.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[List[Union[str, Enum]]] DEFAULT: None

dependencies

A list of dependencies (using Depends()) to be applied to all the path operations in this router.

Read more about it in the FastAPI docs for Bigger Applications - Multiple Files.

Example

from fastapi import Depends, FastAPI

from .dependencies import get_token_header
from .internal import admin

app = FastAPI()

app.include_router(
    admin.router,
    dependencies=[Depends(get_token_header)],
)

TYPE: Optional[Sequence[Depends]] DEFAULT: None

responses

Additional responses to be shown in OpenAPI.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Additional Responses in OpenAPI.

And in the FastAPI docs for Bigger Applications.

TYPE: Optional[Dict[Union[int, str], Dict[str, Any]]] DEFAULT: None

deprecated

Mark all the path operations in this router as deprecated.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Example

from fastapi import FastAPI

from .internal import old_api

app = FastAPI()

app.include_router(
    old_api.router,
    deprecated=True,
)

TYPE: Optional[bool] DEFAULT: None

include_in_schema

Include (or not) all the path operations in this router in the generated OpenAPI schema.

This affects the generated OpenAPI (e.g. visible at /docs).

Example

from fastapi import FastAPI

from .internal import old_api

app = FastAPI()

app.include_router(
    old_api.router,
    include_in_schema=False,
)

TYPE: bool DEFAULT: True

default_response_class

Default response class to be used for the path operations in this router.

Read more in the FastAPI docs for Custom Response - HTML, Stream, File, others.

Example

from fastapi import FastAPI
from fastapi.responses import ORJSONResponse

from .internal import old_api

app = FastAPI()

app.include_router(
    old_api.router,
    default_response_class=ORJSONResponse,
)

TYPE: Type[Response] DEFAULT: Default(JSONResponse)

callbacks

List of path operations that will be used as OpenAPI callbacks.

This is only for OpenAPI documentation, the callbacks won’t be used directly.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for OpenAPI Callbacks.

TYPE: Optional[List[BaseRoute]] DEFAULT: None

generate_unique_id_function

Customize the function used to generate unique IDs for the path operations shown in the generated OpenAPI.

This is particularly useful when automatically generating clients or SDKs for your API.

Read more about it in the FastAPI docs about how to Generate Clients.

TYPE: Callable[[APIRoute], str] DEFAULT: Default(generate_unique_id)

Source code in fastapi/applications.py

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def include_router(
    self,
    router: Annotated[routing.APIRouter, Doc(“The APIRouter to include.”)],
    ,
    prefix: Annotated[str, Doc(“An optional path prefix for the router.”)] = “”,
    tags: Annotated[
        Optional[List[Union[str, Enum]]],
        Doc(
            “””
            A list of tags to be applied to all the path operations in this
            router.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    dependencies: Annotated[
        Optional[Sequence[Depends]],
        Doc(
            “””
            A list of dependencies (using Depends()) to be applied to all the
            path operations in this router.

            Read more about it in the
            FastAPI docs for Bigger Applications - Multiple Files.

            Example

            python</span>
<span>            from fastapi import Depends, FastAPI</span>

<span>            from .dependencies import get_token_header</span>
<span>            from .internal import admin</span>

<span>            app = FastAPI()</span>

<span>            app.include_router(</span>
<span>                admin.router,</span>
<span>                dependencies=[Depends(get_token_header)],</span>
<span>            )</span>
<span>
            “””
        ),
    ] = None,
    responses: Annotated[
        Optional[Dict[Union[int, str], Dict[str, Any]]],
        Doc(
            “””
            Additional responses to be shown in OpenAPI.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Additional Responses in OpenAPI.

            And in the
            FastAPI docs for Bigger Applications.
            “””
        ),
    ] = None,
    deprecated: Annotated[
        Optional[bool],
        Doc(
            “””
            Mark all the path operations in this router as deprecated.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Example

            python</span>
<span>            from fastapi import FastAPI</span>

<span>            from .internal import old_api</span>

<span>            app = FastAPI()</span>

<span>            app.include_router(</span>
<span>                old_api.router,</span>
<span>                deprecated=True,</span>
<span>            )</span>
<span>
            “””
        ),
    ] = None,
    include_in_schema: Annotated[
        bool,
        Doc(
            “””
            Include (or not) all the path operations in this router in the
            generated OpenAPI schema.

            This affects the generated OpenAPI (e.g. visible at /docs).

            Example

            python</span>
<span>            from fastapi import FastAPI</span>

<span>            from .internal import old_api</span>

<span>            app = FastAPI()</span>

<span>            app.include_router(</span>
<span>                old_api.router,</span>
<span>                include_in_schema=False,</span>
<span>            )</span>
<span>
            “””
        ),
    ] = True,
    default_response_class: Annotated[
        Type[Response],
        Doc(
            “””
            Default response class to be used for the path operations in this
            router.

            Read more in the
            FastAPI docs for Custom Response - HTML, Stream, File, others.

            Example

            python</span>
<span>            from fastapi import FastAPI</span>
<span>            from fastapi.responses import ORJSONResponse</span>

<span>            from .internal import old_api</span>

<span>            app = FastAPI()</span>

<span>            app.include_router(</span>
<span>                old_api.router,</span>
<span>                default_response_class=ORJSONResponse,</span>
<span>            )</span>
<span>
            “””
        ),
    ] = Default(JSONResponse),
    callbacks: Annotated[
        Optional[List[BaseRoute]],
        Doc(
            “””
            List of path operations that will be used as OpenAPI callbacks.

            This is only for OpenAPI documentation, the callbacks won’t be used
            directly.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for OpenAPI Callbacks.
            “””
        ),
    ] = None,
    generate_unique_id_function: Annotated[
        Callable[[routing.APIRoute], str],
        Doc(
            “””
            Customize the function used to generate unique IDs for the path
            operations* shown in the generated OpenAPI.

            This is particularly useful when automatically generating clients or
            SDKs for your API.

            Read more about it in the
            FastAPI docs about how to Generate Clients.
            “””
        ),
    ] = Default(generate_unique_id),
) -> None:
    “””
    Include an APIRouter in the same app.

    Read more about it in the
    FastAPI docs for Bigger Applications.

    ## Example

    python</span>
<span>    from fastapi import FastAPI</span>

<span>    from .users import users_router</span>

<span>    app = FastAPI()</span>

<span>    app.include_router(users_router)</span>
<span>
    “””
    self.router.include_router(
        router,
        prefix=prefix,
        tags=tags,
        dependencies=dependencies,
        responses=responses,
        deprecated=deprecated,
        include_in_schema=include_in_schema,
        default_response_class=default_response_class,
        callbacks=callbacks,
        generate_unique_id_function=generate_unique_id_function,
    )

get

get(
    path,
    *,
    response_model=Default(None),
    status_code=None,
    tags=None,
    dependencies=None,
    summary=None,
    description=None,
    response_description="Successful Response",
    responses=None,
    deprecated=None,
    operation_id=None,
    response_model_include=None,
    response_model_exclude=None,
    response_model_by_alias=True,
    response_model_exclude_unset=False,
    response_model_exclude_defaults=False,
    response_model_exclude_none=False,
    include_in_schema=True,
    response_class=Default(JSONResponse),
    name=None,
    callbacks=None,
    openapi_extra=None,
    generate_unique_id_function=Default(generate_unique_id)
)

Add a path operation using an HTTP GET operation.

Example
from fastapi import FastAPI

app = FastAPI()

@app.get("/items/")
def read_items():
    return [{"name": "Empanada"}, {"name": "Arepa"}]
PARAMETERDESCRIPTION
path

The URL path to be used for this path operation.

For example, in http://example.com/items, the path is /items.

TYPE: str

response_model

The type to use for the response.

It could be any valid Pydantic field type. So, it doesn’t have to be a Pydantic model, it could be other things, like a list, dict, etc.

It will be used for:

  • Documentation: the generated OpenAPI (and the UI at /docs) will show it as the response (JSON Schema).
  • Serialization: you could return an arbitrary object and the response_model would be used to serialize that object into the corresponding JSON.
  • Filtering: the JSON sent to the client will only contain the data (fields) defined in the response_model. If you returned an object that contains an attribute password but the response_model does not include that field, the JSON sent to the client would not have that password.
  • Validation: whatever you return will be serialized with the response_model, converting any data as necessary to generate the corresponding JSON. But if the data in the object returned is not valid, that would mean a violation of the contract with the client, so it’s an error from the API developer. So, FastAPI will raise an error and return a 500 error code (Internal Server Error).

Read more about it in the FastAPI docs for Response Model.

TYPE: Any DEFAULT: Default(None)

status_code

The default status code to be used for the response.

You could override the status code by returning a response directly.

Read more about it in the FastAPI docs for Response Status Code.

TYPE: Optional[int] DEFAULT: None

tags

A list of tags to be applied to the path operation.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[List[Union[str, Enum]]] DEFAULT: None

dependencies

A list of dependencies (using Depends()) to be applied to the path operation.

Read more about it in the FastAPI docs for Dependencies in path operation decorators.

TYPE: Optional[Sequence[Depends]] DEFAULT: None

summary

A summary for the path operation.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[str] DEFAULT: None

description

A description for the path operation.

If not provided, it will be extracted automatically from the docstring of the path operation function.

It can contain Markdown.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[str] DEFAULT: None

response_description

The description for the default response.

It will be added to the generated OpenAPI (e.g. visible at /docs).

TYPE: str DEFAULT: ‘Successful Response’

responses

Additional responses that could be returned by this path operation.

It will be added to the generated OpenAPI (e.g. visible at /docs).

TYPE: Optional[Dict[Union[int, str], Dict[str, Any]]] DEFAULT: None

deprecated

Mark this path operation as deprecated.

It will be added to the generated OpenAPI (e.g. visible at /docs).

TYPE: Optional[bool] DEFAULT: None

operation_id

Custom operation ID to be used by this path operation.

By default, it is generated automatically.

If you provide a custom operation ID, you need to make sure it is unique for the whole API.

You can customize the operation ID generation with the parameter generate_unique_id_function in the FastAPI class.

Read more about it in the FastAPI docs about how to Generate Clients.

TYPE: Optional[str] DEFAULT: None

response_model_include

Configuration passed to Pydantic to include only certain fields in the response data.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: Optional[IncEx] DEFAULT: None

response_model_exclude

Configuration passed to Pydantic to exclude certain fields in the response data.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: Optional[IncEx] DEFAULT: None

response_model_by_alias

Configuration passed to Pydantic to define if the response model should be serialized by alias when an alias is used.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: True

response_model_exclude_unset

Configuration passed to Pydantic to define if the response data should have all the fields, including the ones that were not set and have their default values. This is different from response_model_exclude_defaults in that if the fields are set, they will be included in the response, even if the value is the same as the default.

When True, default values are omitted from the response.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: False

response_model_exclude_defaults

Configuration passed to Pydantic to define if the response data should have all the fields, including the ones that have the same value as the default. This is different from response_model_exclude_unset in that if the fields are set but contain the same default values, they will be excluded from the response.

When True, default values are omitted from the response.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: False

response_model_exclude_none

Configuration passed to Pydantic to define if the response data should exclude fields set to None.

This is much simpler (less smart) than response_model_exclude_unset and response_model_exclude_defaults. You probably want to use one of those two instead of this one, as those allow returning None values when it makes sense.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: False

include_in_schema

Include this path operation in the generated OpenAPI schema.

This affects the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Query Parameters and String Validations.

TYPE: bool DEFAULT: True

response_class

Response class to be used for this path operation.

This will not be used if you return a response directly.

Read more about it in the FastAPI docs for Custom Response - HTML, Stream, File, others.

TYPE: Type[Response] DEFAULT: Default(JSONResponse)

name

Name for this path operation. Only used internally.

TYPE: Optional[str] DEFAULT: None

callbacks

List of path operations that will be used as OpenAPI callbacks.

This is only for OpenAPI documentation, the callbacks won’t be used directly.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for OpenAPI Callbacks.

TYPE: Optional[List[BaseRoute]] DEFAULT: None

openapi_extra

Extra metadata to be included in the OpenAPI schema for this path operation.

Read more about it in the FastAPI docs for Path Operation Advanced Configuration.

TYPE: Optional[Dict[str, Any]] DEFAULT: None

generate_unique_id_function

Customize the function used to generate unique IDs for the path operations shown in the generated OpenAPI.

This is particularly useful when automatically generating clients or SDKs for your API.

Read more about it in the FastAPI docs about how to Generate Clients.

TYPE: Callable[[APIRoute], str] DEFAULT: Default(generate_unique_id)

Source code in fastapi/applications.py

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def get(
    self,
    path: Annotated[
        str,
        Doc(
            “””
            The URL path to be used for this path operation.

            For example, in http://example.com/items, the path is /items.
            “””
        ),
    ],
    ,
    response_model: Annotated[
        Any,
        Doc(
            “””
            The type to use for the response.

            It could be any valid Pydantic field type. So, it doesn’t have to
            be a Pydantic model, it could be other things, like a list, dict,
            etc.

            It will be used for:

             Documentation: the generated OpenAPI (and the UI at /docs) will
                show it as the response (JSON Schema).
             Serialization: you could return an arbitrary object and the
                response_model would be used to serialize that object into the
                corresponding JSON.
             Filtering: the JSON sent to the client will only contain the data
                (fields) defined in the response_model. If you returned an object
                that contains an attribute password but the response_model does
                not include that field, the JSON sent to the client would not have
                that password.
             Validation: whatever you return will be serialized with the
                response_model, converting any data as necessary to generate the
                corresponding JSON. But if the data in the object returned is not
                valid, that would mean a violation of the contract with the client,
                so it’s an error from the API developer. So, FastAPI will raise an
                error and return a 500 error code (Internal Server Error).

            Read more about it in the
            FastAPI docs for Response Model.
            “””
        ),
    ] = Default(None),
    status_code: Annotated[
        Optional[int],
        Doc(
            “””
            The default status code to be used for the response.

            You could override the status code by returning a response directly.

            Read more about it in the
            FastAPI docs for Response Status Code.
            “””
        ),
    ] = None,
    tags: Annotated[
        Optional[List[Union[str, Enum]]],
        Doc(
            “””
            A list of tags to be applied to the path operation.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    dependencies: Annotated[
        Optional[Sequence[Depends]],
        Doc(
            “””
            A list of dependencies (using Depends()) to be applied to the
            path operation.

            Read more about it in the
            FastAPI docs for Dependencies in path operation decorators.
            “””
        ),
    ] = None,
    summary: Annotated[
        Optional[str],
        Doc(
            “””
            A summary for the path operation.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    description: Annotated[
        Optional[str],
        Doc(
            “””
            A description for the path operation.

            If not provided, it will be extracted automatically from the docstring
            of the path operation function.

            It can contain Markdown.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    response_description: Annotated[
        str,
        Doc(
            “””
            The description for the default response.

            It will be added to the generated OpenAPI (e.g. visible at /docs).
            “””
        ),
    ] = “Successful Response”,
    responses: Annotated[
        Optional[Dict[Union[int, str], Dict[str, Any]]],
        Doc(
            “””
            Additional responses that could be returned by this path operation.

            It will be added to the generated OpenAPI (e.g. visible at /docs).
            “””
        ),
    ] = None,
    deprecated: Annotated[
        Optional[bool],
        Doc(
            “””
            Mark this path operation as deprecated.

            It will be added to the generated OpenAPI (e.g. visible at /docs).
            “””
        ),
    ] = None,
    operation_id: Annotated[
        Optional[str],
        Doc(
            “””
            Custom operation ID to be used by this path operation.

            By default, it is generated automatically.

            If you provide a custom operation ID, you need to make sure it is
            unique for the whole API.

            You can customize the
            operation ID generation with the parameter
            generate_unique_id_function in the FastAPI class.

            Read more about it in the
            FastAPI docs about how to Generate Clients.
            “””
        ),
    ] = None,
    response_model_include: Annotated[
        Optional[IncEx],
        Doc(
            “””
            Configuration passed to Pydantic to include only certain fields in the
            response data.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = None,
    response_model_exclude: Annotated[
        Optional[IncEx],
        Doc(
            “””
            Configuration passed to Pydantic to exclude certain fields in the
            response data.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = None,
    response_model_by_alias: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response model
            should be serialized by alias when an alias is used.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = True,
    response_model_exclude_unset: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response data
            should have all the fields, including the ones that were not set and
            have their default values. This is different from
            response_model_exclude_defaults in that if the fields are set,
            they will be included in the response, even if the value is the same
            as the default.

            When True, default values are omitted from the response.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = False,
    response_model_exclude_defaults: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response data
            should have all the fields, including the ones that have the same value
            as the default. This is different from response_model_exclude_unset
            in that if the fields are set but contain the same default values,
            they will be excluded from the response.

            When True, default values are omitted from the response.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = False,
    response_model_exclude_none: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response data should
            exclude fields set to None.

            This is much simpler (less smart) than response_model_exclude_unset
            and response_model_exclude_defaults. You probably want to use one of
            those two instead of this one, as those allow returning None values
            when it makes sense.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = False,
    include_in_schema: Annotated[
        bool,
        Doc(
            “””
            Include this path operation in the generated OpenAPI schema.

            This affects the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Query Parameters and String Validations.
            “””
        ),
    ] = True,
    response_class: Annotated[
        Type[Response],
        Doc(
            “””
            Response class to be used for this path operation.

            This will not be used if you return a response directly.

            Read more about it in the
            FastAPI docs for Custom Response - HTML, Stream, File, others.
            “””
        ),
    ] = Default(JSONResponse),
    name: Annotated[
        Optional[str],
        Doc(
            “””
            Name for this path operation. Only used internally.
            “””
        ),
    ] = None,
    callbacks: Annotated[
        Optional[List[BaseRoute]],
        Doc(
            “””
            List of path operations that will be used as OpenAPI callbacks.

            This is only for OpenAPI documentation, the callbacks won’t be used
            directly.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for OpenAPI Callbacks.
            “””
        ),
    ] = None,
    openapi_extra: Annotated[
        Optional[Dict[str, Any]],
        Doc(
            “””
            Extra metadata to be included in the OpenAPI schema for this path
            operation.

            Read more about it in the
            FastAPI docs for Path Operation Advanced Configuration.
            “””
        ),
    ] = None,
    generate_unique_id_function: Annotated[
        Callable[[routing.APIRoute], str],
        Doc(
            “””
            Customize the function used to generate unique IDs for the path
            operations shown in the generated OpenAPI.

            This is particularly useful when automatically generating clients or
            SDKs for your API.

            Read more about it in the
            FastAPI docs about how to Generate Clients.
            “””
        ),
    ] = Default(generate_unique_id),
) -> Callable[[DecoratedCallable], DecoratedCallable]:
    “””
    Add a path operation* using an HTTP GET operation.

    ## Example

    python</span>
<span>    from fastapi import FastAPI</span>

<span>    app = FastAPI()</span>

<span>    @app.get("/items/")</span>
<span>    def read_items():</span>
<span>        return [{"name": "Empanada"}, {"name": "Arepa"}]</span>
<span>
    “””
    return self.router.get(
        path,
        response_model=response_model,
        status_code=status_code,
        tags=tags,
        dependencies=dependencies,
        summary=summary,
        description=description,
        response_description=response_description,
        responses=responses,
        deprecated=deprecated,
        operation_id=operation_id,
        response_model_include=response_model_include,
        response_model_exclude=response_model_exclude,
        response_model_by_alias=response_model_by_alias,
        response_model_exclude_unset=response_model_exclude_unset,
        response_model_exclude_defaults=response_model_exclude_defaults,
        response_model_exclude_none=response_model_exclude_none,
        include_in_schema=include_in_schema,
        response_class=response_class,
        name=name,
        callbacks=callbacks,
        openapi_extra=openapi_extra,
        generate_unique_id_function=generate_unique_id_function,
    )

put

put(
    path,
    *,
    response_model=Default(None),
    status_code=None,
    tags=None,
    dependencies=None,
    summary=None,
    description=None,
    response_description="Successful Response",
    responses=None,
    deprecated=None,
    operation_id=None,
    response_model_include=None,
    response_model_exclude=None,
    response_model_by_alias=True,
    response_model_exclude_unset=False,
    response_model_exclude_defaults=False,
    response_model_exclude_none=False,
    include_in_schema=True,
    response_class=Default(JSONResponse),
    name=None,
    callbacks=None,
    openapi_extra=None,
    generate_unique_id_function=Default(generate_unique_id)
)

Add a path operation using an HTTP PUT operation.

Example
from fastapi import FastAPI
from pydantic import BaseModel

class Item(BaseModel):
    name: str
    description: str | None = None

app = FastAPI()

@app.put("/items/{item_id}")
def replace_item(item_id: str, item: Item):
    return {"message": "Item replaced", "id": item_id}
PARAMETERDESCRIPTION
path

The URL path to be used for this path operation.

For example, in http://example.com/items, the path is /items.

TYPE: str

response_model

The type to use for the response.

It could be any valid Pydantic field type. So, it doesn’t have to be a Pydantic model, it could be other things, like a list, dict, etc.

It will be used for:

  • Documentation: the generated OpenAPI (and the UI at /docs) will show it as the response (JSON Schema).
  • Serialization: you could return an arbitrary object and the response_model would be used to serialize that object into the corresponding JSON.
  • Filtering: the JSON sent to the client will only contain the data (fields) defined in the response_model. If you returned an object that contains an attribute password but the response_model does not include that field, the JSON sent to the client would not have that password.
  • Validation: whatever you return will be serialized with the response_model, converting any data as necessary to generate the corresponding JSON. But if the data in the object returned is not valid, that would mean a violation of the contract with the client, so it’s an error from the API developer. So, FastAPI will raise an error and return a 500 error code (Internal Server Error).

Read more about it in the FastAPI docs for Response Model.

TYPE: Any DEFAULT: Default(None)

status_code

The default status code to be used for the response.

You could override the status code by returning a response directly.

Read more about it in the FastAPI docs for Response Status Code.

TYPE: Optional[int] DEFAULT: None

tags

A list of tags to be applied to the path operation.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[List[Union[str, Enum]]] DEFAULT: None

dependencies

A list of dependencies (using Depends()) to be applied to the path operation.

Read more about it in the FastAPI docs for Dependencies in path operation decorators.

TYPE: Optional[Sequence[Depends]] DEFAULT: None

summary

A summary for the path operation.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[str] DEFAULT: None

description

A description for the path operation.

If not provided, it will be extracted automatically from the docstring of the path operation function.

It can contain Markdown.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[str] DEFAULT: None

response_description

The description for the default response.

It will be added to the generated OpenAPI (e.g. visible at /docs).

TYPE: str DEFAULT: ‘Successful Response’

responses

Additional responses that could be returned by this path operation.

It will be added to the generated OpenAPI (e.g. visible at /docs).

TYPE: Optional[Dict[Union[int, str], Dict[str, Any]]] DEFAULT: None

deprecated

Mark this path operation as deprecated.

It will be added to the generated OpenAPI (e.g. visible at /docs).

TYPE: Optional[bool] DEFAULT: None

operation_id

Custom operation ID to be used by this path operation.

By default, it is generated automatically.

If you provide a custom operation ID, you need to make sure it is unique for the whole API.

You can customize the operation ID generation with the parameter generate_unique_id_function in the FastAPI class.

Read more about it in the FastAPI docs about how to Generate Clients.

TYPE: Optional[str] DEFAULT: None

response_model_include

Configuration passed to Pydantic to include only certain fields in the response data.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: Optional[IncEx] DEFAULT: None

response_model_exclude

Configuration passed to Pydantic to exclude certain fields in the response data.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: Optional[IncEx] DEFAULT: None

response_model_by_alias

Configuration passed to Pydantic to define if the response model should be serialized by alias when an alias is used.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: True

response_model_exclude_unset

Configuration passed to Pydantic to define if the response data should have all the fields, including the ones that were not set and have their default values. This is different from response_model_exclude_defaults in that if the fields are set, they will be included in the response, even if the value is the same as the default.

When True, default values are omitted from the response.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: False

response_model_exclude_defaults

Configuration passed to Pydantic to define if the response data should have all the fields, including the ones that have the same value as the default. This is different from response_model_exclude_unset in that if the fields are set but contain the same default values, they will be excluded from the response.

When True, default values are omitted from the response.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: False

response_model_exclude_none

Configuration passed to Pydantic to define if the response data should exclude fields set to None.

This is much simpler (less smart) than response_model_exclude_unset and response_model_exclude_defaults. You probably want to use one of those two instead of this one, as those allow returning None values when it makes sense.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: False

include_in_schema

Include this path operation in the generated OpenAPI schema.

This affects the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Query Parameters and String Validations.

TYPE: bool DEFAULT: True

response_class

Response class to be used for this path operation.

This will not be used if you return a response directly.

Read more about it in the FastAPI docs for Custom Response - HTML, Stream, File, others.

TYPE: Type[Response] DEFAULT: Default(JSONResponse)

name

Name for this path operation. Only used internally.

TYPE: Optional[str] DEFAULT: None

callbacks

List of path operations that will be used as OpenAPI callbacks.

This is only for OpenAPI documentation, the callbacks won’t be used directly.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for OpenAPI Callbacks.

TYPE: Optional[List[BaseRoute]] DEFAULT: None

openapi_extra

Extra metadata to be included in the OpenAPI schema for this path operation.

Read more about it in the FastAPI docs for Path Operation Advanced Configuration.

TYPE: Optional[Dict[str, Any]] DEFAULT: None

generate_unique_id_function

Customize the function used to generate unique IDs for the path operations shown in the generated OpenAPI.

This is particularly useful when automatically generating clients or SDKs for your API.

Read more about it in the FastAPI docs about how to Generate Clients.

TYPE: Callable[[APIRoute], str] DEFAULT: Default(generate_unique_id)

Source code in fastapi/applications.py

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def put(
    self,
    path: Annotated[
        str,
        Doc(
            “””
            The URL path to be used for this path operation.

            For example, in http://example.com/items, the path is /items.
            “””
        ),
    ],
    ,
    response_model: Annotated[
        Any,
        Doc(
            “””
            The type to use for the response.

            It could be any valid Pydantic field type. So, it doesn’t have to
            be a Pydantic model, it could be other things, like a list, dict,
            etc.

            It will be used for:

             Documentation: the generated OpenAPI (and the UI at /docs) will
                show it as the response (JSON Schema).
             Serialization: you could return an arbitrary object and the
                response_model would be used to serialize that object into the
                corresponding JSON.
             Filtering: the JSON sent to the client will only contain the data
                (fields) defined in the response_model. If you returned an object
                that contains an attribute password but the response_model does
                not include that field, the JSON sent to the client would not have
                that password.
             Validation: whatever you return will be serialized with the
                response_model, converting any data as necessary to generate the
                corresponding JSON. But if the data in the object returned is not
                valid, that would mean a violation of the contract with the client,
                so it’s an error from the API developer. So, FastAPI will raise an
                error and return a 500 error code (Internal Server Error).

            Read more about it in the
            FastAPI docs for Response Model.
            “””
        ),
    ] = Default(None),
    status_code: Annotated[
        Optional[int],
        Doc(
            “””
            The default status code to be used for the response.

            You could override the status code by returning a response directly.

            Read more about it in the
            FastAPI docs for Response Status Code.
            “””
        ),
    ] = None,
    tags: Annotated[
        Optional[List[Union[str, Enum]]],
        Doc(
            “””
            A list of tags to be applied to the path operation.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    dependencies: Annotated[
        Optional[Sequence[Depends]],
        Doc(
            “””
            A list of dependencies (using Depends()) to be applied to the
            path operation.

            Read more about it in the
            FastAPI docs for Dependencies in path operation decorators.
            “””
        ),
    ] = None,
    summary: Annotated[
        Optional[str],
        Doc(
            “””
            A summary for the path operation.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    description: Annotated[
        Optional[str],
        Doc(
            “””
            A description for the path operation.

            If not provided, it will be extracted automatically from the docstring
            of the path operation function.

            It can contain Markdown.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    response_description: Annotated[
        str,
        Doc(
            “””
            The description for the default response.

            It will be added to the generated OpenAPI (e.g. visible at /docs).
            “””
        ),
    ] = “Successful Response”,
    responses: Annotated[
        Optional[Dict[Union[int, str], Dict[str, Any]]],
        Doc(
            “””
            Additional responses that could be returned by this path operation.

            It will be added to the generated OpenAPI (e.g. visible at /docs).
            “””
        ),
    ] = None,
    deprecated: Annotated[
        Optional[bool],
        Doc(
            “””
            Mark this path operation as deprecated.

            It will be added to the generated OpenAPI (e.g. visible at /docs).
            “””
        ),
    ] = None,
    operation_id: Annotated[
        Optional[str],
        Doc(
            “””
            Custom operation ID to be used by this path operation.

            By default, it is generated automatically.

            If you provide a custom operation ID, you need to make sure it is
            unique for the whole API.

            You can customize the
            operation ID generation with the parameter
            generate_unique_id_function in the FastAPI class.

            Read more about it in the
            FastAPI docs about how to Generate Clients.
            “””
        ),
    ] = None,
    response_model_include: Annotated[
        Optional[IncEx],
        Doc(
            “””
            Configuration passed to Pydantic to include only certain fields in the
            response data.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = None,
    response_model_exclude: Annotated[
        Optional[IncEx],
        Doc(
            “””
            Configuration passed to Pydantic to exclude certain fields in the
            response data.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = None,
    response_model_by_alias: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response model
            should be serialized by alias when an alias is used.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = True,
    response_model_exclude_unset: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response data
            should have all the fields, including the ones that were not set and
            have their default values. This is different from
            response_model_exclude_defaults in that if the fields are set,
            they will be included in the response, even if the value is the same
            as the default.

            When True, default values are omitted from the response.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = False,
    response_model_exclude_defaults: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response data
            should have all the fields, including the ones that have the same value
            as the default. This is different from response_model_exclude_unset
            in that if the fields are set but contain the same default values,
            they will be excluded from the response.

            When True, default values are omitted from the response.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = False,
    response_model_exclude_none: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response data should
            exclude fields set to None.

            This is much simpler (less smart) than response_model_exclude_unset
            and response_model_exclude_defaults. You probably want to use one of
            those two instead of this one, as those allow returning None values
            when it makes sense.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = False,
    include_in_schema: Annotated[
        bool,
        Doc(
            “””
            Include this path operation in the generated OpenAPI schema.

            This affects the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Query Parameters and String Validations.
            “””
        ),
    ] = True,
    response_class: Annotated[
        Type[Response],
        Doc(
            “””
            Response class to be used for this path operation.

            This will not be used if you return a response directly.

            Read more about it in the
            FastAPI docs for Custom Response - HTML, Stream, File, others.
            “””
        ),
    ] = Default(JSONResponse),
    name: Annotated[
        Optional[str],
        Doc(
            “””
            Name for this path operation. Only used internally.
            “””
        ),
    ] = None,
    callbacks: Annotated[
        Optional[List[BaseRoute]],
        Doc(
            “””
            List of path operations that will be used as OpenAPI callbacks.

            This is only for OpenAPI documentation, the callbacks won’t be used
            directly.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for OpenAPI Callbacks.
            “””
        ),
    ] = None,
    openapi_extra: Annotated[
        Optional[Dict[str, Any]],
        Doc(
            “””
            Extra metadata to be included in the OpenAPI schema for this path
            operation.

            Read more about it in the
            FastAPI docs for Path Operation Advanced Configuration.
            “””
        ),
    ] = None,
    generate_unique_id_function: Annotated[
        Callable[[routing.APIRoute], str],
        Doc(
            “””
            Customize the function used to generate unique IDs for the path
            operations shown in the generated OpenAPI.

            This is particularly useful when automatically generating clients or
            SDKs for your API.

            Read more about it in the
            FastAPI docs about how to Generate Clients.
            “””
        ),
    ] = Default(generate_unique_id),
) -> Callable[[DecoratedCallable], DecoratedCallable]:
    “””
    Add a path operation* using an HTTP PUT operation.

    ## Example

    python</span>
<span>    from fastapi import FastAPI</span>
<span>    from pydantic import BaseModel</span>

<span>    class Item(BaseModel):</span>
<span>        name: str</span>
<span>        description: str | None = None</span>

<span>    app = FastAPI()</span>

<span>    @app.put("/items/{item_id}")</span>
<span>    def replace_item(item_id: str, item: Item):</span>
<span>        return {"message": "Item replaced", "id": item_id}</span>
<span>
    “””
    return self.router.put(
        path,
        response_model=response_model,
        status_code=status_code,
        tags=tags,
        dependencies=dependencies,
        summary=summary,
        description=description,
        response_description=response_description,
        responses=responses,
        deprecated=deprecated,
        operation_id=operation_id,
        response_model_include=response_model_include,
        response_model_exclude=response_model_exclude,
        response_model_by_alias=response_model_by_alias,
        response_model_exclude_unset=response_model_exclude_unset,
        response_model_exclude_defaults=response_model_exclude_defaults,
        response_model_exclude_none=response_model_exclude_none,
        include_in_schema=include_in_schema,
        response_class=response_class,
        name=name,
        callbacks=callbacks,
        openapi_extra=openapi_extra,
        generate_unique_id_function=generate_unique_id_function,
    )

post

post(
    path,
    *,
    response_model=Default(None),
    status_code=None,
    tags=None,
    dependencies=None,
    summary=None,
    description=None,
    response_description="Successful Response",
    responses=None,
    deprecated=None,
    operation_id=None,
    response_model_include=None,
    response_model_exclude=None,
    response_model_by_alias=True,
    response_model_exclude_unset=False,
    response_model_exclude_defaults=False,
    response_model_exclude_none=False,
    include_in_schema=True,
    response_class=Default(JSONResponse),
    name=None,
    callbacks=None,
    openapi_extra=None,
    generate_unique_id_function=Default(generate_unique_id)
)

Add a path operation using an HTTP POST operation.

Example
from fastapi import FastAPI
from pydantic import BaseModel

class Item(BaseModel):
    name: str
    description: str | None = None

app = FastAPI()

@app.post("/items/")
def create_item(item: Item):
    return {"message": "Item created"}
PARAMETERDESCRIPTION
path

The URL path to be used for this path operation.

For example, in http://example.com/items, the path is /items.

TYPE: str

response_model

The type to use for the response.

It could be any valid Pydantic field type. So, it doesn’t have to be a Pydantic model, it could be other things, like a list, dict, etc.

It will be used for:

  • Documentation: the generated OpenAPI (and the UI at /docs) will show it as the response (JSON Schema).
  • Serialization: you could return an arbitrary object and the response_model would be used to serialize that object into the corresponding JSON.
  • Filtering: the JSON sent to the client will only contain the data (fields) defined in the response_model. If you returned an object that contains an attribute password but the response_model does not include that field, the JSON sent to the client would not have that password.
  • Validation: whatever you return will be serialized with the response_model, converting any data as necessary to generate the corresponding JSON. But if the data in the object returned is not valid, that would mean a violation of the contract with the client, so it’s an error from the API developer. So, FastAPI will raise an error and return a 500 error code (Internal Server Error).

Read more about it in the FastAPI docs for Response Model.

TYPE: Any DEFAULT: Default(None)

status_code

The default status code to be used for the response.

You could override the status code by returning a response directly.

Read more about it in the FastAPI docs for Response Status Code.

TYPE: Optional[int] DEFAULT: None

tags

A list of tags to be applied to the path operation.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[List[Union[str, Enum]]] DEFAULT: None

dependencies

A list of dependencies (using Depends()) to be applied to the path operation.

Read more about it in the FastAPI docs for Dependencies in path operation decorators.

TYPE: Optional[Sequence[Depends]] DEFAULT: None

summary

A summary for the path operation.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[str] DEFAULT: None

description

A description for the path operation.

If not provided, it will be extracted automatically from the docstring of the path operation function.

It can contain Markdown.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[str] DEFAULT: None

response_description

The description for the default response.

It will be added to the generated OpenAPI (e.g. visible at /docs).

TYPE: str DEFAULT: ‘Successful Response’

responses

Additional responses that could be returned by this path operation.

It will be added to the generated OpenAPI (e.g. visible at /docs).

TYPE: Optional[Dict[Union[int, str], Dict[str, Any]]] DEFAULT: None

deprecated

Mark this path operation as deprecated.

It will be added to the generated OpenAPI (e.g. visible at /docs).

TYPE: Optional[bool] DEFAULT: None

operation_id

Custom operation ID to be used by this path operation.

By default, it is generated automatically.

If you provide a custom operation ID, you need to make sure it is unique for the whole API.

You can customize the operation ID generation with the parameter generate_unique_id_function in the FastAPI class.

Read more about it in the FastAPI docs about how to Generate Clients.

TYPE: Optional[str] DEFAULT: None

response_model_include

Configuration passed to Pydantic to include only certain fields in the response data.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: Optional[IncEx] DEFAULT: None

response_model_exclude

Configuration passed to Pydantic to exclude certain fields in the response data.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: Optional[IncEx] DEFAULT: None

response_model_by_alias

Configuration passed to Pydantic to define if the response model should be serialized by alias when an alias is used.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: True

response_model_exclude_unset

Configuration passed to Pydantic to define if the response data should have all the fields, including the ones that were not set and have their default values. This is different from response_model_exclude_defaults in that if the fields are set, they will be included in the response, even if the value is the same as the default.

When True, default values are omitted from the response.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: False

response_model_exclude_defaults

Configuration passed to Pydantic to define if the response data should have all the fields, including the ones that have the same value as the default. This is different from response_model_exclude_unset in that if the fields are set but contain the same default values, they will be excluded from the response.

When True, default values are omitted from the response.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: False

response_model_exclude_none

Configuration passed to Pydantic to define if the response data should exclude fields set to None.

This is much simpler (less smart) than response_model_exclude_unset and response_model_exclude_defaults. You probably want to use one of those two instead of this one, as those allow returning None values when it makes sense.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: False

include_in_schema

Include this path operation in the generated OpenAPI schema.

This affects the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Query Parameters and String Validations.

TYPE: bool DEFAULT: True

response_class

Response class to be used for this path operation.

This will not be used if you return a response directly.

Read more about it in the FastAPI docs for Custom Response - HTML, Stream, File, others.

TYPE: Type[Response] DEFAULT: Default(JSONResponse)

name

Name for this path operation. Only used internally.

TYPE: Optional[str] DEFAULT: None

callbacks

List of path operations that will be used as OpenAPI callbacks.

This is only for OpenAPI documentation, the callbacks won’t be used directly.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for OpenAPI Callbacks.

TYPE: Optional[List[BaseRoute]] DEFAULT: None

openapi_extra

Extra metadata to be included in the OpenAPI schema for this path operation.

Read more about it in the FastAPI docs for Path Operation Advanced Configuration.

TYPE: Optional[Dict[str, Any]] DEFAULT: None

generate_unique_id_function

Customize the function used to generate unique IDs for the path operations shown in the generated OpenAPI.

This is particularly useful when automatically generating clients or SDKs for your API.

Read more about it in the FastAPI docs about how to Generate Clients.

TYPE: Callable[[APIRoute], str] DEFAULT: Default(generate_unique_id)

Source code in fastapi/applications.py

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def post(
    self,
    path: Annotated[
        str,
        Doc(
            “””
            The URL path to be used for this path operation.

            For example, in http://example.com/items, the path is /items.
            “””
        ),
    ],
    ,
    response_model: Annotated[
        Any,
        Doc(
            “””
            The type to use for the response.

            It could be any valid Pydantic field type. So, it doesn’t have to
            be a Pydantic model, it could be other things, like a list, dict,
            etc.

            It will be used for:

             Documentation: the generated OpenAPI (and the UI at /docs) will
                show it as the response (JSON Schema).
             Serialization: you could return an arbitrary object and the
                response_model would be used to serialize that object into the
                corresponding JSON.
             Filtering: the JSON sent to the client will only contain the data
                (fields) defined in the response_model. If you returned an object
                that contains an attribute password but the response_model does
                not include that field, the JSON sent to the client would not have
                that password.
             Validation: whatever you return will be serialized with the
                response_model, converting any data as necessary to generate the
                corresponding JSON. But if the data in the object returned is not
                valid, that would mean a violation of the contract with the client,
                so it’s an error from the API developer. So, FastAPI will raise an
                error and return a 500 error code (Internal Server Error).

            Read more about it in the
            FastAPI docs for Response Model.
            “””
        ),
    ] = Default(None),
    status_code: Annotated[
        Optional[int],
        Doc(
            “””
            The default status code to be used for the response.

            You could override the status code by returning a response directly.

            Read more about it in the
            FastAPI docs for Response Status Code.
            “””
        ),
    ] = None,
    tags: Annotated[
        Optional[List[Union[str, Enum]]],
        Doc(
            “””
            A list of tags to be applied to the path operation.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    dependencies: Annotated[
        Optional[Sequence[Depends]],
        Doc(
            “””
            A list of dependencies (using Depends()) to be applied to the
            path operation.

            Read more about it in the
            FastAPI docs for Dependencies in path operation decorators.
            “””
        ),
    ] = None,
    summary: Annotated[
        Optional[str],
        Doc(
            “””
            A summary for the path operation.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    description: Annotated[
        Optional[str],
        Doc(
            “””
            A description for the path operation.

            If not provided, it will be extracted automatically from the docstring
            of the path operation function.

            It can contain Markdown.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    response_description: Annotated[
        str,
        Doc(
            “””
            The description for the default response.

            It will be added to the generated OpenAPI (e.g. visible at /docs).
            “””
        ),
    ] = “Successful Response”,
    responses: Annotated[
        Optional[Dict[Union[int, str], Dict[str, Any]]],
        Doc(
            “””
            Additional responses that could be returned by this path operation.

            It will be added to the generated OpenAPI (e.g. visible at /docs).
            “””
        ),
    ] = None,
    deprecated: Annotated[
        Optional[bool],
        Doc(
            “””
            Mark this path operation as deprecated.

            It will be added to the generated OpenAPI (e.g. visible at /docs).
            “””
        ),
    ] = None,
    operation_id: Annotated[
        Optional[str],
        Doc(
            “””
            Custom operation ID to be used by this path operation.

            By default, it is generated automatically.

            If you provide a custom operation ID, you need to make sure it is
            unique for the whole API.

            You can customize the
            operation ID generation with the parameter
            generate_unique_id_function in the FastAPI class.

            Read more about it in the
            FastAPI docs about how to Generate Clients.
            “””
        ),
    ] = None,
    response_model_include: Annotated[
        Optional[IncEx],
        Doc(
            “””
            Configuration passed to Pydantic to include only certain fields in the
            response data.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = None,
    response_model_exclude: Annotated[
        Optional[IncEx],
        Doc(
            “””
            Configuration passed to Pydantic to exclude certain fields in the
            response data.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = None,
    response_model_by_alias: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response model
            should be serialized by alias when an alias is used.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = True,
    response_model_exclude_unset: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response data
            should have all the fields, including the ones that were not set and
            have their default values. This is different from
            response_model_exclude_defaults in that if the fields are set,
            they will be included in the response, even if the value is the same
            as the default.

            When True, default values are omitted from the response.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = False,
    response_model_exclude_defaults: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response data
            should have all the fields, including the ones that have the same value
            as the default. This is different from response_model_exclude_unset
            in that if the fields are set but contain the same default values,
            they will be excluded from the response.

            When True, default values are omitted from the response.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = False,
    response_model_exclude_none: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response data should
            exclude fields set to None.

            This is much simpler (less smart) than response_model_exclude_unset
            and response_model_exclude_defaults. You probably want to use one of
            those two instead of this one, as those allow returning None values
            when it makes sense.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = False,
    include_in_schema: Annotated[
        bool,
        Doc(
            “””
            Include this path operation in the generated OpenAPI schema.

            This affects the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Query Parameters and String Validations.
            “””
        ),
    ] = True,
    response_class: Annotated[
        Type[Response],
        Doc(
            “””
            Response class to be used for this path operation.

            This will not be used if you return a response directly.

            Read more about it in the
            FastAPI docs for Custom Response - HTML, Stream, File, others.
            “””
        ),
    ] = Default(JSONResponse),
    name: Annotated[
        Optional[str],
        Doc(
            “””
            Name for this path operation. Only used internally.
            “””
        ),
    ] = None,
    callbacks: Annotated[
        Optional[List[BaseRoute]],
        Doc(
            “””
            List of path operations that will be used as OpenAPI callbacks.

            This is only for OpenAPI documentation, the callbacks won’t be used
            directly.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for OpenAPI Callbacks.
            “””
        ),
    ] = None,
    openapi_extra: Annotated[
        Optional[Dict[str, Any]],
        Doc(
            “””
            Extra metadata to be included in the OpenAPI schema for this path
            operation.

            Read more about it in the
            FastAPI docs for Path Operation Advanced Configuration.
            “””
        ),
    ] = None,
    generate_unique_id_function: Annotated[
        Callable[[routing.APIRoute], str],
        Doc(
            “””
            Customize the function used to generate unique IDs for the path
            operations shown in the generated OpenAPI.

            This is particularly useful when automatically generating clients or
            SDKs for your API.

            Read more about it in the
            FastAPI docs about how to Generate Clients.
            “””
        ),
    ] = Default(generate_unique_id),
) -> Callable[[DecoratedCallable], DecoratedCallable]:
    “””
    Add a path operation* using an HTTP POST operation.

    ## Example

    python</span>
<span>    from fastapi import FastAPI</span>
<span>    from pydantic import BaseModel</span>

<span>    class Item(BaseModel):</span>
<span>        name: str</span>
<span>        description: str | None = None</span>

<span>    app = FastAPI()</span>

<span>    @app.post("/items/")</span>
<span>    def create_item(item: Item):</span>
<span>        return {"message": "Item created"}</span>
<span>
    “””
    return self.router.post(
        path,
        response_model=response_model,
        status_code=status_code,
        tags=tags,
        dependencies=dependencies,
        summary=summary,
        description=description,
        response_description=response_description,
        responses=responses,
        deprecated=deprecated,
        operation_id=operation_id,
        response_model_include=response_model_include,
        response_model_exclude=response_model_exclude,
        response_model_by_alias=response_model_by_alias,
        response_model_exclude_unset=response_model_exclude_unset,
        response_model_exclude_defaults=response_model_exclude_defaults,
        response_model_exclude_none=response_model_exclude_none,
        include_in_schema=include_in_schema,
        response_class=response_class,
        name=name,
        callbacks=callbacks,
        openapi_extra=openapi_extra,
        generate_unique_id_function=generate_unique_id_function,
    )

delete

delete(
    path,
    *,
    response_model=Default(None),
    status_code=None,
    tags=None,
    dependencies=None,
    summary=None,
    description=None,
    response_description="Successful Response",
    responses=None,
    deprecated=None,
    operation_id=None,
    response_model_include=None,
    response_model_exclude=None,
    response_model_by_alias=True,
    response_model_exclude_unset=False,
    response_model_exclude_defaults=False,
    response_model_exclude_none=False,
    include_in_schema=True,
    response_class=Default(JSONResponse),
    name=None,
    callbacks=None,
    openapi_extra=None,
    generate_unique_id_function=Default(generate_unique_id)
)

Add a path operation using an HTTP DELETE operation.

Example
from fastapi import FastAPI

app = FastAPI()

@app.delete("/items/{item_id}")
def delete_item(item_id: str):
    return {"message": "Item deleted"}
PARAMETERDESCRIPTION
path

The URL path to be used for this path operation.

For example, in http://example.com/items, the path is /items.

TYPE: str

response_model

The type to use for the response.

It could be any valid Pydantic field type. So, it doesn’t have to be a Pydantic model, it could be other things, like a list, dict, etc.

It will be used for:

  • Documentation: the generated OpenAPI (and the UI at /docs) will show it as the response (JSON Schema).
  • Serialization: you could return an arbitrary object and the response_model would be used to serialize that object into the corresponding JSON.
  • Filtering: the JSON sent to the client will only contain the data (fields) defined in the response_model. If you returned an object that contains an attribute password but the response_model does not include that field, the JSON sent to the client would not have that password.
  • Validation: whatever you return will be serialized with the response_model, converting any data as necessary to generate the corresponding JSON. But if the data in the object returned is not valid, that would mean a violation of the contract with the client, so it’s an error from the API developer. So, FastAPI will raise an error and return a 500 error code (Internal Server Error).

Read more about it in the FastAPI docs for Response Model.

TYPE: Any DEFAULT: Default(None)

status_code

The default status code to be used for the response.

You could override the status code by returning a response directly.

Read more about it in the FastAPI docs for Response Status Code.

TYPE: Optional[int] DEFAULT: None

tags

A list of tags to be applied to the path operation.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[List[Union[str, Enum]]] DEFAULT: None

dependencies

A list of dependencies (using Depends()) to be applied to the path operation.

Read more about it in the FastAPI docs for Dependencies in path operation decorators.

TYPE: Optional[Sequence[Depends]] DEFAULT: None

summary

A summary for the path operation.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[str] DEFAULT: None

description

A description for the path operation.

If not provided, it will be extracted automatically from the docstring of the path operation function.

It can contain Markdown.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[str] DEFAULT: None

response_description

The description for the default response.

It will be added to the generated OpenAPI (e.g. visible at /docs).

TYPE: str DEFAULT: ‘Successful Response’

responses

Additional responses that could be returned by this path operation.

It will be added to the generated OpenAPI (e.g. visible at /docs).

TYPE: Optional[Dict[Union[int, str], Dict[str, Any]]] DEFAULT: None

deprecated

Mark this path operation as deprecated.

It will be added to the generated OpenAPI (e.g. visible at /docs).

TYPE: Optional[bool] DEFAULT: None

operation_id

Custom operation ID to be used by this path operation.

By default, it is generated automatically.

If you provide a custom operation ID, you need to make sure it is unique for the whole API.

You can customize the operation ID generation with the parameter generate_unique_id_function in the FastAPI class.

Read more about it in the FastAPI docs about how to Generate Clients.

TYPE: Optional[str] DEFAULT: None

response_model_include

Configuration passed to Pydantic to include only certain fields in the response data.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: Optional[IncEx] DEFAULT: None

response_model_exclude

Configuration passed to Pydantic to exclude certain fields in the response data.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: Optional[IncEx] DEFAULT: None

response_model_by_alias

Configuration passed to Pydantic to define if the response model should be serialized by alias when an alias is used.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: True

response_model_exclude_unset

Configuration passed to Pydantic to define if the response data should have all the fields, including the ones that were not set and have their default values. This is different from response_model_exclude_defaults in that if the fields are set, they will be included in the response, even if the value is the same as the default.

When True, default values are omitted from the response.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: False

response_model_exclude_defaults

Configuration passed to Pydantic to define if the response data should have all the fields, including the ones that have the same value as the default. This is different from response_model_exclude_unset in that if the fields are set but contain the same default values, they will be excluded from the response.

When True, default values are omitted from the response.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: False

response_model_exclude_none

Configuration passed to Pydantic to define if the response data should exclude fields set to None.

This is much simpler (less smart) than response_model_exclude_unset and response_model_exclude_defaults. You probably want to use one of those two instead of this one, as those allow returning None values when it makes sense.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: False

include_in_schema

Include this path operation in the generated OpenAPI schema.

This affects the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Query Parameters and String Validations.

TYPE: bool DEFAULT: True

response_class

Response class to be used for this path operation.

This will not be used if you return a response directly.

Read more about it in the FastAPI docs for Custom Response - HTML, Stream, File, others.

TYPE: Type[Response] DEFAULT: Default(JSONResponse)

name

Name for this path operation. Only used internally.

TYPE: Optional[str] DEFAULT: None

callbacks

List of path operations that will be used as OpenAPI callbacks.

This is only for OpenAPI documentation, the callbacks won’t be used directly.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for OpenAPI Callbacks.

TYPE: Optional[List[BaseRoute]] DEFAULT: None

openapi_extra

Extra metadata to be included in the OpenAPI schema for this path operation.

Read more about it in the FastAPI docs for Path Operation Advanced Configuration.

TYPE: Optional[Dict[str, Any]] DEFAULT: None

generate_unique_id_function

Customize the function used to generate unique IDs for the path operations shown in the generated OpenAPI.

This is particularly useful when automatically generating clients or SDKs for your API.

Read more about it in the FastAPI docs about how to Generate Clients.

TYPE: Callable[[APIRoute], str] DEFAULT: Default(generate_unique_id)

Source code in fastapi/applications.py

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def delete(
    self,
    path: Annotated[
        str,
        Doc(
            “””
            The URL path to be used for this path operation.

            For example, in http://example.com/items, the path is /items.
            “””
        ),
    ],
    ,
    response_model: Annotated[
        Any,
        Doc(
            “””
            The type to use for the response.

            It could be any valid Pydantic field type. So, it doesn’t have to
            be a Pydantic model, it could be other things, like a list, dict,
            etc.

            It will be used for:

             Documentation: the generated OpenAPI (and the UI at /docs) will
                show it as the response (JSON Schema).
             Serialization: you could return an arbitrary object and the
                response_model would be used to serialize that object into the
                corresponding JSON.
             Filtering: the JSON sent to the client will only contain the data
                (fields) defined in the response_model. If you returned an object
                that contains an attribute password but the response_model does
                not include that field, the JSON sent to the client would not have
                that password.
             Validation: whatever you return will be serialized with the
                response_model, converting any data as necessary to generate the
                corresponding JSON. But if the data in the object returned is not
                valid, that would mean a violation of the contract with the client,
                so it’s an error from the API developer. So, FastAPI will raise an
                error and return a 500 error code (Internal Server Error).

            Read more about it in the
            FastAPI docs for Response Model.
            “””
        ),
    ] = Default(None),
    status_code: Annotated[
        Optional[int],
        Doc(
            “””
            The default status code to be used for the response.

            You could override the status code by returning a response directly.

            Read more about it in the
            FastAPI docs for Response Status Code.
            “””
        ),
    ] = None,
    tags: Annotated[
        Optional[List[Union[str, Enum]]],
        Doc(
            “””
            A list of tags to be applied to the path operation.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    dependencies: Annotated[
        Optional[Sequence[Depends]],
        Doc(
            “””
            A list of dependencies (using Depends()) to be applied to the
            path operation.

            Read more about it in the
            FastAPI docs for Dependencies in path operation decorators.
            “””
        ),
    ] = None,
    summary: Annotated[
        Optional[str],
        Doc(
            “””
            A summary for the path operation.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    description: Annotated[
        Optional[str],
        Doc(
            “””
            A description for the path operation.

            If not provided, it will be extracted automatically from the docstring
            of the path operation function.

            It can contain Markdown.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    response_description: Annotated[
        str,
        Doc(
            “””
            The description for the default response.

            It will be added to the generated OpenAPI (e.g. visible at /docs).
            “””
        ),
    ] = “Successful Response”,
    responses: Annotated[
        Optional[Dict[Union[int, str], Dict[str, Any]]],
        Doc(
            “””
            Additional responses that could be returned by this path operation.

            It will be added to the generated OpenAPI (e.g. visible at /docs).
            “””
        ),
    ] = None,
    deprecated: Annotated[
        Optional[bool],
        Doc(
            “””
            Mark this path operation as deprecated.

            It will be added to the generated OpenAPI (e.g. visible at /docs).
            “””
        ),
    ] = None,
    operation_id: Annotated[
        Optional[str],
        Doc(
            “””
            Custom operation ID to be used by this path operation.

            By default, it is generated automatically.

            If you provide a custom operation ID, you need to make sure it is
            unique for the whole API.

            You can customize the
            operation ID generation with the parameter
            generate_unique_id_function in the FastAPI class.

            Read more about it in the
            FastAPI docs about how to Generate Clients.
            “””
        ),
    ] = None,
    response_model_include: Annotated[
        Optional[IncEx],
        Doc(
            “””
            Configuration passed to Pydantic to include only certain fields in the
            response data.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = None,
    response_model_exclude: Annotated[
        Optional[IncEx],
        Doc(
            “””
            Configuration passed to Pydantic to exclude certain fields in the
            response data.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = None,
    response_model_by_alias: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response model
            should be serialized by alias when an alias is used.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = True,
    response_model_exclude_unset: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response data
            should have all the fields, including the ones that were not set and
            have their default values. This is different from
            response_model_exclude_defaults in that if the fields are set,
            they will be included in the response, even if the value is the same
            as the default.

            When True, default values are omitted from the response.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = False,
    response_model_exclude_defaults: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response data
            should have all the fields, including the ones that have the same value
            as the default. This is different from response_model_exclude_unset
            in that if the fields are set but contain the same default values,
            they will be excluded from the response.

            When True, default values are omitted from the response.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = False,
    response_model_exclude_none: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response data should
            exclude fields set to None.

            This is much simpler (less smart) than response_model_exclude_unset
            and response_model_exclude_defaults. You probably want to use one of
            those two instead of this one, as those allow returning None values
            when it makes sense.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = False,
    include_in_schema: Annotated[
        bool,
        Doc(
            “””
            Include this path operation in the generated OpenAPI schema.

            This affects the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Query Parameters and String Validations.
            “””
        ),
    ] = True,
    response_class: Annotated[
        Type[Response],
        Doc(
            “””
            Response class to be used for this path operation.

            This will not be used if you return a response directly.

            Read more about it in the
            FastAPI docs for Custom Response - HTML, Stream, File, others.
            “””
        ),
    ] = Default(JSONResponse),
    name: Annotated[
        Optional[str],
        Doc(
            “””
            Name for this path operation. Only used internally.
            “””
        ),
    ] = None,
    callbacks: Annotated[
        Optional[List[BaseRoute]],
        Doc(
            “””
            List of path operations that will be used as OpenAPI callbacks.

            This is only for OpenAPI documentation, the callbacks won’t be used
            directly.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for OpenAPI Callbacks.
            “””
        ),
    ] = None,
    openapi_extra: Annotated[
        Optional[Dict[str, Any]],
        Doc(
            “””
            Extra metadata to be included in the OpenAPI schema for this path
            operation.

            Read more about it in the
            FastAPI docs for Path Operation Advanced Configuration.
            “””
        ),
    ] = None,
    generate_unique_id_function: Annotated[
        Callable[[routing.APIRoute], str],
        Doc(
            “””
            Customize the function used to generate unique IDs for the path
            operations shown in the generated OpenAPI.

            This is particularly useful when automatically generating clients or
            SDKs for your API.

            Read more about it in the
            FastAPI docs about how to Generate Clients.
            “””
        ),
    ] = Default(generate_unique_id),
) -> Callable[[DecoratedCallable], DecoratedCallable]:
    “””
    Add a path operation* using an HTTP DELETE operation.

    ## Example

    python</span>
<span>    from fastapi import FastAPI</span>

<span>    app = FastAPI()</span>

<span>    @app.delete("/items/{item_id}")</span>
<span>    def delete_item(item_id: str):</span>
<span>        return {"message": "Item deleted"}</span>
<span>
    “””
    return self.router.delete(
        path,
        response_model=response_model,
        status_code=status_code,
        tags=tags,
        dependencies=dependencies,
        summary=summary,
        description=description,
        response_description=response_description,
        responses=responses,
        deprecated=deprecated,
        operation_id=operation_id,
        response_model_include=response_model_include,
        response_model_exclude=response_model_exclude,
        response_model_by_alias=response_model_by_alias,
        response_model_exclude_unset=response_model_exclude_unset,
        response_model_exclude_defaults=response_model_exclude_defaults,
        response_model_exclude_none=response_model_exclude_none,
        include_in_schema=include_in_schema,
        response_class=response_class,
        name=name,
        callbacks=callbacks,
        openapi_extra=openapi_extra,
        generate_unique_id_function=generate_unique_id_function,
    )

options

options(
    path,
    *,
    response_model=Default(None),
    status_code=None,
    tags=None,
    dependencies=None,
    summary=None,
    description=None,
    response_description="Successful Response",
    responses=None,
    deprecated=None,
    operation_id=None,
    response_model_include=None,
    response_model_exclude=None,
    response_model_by_alias=True,
    response_model_exclude_unset=False,
    response_model_exclude_defaults=False,
    response_model_exclude_none=False,
    include_in_schema=True,
    response_class=Default(JSONResponse),
    name=None,
    callbacks=None,
    openapi_extra=None,
    generate_unique_id_function=Default(generate_unique_id)
)

Add a path operation using an HTTP OPTIONS operation.

Example
from fastapi import FastAPI

app = FastAPI()

@app.options("/items/")
def get_item_options():
    return {"additions": ["Aji", "Guacamole"]}
PARAMETERDESCRIPTION
path

The URL path to be used for this path operation.

For example, in http://example.com/items, the path is /items.

TYPE: str

response_model

The type to use for the response.

It could be any valid Pydantic field type. So, it doesn’t have to be a Pydantic model, it could be other things, like a list, dict, etc.

It will be used for:

  • Documentation: the generated OpenAPI (and the UI at /docs) will show it as the response (JSON Schema).
  • Serialization: you could return an arbitrary object and the response_model would be used to serialize that object into the corresponding JSON.
  • Filtering: the JSON sent to the client will only contain the data (fields) defined in the response_model. If you returned an object that contains an attribute password but the response_model does not include that field, the JSON sent to the client would not have that password.
  • Validation: whatever you return will be serialized with the response_model, converting any data as necessary to generate the corresponding JSON. But if the data in the object returned is not valid, that would mean a violation of the contract with the client, so it’s an error from the API developer. So, FastAPI will raise an error and return a 500 error code (Internal Server Error).

Read more about it in the FastAPI docs for Response Model.

TYPE: Any DEFAULT: Default(None)

status_code

The default status code to be used for the response.

You could override the status code by returning a response directly.

Read more about it in the FastAPI docs for Response Status Code.

TYPE: Optional[int] DEFAULT: None

tags

A list of tags to be applied to the path operation.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[List[Union[str, Enum]]] DEFAULT: None

dependencies

A list of dependencies (using Depends()) to be applied to the path operation.

Read more about it in the FastAPI docs for Dependencies in path operation decorators.

TYPE: Optional[Sequence[Depends]] DEFAULT: None

summary

A summary for the path operation.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[str] DEFAULT: None

description

A description for the path operation.

If not provided, it will be extracted automatically from the docstring of the path operation function.

It can contain Markdown.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[str] DEFAULT: None

response_description

The description for the default response.

It will be added to the generated OpenAPI (e.g. visible at /docs).

TYPE: str DEFAULT: ‘Successful Response’

responses

Additional responses that could be returned by this path operation.

It will be added to the generated OpenAPI (e.g. visible at /docs).

TYPE: Optional[Dict[Union[int, str], Dict[str, Any]]] DEFAULT: None

deprecated

Mark this path operation as deprecated.

It will be added to the generated OpenAPI (e.g. visible at /docs).

TYPE: Optional[bool] DEFAULT: None

operation_id

Custom operation ID to be used by this path operation.

By default, it is generated automatically.

If you provide a custom operation ID, you need to make sure it is unique for the whole API.

You can customize the operation ID generation with the parameter generate_unique_id_function in the FastAPI class.

Read more about it in the FastAPI docs about how to Generate Clients.

TYPE: Optional[str] DEFAULT: None

response_model_include

Configuration passed to Pydantic to include only certain fields in the response data.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: Optional[IncEx] DEFAULT: None

response_model_exclude

Configuration passed to Pydantic to exclude certain fields in the response data.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: Optional[IncEx] DEFAULT: None

response_model_by_alias

Configuration passed to Pydantic to define if the response model should be serialized by alias when an alias is used.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: True

response_model_exclude_unset

Configuration passed to Pydantic to define if the response data should have all the fields, including the ones that were not set and have their default values. This is different from response_model_exclude_defaults in that if the fields are set, they will be included in the response, even if the value is the same as the default.

When True, default values are omitted from the response.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: False

response_model_exclude_defaults

Configuration passed to Pydantic to define if the response data should have all the fields, including the ones that have the same value as the default. This is different from response_model_exclude_unset in that if the fields are set but contain the same default values, they will be excluded from the response.

When True, default values are omitted from the response.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: False

response_model_exclude_none

Configuration passed to Pydantic to define if the response data should exclude fields set to None.

This is much simpler (less smart) than response_model_exclude_unset and response_model_exclude_defaults. You probably want to use one of those two instead of this one, as those allow returning None values when it makes sense.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: False

include_in_schema

Include this path operation in the generated OpenAPI schema.

This affects the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Query Parameters and String Validations.

TYPE: bool DEFAULT: True

response_class

Response class to be used for this path operation.

This will not be used if you return a response directly.

Read more about it in the FastAPI docs for Custom Response - HTML, Stream, File, others.

TYPE: Type[Response] DEFAULT: Default(JSONResponse)

name

Name for this path operation. Only used internally.

TYPE: Optional[str] DEFAULT: None

callbacks

List of path operations that will be used as OpenAPI callbacks.

This is only for OpenAPI documentation, the callbacks won’t be used directly.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for OpenAPI Callbacks.

TYPE: Optional[List[BaseRoute]] DEFAULT: None

openapi_extra

Extra metadata to be included in the OpenAPI schema for this path operation.

Read more about it in the FastAPI docs for Path Operation Advanced Configuration.

TYPE: Optional[Dict[str, Any]] DEFAULT: None

generate_unique_id_function

Customize the function used to generate unique IDs for the path operations shown in the generated OpenAPI.

This is particularly useful when automatically generating clients or SDKs for your API.

Read more about it in the FastAPI docs about how to Generate Clients.

TYPE: Callable[[APIRoute], str] DEFAULT: Default(generate_unique_id)

Source code in fastapi/applications.py

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def options(
    self,
    path: Annotated[
        str,
        Doc(
            “””
            The URL path to be used for this path operation.

            For example, in http://example.com/items, the path is /items.
            “””
        ),
    ],
    ,
    response_model: Annotated[
        Any,
        Doc(
            “””
            The type to use for the response.

            It could be any valid Pydantic field type. So, it doesn’t have to
            be a Pydantic model, it could be other things, like a list, dict,
            etc.

            It will be used for:

             Documentation: the generated OpenAPI (and the UI at /docs) will
                show it as the response (JSON Schema).
             Serialization: you could return an arbitrary object and the
                response_model would be used to serialize that object into the
                corresponding JSON.
             Filtering: the JSON sent to the client will only contain the data
                (fields) defined in the response_model. If you returned an object
                that contains an attribute password but the response_model does
                not include that field, the JSON sent to the client would not have
                that password.
             Validation: whatever you return will be serialized with the
                response_model, converting any data as necessary to generate the
                corresponding JSON. But if the data in the object returned is not
                valid, that would mean a violation of the contract with the client,
                so it’s an error from the API developer. So, FastAPI will raise an
                error and return a 500 error code (Internal Server Error).

            Read more about it in the
            FastAPI docs for Response Model.
            “””
        ),
    ] = Default(None),
    status_code: Annotated[
        Optional[int],
        Doc(
            “””
            The default status code to be used for the response.

            You could override the status code by returning a response directly.

            Read more about it in the
            FastAPI docs for Response Status Code.
            “””
        ),
    ] = None,
    tags: Annotated[
        Optional[List[Union[str, Enum]]],
        Doc(
            “””
            A list of tags to be applied to the path operation.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    dependencies: Annotated[
        Optional[Sequence[Depends]],
        Doc(
            “””
            A list of dependencies (using Depends()) to be applied to the
            path operation.

            Read more about it in the
            FastAPI docs for Dependencies in path operation decorators.
            “””
        ),
    ] = None,
    summary: Annotated[
        Optional[str],
        Doc(
            “””
            A summary for the path operation.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    description: Annotated[
        Optional[str],
        Doc(
            “””
            A description for the path operation.

            If not provided, it will be extracted automatically from the docstring
            of the path operation function.

            It can contain Markdown.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    response_description: Annotated[
        str,
        Doc(
            “””
            The description for the default response.

            It will be added to the generated OpenAPI (e.g. visible at /docs).
            “””
        ),
    ] = “Successful Response”,
    responses: Annotated[
        Optional[Dict[Union[int, str], Dict[str, Any]]],
        Doc(
            “””
            Additional responses that could be returned by this path operation.

            It will be added to the generated OpenAPI (e.g. visible at /docs).
            “””
        ),
    ] = None,
    deprecated: Annotated[
        Optional[bool],
        Doc(
            “””
            Mark this path operation as deprecated.

            It will be added to the generated OpenAPI (e.g. visible at /docs).
            “””
        ),
    ] = None,
    operation_id: Annotated[
        Optional[str],
        Doc(
            “””
            Custom operation ID to be used by this path operation.

            By default, it is generated automatically.

            If you provide a custom operation ID, you need to make sure it is
            unique for the whole API.

            You can customize the
            operation ID generation with the parameter
            generate_unique_id_function in the FastAPI class.

            Read more about it in the
            FastAPI docs about how to Generate Clients.
            “””
        ),
    ] = None,
    response_model_include: Annotated[
        Optional[IncEx],
        Doc(
            “””
            Configuration passed to Pydantic to include only certain fields in the
            response data.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = None,
    response_model_exclude: Annotated[
        Optional[IncEx],
        Doc(
            “””
            Configuration passed to Pydantic to exclude certain fields in the
            response data.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = None,
    response_model_by_alias: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response model
            should be serialized by alias when an alias is used.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = True,
    response_model_exclude_unset: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response data
            should have all the fields, including the ones that were not set and
            have their default values. This is different from
            response_model_exclude_defaults in that if the fields are set,
            they will be included in the response, even if the value is the same
            as the default.

            When True, default values are omitted from the response.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = False,
    response_model_exclude_defaults: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response data
            should have all the fields, including the ones that have the same value
            as the default. This is different from response_model_exclude_unset
            in that if the fields are set but contain the same default values,
            they will be excluded from the response.

            When True, default values are omitted from the response.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = False,
    response_model_exclude_none: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response data should
            exclude fields set to None.

            This is much simpler (less smart) than response_model_exclude_unset
            and response_model_exclude_defaults. You probably want to use one of
            those two instead of this one, as those allow returning None values
            when it makes sense.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = False,
    include_in_schema: Annotated[
        bool,
        Doc(
            “””
            Include this path operation in the generated OpenAPI schema.

            This affects the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Query Parameters and String Validations.
            “””
        ),
    ] = True,
    response_class: Annotated[
        Type[Response],
        Doc(
            “””
            Response class to be used for this path operation.

            This will not be used if you return a response directly.

            Read more about it in the
            FastAPI docs for Custom Response - HTML, Stream, File, others.
            “””
        ),
    ] = Default(JSONResponse),
    name: Annotated[
        Optional[str],
        Doc(
            “””
            Name for this path operation. Only used internally.
            “””
        ),
    ] = None,
    callbacks: Annotated[
        Optional[List[BaseRoute]],
        Doc(
            “””
            List of path operations that will be used as OpenAPI callbacks.

            This is only for OpenAPI documentation, the callbacks won’t be used
            directly.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for OpenAPI Callbacks.
            “””
        ),
    ] = None,
    openapi_extra: Annotated[
        Optional[Dict[str, Any]],
        Doc(
            “””
            Extra metadata to be included in the OpenAPI schema for this path
            operation.

            Read more about it in the
            FastAPI docs for Path Operation Advanced Configuration.
            “””
        ),
    ] = None,
    generate_unique_id_function: Annotated[
        Callable[[routing.APIRoute], str],
        Doc(
            “””
            Customize the function used to generate unique IDs for the path
            operations shown in the generated OpenAPI.

            This is particularly useful when automatically generating clients or
            SDKs for your API.

            Read more about it in the
            FastAPI docs about how to Generate Clients.
            “””
        ),
    ] = Default(generate_unique_id),
) -> Callable[[DecoratedCallable], DecoratedCallable]:
    “””
    Add a path operation* using an HTTP OPTIONS operation.

    ## Example

    python</span>
<span>    from fastapi import FastAPI</span>

<span>    app = FastAPI()</span>

<span>    @app.options("/items/")</span>
<span>    def get_item_options():</span>
<span>        return {"additions": ["Aji", "Guacamole"]}</span>
<span>
    “””
    return self.router.options(
        path,
        response_model=response_model,
        status_code=status_code,
        tags=tags,
        dependencies=dependencies,
        summary=summary,
        description=description,
        response_description=response_description,
        responses=responses,
        deprecated=deprecated,
        operation_id=operation_id,
        response_model_include=response_model_include,
        response_model_exclude=response_model_exclude,
        response_model_by_alias=response_model_by_alias,
        response_model_exclude_unset=response_model_exclude_unset,
        response_model_exclude_defaults=response_model_exclude_defaults,
        response_model_exclude_none=response_model_exclude_none,
        include_in_schema=include_in_schema,
        response_class=response_class,
        name=name,
        callbacks=callbacks,
        openapi_extra=openapi_extra,
        generate_unique_id_function=generate_unique_id_function,
    )

head

head(
    path,
    *,
    response_model=Default(None),
    status_code=None,
    tags=None,
    dependencies=None,
    summary=None,
    description=None,
    response_description="Successful Response",
    responses=None,
    deprecated=None,
    operation_id=None,
    response_model_include=None,
    response_model_exclude=None,
    response_model_by_alias=True,
    response_model_exclude_unset=False,
    response_model_exclude_defaults=False,
    response_model_exclude_none=False,
    include_in_schema=True,
    response_class=Default(JSONResponse),
    name=None,
    callbacks=None,
    openapi_extra=None,
    generate_unique_id_function=Default(generate_unique_id)
)

Add a path operation using an HTTP HEAD operation.

Example
from fastapi import FastAPI, Response

app = FastAPI()

@app.head("/items/", status_code=204)
def get_items_headers(response: Response):
    response.headers["X-Cat-Dog"] = "Alone in the world"
PARAMETERDESCRIPTION
path

The URL path to be used for this path operation.

For example, in http://example.com/items, the path is /items.

TYPE: str

response_model

The type to use for the response.

It could be any valid Pydantic field type. So, it doesn’t have to be a Pydantic model, it could be other things, like a list, dict, etc.

It will be used for:

  • Documentation: the generated OpenAPI (and the UI at /docs) will show it as the response (JSON Schema).
  • Serialization: you could return an arbitrary object and the response_model would be used to serialize that object into the corresponding JSON.
  • Filtering: the JSON sent to the client will only contain the data (fields) defined in the response_model. If you returned an object that contains an attribute password but the response_model does not include that field, the JSON sent to the client would not have that password.
  • Validation: whatever you return will be serialized with the response_model, converting any data as necessary to generate the corresponding JSON. But if the data in the object returned is not valid, that would mean a violation of the contract with the client, so it’s an error from the API developer. So, FastAPI will raise an error and return a 500 error code (Internal Server Error).

Read more about it in the FastAPI docs for Response Model.

TYPE: Any DEFAULT: Default(None)

status_code

The default status code to be used for the response.

You could override the status code by returning a response directly.

Read more about it in the FastAPI docs for Response Status Code.

TYPE: Optional[int] DEFAULT: None

tags

A list of tags to be applied to the path operation.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[List[Union[str, Enum]]] DEFAULT: None

dependencies

A list of dependencies (using Depends()) to be applied to the path operation.

Read more about it in the FastAPI docs for Dependencies in path operation decorators.

TYPE: Optional[Sequence[Depends]] DEFAULT: None

summary

A summary for the path operation.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[str] DEFAULT: None

description

A description for the path operation.

If not provided, it will be extracted automatically from the docstring of the path operation function.

It can contain Markdown.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[str] DEFAULT: None

response_description

The description for the default response.

It will be added to the generated OpenAPI (e.g. visible at /docs).

TYPE: str DEFAULT: ‘Successful Response’

responses

Additional responses that could be returned by this path operation.

It will be added to the generated OpenAPI (e.g. visible at /docs).

TYPE: Optional[Dict[Union[int, str], Dict[str, Any]]] DEFAULT: None

deprecated

Mark this path operation as deprecated.

It will be added to the generated OpenAPI (e.g. visible at /docs).

TYPE: Optional[bool] DEFAULT: None

operation_id

Custom operation ID to be used by this path operation.

By default, it is generated automatically.

If you provide a custom operation ID, you need to make sure it is unique for the whole API.

You can customize the operation ID generation with the parameter generate_unique_id_function in the FastAPI class.

Read more about it in the FastAPI docs about how to Generate Clients.

TYPE: Optional[str] DEFAULT: None

response_model_include

Configuration passed to Pydantic to include only certain fields in the response data.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: Optional[IncEx] DEFAULT: None

response_model_exclude

Configuration passed to Pydantic to exclude certain fields in the response data.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: Optional[IncEx] DEFAULT: None

response_model_by_alias

Configuration passed to Pydantic to define if the response model should be serialized by alias when an alias is used.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: True

response_model_exclude_unset

Configuration passed to Pydantic to define if the response data should have all the fields, including the ones that were not set and have their default values. This is different from response_model_exclude_defaults in that if the fields are set, they will be included in the response, even if the value is the same as the default.

When True, default values are omitted from the response.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: False

response_model_exclude_defaults

Configuration passed to Pydantic to define if the response data should have all the fields, including the ones that have the same value as the default. This is different from response_model_exclude_unset in that if the fields are set but contain the same default values, they will be excluded from the response.

When True, default values are omitted from the response.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: False

response_model_exclude_none

Configuration passed to Pydantic to define if the response data should exclude fields set to None.

This is much simpler (less smart) than response_model_exclude_unset and response_model_exclude_defaults. You probably want to use one of those two instead of this one, as those allow returning None values when it makes sense.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: False

include_in_schema

Include this path operation in the generated OpenAPI schema.

This affects the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Query Parameters and String Validations.

TYPE: bool DEFAULT: True

response_class

Response class to be used for this path operation.

This will not be used if you return a response directly.

Read more about it in the FastAPI docs for Custom Response - HTML, Stream, File, others.

TYPE: Type[Response] DEFAULT: Default(JSONResponse)

name

Name for this path operation. Only used internally.

TYPE: Optional[str] DEFAULT: None

callbacks

List of path operations that will be used as OpenAPI callbacks.

This is only for OpenAPI documentation, the callbacks won’t be used directly.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for OpenAPI Callbacks.

TYPE: Optional[List[BaseRoute]] DEFAULT: None

openapi_extra

Extra metadata to be included in the OpenAPI schema for this path operation.

Read more about it in the FastAPI docs for Path Operation Advanced Configuration.

TYPE: Optional[Dict[str, Any]] DEFAULT: None

generate_unique_id_function

Customize the function used to generate unique IDs for the path operations shown in the generated OpenAPI.

This is particularly useful when automatically generating clients or SDKs for your API.

Read more about it in the FastAPI docs about how to Generate Clients.

TYPE: Callable[[APIRoute], str] DEFAULT: Default(generate_unique_id)

Source code in fastapi/applications.py

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def head(
    self,
    path: Annotated[
        str,
        Doc(
            “””
            The URL path to be used for this path operation.

            For example, in http://example.com/items, the path is /items.
            “””
        ),
    ],
    ,
    response_model: Annotated[
        Any,
        Doc(
            “””
            The type to use for the response.

            It could be any valid Pydantic field type. So, it doesn’t have to
            be a Pydantic model, it could be other things, like a list, dict,
            etc.

            It will be used for:

             Documentation: the generated OpenAPI (and the UI at /docs) will
                show it as the response (JSON Schema).
             Serialization: you could return an arbitrary object and the
                response_model would be used to serialize that object into the
                corresponding JSON.
             Filtering: the JSON sent to the client will only contain the data
                (fields) defined in the response_model. If you returned an object
                that contains an attribute password but the response_model does
                not include that field, the JSON sent to the client would not have
                that password.
             Validation: whatever you return will be serialized with the
                response_model, converting any data as necessary to generate the
                corresponding JSON. But if the data in the object returned is not
                valid, that would mean a violation of the contract with the client,
                so it’s an error from the API developer. So, FastAPI will raise an
                error and return a 500 error code (Internal Server Error).

            Read more about it in the
            FastAPI docs for Response Model.
            “””
        ),
    ] = Default(None),
    status_code: Annotated[
        Optional[int],
        Doc(
            “””
            The default status code to be used for the response.

            You could override the status code by returning a response directly.

            Read more about it in the
            FastAPI docs for Response Status Code.
            “””
        ),
    ] = None,
    tags: Annotated[
        Optional[List[Union[str, Enum]]],
        Doc(
            “””
            A list of tags to be applied to the path operation.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    dependencies: Annotated[
        Optional[Sequence[Depends]],
        Doc(
            “””
            A list of dependencies (using Depends()) to be applied to the
            path operation.

            Read more about it in the
            FastAPI docs for Dependencies in path operation decorators.
            “””
        ),
    ] = None,
    summary: Annotated[
        Optional[str],
        Doc(
            “””
            A summary for the path operation.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    description: Annotated[
        Optional[str],
        Doc(
            “””
            A description for the path operation.

            If not provided, it will be extracted automatically from the docstring
            of the path operation function.

            It can contain Markdown.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    response_description: Annotated[
        str,
        Doc(
            “””
            The description for the default response.

            It will be added to the generated OpenAPI (e.g. visible at /docs).
            “””
        ),
    ] = “Successful Response”,
    responses: Annotated[
        Optional[Dict[Union[int, str], Dict[str, Any]]],
        Doc(
            “””
            Additional responses that could be returned by this path operation.

            It will be added to the generated OpenAPI (e.g. visible at /docs).
            “””
        ),
    ] = None,
    deprecated: Annotated[
        Optional[bool],
        Doc(
            “””
            Mark this path operation as deprecated.

            It will be added to the generated OpenAPI (e.g. visible at /docs).
            “””
        ),
    ] = None,
    operation_id: Annotated[
        Optional[str],
        Doc(
            “””
            Custom operation ID to be used by this path operation.

            By default, it is generated automatically.

            If you provide a custom operation ID, you need to make sure it is
            unique for the whole API.

            You can customize the
            operation ID generation with the parameter
            generate_unique_id_function in the FastAPI class.

            Read more about it in the
            FastAPI docs about how to Generate Clients.
            “””
        ),
    ] = None,
    response_model_include: Annotated[
        Optional[IncEx],
        Doc(
            “””
            Configuration passed to Pydantic to include only certain fields in the
            response data.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = None,
    response_model_exclude: Annotated[
        Optional[IncEx],
        Doc(
            “””
            Configuration passed to Pydantic to exclude certain fields in the
            response data.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = None,
    response_model_by_alias: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response model
            should be serialized by alias when an alias is used.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = True,
    response_model_exclude_unset: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response data
            should have all the fields, including the ones that were not set and
            have their default values. This is different from
            response_model_exclude_defaults in that if the fields are set,
            they will be included in the response, even if the value is the same
            as the default.

            When True, default values are omitted from the response.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = False,
    response_model_exclude_defaults: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response data
            should have all the fields, including the ones that have the same value
            as the default. This is different from response_model_exclude_unset
            in that if the fields are set but contain the same default values,
            they will be excluded from the response.

            When True, default values are omitted from the response.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = False,
    response_model_exclude_none: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response data should
            exclude fields set to None.

            This is much simpler (less smart) than response_model_exclude_unset
            and response_model_exclude_defaults. You probably want to use one of
            those two instead of this one, as those allow returning None values
            when it makes sense.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = False,
    include_in_schema: Annotated[
        bool,
        Doc(
            “””
            Include this path operation in the generated OpenAPI schema.

            This affects the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Query Parameters and String Validations.
            “””
        ),
    ] = True,
    response_class: Annotated[
        Type[Response],
        Doc(
            “””
            Response class to be used for this path operation.

            This will not be used if you return a response directly.

            Read more about it in the
            FastAPI docs for Custom Response - HTML, Stream, File, others.
            “””
        ),
    ] = Default(JSONResponse),
    name: Annotated[
        Optional[str],
        Doc(
            “””
            Name for this path operation. Only used internally.
            “””
        ),
    ] = None,
    callbacks: Annotated[
        Optional[List[BaseRoute]],
        Doc(
            “””
            List of path operations that will be used as OpenAPI callbacks.

            This is only for OpenAPI documentation, the callbacks won’t be used
            directly.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for OpenAPI Callbacks.
            “””
        ),
    ] = None,
    openapi_extra: Annotated[
        Optional[Dict[str, Any]],
        Doc(
            “””
            Extra metadata to be included in the OpenAPI schema for this path
            operation.

            Read more about it in the
            FastAPI docs for Path Operation Advanced Configuration.
            “””
        ),
    ] = None,
    generate_unique_id_function: Annotated[
        Callable[[routing.APIRoute], str],
        Doc(
            “””
            Customize the function used to generate unique IDs for the path
            operations shown in the generated OpenAPI.

            This is particularly useful when automatically generating clients or
            SDKs for your API.

            Read more about it in the
            FastAPI docs about how to Generate Clients.
            “””
        ),
    ] = Default(generate_unique_id),
) -> Callable[[DecoratedCallable], DecoratedCallable]:
    “””
    Add a path operation* using an HTTP HEAD operation.

    ## Example

    python</span>
<span>    from fastapi import FastAPI, Response</span>

<span>    app = FastAPI()</span>

<span>    @app.head("/items/", status_code=204)</span>
<span>    def get_items_headers(response: Response):</span>
<span>        response.headers["X-Cat-Dog"] = "Alone in the world"</span>
<span>
    “””
    return self.router.head(
        path,
        response_model=response_model,
        status_code=status_code,
        tags=tags,
        dependencies=dependencies,
        summary=summary,
        description=description,
        response_description=response_description,
        responses=responses,
        deprecated=deprecated,
        operation_id=operation_id,
        response_model_include=response_model_include,
        response_model_exclude=response_model_exclude,
        response_model_by_alias=response_model_by_alias,
        response_model_exclude_unset=response_model_exclude_unset,
        response_model_exclude_defaults=response_model_exclude_defaults,
        response_model_exclude_none=response_model_exclude_none,
        include_in_schema=include_in_schema,
        response_class=response_class,
        name=name,
        callbacks=callbacks,
        openapi_extra=openapi_extra,
        generate_unique_id_function=generate_unique_id_function,
    )

patch

patch(
    path,
    *,
    response_model=Default(None),
    status_code=None,
    tags=None,
    dependencies=None,
    summary=None,
    description=None,
    response_description="Successful Response",
    responses=None,
    deprecated=None,
    operation_id=None,
    response_model_include=None,
    response_model_exclude=None,
    response_model_by_alias=True,
    response_model_exclude_unset=False,
    response_model_exclude_defaults=False,
    response_model_exclude_none=False,
    include_in_schema=True,
    response_class=Default(JSONResponse),
    name=None,
    callbacks=None,
    openapi_extra=None,
    generate_unique_id_function=Default(generate_unique_id)
)

Add a path operation using an HTTP PATCH operation.

Example
from fastapi import FastAPI
from pydantic import BaseModel

class Item(BaseModel):
    name: str
    description: str | None = None

app = FastAPI()

@app.patch("/items/")
def update_item(item: Item):
    return {"message": "Item updated in place"}
PARAMETERDESCRIPTION
path

The URL path to be used for this path operation.

For example, in http://example.com/items, the path is /items.

TYPE: str

response_model

The type to use for the response.

It could be any valid Pydantic field type. So, it doesn’t have to be a Pydantic model, it could be other things, like a list, dict, etc.

It will be used for:

  • Documentation: the generated OpenAPI (and the UI at /docs) will show it as the response (JSON Schema).
  • Serialization: you could return an arbitrary object and the response_model would be used to serialize that object into the corresponding JSON.
  • Filtering: the JSON sent to the client will only contain the data (fields) defined in the response_model. If you returned an object that contains an attribute password but the response_model does not include that field, the JSON sent to the client would not have that password.
  • Validation: whatever you return will be serialized with the response_model, converting any data as necessary to generate the corresponding JSON. But if the data in the object returned is not valid, that would mean a violation of the contract with the client, so it’s an error from the API developer. So, FastAPI will raise an error and return a 500 error code (Internal Server Error).

Read more about it in the FastAPI docs for Response Model.

TYPE: Any DEFAULT: Default(None)

status_code

The default status code to be used for the response.

You could override the status code by returning a response directly.

Read more about it in the FastAPI docs for Response Status Code.

TYPE: Optional[int] DEFAULT: None

tags

A list of tags to be applied to the path operation.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[List[Union[str, Enum]]] DEFAULT: None

dependencies

A list of dependencies (using Depends()) to be applied to the path operation.

Read more about it in the FastAPI docs for Dependencies in path operation decorators.

TYPE: Optional[Sequence[Depends]] DEFAULT: None

summary

A summary for the path operation.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[str] DEFAULT: None

description

A description for the path operation.

If not provided, it will be extracted automatically from the docstring of the path operation function.

It can contain Markdown.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[str] DEFAULT: None

response_description

The description for the default response.

It will be added to the generated OpenAPI (e.g. visible at /docs).

TYPE: str DEFAULT: ‘Successful Response’

responses

Additional responses that could be returned by this path operation.

It will be added to the generated OpenAPI (e.g. visible at /docs).

TYPE: Optional[Dict[Union[int, str], Dict[str, Any]]] DEFAULT: None

deprecated

Mark this path operation as deprecated.

It will be added to the generated OpenAPI (e.g. visible at /docs).

TYPE: Optional[bool] DEFAULT: None

operation_id

Custom operation ID to be used by this path operation.

By default, it is generated automatically.

If you provide a custom operation ID, you need to make sure it is unique for the whole API.

You can customize the operation ID generation with the parameter generate_unique_id_function in the FastAPI class.

Read more about it in the FastAPI docs about how to Generate Clients.

TYPE: Optional[str] DEFAULT: None

response_model_include

Configuration passed to Pydantic to include only certain fields in the response data.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: Optional[IncEx] DEFAULT: None

response_model_exclude

Configuration passed to Pydantic to exclude certain fields in the response data.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: Optional[IncEx] DEFAULT: None

response_model_by_alias

Configuration passed to Pydantic to define if the response model should be serialized by alias when an alias is used.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: True

response_model_exclude_unset

Configuration passed to Pydantic to define if the response data should have all the fields, including the ones that were not set and have their default values. This is different from response_model_exclude_defaults in that if the fields are set, they will be included in the response, even if the value is the same as the default.

When True, default values are omitted from the response.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: False

response_model_exclude_defaults

Configuration passed to Pydantic to define if the response data should have all the fields, including the ones that have the same value as the default. This is different from response_model_exclude_unset in that if the fields are set but contain the same default values, they will be excluded from the response.

When True, default values are omitted from the response.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: False

response_model_exclude_none

Configuration passed to Pydantic to define if the response data should exclude fields set to None.

This is much simpler (less smart) than response_model_exclude_unset and response_model_exclude_defaults. You probably want to use one of those two instead of this one, as those allow returning None values when it makes sense.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: False

include_in_schema

Include this path operation in the generated OpenAPI schema.

This affects the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Query Parameters and String Validations.

TYPE: bool DEFAULT: True

response_class

Response class to be used for this path operation.

This will not be used if you return a response directly.

Read more about it in the FastAPI docs for Custom Response - HTML, Stream, File, others.

TYPE: Type[Response] DEFAULT: Default(JSONResponse)

name

Name for this path operation. Only used internally.

TYPE: Optional[str] DEFAULT: None

callbacks

List of path operations that will be used as OpenAPI callbacks.

This is only for OpenAPI documentation, the callbacks won’t be used directly.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for OpenAPI Callbacks.

TYPE: Optional[List[BaseRoute]] DEFAULT: None

openapi_extra

Extra metadata to be included in the OpenAPI schema for this path operation.

Read more about it in the FastAPI docs for Path Operation Advanced Configuration.

TYPE: Optional[Dict[str, Any]] DEFAULT: None

generate_unique_id_function

Customize the function used to generate unique IDs for the path operations shown in the generated OpenAPI.

This is particularly useful when automatically generating clients or SDKs for your API.

Read more about it in the FastAPI docs about how to Generate Clients.

TYPE: Callable[[APIRoute], str] DEFAULT: Default(generate_unique_id)

Source code in fastapi/applications.py

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def patch(
    self,
    path: Annotated[
        str,
        Doc(
            “””
            The URL path to be used for this path operation.

            For example, in http://example.com/items, the path is /items.
            “””
        ),
    ],
    ,
    response_model: Annotated[
        Any,
        Doc(
            “””
            The type to use for the response.

            It could be any valid Pydantic field type. So, it doesn’t have to
            be a Pydantic model, it could be other things, like a list, dict,
            etc.

            It will be used for:

             Documentation: the generated OpenAPI (and the UI at /docs) will
                show it as the response (JSON Schema).
             Serialization: you could return an arbitrary object and the
                response_model would be used to serialize that object into the
                corresponding JSON.
             Filtering: the JSON sent to the client will only contain the data
                (fields) defined in the response_model. If you returned an object
                that contains an attribute password but the response_model does
                not include that field, the JSON sent to the client would not have
                that password.
             Validation: whatever you return will be serialized with the
                response_model, converting any data as necessary to generate the
                corresponding JSON. But if the data in the object returned is not
                valid, that would mean a violation of the contract with the client,
                so it’s an error from the API developer. So, FastAPI will raise an
                error and return a 500 error code (Internal Server Error).

            Read more about it in the
            FastAPI docs for Response Model.
            “””
        ),
    ] = Default(None),
    status_code: Annotated[
        Optional[int],
        Doc(
            “””
            The default status code to be used for the response.

            You could override the status code by returning a response directly.

            Read more about it in the
            FastAPI docs for Response Status Code.
            “””
        ),
    ] = None,
    tags: Annotated[
        Optional[List[Union[str, Enum]]],
        Doc(
            “””
            A list of tags to be applied to the path operation.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    dependencies: Annotated[
        Optional[Sequence[Depends]],
        Doc(
            “””
            A list of dependencies (using Depends()) to be applied to the
            path operation.

            Read more about it in the
            FastAPI docs for Dependencies in path operation decorators.
            “””
        ),
    ] = None,
    summary: Annotated[
        Optional[str],
        Doc(
            “””
            A summary for the path operation.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    description: Annotated[
        Optional[str],
        Doc(
            “””
            A description for the path operation.

            If not provided, it will be extracted automatically from the docstring
            of the path operation function.

            It can contain Markdown.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    response_description: Annotated[
        str,
        Doc(
            “””
            The description for the default response.

            It will be added to the generated OpenAPI (e.g. visible at /docs).
            “””
        ),
    ] = “Successful Response”,
    responses: Annotated[
        Optional[Dict[Union[int, str], Dict[str, Any]]],
        Doc(
            “””
            Additional responses that could be returned by this path operation.

            It will be added to the generated OpenAPI (e.g. visible at /docs).
            “””
        ),
    ] = None,
    deprecated: Annotated[
        Optional[bool],
        Doc(
            “””
            Mark this path operation as deprecated.

            It will be added to the generated OpenAPI (e.g. visible at /docs).
            “””
        ),
    ] = None,
    operation_id: Annotated[
        Optional[str],
        Doc(
            “””
            Custom operation ID to be used by this path operation.

            By default, it is generated automatically.

            If you provide a custom operation ID, you need to make sure it is
            unique for the whole API.

            You can customize the
            operation ID generation with the parameter
            generate_unique_id_function in the FastAPI class.

            Read more about it in the
            FastAPI docs about how to Generate Clients.
            “””
        ),
    ] = None,
    response_model_include: Annotated[
        Optional[IncEx],
        Doc(
            “””
            Configuration passed to Pydantic to include only certain fields in the
            response data.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = None,
    response_model_exclude: Annotated[
        Optional[IncEx],
        Doc(
            “””
            Configuration passed to Pydantic to exclude certain fields in the
            response data.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = None,
    response_model_by_alias: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response model
            should be serialized by alias when an alias is used.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = True,
    response_model_exclude_unset: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response data
            should have all the fields, including the ones that were not set and
            have their default values. This is different from
            response_model_exclude_defaults in that if the fields are set,
            they will be included in the response, even if the value is the same
            as the default.

            When True, default values are omitted from the response.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = False,
    response_model_exclude_defaults: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response data
            should have all the fields, including the ones that have the same value
            as the default. This is different from response_model_exclude_unset
            in that if the fields are set but contain the same default values,
            they will be excluded from the response.

            When True, default values are omitted from the response.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = False,
    response_model_exclude_none: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response data should
            exclude fields set to None.

            This is much simpler (less smart) than response_model_exclude_unset
            and response_model_exclude_defaults. You probably want to use one of
            those two instead of this one, as those allow returning None values
            when it makes sense.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = False,
    include_in_schema: Annotated[
        bool,
        Doc(
            “””
            Include this path operation in the generated OpenAPI schema.

            This affects the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Query Parameters and String Validations.
            “””
        ),
    ] = True,
    response_class: Annotated[
        Type[Response],
        Doc(
            “””
            Response class to be used for this path operation.

            This will not be used if you return a response directly.

            Read more about it in the
            FastAPI docs for Custom Response - HTML, Stream, File, others.
            “””
        ),
    ] = Default(JSONResponse),
    name: Annotated[
        Optional[str],
        Doc(
            “””
            Name for this path operation. Only used internally.
            “””
        ),
    ] = None,
    callbacks: Annotated[
        Optional[List[BaseRoute]],
        Doc(
            “””
            List of path operations that will be used as OpenAPI callbacks.

            This is only for OpenAPI documentation, the callbacks won’t be used
            directly.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for OpenAPI Callbacks.
            “””
        ),
    ] = None,
    openapi_extra: Annotated[
        Optional[Dict[str, Any]],
        Doc(
            “””
            Extra metadata to be included in the OpenAPI schema for this path
            operation.

            Read more about it in the
            FastAPI docs for Path Operation Advanced Configuration.
            “””
        ),
    ] = None,
    generate_unique_id_function: Annotated[
        Callable[[routing.APIRoute], str],
        Doc(
            “””
            Customize the function used to generate unique IDs for the path
            operations shown in the generated OpenAPI.

            This is particularly useful when automatically generating clients or
            SDKs for your API.

            Read more about it in the
            FastAPI docs about how to Generate Clients.
            “””
        ),
    ] = Default(generate_unique_id),
) -> Callable[[DecoratedCallable], DecoratedCallable]:
    “””
    Add a path operation* using an HTTP PATCH operation.

    ## Example

    python</span>
<span>    from fastapi import FastAPI</span>
<span>    from pydantic import BaseModel</span>

<span>    class Item(BaseModel):</span>
<span>        name: str</span>
<span>        description: str | None = None</span>

<span>    app = FastAPI()</span>

<span>    @app.patch("/items/")</span>
<span>    def update_item(item: Item):</span>
<span>        return {"message": "Item updated in place"}</span>
<span>
    “””
    return self.router.patch(
        path,
        response_model=response_model,
        status_code=status_code,
        tags=tags,
        dependencies=dependencies,
        summary=summary,
        description=description,
        response_description=response_description,
        responses=responses,
        deprecated=deprecated,
        operation_id=operation_id,
        response_model_include=response_model_include,
        response_model_exclude=response_model_exclude,
        response_model_by_alias=response_model_by_alias,
        response_model_exclude_unset=response_model_exclude_unset,
        response_model_exclude_defaults=response_model_exclude_defaults,
        response_model_exclude_none=response_model_exclude_none,
        include_in_schema=include_in_schema,
        response_class=response_class,
        name=name,
        callbacks=callbacks,
        openapi_extra=openapi_extra,
        generate_unique_id_function=generate_unique_id_function,
    )

trace

trace(
    path,
    *,
    response_model=Default(None),
    status_code=None,
    tags=None,
    dependencies=None,
    summary=None,
    description=None,
    response_description="Successful Response",
    responses=None,
    deprecated=None,
    operation_id=None,
    response_model_include=None,
    response_model_exclude=None,
    response_model_by_alias=True,
    response_model_exclude_unset=False,
    response_model_exclude_defaults=False,
    response_model_exclude_none=False,
    include_in_schema=True,
    response_class=Default(JSONResponse),
    name=None,
    callbacks=None,
    openapi_extra=None,
    generate_unique_id_function=Default(generate_unique_id)
)

Add a path operation using an HTTP TRACE operation.

Example
from fastapi import FastAPI

app = FastAPI()

@app.put("/items/{item_id}")
def trace_item(item_id: str):
    return None
PARAMETERDESCRIPTION
path

The URL path to be used for this path operation.

For example, in http://example.com/items, the path is /items.

TYPE: str

response_model

The type to use for the response.

It could be any valid Pydantic field type. So, it doesn’t have to be a Pydantic model, it could be other things, like a list, dict, etc.

It will be used for:

  • Documentation: the generated OpenAPI (and the UI at /docs) will show it as the response (JSON Schema).
  • Serialization: you could return an arbitrary object and the response_model would be used to serialize that object into the corresponding JSON.
  • Filtering: the JSON sent to the client will only contain the data (fields) defined in the response_model. If you returned an object that contains an attribute password but the response_model does not include that field, the JSON sent to the client would not have that password.
  • Validation: whatever you return will be serialized with the response_model, converting any data as necessary to generate the corresponding JSON. But if the data in the object returned is not valid, that would mean a violation of the contract with the client, so it’s an error from the API developer. So, FastAPI will raise an error and return a 500 error code (Internal Server Error).

Read more about it in the FastAPI docs for Response Model.

TYPE: Any DEFAULT: Default(None)

status_code

The default status code to be used for the response.

You could override the status code by returning a response directly.

Read more about it in the FastAPI docs for Response Status Code.

TYPE: Optional[int] DEFAULT: None

tags

A list of tags to be applied to the path operation.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[List[Union[str, Enum]]] DEFAULT: None

dependencies

A list of dependencies (using Depends()) to be applied to the path operation.

Read more about it in the FastAPI docs for Dependencies in path operation decorators.

TYPE: Optional[Sequence[Depends]] DEFAULT: None

summary

A summary for the path operation.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[str] DEFAULT: None

description

A description for the path operation.

If not provided, it will be extracted automatically from the docstring of the path operation function.

It can contain Markdown.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Path Operation Configuration.

TYPE: Optional[str] DEFAULT: None

response_description

The description for the default response.

It will be added to the generated OpenAPI (e.g. visible at /docs).

TYPE: str DEFAULT: ‘Successful Response’

responses

Additional responses that could be returned by this path operation.

It will be added to the generated OpenAPI (e.g. visible at /docs).

TYPE: Optional[Dict[Union[int, str], Dict[str, Any]]] DEFAULT: None

deprecated

Mark this path operation as deprecated.

It will be added to the generated OpenAPI (e.g. visible at /docs).

TYPE: Optional[bool] DEFAULT: None

operation_id

Custom operation ID to be used by this path operation.

By default, it is generated automatically.

If you provide a custom operation ID, you need to make sure it is unique for the whole API.

You can customize the operation ID generation with the parameter generate_unique_id_function in the FastAPI class.

Read more about it in the FastAPI docs about how to Generate Clients.

TYPE: Optional[str] DEFAULT: None

response_model_include

Configuration passed to Pydantic to include only certain fields in the response data.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: Optional[IncEx] DEFAULT: None

response_model_exclude

Configuration passed to Pydantic to exclude certain fields in the response data.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: Optional[IncEx] DEFAULT: None

response_model_by_alias

Configuration passed to Pydantic to define if the response model should be serialized by alias when an alias is used.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: True

response_model_exclude_unset

Configuration passed to Pydantic to define if the response data should have all the fields, including the ones that were not set and have their default values. This is different from response_model_exclude_defaults in that if the fields are set, they will be included in the response, even if the value is the same as the default.

When True, default values are omitted from the response.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: False

response_model_exclude_defaults

Configuration passed to Pydantic to define if the response data should have all the fields, including the ones that have the same value as the default. This is different from response_model_exclude_unset in that if the fields are set but contain the same default values, they will be excluded from the response.

When True, default values are omitted from the response.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: False

response_model_exclude_none

Configuration passed to Pydantic to define if the response data should exclude fields set to None.

This is much simpler (less smart) than response_model_exclude_unset and response_model_exclude_defaults. You probably want to use one of those two instead of this one, as those allow returning None values when it makes sense.

Read more about it in the FastAPI docs for Response Model - Return Type.

TYPE: bool DEFAULT: False

include_in_schema

Include this path operation in the generated OpenAPI schema.

This affects the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for Query Parameters and String Validations.

TYPE: bool DEFAULT: True

response_class

Response class to be used for this path operation.

This will not be used if you return a response directly.

Read more about it in the FastAPI docs for Custom Response - HTML, Stream, File, others.

TYPE: Type[Response] DEFAULT: Default(JSONResponse)

name

Name for this path operation. Only used internally.

TYPE: Optional[str] DEFAULT: None

callbacks

List of path operations that will be used as OpenAPI callbacks.

This is only for OpenAPI documentation, the callbacks won’t be used directly.

It will be added to the generated OpenAPI (e.g. visible at /docs).

Read more about it in the FastAPI docs for OpenAPI Callbacks.

TYPE: Optional[List[BaseRoute]] DEFAULT: None

openapi_extra

Extra metadata to be included in the OpenAPI schema for this path operation.

Read more about it in the FastAPI docs for Path Operation Advanced Configuration.

TYPE: Optional[Dict[str, Any]] DEFAULT: None

generate_unique_id_function

Customize the function used to generate unique IDs for the path operations shown in the generated OpenAPI.

This is particularly useful when automatically generating clients or SDKs for your API.

Read more about it in the FastAPI docs about how to Generate Clients.

TYPE: Callable[[APIRoute], str] DEFAULT: Default(generate_unique_id)

Source code in fastapi/applications.py

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def trace(
    self,
    path: Annotated[
        str,
        Doc(
            “””
            The URL path to be used for this path operation.

            For example, in http://example.com/items, the path is /items.
            “””
        ),
    ],
    ,
    response_model: Annotated[
        Any,
        Doc(
            “””
            The type to use for the response.

            It could be any valid Pydantic field type. So, it doesn’t have to
            be a Pydantic model, it could be other things, like a list, dict,
            etc.

            It will be used for:

             Documentation: the generated OpenAPI (and the UI at /docs) will
                show it as the response (JSON Schema).
             Serialization: you could return an arbitrary object and the
                response_model would be used to serialize that object into the
                corresponding JSON.
             Filtering: the JSON sent to the client will only contain the data
                (fields) defined in the response_model. If you returned an object
                that contains an attribute password but the response_model does
                not include that field, the JSON sent to the client would not have
                that password.
             Validation: whatever you return will be serialized with the
                response_model, converting any data as necessary to generate the
                corresponding JSON. But if the data in the object returned is not
                valid, that would mean a violation of the contract with the client,
                so it’s an error from the API developer. So, FastAPI will raise an
                error and return a 500 error code (Internal Server Error).

            Read more about it in the
            FastAPI docs for Response Model.
            “””
        ),
    ] = Default(None),
    status_code: Annotated[
        Optional[int],
        Doc(
            “””
            The default status code to be used for the response.

            You could override the status code by returning a response directly.

            Read more about it in the
            FastAPI docs for Response Status Code.
            “””
        ),
    ] = None,
    tags: Annotated[
        Optional[List[Union[str, Enum]]],
        Doc(
            “””
            A list of tags to be applied to the path operation.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    dependencies: Annotated[
        Optional[Sequence[Depends]],
        Doc(
            “””
            A list of dependencies (using Depends()) to be applied to the
            path operation.

            Read more about it in the
            FastAPI docs for Dependencies in path operation decorators.
            “””
        ),
    ] = None,
    summary: Annotated[
        Optional[str],
        Doc(
            “””
            A summary for the path operation.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    description: Annotated[
        Optional[str],
        Doc(
            “””
            A description for the path operation.

            If not provided, it will be extracted automatically from the docstring
            of the path operation function.

            It can contain Markdown.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Path Operation Configuration.
            “””
        ),
    ] = None,
    response_description: Annotated[
        str,
        Doc(
            “””
            The description for the default response.

            It will be added to the generated OpenAPI (e.g. visible at /docs).
            “””
        ),
    ] = “Successful Response”,
    responses: Annotated[
        Optional[Dict[Union[int, str], Dict[str, Any]]],
        Doc(
            “””
            Additional responses that could be returned by this path operation.

            It will be added to the generated OpenAPI (e.g. visible at /docs).
            “””
        ),
    ] = None,
    deprecated: Annotated[
        Optional[bool],
        Doc(
            “””
            Mark this path operation as deprecated.

            It will be added to the generated OpenAPI (e.g. visible at /docs).
            “””
        ),
    ] = None,
    operation_id: Annotated[
        Optional[str],
        Doc(
            “””
            Custom operation ID to be used by this path operation.

            By default, it is generated automatically.

            If you provide a custom operation ID, you need to make sure it is
            unique for the whole API.

            You can customize the
            operation ID generation with the parameter
            generate_unique_id_function in the FastAPI class.

            Read more about it in the
            FastAPI docs about how to Generate Clients.
            “””
        ),
    ] = None,
    response_model_include: Annotated[
        Optional[IncEx],
        Doc(
            “””
            Configuration passed to Pydantic to include only certain fields in the
            response data.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = None,
    response_model_exclude: Annotated[
        Optional[IncEx],
        Doc(
            “””
            Configuration passed to Pydantic to exclude certain fields in the
            response data.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = None,
    response_model_by_alias: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response model
            should be serialized by alias when an alias is used.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = True,
    response_model_exclude_unset: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response data
            should have all the fields, including the ones that were not set and
            have their default values. This is different from
            response_model_exclude_defaults in that if the fields are set,
            they will be included in the response, even if the value is the same
            as the default.

            When True, default values are omitted from the response.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = False,
    response_model_exclude_defaults: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response data
            should have all the fields, including the ones that have the same value
            as the default. This is different from response_model_exclude_unset
            in that if the fields are set but contain the same default values,
            they will be excluded from the response.

            When True, default values are omitted from the response.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = False,
    response_model_exclude_none: Annotated[
        bool,
        Doc(
            “””
            Configuration passed to Pydantic to define if the response data should
            exclude fields set to None.

            This is much simpler (less smart) than response_model_exclude_unset
            and response_model_exclude_defaults. You probably want to use one of
            those two instead of this one, as those allow returning None values
            when it makes sense.

            Read more about it in the
            FastAPI docs for Response Model - Return Type.
            “””
        ),
    ] = False,
    include_in_schema: Annotated[
        bool,
        Doc(
            “””
            Include this path operation in the generated OpenAPI schema.

            This affects the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for Query Parameters and String Validations.
            “””
        ),
    ] = True,
    response_class: Annotated[
        Type[Response],
        Doc(
            “””
            Response class to be used for this path operation.

            This will not be used if you return a response directly.

            Read more about it in the
            FastAPI docs for Custom Response - HTML, Stream, File, others.
            “””
        ),
    ] = Default(JSONResponse),
    name: Annotated[
        Optional[str],
        Doc(
            “””
            Name for this path operation. Only used internally.
            “””
        ),
    ] = None,
    callbacks: Annotated[
        Optional[List[BaseRoute]],
        Doc(
            “””
            List of path operations that will be used as OpenAPI callbacks.

            This is only for OpenAPI documentation, the callbacks won’t be used
            directly.

            It will be added to the generated OpenAPI (e.g. visible at /docs).

            Read more about it in the
            FastAPI docs for OpenAPI Callbacks.
            “””
        ),
    ] = None,
    openapi_extra: Annotated[
        Optional[Dict[str, Any]],
        Doc(
            “””
            Extra metadata to be included in the OpenAPI schema for this path
            operation.

            Read more about it in the
            FastAPI docs for Path Operation Advanced Configuration.
            “””
        ),
    ] = None,
    generate_unique_id_function: Annotated[
        Callable[[routing.APIRoute], str],
        Doc(
            “””
            Customize the function used to generate unique IDs for the path
            operations shown in the generated OpenAPI.

            This is particularly useful when automatically generating clients or
            SDKs for your API.

            Read more about it in the
            FastAPI docs about how to Generate Clients.
            “””
        ),
    ] = Default(generate_unique_id),
) -> Callable[[DecoratedCallable], DecoratedCallable]:
    “””
    Add a path operation* using an HTTP TRACE operation.

    ## Example

    python</span>
<span>    from fastapi import FastAPI</span>

<span>    app = FastAPI()</span>

<span>    @app.put("/items/{item_id}")</span>
<span>    def trace_item(item_id: str):</span>
<span>        return None</span>
<span>
    “””
    return self.router.trace(
        path,
        response_model=response_model,
        status_code=status_code,
        tags=tags,
        dependencies=dependencies,
        summary=summary,
        description=description,
        response_description=response_description,
        responses=responses,
        deprecated=deprecated,
        operation_id=operation_id,
        response_model_include=response_model_include,
        response_model_exclude=response_model_exclude,
        response_model_by_alias=response_model_by_alias,
        response_model_exclude_unset=response_model_exclude_unset,
        response_model_exclude_defaults=response_model_exclude_defaults,
        response_model_exclude_none=response_model_exclude_none,
        include_in_schema=include_in_schema,
        response_class=response_class,
        name=name,
        callbacks=callbacks,
        openapi_extra=openapi_extra,
        generate_unique_id_function=generate_unique_id_function,
    )

on_event

on_event(event_type)

Add an event handler for the application.

on_event is deprecated, use lifespan event handlers instead.

Read more about it in the FastAPI docs for Lifespan Events.

PARAMETERDESCRIPTION
event_type

The type of event. startup or shutdown.

TYPE: str

Source code in fastapi/applications.py

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@deprecated(
    “””
    on_event is deprecated, use lifespan event handlers instead.

    Read more about it in the
    FastAPI docs for Lifespan Events.
    “””
)
def on_event(
    self,
    event_type: Annotated[
        str,
        Doc(
            “””
            The type of event. startup or shutdown.
            “””
        ),
    ],
) -> Callable[[DecoratedCallable], DecoratedCallable]:
    “””
    Add an event handler for the application.

    on_event is deprecated, use lifespan event handlers instead.

    Read more about it in the
    FastAPI docs for Lifespan Events.
    “””
    return self.router.on_event(event_type)

middleware

middleware(middleware_type)

Add a middleware to the application.

Read more about it in the FastAPI docs for Middleware.

Example
import time

from fastapi import FastAPI, Request

app = FastAPI()

@app.middleware("http")
async def add_process_time_header(request: Request, call_next):
    start_time = time.time()
    response = await call_next(request)
    process_time = time.time() - start_time
    response.headers["X-Process-Time"] = str(process_time)
    return response
PARAMETERDESCRIPTION
middleware_type

The type of middleware. Currently only supports http.

TYPE: str

Source code in fastapi/applications.py

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def middleware(
    self,
    middleware_type: Annotated[
        str,
        Doc(
            “””
            The type of middleware. Currently only supports http.
            “””
        ),
    ],
) -> Callable[[DecoratedCallable], DecoratedCallable]:
    “””
    Add a middleware to the application.

    Read more about it in the
    FastAPI docs for Middleware.

    ## Example

    python</span>
<span>    import time</span>

<span>    from fastapi import FastAPI, Request</span>

<span>    app = FastAPI()</span>


<span>    @app.middleware("http")</span>
<span>    async def add_process_time_header(request: Request, call_next):</span>
<span>        start_time = time.time()</span>
<span>        response = await call_next(request)</span>
<span>        process_time = time.time() - start_time</span>
<span>        response.headers["X-Process-Time"] = str(process_time)</span>
<span>        return response</span>
<span>
    “””

    def decorator(func: DecoratedCallable) -> DecoratedCallable:
        self.add_middleware(BaseHTTPMiddleware, dispatch=func)
        return func

    return decorator

exception_handler

exception_handler(exc_class_or_status_code)

Add an exception handler to the app.

Read more about it in the FastAPI docs for Handling Errors.

Example
from fastapi import FastAPI, Request
from fastapi.responses import JSONResponse

class UnicornException(Exception):
    def __init__(self, name: str):
        self.name = name

app = FastAPI()

@app.exception_handler(UnicornException)
async def unicorn_exception_handler(request: Request, exc: UnicornException):
    return JSONResponse(
        status_code=418,
        content={"message": f"Oops! {exc.name} did something. There goes a rainbow..."},
    )
PARAMETERDESCRIPTION
exc_class_or_status_code

The Exception class this would handle, or a status code.

TYPE: Union[int, Type[Exception]]

Source code in fastapi/applications.py

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def exceptionhandler(
    self,
    excclass_or_status_code: Annotated[
        Union[int, Type[Exception]],
        Doc(
            “””
            The Exception class this would handle, or a status code.
            “””
        ),
    ],
) -> Callable[[DecoratedCallable], DecoratedCallable]:
    “””
    Add an exception handler to the app.

    Read more about it in the
    FastAPI docs for Handling Errors.

    ## Example

    ```python
    from fastapi import FastAPI, Request
    from fastapi.responses import JSONResponse


    class UnicornException(Exception):
        def __init(self, name: str):
            self.name = name


    app = FastAPI()


    @app.exception_handler(UnicornException)
    async def unicorn_exception_handler(request: Request, exc: UnicornException):
        return JSONResponse(
            status_code=418,
            content={“message”: f”Oops! {exc.name} did something. There goes a rainbow…”},
        )
    ```
    “””

    def decorator(func: DecoratedCallable) -> DecoratedCallable:
        self.add_exception_handler(exc_class_or_status_code, func)
        return func

    return decorator