Security Tools¶
When you need to declare dependencies with OAuth2 scopes you use Security().
But you still need to define what is the dependable, the callable that you pass as a parameter to Depends() or Security().
There are multiple tools that you can use to create those dependables, and they get integrated into OpenAPI so they are shown in the automatic docs UI, they can be used by automatically generated clients and SDKs, etc.
You can import them from fastapi.security:
from fastapi.security import (
APIKeyCookie,
APIKeyHeader,
APIKeyQuery,
HTTPAuthorizationCredentials,
HTTPBasic,
HTTPBasicCredentials,
HTTPBearer,
HTTPDigest,
OAuth2,
OAuth2AuthorizationCodeBearer,
OAuth2PasswordBearer,
OAuth2PasswordRequestForm,
OAuth2PasswordRequestFormStrict,
OpenIdConnect,
SecurityScopes,
)
Read more about them in the FastAPI docs about Security.
API Key Security Schemes¶
APIKeyCookie(
*,
name,
scheme_name=None,
description=None,
auto_error=True
)
Bases: APIKeyBase
API key authentication using a cookie.
This defines the name of the cookie that should be provided in the request with the API key and integrates that into the OpenAPI documentation. It extracts the key value sent in the cookie automatically and provides it as the dependency result. But it doesn't define how to set that cookie.
Usage¶
Create an instance object and use that object as the dependency in Depends().
The dependency result will be a string containing the key value.
Example¶
from fastapi import Depends, FastAPI
from fastapi.security import APIKeyCookie
app = FastAPI()
cookie_scheme = APIKeyCookie(name="session")
@app.get("/items/")
async def read_items(session: str = Depends(cookie_scheme)):
return {"session": session}
| PARAMETER | DESCRIPTION |
|---|---|
name
|
Cookie name.
TYPE:
|
scheme_name
|
Security scheme name. It will be included in the generated OpenAPI (e.g. visible at
TYPE:
|
description
|
Security scheme description. It will be included in the generated OpenAPI (e.g. visible at
TYPE:
|
auto_error
|
By default, if the cookie is not provided, If This is useful when you want to have optional authentication. It is also useful when you want to have authentication that can be provided in one of multiple optional ways (for example, in a cookie or in an HTTP Bearer token).
TYPE:
|
Source code in fastapi/security/api_key.py
def __init__(
self,
*,
name: Annotated[str, Doc("Cookie name.")],
scheme_name: Annotated[
str | None,
Doc(
"""
Security scheme name.
It will be included in the generated OpenAPI (e.g. visible at `/docs`).
"""
),
] = None,
description: Annotated[
str | None,
Doc(
"""
Security scheme description.
It will be included in the generated OpenAPI (e.g. visible at `/docs`).
"""
),
] = None,
auto_error: Annotated[
bool,
Doc(
"""
By default, if the cookie is not provided, `APIKeyCookie` will
automatically cancel the request and send the client an error.
If `auto_error` is set to `False`, when the cookie is not available,
instead of erroring out, the dependency result will be `None`.
This is useful when you want to have optional authentication.
It is also useful when you want to have authentication that can be
provided in one of multiple optional ways (for example, in a cookie or
in an HTTP Bearer token).
"""
),
] = True,
):
super().__init__(
location=APIKeyIn.cookie,
name=name,
scheme_name=scheme_name,
description=description,
auto_error=auto_error,
)
make_not_authenticated_error()
The WWW-Authenticate header is not standardized for API Key authentication but the HTTP specification requires that an error of 401 "Unauthorized" must include a WWW-Authenticate header.
Ref: https://datatracker.ietf.org/doc/html/rfc9110#name-401-unauthorized
For this, this method sends a custom challenge APIKey.
Source code in fastapi/security/api_key.py
def make_not_authenticated_error(self) -> HTTPException:
"""
The WWW-Authenticate header is not standardized for API Key authentication but
the HTTP specification requires that an error of 401 "Unauthorized" must
include a WWW-Authenticate header.
Ref: https://datatracker.ietf.org/doc/html/rfc9110#name-401-unauthorized
For this, this method sends a custom challenge `APIKey`.
"""
return HTTPException(
status_code=HTTP_401_UNAUTHORIZED,
detail="Not authenticated",
headers={"WWW-Authenticate": "APIKey"},
)
check_api_key(api_key)
Source code in fastapi/security/api_key.py
def check_api_key(self, api_key: str | None) -> str | None:
if not api_key:
if self.auto_error:
raise self.make_not_authenticated_error()
return None
return api_key
APIKeyHeader(
*,
name,
scheme_name=None,
description=None,
auto_error=True
)
Bases: APIKeyBase
API key authentication using a header.
This defines the name of the header that should be provided in the request with the API key and integrates that into the OpenAPI documentation. It extracts the key value sent in the header automatically and provides it as the dependency result. But it doesn't define how to send that key to the client.
Usage¶
Create an instance object and use that object as the dependency in Depends().
The dependency result will be a string containing the key value.
Example¶
from fastapi import Depends, FastAPI
from fastapi.security import APIKeyHeader
app = FastAPI()
header_scheme = APIKeyHeader(name="x-key")
@app.get("/items/")
async def read_items(key: str = Depends(header_scheme)):
return {"key": key}
| PARAMETER | DESCRIPTION |
|---|---|
name
|
Header name.
TYPE:
|
scheme_name
|
Security scheme name. It will be included in the generated OpenAPI (e.g. visible at
TYPE:
|
description
|
Security scheme description. It will be included in the generated OpenAPI (e.g. visible at
TYPE:
|
auto_error
|
By default, if the header is not provided, If This is useful when you want to have optional authentication. It is also useful when you want to have authentication that can be provided in one of multiple optional ways (for example, in a header or in an HTTP Bearer token).
TYPE:
|
Source code in fastapi/security/api_key.py
def __init__(
self,
*,
name: Annotated[str, Doc("Header name.")],
scheme_name: Annotated[
str | None,
Doc(
"""
Security scheme name.
It will be included in the generated OpenAPI (e.g. visible at `/docs`).
"""
),
] = None,
description: Annotated[
str | None,
Doc(
"""
Security scheme description.
It will be included in the generated OpenAPI (e.g. visible at `/docs`).
"""
),
] = None,
auto_error: Annotated[
bool,
Doc(
"""
By default, if the header is not provided, `APIKeyHeader` will
automatically cancel the request and send the client an error.
If `auto_error` is set to `False`, when the header is not available,
instead of erroring out, the dependency result will be `None`.
This is useful when you want to have optional authentication.
It is also useful when you want to have authentication that can be
provided in one of multiple optional ways (for example, in a header or
in an HTTP Bearer token).
"""
),
] = True,
):
super().__init__(
location=APIKeyIn.header,
name=name,
scheme_name=scheme_name,
description=description,
auto_error=auto_error,
)
make_not_authenticated_error()
The WWW-Authenticate header is not standardized for API Key authentication but the HTTP specification requires that an error of 401 "Unauthorized" must include a WWW-Authenticate header.
Ref: https://datatracker.ietf.org/doc/html/rfc9110#name-401-unauthorized
For this, this method sends a custom challenge APIKey.
Source code in fastapi/security/api_key.py
def make_not_authenticated_error(self) -> HTTPException:
"""
The WWW-Authenticate header is not standardized for API Key authentication but
the HTTP specification requires that an error of 401 "Unauthorized" must
include a WWW-Authenticate header.
Ref: https://datatracker.ietf.org/doc/html/rfc9110#name-401-unauthorized
For this, this method sends a custom challenge `APIKey`.
"""
return HTTPException(
status_code=HTTP_401_UNAUTHORIZED,
detail="Not authenticated",
headers={"WWW-Authenticate": "APIKey"},
)
check_api_key(api_key)
Source code in fastapi/security/api_key.py
def check_api_key(self, api_key: str | None) -> str | None:
if not api_key:
if self.auto_error:
raise self.make_not_authenticated_error()
return None
return api_key
APIKeyQuery(
*,
name,
scheme_name=None,
description=None,
auto_error=True
)
Bases: APIKeyBase
API key authentication using a query parameter.
This defines the name of the query parameter that should be provided in the request with the API key and integrates that into the OpenAPI documentation. It extracts the key value sent in the query parameter automatically and provides it as the dependency result. But it doesn't define how to send that API key to the client.
Usage¶
Create an instance object and use that object as the dependency in Depends().
The dependency result will be a string containing the key value.
Example¶
from fastapi import Depends, FastAPI
from fastapi.security import APIKeyQuery
app = FastAPI()
query_scheme = APIKeyQuery(name="api_key")
@app.get("/items/")
async def read_items(api_key: str = Depends(query_scheme)):
return {"api_key": api_key}
| PARAMETER | DESCRIPTION |
|---|---|
name
|
Query parameter name.
TYPE:
|
scheme_name
|
Security scheme name. It will be included in the generated OpenAPI (e.g. visible at
TYPE:
|
description
|
Security scheme description. It will be included in the generated OpenAPI (e.g. visible at
TYPE:
|
auto_error
|
By default, if the query parameter is not provided, If This is useful when you want to have optional authentication. It is also useful when you want to have authentication that can be provided in one of multiple optional ways (for example, in a query parameter or in an HTTP Bearer token).
TYPE:
|
Source code in fastapi/security/api_key.py
def __init__(
self,
*,
name: Annotated[
str,
Doc("Query parameter name."),
],
scheme_name: Annotated[
str | None,
Doc(
"""
Security scheme name.
It will be included in the generated OpenAPI (e.g. visible at `/docs`).
"""
),
] = None,
description: Annotated[
str | None,
Doc(
"""
Security scheme description.
It will be included in the generated OpenAPI (e.g. visible at `/docs`).
"""
),
] = None,
auto_error: Annotated[
bool,
Doc(
"""
By default, if the query parameter is not provided, `APIKeyQuery` will
automatically cancel the request and send the client an error.
If `auto_error` is set to `False`, when the query parameter is not
available, instead of erroring out, the dependency result will be
`None`.
This is useful when you want to have optional authentication.
It is also useful when you want to have authentication that can be
provided in one of multiple optional ways (for example, in a query
parameter or in an HTTP Bearer token).
"""
),
] = True,
):
super().__init__(
location=APIKeyIn.query,
name=name,
scheme_name=scheme_name,
description=description,
auto_error=auto_error,
)
make_not_authenticated_error()
The WWW-Authenticate header is not standardized for API Key authentication but the HTTP specification requires that an error of 401 "Unauthorized" must include a WWW-Authenticate header.
Ref: https://datatracker.ietf.org/doc/html/rfc9110#name-401-unauthorized
For this, this method sends a custom challenge APIKey.
Source code in fastapi/security/api_key.py
def make_not_authenticated_error(self) -> HTTPException:
"""
The WWW-Authenticate header is not standardized for API Key authentication but
the HTTP specification requires that an error of 401 "Unauthorized" must
include a WWW-Authenticate header.
Ref: https://datatracker.ietf.org/doc/html/rfc9110#name-401-unauthorized
For this, this method sends a custom challenge `APIKey`.
"""
return HTTPException(
status_code=HTTP_401_UNAUTHORIZED,
detail="Not authenticated",
headers={"WWW-Authenticate": "APIKey"},
)
check_api_key(api_key)
Source code in fastapi/security/api_key.py
def check_api_key(self, api_key: str | None) -> str | None:
if not api_key:
if self.auto_error:
raise self.make_not_authenticated_error()
return None
return api_key
HTTP Authentication Schemes¶
HTTPBasic(
*,
scheme_name=None,
realm=None,
description=None,
auto_error=True
)
Bases: HTTPBase
HTTP Basic authentication.
Ref: https://datatracker.ietf.org/doc/html/rfc7617
Usage¶
Create an instance object and use that object as the dependency in Depends().
The dependency result will be an HTTPBasicCredentials object containing the
username and the password.
Read more about it in the FastAPI docs for HTTP Basic Auth.
Example¶
from typing import Annotated
from fastapi import Depends, FastAPI
from fastapi.security import HTTPBasic, HTTPBasicCredentials
app = FastAPI()
security = HTTPBasic()
@app.get("/users/me")
def read_current_user(credentials: Annotated[HTTPBasicCredentials, Depends(security)]):
return {"username": credentials.username, "password": credentials.password}
| PARAMETER | DESCRIPTION |
|---|---|
scheme_name
|
Security scheme name. It will be included in the generated OpenAPI (e.g. visible at
TYPE:
|
realm
|
HTTP Basic authentication realm.
TYPE:
|
description
|
Security scheme description. It will be included in the generated OpenAPI (e.g. visible at
TYPE:
|
auto_error
|
By default, if the HTTP Basic authentication is not provided (a
header), If This is useful when you want to have optional authentication. It is also useful when you want to have authentication that can be provided in one of multiple optional ways (for example, in HTTP Basic authentication or in an HTTP Bearer token).
TYPE:
|
Source code in fastapi/security/http.py
def __init__(
self,
*,
scheme_name: Annotated[
str | None,
Doc(
"""
Security scheme name.
It will be included in the generated OpenAPI (e.g. visible at `/docs`).
"""
),
] = None,
realm: Annotated[
str | None,
Doc(
"""
HTTP Basic authentication realm.
"""
),
] = None,
description: Annotated[
str | None,
Doc(
"""
Security scheme description.
It will be included in the generated OpenAPI (e.g. visible at `/docs`).
"""
),
] = None,
auto_error: Annotated[
bool,
Doc(
"""
By default, if the HTTP Basic authentication is not provided (a
header), `HTTPBasic` will automatically cancel the request and send the
client an error.
If `auto_error` is set to `False`, when the HTTP Basic authentication
is not available, instead of erroring out, the dependency result will
be `None`.
This is useful when you want to have optional authentication.
It is also useful when you want to have authentication that can be
provided in one of multiple optional ways (for example, in HTTP Basic
authentication or in an HTTP Bearer token).
"""
),
] = True,
):
self.model = HTTPBaseModel(scheme="basic", description=description)
self.scheme_name = scheme_name or self.__class__.__name__
self.realm = realm
self.auto_error = auto_error
make_not_authenticated_error()
Source code in fastapi/security/http.py
def make_not_authenticated_error(self) -> HTTPException:
return HTTPException(
status_code=HTTP_401_UNAUTHORIZED,
detail="Not authenticated",
headers=self.make_authenticate_headers(),
)
make_authenticate_headers()
Source code in fastapi/security/http.py
def make_authenticate_headers(self) -> dict[str, str]:
if self.realm:
return {"WWW-Authenticate": f'Basic realm="{self.realm}"'}
return {"WWW-Authenticate": "Basic"}
HTTPBearer(
*,
bearerFormat=None,
scheme_name=None,
description=None,
auto_error=True
)
Bases: HTTPBase
HTTP Bearer token authentication.
Usage¶
Create an instance object and use that object as the dependency in Depends().
The dependency result will be an HTTPAuthorizationCredentials object containing
the scheme and the credentials.
Example¶
from typing import Annotated
from fastapi import Depends, FastAPI
from fastapi.security import HTTPAuthorizationCredentials, HTTPBearer
app = FastAPI()
security = HTTPBearer()
@app.get("/users/me")
def read_current_user(
credentials: Annotated[HTTPAuthorizationCredentials, Depends(security)]
):
return {"scheme": credentials.scheme, "credentials": credentials.credentials}
| PARAMETER | DESCRIPTION |
|---|---|
bearerFormat
|
Bearer token format.
TYPE:
|
scheme_name
|
Security scheme name. It will be included in the generated OpenAPI (e.g. visible at
TYPE:
|
description
|
Security scheme description. It will be included in the generated OpenAPI (e.g. visible at
TYPE:
|
auto_error
|
By default, if the HTTP Bearer token is not provided (in an
If This is useful when you want to have optional authentication. It is also useful when you want to have authentication that can be provided in one of multiple optional ways (for example, in an HTTP Bearer token or in a cookie).
TYPE:
|
Source code in fastapi/security/http.py
def __init__(
self,
*,
bearerFormat: Annotated[str | None, Doc("Bearer token format.")] = None,
scheme_name: Annotated[
str | None,
Doc(
"""
Security scheme name.
It will be included in the generated OpenAPI (e.g. visible at `/docs`).
"""
),
] = None,
description: Annotated[
str | None,
Doc(
"""
Security scheme description.
It will be included in the generated OpenAPI (e.g. visible at `/docs`).
"""
),
] = None,
auto_error: Annotated[
bool,
Doc(
"""
By default, if the HTTP Bearer token is not provided (in an
`Authorization` header), `HTTPBearer` will automatically cancel the
request and send the client an error.
If `auto_error` is set to `False`, when the HTTP Bearer token
is not available, instead of erroring out, the dependency result will
be `None`.
This is useful when you want to have optional authentication.
It is also useful when you want to have authentication that can be
provided in one of multiple optional ways (for example, in an HTTP
Bearer token or in a cookie).
"""
),
] = True,
):
self.model = HTTPBearerModel(bearerFormat=bearerFormat, description=description)
self.scheme_name = scheme_name or self.__class__.__name__
self.auto_error = auto_error
make_authenticate_headers()
Source code in fastapi/security/http.py
def make_authenticate_headers(self) -> dict[str, str]:
return {"WWW-Authenticate": f"{self.model.scheme.title()}"}
make_not_authenticated_error()
Source code in fastapi/security/http.py
def make_not_authenticated_error(self) -> HTTPException:
return HTTPException(
status_code=HTTP_401_UNAUTHORIZED,
detail="Not authenticated",
headers=self.make_authenticate_headers(),
)
HTTPDigest(
*, scheme_name=None, description=None, auto_error=True
)
Bases: HTTPBase
HTTP Digest authentication.
Warning: this is only a stub to connect the components with OpenAPI in FastAPI, but it doesn't implement the full Digest scheme, you would need to subclass it and implement it in your code.
Ref: https://datatracker.ietf.org/doc/html/rfc7616
Usage¶
Create an instance object and use that object as the dependency in Depends().
The dependency result will be an HTTPAuthorizationCredentials object containing
the scheme and the credentials.
Example¶
from typing import Annotated
from fastapi import Depends, FastAPI
from fastapi.security import HTTPAuthorizationCredentials, HTTPDigest
app = FastAPI()
security = HTTPDigest()
@app.get("/users/me")
def read_current_user(
credentials: Annotated[HTTPAuthorizationCredentials, Depends(security)]
):
return {"scheme": credentials.scheme, "credentials": credentials.credentials}
| PARAMETER | DESCRIPTION |
|---|---|
scheme_name
|
Security scheme name. It will be included in the generated OpenAPI (e.g. visible at
TYPE:
|
description
|
Security scheme description. It will be included in the generated OpenAPI (e.g. visible at
TYPE:
|
auto_error
|
By default, if the HTTP Digest is not provided, If This is useful when you want to have optional authentication. It is also useful when you want to have authentication that can be provided in one of multiple optional ways (for example, in HTTP Digest or in a cookie).
TYPE:
|
Source code in fastapi/security/http.py
def __init__(
self,
*,
scheme_name: Annotated[
str | None,
Doc(
"""
Security scheme name.
It will be included in the generated OpenAPI (e.g. visible at `/docs`).
"""
),
] = None,
description: Annotated[
str | None,
Doc(
"""
Security scheme description.
It will be included in the generated OpenAPI (e.g. visible at `/docs`).
"""
),
] = None,
auto_error: Annotated[
bool,
Doc(
"""
By default, if the HTTP Digest is not provided, `HTTPDigest` will
automatically cancel the request and send the client an error.
If `auto_error` is set to `False`, when the HTTP Digest is not
available, instead of erroring out, the dependency result will
be `None`.
This is useful when you want to have optional authentication.
It is also useful when you want to have authentication that can be
provided in one of multiple optional ways (for example, in HTTP
Digest or in a cookie).
"""
),
] = True,
):
self.model = HTTPBaseModel(scheme="digest", description=description)
self.scheme_name = scheme_name or self.__class__.__name__
self.auto_error = auto_error
make_authenticate_headers()
Source code in fastapi/security/http.py
def make_authenticate_headers(self) -> dict[str, str]:
return {"WWW-Authenticate": f"{self.model.scheme.title()}"}
make_not_authenticated_error()
Source code in fastapi/security/http.py
def make_not_authenticated_error(self) -> HTTPException:
return HTTPException(
status_code=HTTP_401_UNAUTHORIZED,
detail="Not authenticated",
headers=self.make_authenticate_headers(),
)
HTTP Credentials¶
Bases: BaseModel
The HTTP authorization credentials in the result of using HTTPBearer or
HTTPDigest in a dependency.
The HTTP authorization header value is split by the first space.
The first part is the scheme, the second part is the credentials.
For example, in an HTTP Bearer token scheme, the client will send a header like:
Authorization: Bearer deadbeef12346
In this case:
schemewill have the value"Bearer"credentialswill have the value"deadbeef12346"
Bases: BaseModel
The HTTP Basic credentials given as the result of using HTTPBasic in a
dependency.
Read more about it in the FastAPI docs for HTTP Basic Auth.
OAuth2 Authentication¶
OAuth2(
*,
flows=OAuthFlows(),
scheme_name=None,
description=None,
auto_error=True
)
Bases: SecurityBase
This is the base class for OAuth2 authentication, an instance of it would be used as a dependency. All other OAuth2 classes inherit from it and customize it for each OAuth2 flow.
You normally would not create a new class inheriting from it but use one of the existing subclasses, and maybe compose them if you want to support multiple flows.
Read more about it in the FastAPI docs for Security.
| PARAMETER | DESCRIPTION |
|---|---|
flows
|
The dictionary of OAuth2 flows.
TYPE:
|
scheme_name
|
Security scheme name. It will be included in the generated OpenAPI (e.g. visible at
TYPE:
|
description
|
Security scheme description. It will be included in the generated OpenAPI (e.g. visible at
TYPE:
|
auto_error
|
By default, if no HTTP Authorization header is provided, required for OAuth2 authentication, it will automatically cancel the request and send the client an error. If This is useful when you want to have optional authentication. It is also useful when you want to have authentication that can be provided in one of multiple optional ways (for example, with OAuth2 or in a cookie).
TYPE:
|
Source code in fastapi/security/oauth2.py
def __init__(
self,
*,
flows: Annotated[
OAuthFlowsModel | dict[str, dict[str, Any]],
Doc(
"""
The dictionary of OAuth2 flows.
"""
),
] = OAuthFlowsModel(),
scheme_name: Annotated[
str | None,
Doc(
"""
Security scheme name.
It will be included in the generated OpenAPI (e.g. visible at `/docs`).
"""
),
] = None,
description: Annotated[
str | None,
Doc(
"""
Security scheme description.
It will be included in the generated OpenAPI (e.g. visible at `/docs`).
"""
),
] = None,
auto_error: Annotated[
bool,
Doc(
"""
By default, if no HTTP Authorization header is provided, required for
OAuth2 authentication, it will automatically cancel the request and
send the client an error.
If `auto_error` is set to `False`, when the HTTP Authorization header
is not available, instead of erroring out, the dependency result will
be `None`.
This is useful when you want to have optional authentication.
It is also useful when you want to have authentication that can be
provided in one of multiple optional ways (for example, with OAuth2
or in a cookie).
"""
),
] = True,
):
self.model = OAuth2Model(
flows=cast(OAuthFlowsModel, flows), description=description
)
self.scheme_name = scheme_name or self.__class__.__name__
self.auto_error = auto_error
make_not_authenticated_error()
The OAuth 2 specification doesn't define the challenge that should be used,
because a Bearer token is not really the only option to authenticate.
But declaring any other authentication challenge would be application-specific as it's not defined in the specification.
For practical reasons, this method uses the Bearer challenge by default, as
it's probably the most common one.
If you are implementing an OAuth2 authentication scheme other than the provided ones in FastAPI (based on bearer tokens), you might want to override this.
Ref: https://datatracker.ietf.org/doc/html/rfc6749
Source code in fastapi/security/oauth2.py
def make_not_authenticated_error(self) -> HTTPException:
"""
The OAuth 2 specification doesn't define the challenge that should be used,
because a `Bearer` token is not really the only option to authenticate.
But declaring any other authentication challenge would be application-specific
as it's not defined in the specification.
For practical reasons, this method uses the `Bearer` challenge by default, as
it's probably the most common one.
If you are implementing an OAuth2 authentication scheme other than the provided
ones in FastAPI (based on bearer tokens), you might want to override this.
Ref: https://datatracker.ietf.org/doc/html/rfc6749
"""
return HTTPException(
status_code=HTTP_401_UNAUTHORIZED,
detail="Not authenticated",
headers={"WWW-Authenticate": "Bearer"},
)
OAuth2AuthorizationCodeBearer(
authorizationUrl,
tokenUrl,
refreshUrl=None,
scheme_name=None,
scopes=None,
description=None,
auto_error=True,
)
Bases: OAuth2
OAuth2 flow for authentication using a bearer token obtained with an OAuth2 code flow. An instance of it would be used as a dependency.
| PARAMETER | DESCRIPTION |
|---|---|
tokenUrl
|
The URL to obtain the OAuth2 token.
TYPE:
|
refreshUrl
|
The URL to refresh the token and obtain a new one.
TYPE:
|
scheme_name
|
Security scheme name. It will be included in the generated OpenAPI (e.g. visible at
TYPE:
|
scopes
|
The OAuth2 scopes that would be required by the path operations that use this dependency.
TYPE:
|
description
|
Security scheme description. It will be included in the generated OpenAPI (e.g. visible at
TYPE:
|
auto_error
|
By default, if no HTTP Authorization header is provided, required for OAuth2 authentication, it will automatically cancel the request and send the client an error. If This is useful when you want to have optional authentication. It is also useful when you want to have authentication that can be provided in one of multiple optional ways (for example, with OAuth2 or in a cookie).
TYPE:
|
Source code in fastapi/security/oauth2.py
def __init__(
self,
authorizationUrl: str,
tokenUrl: Annotated[
str,
Doc(
"""
The URL to obtain the OAuth2 token.
"""
),
],
refreshUrl: Annotated[
str | None,
Doc(
"""
The URL to refresh the token and obtain a new one.
"""
),
] = None,
scheme_name: Annotated[
str | None,
Doc(
"""
Security scheme name.
It will be included in the generated OpenAPI (e.g. visible at `/docs`).
"""
),
] = None,
scopes: Annotated[
dict[str, str] | None,
Doc(
"""
The OAuth2 scopes that would be required by the *path operations* that
use this dependency.
"""
),
] = None,
description: Annotated[
str | None,
Doc(
"""
Security scheme description.
It will be included in the generated OpenAPI (e.g. visible at `/docs`).
"""
),
] = None,
auto_error: Annotated[
bool,
Doc(
"""
By default, if no HTTP Authorization header is provided, required for
OAuth2 authentication, it will automatically cancel the request and
send the client an error.
If `auto_error` is set to `False`, when the HTTP Authorization header
is not available, instead of erroring out, the dependency result will
be `None`.
This is useful when you want to have optional authentication.
It is also useful when you want to have authentication that can be
provided in one of multiple optional ways (for example, with OAuth2
or in a cookie).
"""
),
] = True,
):
if not scopes:
scopes = {}
flows = OAuthFlowsModel(
authorizationCode=cast(
Any,
{
"authorizationUrl": authorizationUrl,
"tokenUrl": tokenUrl,
"refreshUrl": refreshUrl,
"scopes": scopes,
},
)
)
super().__init__(
flows=flows,
scheme_name=scheme_name,
description=description,
auto_error=auto_error,
)
make_not_authenticated_error()
The OAuth 2 specification doesn't define the challenge that should be used,
because a Bearer token is not really the only option to authenticate.
But declaring any other authentication challenge would be application-specific as it's not defined in the specification.
For practical reasons, this method uses the Bearer challenge by default, as
it's probably the most common one.
If you are implementing an OAuth2 authentication scheme other than the provided ones in FastAPI (based on bearer tokens), you might want to override this.
Ref: https://datatracker.ietf.org/doc/html/rfc6749
Source code in fastapi/security/oauth2.py
def make_not_authenticated_error(self) -> HTTPException:
"""
The OAuth 2 specification doesn't define the challenge that should be used,
because a `Bearer` token is not really the only option to authenticate.
But declaring any other authentication challenge would be application-specific
as it's not defined in the specification.
For practical reasons, this method uses the `Bearer` challenge by default, as
it's probably the most common one.
If you are implementing an OAuth2 authentication scheme other than the provided
ones in FastAPI (based on bearer tokens), you might want to override this.
Ref: https://datatracker.ietf.org/doc/html/rfc6749
"""
return HTTPException(
status_code=HTTP_401_UNAUTHORIZED,
detail="Not authenticated",
headers={"WWW-Authenticate": "Bearer"},
)
OAuth2PasswordBearer(
tokenUrl,
scheme_name=None,
scopes=None,
description=None,
auto_error=True,
refreshUrl=None,
)
Bases: OAuth2
OAuth2 flow for authentication using a bearer token obtained with a password. An instance of it would be used as a dependency.
Read more about it in the FastAPI docs for Simple OAuth2 with Password and Bearer.
| PARAMETER | DESCRIPTION |
|---|---|
tokenUrl
|
The URL to obtain the OAuth2 token. This would be the path operation
that has Read more about it in the FastAPI docs for Simple OAuth2 with Password and Bearer.
TYPE:
|
scheme_name
|
Security scheme name. It will be included in the generated OpenAPI (e.g. visible at
TYPE:
|
scopes
|
The OAuth2 scopes that would be required by the path operations that use this dependency. Read more about it in the FastAPI docs for Simple OAuth2 with Password and Bearer.
TYPE:
|
description
|
Security scheme description. It will be included in the generated OpenAPI (e.g. visible at
TYPE:
|
auto_error
|
By default, if no HTTP Authorization header is provided, required for OAuth2 authentication, it will automatically cancel the request and send the client an error. If This is useful when you want to have optional authentication. It is also useful when you want to have authentication that can be provided in one of multiple optional ways (for example, with OAuth2 or in a cookie).
TYPE:
|
refreshUrl
|
The URL to refresh the token and obtain a new one.
TYPE:
|
Source code in fastapi/security/oauth2.py
def __init__(
self,
tokenUrl: Annotated[
str,
Doc(
"""
The URL to obtain the OAuth2 token. This would be the *path operation*
that has `OAuth2PasswordRequestForm` as a dependency.
Read more about it in the
[FastAPI docs for Simple OAuth2 with Password and Bearer](https://fastapi.tiangolo.com/tutorial/security/simple-oauth2/).
"""
),
],
scheme_name: Annotated[
str | None,
Doc(
"""
Security scheme name.
It will be included in the generated OpenAPI (e.g. visible at `/docs`).
"""
),
] = None,
scopes: Annotated[
dict[str, str] | None,
Doc(
"""
The OAuth2 scopes that would be required by the *path operations* that
use this dependency.
Read more about it in the
[FastAPI docs for Simple OAuth2 with Password and Bearer](https://fastapi.tiangolo.com/tutorial/security/simple-oauth2/).
"""
),
] = None,
description: Annotated[
str | None,
Doc(
"""
Security scheme description.
It will be included in the generated OpenAPI (e.g. visible at `/docs`).
"""
),
] = None,
auto_error: Annotated[
bool,
Doc(
"""
By default, if no HTTP Authorization header is provided, required for
OAuth2 authentication, it will automatically cancel the request and
send the client an error.
If `auto_error` is set to `False`, when the HTTP Authorization header
is not available, instead of erroring out, the dependency result will
be `None`.
This is useful when you want to have optional authentication.
It is also useful when you want to have authentication that can be
provided in one of multiple optional ways (for example, with OAuth2
or in a cookie).
"""
),
] = True,
refreshUrl: Annotated[
str | None,
Doc(
"""
The URL to refresh the token and obtain a new one.
"""
),
] = None,
):
if not scopes:
scopes = {}
flows = OAuthFlowsModel(
password=cast(
Any,
{
"tokenUrl": tokenUrl,
"refreshUrl": refreshUrl,
"scopes": scopes,
},
)
)
super().__init__(
flows=flows,
scheme_name=scheme_name,
description=description,
auto_error=auto_error,
)
make_not_authenticated_error()
The OAuth 2 specification doesn't define the challenge that should be used,
because a Bearer token is not really the only option to authenticate.
But declaring any other authentication challenge would be application-specific as it's not defined in the specification.
For practical reasons, this method uses the Bearer challenge by default, as
it's probably the most common one.
If you are implementing an OAuth2 authentication scheme other than the provided ones in FastAPI (based on bearer tokens), you might want to override this.
Ref: https://datatracker.ietf.org/doc/html/rfc6749
Source code in fastapi/security/oauth2.py
def make_not_authenticated_error(self) -> HTTPException:
"""
The OAuth 2 specification doesn't define the challenge that should be used,
because a `Bearer` token is not really the only option to authenticate.
But declaring any other authentication challenge would be application-specific
as it's not defined in the specification.
For practical reasons, this method uses the `Bearer` challenge by default, as
it's probably the most common one.
If you are implementing an OAuth2 authentication scheme other than the provided
ones in FastAPI (based on bearer tokens), you might want to override this.
Ref: https://datatracker.ietf.org/doc/html/rfc6749
"""
return HTTPException(
status_code=HTTP_401_UNAUTHORIZED,
detail="Not authenticated",
headers={"WWW-Authenticate": "Bearer"},
)
OAuth2 Password Form¶
OAuth2PasswordRequestForm(
*,
grant_type=None,
username,
password,
scope="",
client_id=None,
client_secret=None
)
This is a dependency class to collect the username and password as form data
for an OAuth2 password flow.
The OAuth2 specification dictates that for a password flow the data should be
collected using form data (instead of JSON) and that it should have the specific
fields username and password.
All the initialization parameters are extracted from the request.
Read more about it in the FastAPI docs for Simple OAuth2 with Password and Bearer.
Example¶
from typing import Annotated
from fastapi import Depends, FastAPI
from fastapi.security import OAuth2PasswordRequestForm
app = FastAPI()
@app.post("/login")
def login(form_data: Annotated[OAuth2PasswordRequestForm, Depends()]):
data = {}
data["scopes"] = []
for scope in form_data.scopes:
data["scopes"].append(scope)
if form_data.client_id:
data["client_id"] = form_data.client_id
if form_data.client_secret:
data["client_secret"] = form_data.client_secret
return data
Note that for OAuth2 the scope items:read is a single scope in an opaque string.
You could have custom internal logic to separate it by colon characters (:) or
similar, and get the two parts items and read. Many applications do that to
group and organize permissions, you could do it as well in your application, just
know that it is application specific, it's not part of the specification.
| PARAMETER | DESCRIPTION |
|---|---|
grant_type
|
The OAuth2 spec says it is required and MUST be the fixed string
"password". Nevertheless, this dependency class is permissive and
allows not passing it. If you want to enforce it, use instead the
Read more about it in the FastAPI docs for Simple OAuth2 with Password and Bearer.
TYPE:
|
username
|
Read more about it in the FastAPI docs for Simple OAuth2 with Password and Bearer.
TYPE:
|
password
|
Read more about it in the FastAPI docs for Simple OAuth2 with Password and Bearer.
TYPE:
|
scope
|
A single string with actually several scopes separated by spaces. Each scope is also a string. For example, a single string with: ```python "items:read items:write users:read profile openid" ```` would represent the scopes:
Read more about it in the FastAPI docs for Simple OAuth2 with Password and Bearer.
TYPE:
|
client_id
|
If there's a
TYPE:
|
client_secret
|
If there's a
TYPE:
|
Source code in fastapi/security/oauth2.py
def __init__(
self,
*,
grant_type: Annotated[
str | None,
Form(pattern="^password$"),
Doc(
"""
The OAuth2 spec says it is required and MUST be the fixed string
"password". Nevertheless, this dependency class is permissive and
allows not passing it. If you want to enforce it, use instead the
`OAuth2PasswordRequestFormStrict` dependency.
Read more about it in the
[FastAPI docs for Simple OAuth2 with Password and Bearer](https://fastapi.tiangolo.com/tutorial/security/simple-oauth2/).
"""
),
] = None,
username: Annotated[
str,
Form(),
Doc(
"""
`username` string. The OAuth2 spec requires the exact field name
`username`.
Read more about it in the
[FastAPI docs for Simple OAuth2 with Password and Bearer](https://fastapi.tiangolo.com/tutorial/security/simple-oauth2/).
"""
),
],
password: Annotated[
str,
Form(json_schema_extra={"format": "password"}),
Doc(
"""
`password` string. The OAuth2 spec requires the exact field name
`password`.
Read more about it in the
[FastAPI docs for Simple OAuth2 with Password and Bearer](https://fastapi.tiangolo.com/tutorial/security/simple-oauth2/).
"""
),
],
scope: Annotated[
str,
Form(),
Doc(
"""
A single string with actually several scopes separated by spaces. Each
scope is also a string.
For example, a single string with:
```python
"items:read items:write users:read profile openid"
````
would represent the scopes:
* `items:read`
* `items:write`
* `users:read`
* `profile`
* `openid`
Read more about it in the
[FastAPI docs for Simple OAuth2 with Password and Bearer](https://fastapi.tiangolo.com/tutorial/security/simple-oauth2/).
"""
),
] = "",
client_id: Annotated[
str | None,
Form(),
Doc(
"""
If there's a `client_id`, it can be sent as part of the form fields.
But the OAuth2 specification recommends sending the `client_id` and
`client_secret` (if any) using HTTP Basic auth.
"""
),
] = None,
client_secret: Annotated[
str | None,
Form(json_schema_extra={"format": "password"}),
Doc(
"""
If there's a `client_password` (and a `client_id`), they can be sent
as part of the form fields. But the OAuth2 specification recommends
sending the `client_id` and `client_secret` (if any) using HTTP Basic
auth.
"""
),
] = None,
):
self.grant_type = grant_type
self.username = username
self.password = password
self.scopes = scope.split()
self.client_id = client_id
self.client_secret = client_secret
OAuth2PasswordRequestFormStrict(
grant_type,
username,
password,
scope="",
client_id=None,
client_secret=None,
)
Bases: OAuth2PasswordRequestForm
This is a dependency class to collect the username and password as form data
for an OAuth2 password flow.
The OAuth2 specification dictates that for a password flow the data should be
collected using form data (instead of JSON) and that it should have the specific
fields username and password.
All the initialization parameters are extracted from the request.
The only difference between OAuth2PasswordRequestFormStrict and
OAuth2PasswordRequestForm is that OAuth2PasswordRequestFormStrict requires the
client to send the form field grant_type with the value "password", which
is required in the OAuth2 specification (it seems that for no particular reason),
while for OAuth2PasswordRequestForm grant_type is optional.
Read more about it in the FastAPI docs for Simple OAuth2 with Password and Bearer.
Example¶
from typing import Annotated
from fastapi import Depends, FastAPI
from fastapi.security import OAuth2PasswordRequestForm
app = FastAPI()
@app.post("/login")
def login(form_data: Annotated[OAuth2PasswordRequestFormStrict, Depends()]):
data = {}
data["scopes"] = []
for scope in form_data.scopes:
data["scopes"].append(scope)
if form_data.client_id:
data["client_id"] = form_data.client_id
if form_data.client_secret:
data["client_secret"] = form_data.client_secret
return data
Note that for OAuth2 the scope items:read is a single scope in an opaque string.
You could have custom internal logic to separate it by colon characters (:) or
similar, and get the two parts items and read. Many applications do that to
group and organize permissions, you could do it as well in your application, just
know that it is application specific, it's not part of the specification.
the OAuth2 spec says it is required and MUST be the fixed string "password".
This dependency is strict about it. If you want to be permissive, use instead the OAuth2PasswordRequestForm dependency class.
username: username string. The OAuth2 spec requires the exact field name "username". password: password string. The OAuth2 spec requires the exact field name "password". scope: Optional string. Several scopes (each one a string) separated by spaces. E.g. "items:read items:write users:read profile openid" client_id: optional string. OAuth2 recommends sending the client_id and client_secret (if any) using HTTP Basic auth, as: client_id:client_secret client_secret: optional string. OAuth2 recommends sending the client_id and client_secret (if any) using HTTP Basic auth, as: client_id:client_secret
| PARAMETER | DESCRIPTION |
|---|---|
grant_type
|
The OAuth2 spec says it is required and MUST be the fixed string
"password". This dependency is strict about it. If you want to be
permissive, use instead the Read more about it in the FastAPI docs for Simple OAuth2 with Password and Bearer.
TYPE:
|
username
|
Read more about it in the FastAPI docs for Simple OAuth2 with Password and Bearer.
TYPE:
|
password
|
Read more about it in the FastAPI docs for Simple OAuth2 with Password and Bearer.
TYPE:
|
scope
|
A single string with actually several scopes separated by spaces. Each scope is also a string. For example, a single string with: ```python "items:read items:write users:read profile openid" ```` would represent the scopes:
Read more about it in the FastAPI docs for Simple OAuth2 with Password and Bearer.
TYPE:
|
client_id
|
If there's a
TYPE:
|
client_secret
|
If there's a
TYPE:
|
Source code in fastapi/security/oauth2.py
def __init__(
self,
grant_type: Annotated[
str,
Form(pattern="^password$"),
Doc(
"""
The OAuth2 spec says it is required and MUST be the fixed string
"password". This dependency is strict about it. If you want to be
permissive, use instead the `OAuth2PasswordRequestForm` dependency
class.
Read more about it in the
[FastAPI docs for Simple OAuth2 with Password and Bearer](https://fastapi.tiangolo.com/tutorial/security/simple-oauth2/).
"""
),
],
username: Annotated[
str,
Form(),
Doc(
"""
`username` string. The OAuth2 spec requires the exact field name
`username`.
Read more about it in the
[FastAPI docs for Simple OAuth2 with Password and Bearer](https://fastapi.tiangolo.com/tutorial/security/simple-oauth2/).
"""
),
],
password: Annotated[
str,
Form(),
Doc(
"""
`password` string. The OAuth2 spec requires the exact field name
`password`.
Read more about it in the
[FastAPI docs for Simple OAuth2 with Password and Bearer](https://fastapi.tiangolo.com/tutorial/security/simple-oauth2/).
"""
),
],
scope: Annotated[
str,
Form(),
Doc(
"""
A single string with actually several scopes separated by spaces. Each
scope is also a string.
For example, a single string with:
```python
"items:read items:write users:read profile openid"
````
would represent the scopes:
* `items:read`
* `items:write`
* `users:read`
* `profile`
* `openid`
Read more about it in the
[FastAPI docs for Simple OAuth2 with Password and Bearer](https://fastapi.tiangolo.com/tutorial/security/simple-oauth2/).
"""
),
] = "",
client_id: Annotated[
str | None,
Form(),
Doc(
"""
If there's a `client_id`, it can be sent as part of the form fields.
But the OAuth2 specification recommends sending the `client_id` and
`client_secret` (if any) using HTTP Basic auth.
"""
),
] = None,
client_secret: Annotated[
str | None,
Form(),
Doc(
"""
If there's a `client_password` (and a `client_id`), they can be sent
as part of the form fields. But the OAuth2 specification recommends
sending the `client_id` and `client_secret` (if any) using HTTP Basic
auth.
"""
),
] = None,
):
super().__init__(
grant_type=grant_type,
username=username,
password=password,
scope=scope,
client_id=client_id,
client_secret=client_secret,
)
OAuth2 Security Scopes in Dependencies¶
SecurityScopes(scopes=None)
This is a special class that you can define in a parameter in a dependency to obtain the OAuth2 scopes required by all the dependencies in the same chain.
This way, multiple dependencies can have different scopes, even when used in the same path operation. And with this, you can access all the scopes required in all those dependencies in a single place.
Read more about it in the FastAPI docs for OAuth2 scopes.
| PARAMETER | DESCRIPTION |
|---|---|
scopes
|
This will be filled by FastAPI.
TYPE:
|
Source code in fastapi/security/oauth2.py
def __init__(
self,
scopes: Annotated[
list[str] | None,
Doc(
"""
This will be filled by FastAPI.
"""
),
] = None,
):
self.scopes: Annotated[
list[str],
Doc(
"""
The list of all the scopes required by dependencies.
"""
),
] = scopes or []
self.scope_str: Annotated[
str,
Doc(
"""
All the scopes required by all the dependencies in a single string
separated by spaces, as defined in the OAuth2 specification.
"""
),
] = " ".join(self.scopes)
OpenID Connect¶
OpenIdConnect(
*,
openIdConnectUrl,
scheme_name=None,
description=None,
auto_error=True
)
Bases: SecurityBase
OpenID Connect authentication class. An instance of it would be used as a dependency.
Warning: this is only a stub to connect the components with OpenAPI in FastAPI, but it doesn't implement the full OpenIdConnect scheme, for example, it doesn't use the OpenIDConnect URL. You would need to subclass it and implement it in your code.
| PARAMETER | DESCRIPTION |
|---|---|
openIdConnectUrl
|
The OpenID Connect URL.
TYPE:
|
scheme_name
|
Security scheme name. It will be included in the generated OpenAPI (e.g. visible at
TYPE:
|
description
|
Security scheme description. It will be included in the generated OpenAPI (e.g. visible at
TYPE:
|
auto_error
|
By default, if no HTTP Authorization header is provided, required for OpenID Connect authentication, it will automatically cancel the request and send the client an error. If This is useful when you want to have optional authentication. It is also useful when you want to have authentication that can be provided in one of multiple optional ways (for example, with OpenID Connect or in a cookie).
TYPE:
|
Source code in fastapi/security/open_id_connect_url.py
def __init__(
self,
*,
openIdConnectUrl: Annotated[
str,
Doc(
"""
The OpenID Connect URL.
"""
),
],
scheme_name: Annotated[
str | None,
Doc(
"""
Security scheme name.
It will be included in the generated OpenAPI (e.g. visible at `/docs`).
"""
),
] = None,
description: Annotated[
str | None,
Doc(
"""
Security scheme description.
It will be included in the generated OpenAPI (e.g. visible at `/docs`).
"""
),
] = None,
auto_error: Annotated[
bool,
Doc(
"""
By default, if no HTTP Authorization header is provided, required for
OpenID Connect authentication, it will automatically cancel the request
and send the client an error.
If `auto_error` is set to `False`, when the HTTP Authorization header
is not available, instead of erroring out, the dependency result will
be `None`.
This is useful when you want to have optional authentication.
It is also useful when you want to have authentication that can be
provided in one of multiple optional ways (for example, with OpenID
Connect or in a cookie).
"""
),
] = True,
):
self.model = OpenIdConnectModel(
openIdConnectUrl=openIdConnectUrl, description=description
)
self.scheme_name = scheme_name or self.__class__.__name__
self.auto_error = auto_error
instance-attribute
¶
model = OpenIdConnect(
openIdConnectUrl=openIdConnectUrl,
description=description,
)
make_not_authenticated_error()
Source code in fastapi/security/open_id_connect_url.py
def make_not_authenticated_error(self) -> HTTPException:
return HTTPException(
status_code=HTTP_401_UNAUTHORIZED,
detail="Not authenticated",
headers={"WWW-Authenticate": "Bearer"},
)