developers.home-assistant/docs/core/platform/application_credentials.md

title
Application Credentials

Integrations may support Configuration via OAuth2 allowing users to link their accounts. Integrations may add a application_credentials.py file and implement the functions described below.

OAuth2 requires credentials that are shared between an application and provider. In Home Assistant, integration specific OAuth2 credentials are provided using one or more approaches:

• Local OAuth with Application Credentials Component: Users create their own credentials with the cloud provider, often acting as an application developer, and register the credentials with Home Assistant and integration. This approach is required by all integrations that support OAuth2.
• Cloud Account Linking with Cloud Component: Nabu Casa registers credentials with the cloud provider, providing a seamless user experience. This approach provides a seamless user experience and is recommended (more info).

Adding support

Integrations support application credentials with a file in the integration folder called application_credentials.py and implement the following:

from homeassistant.core import HomeAssistant
from homeassistant.components.application_credentials import AuthorizationServer


async def async_get_authorization_server(
    self, hass: HomeAssistant
) -> AuthorizationServer:
    """Return authorization server."""
    return AuthorizationServer(
        authorize_url="https://example.com/auth",
        token_url="https://example.com/oauth2/v4/token"
    )

AuthorizationServer

An AuthorizationServer represents the OAuth2 Authorization server used for an integration.

Name	Type		Description
authorize_url	str	Required	The OAuth authorize URL that the user is redirected to during the configuration flow.
token_url	str	Required	The URL used for obtaining an access token.

Import YAML credentials

Credentials may be imported by integrations that used to accept YAML credentials using the import API async_import_client_credential provided by the application credentials integration.

ClientCredential

A ClientCredential represents a client credential provided by the user.

Name	Type		Description
client_id	str	Required	The OAuth Client ID provided by the user.
client_secret	str	Required	The OAuth Client Secret provided by the user.