home-assistant/core · error · ValueError

No application_credentials platform for {domain}

Error message

No application_credentials platform for {domain}

What it means

Raised by ApplicationCredentialsStorageCollection._process_create_data when a client credential is created for an integration domain that does not implement the application_credentials platform. Home Assistant only stores OAuth client credentials for integrations that declare their authorization server via a components/<domain>/application_credentials.py module. Creating a credential for any other domain is rejected with this ValueError.

Source

Thrown at homeassistant/components/application_credentials/__init__.py:94

class AuthorizationServer:
    """Represent an OAuth2 Authorization Server."""

    authorize_url: str
    token_url: str


class ApplicationCredentialsStorageCollection(collection.DictStorageCollection):
    """Application credential collection stored in storage."""

    CREATE_SCHEMA = vol.Schema(CREATE_FIELDS)

    @override
    async def _process_create_data(self, data: dict[str, str]) -> dict[str, str]:
        """Validate the config is valid."""
        result = self.CREATE_SCHEMA(data)
        domain = result[CONF_DOMAIN]
        if not await _get_platform(self.hass, domain):
            raise ValueError(f"No application_credentials platform for {domain}")
        return result

    @callback
    @override
    def _get_suggested_id(self, info: dict[str, str]) -> str:
        """Suggest an ID based on the config."""
        return f"{info[CONF_DOMAIN]}.{info[CONF_CLIENT_ID]}"

    @override
    async def _update_data(
        self, item: dict[str, str], update_data: dict[str, str]
    ) -> dict[str, str]:
        """Return a new updated data object."""
        raise ValueError("Updates not supported")

    @override
    async def async_delete_item(self, item_id: str) -> None:
        """Delete item, verifying credential is not in use."""

View on GitHub (pinned to 58a3fdb3ea)

Solutions

  1. Verify the integration actually supports application credentials: check that homeassistant/components/<domain>/application_credentials.py exists (or the integration docs mention setting up an 'Application Credentials' helper).
  2. Fix the domain value in the create request to match a supported integration's domain exactly.
  3. If you develop the integration, add an application_credentials.py module with async_get_authorization_server() (and async_get_auth_implementation() if needed).
  4. If the platform file exists but the integration is not loaded, load the integration first (e.g. via config flow) so _get_platform resolves.

Example fix

# custom_components/my_integration/application_credentials.py
from homeassistant.core import HomeAssistant
from homeassistant.components.application_credentials import AuthorizationServer, ClientCredential, async_register_client_credential

async def async_get_authorization_server(hass: HomeAssistant) -> AuthorizationServer:
    return AuthorizationServer(
        authorize_url="https://example.com/oauth/authorize",
        token_url="https://example.com/oauth/token",
    )
Defensive patterns

Strategy: validation

Validate before calling

from homeassistant.helpers import config_validation as cv
from homeassistant.components.application_credentials import async_get_application_credentials
from homeassistant.loader import async_get_integration

async def domain_supports_app_credentials(hass, domain: str) -> bool:
    integration = await async_get_integration(hass, domain)
    return (integration.file_path / "application_credentials.py").exists()

Try / catch

try:
    await collection.async_create_item({"domain": domain, "client_id": cid, "client_secret": secret})
except ValueError as err:
    if "No application_credentials platform" in str(err):
        # surface to user: integration lacks OAuth app credential support
        raise

Prevention

When it happens

Trigger: Calling the websocket command application_credentials/create (or YAML import via async_import_item) with a 'domain' field whose integration has no application_credentials.py platform. Also triggered when _get_platform(hass, domain) returns None because the integration is not loaded or has no async_get_authorization_server implementation.

Common situations: Typos in the domain field when creating credentials through a websocket/API client; attempting to add OAuth app credentials for an integration that only supports config-flow auth without application credentials; a custom integration missing the application_credentials platform; the domain from a config entry that was set up before OAuth support was added.

Related errors

AI-assisted analysis of home-assistant/core@58a3fdb3ea (2026-08-14). Data as JSON: /api/errors/b61ba9b54bbd33c7. Report an issue: GitHub.