Document public user login functions

src/tabpfn_client/config.py

@@ -30,6 +30,17 @@ def __new__(cls, *args, **kwargs):
 
 
 def init(use_server=True):
+    """
+    Initializes the TabPFN client and handles user authentication.
+
+    This function checks for existing credentials, prompts for login/registration 
+    if necessary, and verifies email status. It must be called before performing 
+    any inference tasks.
+
+    :param use_server: Whether to use the TabPFN cloud service. Currently, only 
+                       True is supported.
+    :raises RuntimeError: If local inference is requested or if the server is unreachable.
+    """
     # initialize config
     Config.use_server = use_server
 
@@ -91,6 +102,12 @@ def init(use_server=True):
 
 
 def reset():
+    """
+    Resets the client state and clears local authentication caches.
+
+    Use this function if you need to log out or clear stored session data 
+    from the local machine.
+    """
     Config.is_initialized = False
     # reset user auth handler
     if Config.use_server:
@@ -101,16 +118,42 @@ def reset():
 
 
 def get_access_token() -> str:
+    """
+    Retrieves the current active access token.
+
+    If the client is not yet initialized, this will trigger the `init()` login flow.
+
+    :return: The access token string used for API requests.
+    """
     init()
     return ServiceClient.get_access_token()
 
 
 def set_access_token(access_token: str):
+    """
+    Manually sets the access token for the session.
+
+    This is useful for non-interactive environments
+    (e.g., CI/CD, Notebooks) where you want to skip 
+    the interactive login prompt.
+
+    You can obtain your access token via the TabPFN 
+    UX as explained at:
+    https://docs.priorlabs.ai/api-reference/getting-started#1-get-your-access-token
+
+    :param access_token: A valid TabPFN access token string.
+    """
     UserAuthenticationClient.set_token(access_token)
     Config.is_initialized = True
 
 
-def get_api_usage() -> dict:
+def get_api_usage() -> str:
+    """
+    Fetches and formats the current API usage statistics for the user.
+
+    :return: A human-readable string detailing current credit usage, 
+             the total limit, and when the limit resets.
+    """
     access_token = get_access_token()
     response = ServiceClient.get_api_usage(access_token)
     return f"Currently, you have used {response['current_usage']} of the allowed limit of {'Unlimited' if int(response['usage_limit']) == -1 else response['usage_limit']} credits. The limit will reset at {response['reset_time']}."