MCPcopy
hub / github.com/fastapi/fastapi / __init__

Method __init__

fastapi/applications.py:58–1018  ·  view source on GitHub ↗
(
        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](https://www.starlette.dev/applications/#instantiating-the-application).
                """
            ),
        ] = False,
        routes: Annotated[
            list[BaseRoute] | None,
            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](https://fastapi.tiangolo.com/tutorial/metadata/#metadata-for-api).

                **Example**

                ```python
                from fastapi import FastAPI

                app = FastAPI(title="ChimichangApp")
                ```
                """
            ),
        ] = "FastAPI",
        summary: Annotated[
            str | None,
            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](https://fastapi.tiangolo.com/tutorial/metadata/#metadata-for-api).

                **Example**

                ```python
                from fastapi import FastAPI

                app = FastAPI(summary="Deadpond's favorite app. Nuff said.")
                ```
                """
            ),
        ] = None,
        description: Annotated[
            str,
            Doc(
                '''
                A description of the API. Supports Markdown (using
                [CommonMark syntax](https://commonmark.org/)).

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

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

                **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_).

                                """
                )
                ```
                '''
            ),
        ] = "",
        version: Annotated[
            str,
            Doc(
                """
                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](https://fastapi.tiangolo.com/tutorial/metadata/#metadata-for-api).

                **Example**

                ```python
                from fastapi import FastAPI

                app = FastAPI(version="0.0.1")
                ```
                """
            ),
        ] = "0.1.0",
        openapi_url: Annotated[
            str | None,
            Doc(
                """
                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](https://fastapi.tiangolo.com/tutorial/metadata/#openapi-url).

                **Example**

                ```python
                from fastapi import FastAPI

                app = FastAPI(openapi_url="/api/v1/openapi.json")
                ```
                """
            ),
        ] = "/openapi.json",
        openapi_tags: Annotated[
            list[dict[str, Any]] | None,
            Doc(
                """
                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](https://commonmark.org/) 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](https://commonmark.org/) 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](https://fastapi.tiangolo.com/tutorial/metadata/#metadata-for-tags).

                **Example**

                ```python
                from fastapi import FastAPI

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

                app = FastAPI(openapi_tags=tags_metadata)
                ```
                """
            ),
        ] = None,
        servers: Annotated[
            list[dict[str, str | Any]] | None,
            Doc(
                """
                A `list` of `dict`s 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
                `servers` property in the generated OpenAPI will be:

                * a `dict` with a `url` value of the application's mounting point
                (`root_path`) if it's different from `/`.
                * otherwise, the `servers` property will be omitted from the OpenAPI
                schema.

                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](https://commonmark.org/) 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](https://fastapi.tiangolo.com/advanced/behind-a-proxy/#additional-servers).

                **Example**

                ```python
                from fastapi import FastAPI

                app = FastAPI(
                    servers=[
                        {"url": "https://stag.example.com", "description": "Staging environment"},
                        {"url": "https://prod.example.com", "description": "Production environment"},
                    ]
                )
                ```
                """
            ),
        ] = None,
        dependencies: Annotated[
            Sequence[Depends] | None,
            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](https://fastapi.tiangolo.com/tutorial/dependencies/global-dependencies/).

                **Example**

                ```python
                from fastapi import Depends, FastAPI

                from .dependencies import func_dep_1, func_dep_2

                app = FastAPI(dependencies=[Depends(func_dep_1), Depends(func_dep_2)])
                ```
                """
            ),
        ] = 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](https://fastapi.tiangolo.com/advanced/custom-response/#default-response-class).

                **Example**

                ```python
                from fastapi import FastAPI
                from fastapi.responses import ORJSONResponse

                app = FastAPI(default_response_class=ORJSONResponse)
                ```
                """
            ),
        ] = 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
                from fastapi import FastAPI

                app = FastAPI(redirect_slashes=True)  # the default

                @app.get("/items/")
                async def read_items():
                    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/`.
                """
            ),
        ] = True,
        docs_url: Annotated[
            str | None,
            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](https://fastapi.tiangolo.com/tutorial/metadata/#docs-urls).

                **Example**

                ```python
                from fastapi import FastAPI

                app = FastAPI(docs_url="/documentation", redoc_url=None)
                ```
                """
            ),
        ] = "/docs",
        redoc_url: Annotated[
            str | None,
            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](https://fastapi.tiangolo.com/tutorial/metadata/#docs-urls).

                **Example**

                ```python
                from fastapi import FastAPI

                app = FastAPI(docs_url="/documentation", redoc_url="redocumentation")
                ```
                """
            ),
        ] = "/redoc",
        swagger_ui_oauth2_redirect_url: Annotated[
            str | None,
            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[
            dict[str, Any] | None,
            Doc(
                """
                OAuth2 configuration for the Swagger UI, by default shown at `/docs`.

                Read more about the available configuration options in the
                [Swagger UI docs](https://swagger.io/docs/open-source-tools/swagger-ui/usage/oauth2/).
                """
            ),
        ] = None,
        middleware: Annotated[
            Sequence[Middleware] | None,
            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](https://fastapi.tiangolo.com/tutorial/middleware/).
                """
            ),
        ] = None,
        exception_handlers: Annotated[
            dict[
                int | type[Exception],
                Callable[[Request, Any], Coroutine[Any, Any, Response]],
            ]
            | None,
            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](https://fastapi.tiangolo.com/tutorial/handling-errors/).
                """
            ),
        ] = None,
        on_startup: Annotated[
            Sequence[Callable[[], Any]] | None,
            Doc(
                """
                A list of startup event handler functions.

                You should instead use the `lifespan` handlers.

                Read more in the [FastAPI docs for `lifespan`](https://fastapi.tiangolo.com/advanced/events/).
                """
            ),
        ] = None,
        on_shutdown: Annotated[
            Sequence[Callable[[], Any]] | None,
            Doc(
                """
                A list of shutdown event handler functions.

                You should instead use the `lifespan` handlers.

                Read more in the
                [FastAPI docs for `lifespan`](https://fastapi.tiangolo.com/advanced/events/).
                """
            ),
        ] = None,
        lifespan: Annotated[
            Lifespan[AppType] | None,
            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`](https://fastapi.tiangolo.com/advanced/events/).
                """
            ),
        ] = None,
        terms_of_service: Annotated[
            str | None,
            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](https://fastapi.tiangolo.com/tutorial/metadata/#metadata-for-api).

                **Example**

                ```python
                app = FastAPI(terms_of_service="http://example.com/terms/")
                ```
                """
            ),
        ] = None,
        contact: Annotated[
            dict[str, str | Any] | None,
            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](https://fastapi.tiangolo.com/tutorial/metadata/#metadata-for-api).

                **Example**

                ```python
                app = FastAPI(
                    contact={
                        "name": "Deadpoolio the Amazing",
                        "url": "http://x-force.example.com/contact/",
                        "email": "dp@x-force.example.com",
                    }
                )
                ```
                """
            ),
        ] = None,
        license_info: Annotated[
            dict[str, str | Any] | None,
            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](https://spdx.dev/) 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](https://fastapi.tiangolo.com/tutorial/metadata/#metadata-for-api).

                **Example**

                ```python
                app = FastAPI(
                    license_info={
                        "name": "Apache 2.0",
                        "url": "https://www.apache.org/licenses/LICENSE-2.0.html",
                    }
                )
                ```
                """
            ),
        ] = 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](https://fastapi.tiangolo.com/advanced/behind-a-proxy/).

                **Example**

                ```python
                from fastapi import FastAPI

                app = FastAPI(root_path="/api/v1")
                ```
                """
            ),
        ] = "",
        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](https://fastapi.tiangolo.com/advanced/behind-a-proxy/#disable-automatic-server-from-root-path).

                **Example**

                ```python
                from fastapi import FastAPI

                app = FastAPI(root_path_in_servers=False)
                ```
                """
            ),
        ] = True,
        responses: Annotated[
            dict[int | str, dict[str, Any]] | None,
            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](https://fastapi.tiangolo.com/advanced/additional-responses/).

                And in the
                [FastAPI docs for Bigger Applications](https://fastapi.tiangolo.com/tutorial/bigger-applications/#include-an-apirouter-with-a-custom-prefix-tags-responses-and-dependencies).
                """
            ),
        ] = None,
        callbacks: Annotated[
            list[BaseRoute] | None,
            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](https://fastapi.tiangolo.com/advanced/openapi-callbacks/).
                """
            ),
        ] = None,
        webhooks: Annotated[
            routing.APIRouter | None,
            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](https://fastapi.tiangolo.com/advanced/openapi-webhooks/).
                """
            ),
        ] = None,
        deprecated: Annotated[
            bool | None,
            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](https://fastapi.tiangolo.com/tutorial/path-operation-configuration/#deprecate-a-path-operation).
                """
            ),
        ] = 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](https://fastapi.tiangolo.com/tutorial/query-params-str-validations/#exclude-parameters-from-openapi).
                """
            ),
        ] = True,
        swagger_ui_parameters: Annotated[
            dict[str, Any] | None,
            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](https://fastapi.tiangolo.com/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](https://fastapi.tiangolo.com/advanced/generate-clients/#custom-generate-unique-id-function).
                """
            ),
        ] = 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
                from pydantic import BaseModel

                class Item(BaseModel):
                    name: str
                    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.

                Read more about it in the
                [FastAPI docs about how to separate schemas for input and output](https://fastapi.tiangolo.com/how-to/separate-openapi-schemas)
                """
            ),
        ] = True,
        openapi_external_docs: Annotated[
            dict[str, Any] | None,
            Doc(
                """
                This field allows you to provide additional external documentation links.
                If provided, it must be a dictionary containing:

                * `description`: A brief description of the external documentation.
                * `url`: The URL pointing to the external documentation. The value **MUST**
                be a valid URL format.

                **Example**:

                ```python
                from fastapi import FastAPI

                external_docs = {
                    "description": "Detailed API Reference",
                    "url": "https://example.com/api-docs",
                }

                app = FastAPI(openapi_external_docs=external_docs)
                ```
                """
            ),
        ] = None,
        strict_content_type: Annotated[
            bool,
            Doc(
                """
                Enable strict checking for request Content-Type headers.

                When `True` (the default), requests with a body that do not include
                a `Content-Type` header will **not** be parsed as JSON.

                This prevents potential cross-site request forgery (CSRF) attacks
                that exploit the browser's ability to send requests without a
                Content-Type header, bypassing CORS preflight checks. In particular
                applicable for apps that need to be run locally (in localhost).

                When `False`, requests without a `Content-Type` header will have
                their body parsed as JSON, which maintains compatibility with
                certain clients that don't send `Content-Type` headers.

                Read more about it in the
                [FastAPI docs for Strict Content-Type](https://fastapi.tiangolo.com/advanced/strict-content-type/).
                """
            ),
        ] = True,
        **extra: Annotated[
            Any,
            Doc(
                """
                Extra keyword arguments to be stored in the app, not used by FastAPI
                anywhere.
                """
            ),
        ],
    )

Source from the content-addressed store, hash-verified

56 """
57
58 def __init__(
59 self: AppType,
60 *,
61 debug: Annotated[
62 bool,
63 Doc(
64 """
65 Boolean indicating if debug tracebacks should be returned on server
66 errors.
67
68 Read more in the
69 [Starlette docs for Applications](https://www.starlette.dev/applications/#instantiating-the-application).
70 """
71 ),
72 ] = False,
73 routes: Annotated[
74 list[BaseRoute] | None,
75 Doc(
76 """
77 **Note**: you probably shouldn't use this parameter, it is inherited
78 from Starlette and supported for compatibility.
79
80 ---
81
82 A list of routes to serve incoming HTTP and WebSocket requests.
83 """
84 ),
85 deprecated(
86 """
87 You normally wouldn't use this parameter with FastAPI, it is inherited
88 from Starlette and supported for compatibility.
89
90 In FastAPI, you normally would use the *path operation methods*,
91 like `app.get()`, `app.post()`, etc.
92 """
93 ),
94 ] = None,
95 title: Annotated[
96 str,
97 Doc(
98 """
99 The title of the API.
100
101 It will be added to the generated OpenAPI (e.g. visible at `/docs`).
102
103 Read more in the
104 [FastAPI docs for Metadata and Docs URLs](https://fastapi.tiangolo.com/tutorial/metadata/#metadata-for-api).
105
106 **Example**
107
108 ```python
109 from fastapi import FastAPI
110
111 app = FastAPI(title="ChimichangApp")
112 ```
113 """
114 ),
115 ] = "FastAPI",

Callers

nothing calls this directly

Calls 3

setupMethod · 0.95
DefaultFunction · 0.90
StateClass · 0.85

Tested by

no test coverage detected