Reference for ultralytics/hub/auth.py

class Auth:
    """
    Manages authentication processes including API key handling, cookie-based authentication, and header generation.

    The class supports different methods of authentication:
    1. Directly using an API key.
    2. Authenticating using browser cookies (specifically in Google Colab).
    3. Prompting the user to enter an API key.

    Attributes:
        id_token (str or bool): Token used for identity verification, initialized as False.
        api_key (str or bool): API key for authentication, initialized as False.
        model_key (bool): Placeholder for model key, initialized as False.
    """

    id_token = api_key = model_key = False

    def __init__(self, api_key="", verbose=False):
        """
        Initialize the Auth class with an optional API key.

        Args:
            api_key (str, optional): May be an API key or a combination API key and model ID, i.e. key_id
        """
        # Split the input API key in case it contains a combined key_model and keep only the API key part
        api_key = api_key.split("_")[0]

        # Set API key attribute as value passed or SETTINGS API key if none passed
        self.api_key = api_key or SETTINGS.get("api_key", "")

        # If an API key is provided
        if self.api_key:
            # If the provided API key matches the API key in the SETTINGS
            if self.api_key == SETTINGS.get("api_key"):
                # Log that the user is already logged in
                if verbose:
                    LOGGER.info(f"{PREFIX}Authenticated ✅")
                return
            else:
                # Attempt to authenticate with the provided API key
                success = self.authenticate()
        # If the API key is not provided and the environment is a Google Colab notebook
        elif IS_COLAB:
            # Attempt to authenticate using browser cookies
            success = self.auth_with_cookies()
        else:
            # Request an API key
            success = self.request_api_key()

        # Update SETTINGS with the new API key after successful authentication
        if success:
            SETTINGS.update({"api_key": self.api_key})
            # Log that the new login was successful
            if verbose:
                LOGGER.info(f"{PREFIX}New authentication successful ✅")
        elif verbose:
            LOGGER.info(f"{PREFIX}Get API key from {API_KEY_URL} and then run 'yolo hub login API_KEY'")

    def request_api_key(self, max_attempts=3):
        """
        Prompt the user to input their API key.

        Returns the model ID.
        """
        import getpass

        for attempts in range(max_attempts):
            LOGGER.info(f"{PREFIX}Login. Attempt {attempts + 1} of {max_attempts}")
            input_key = getpass.getpass(f"Enter API key from {API_KEY_URL} ")
            self.api_key = input_key.split("_")[0]  # remove model id if present
            if self.authenticate():
                return True
        raise ConnectionError(emojis(f"{PREFIX}Failed to authenticate ❌"))

    def authenticate(self) -> bool:
        """
        Attempt to authenticate with the server using either id_token or API key.

        Returns:
            (bool): True if authentication is successful, False otherwise.
        """
        try:
            if header := self.get_auth_header():
                r = requests.post(f"{HUB_API_ROOT}/v1/auth", headers=header)
                if not r.json().get("success", False):
                    raise ConnectionError("Unable to authenticate.")
                return True
            raise ConnectionError("User has not authenticated locally.")
        except ConnectionError:
            self.id_token = self.api_key = False  # reset invalid
            LOGGER.warning(f"{PREFIX}Invalid API key ⚠️")
            return False

    def auth_with_cookies(self) -> bool:
        """
        Attempt to fetch authentication via cookies and set id_token. User must be logged in to HUB and running in a
        supported browser.

        Returns:
            (bool): True if authentication is successful, False otherwise.
        """
        if not IS_COLAB:
            return False  # Currently only works with Colab
        try:
            authn = request_with_credentials(f"{HUB_API_ROOT}/v1/auth/auto")
            if authn.get("success", False):
                self.id_token = authn.get("data", {}).get("idToken", None)
                self.authenticate()
                return True
            raise ConnectionError("Unable to fetch browser authentication details.")
        except ConnectionError:
            self.id_token = False  # reset invalid
            return False

    def get_auth_header(self):
        """
        Get the authentication header for making API requests.

        Returns:
            (dict): The authentication header if id_token or API key is set, None otherwise.
        """
        if self.id_token:
            return {"authorization": f"Bearer {self.id_token}"}
        elif self.api_key:
            return {"x-api-key": self.api_key}