microsoft/qlib · error · NotImplementedError

Please implement the `get_online_tag` method.

Error message

Please implement the `get_online_tag` method.

What it means

OnlineTool.get_online_tag is an abstract method of the OnlineTool base class. It must return the current online/offline tag string for a given model recorder; the base class intentionally raises NotImplementedError. The error means get_online_tag was invoked on the base class or an incomplete subclass.

Source

Thrown at qlib/workflow/online/utils.py:54

        Set `tag` to the model to sign whether online.

        Args:
            tag (str): the tags in `ONLINE_TAG`, `OFFLINE_TAG`
            recorder (Union[list,object]): the model's recorder
        """
        raise NotImplementedError(f"Please implement the `set_online_tag` method.")

    def get_online_tag(self, recorder: object) -> str:
        """
        Given a model recorder and return its online tag.

        Args:
            recorder (Object): the model's recorder

        Returns:
            str: the online tag
        """
        raise NotImplementedError(f"Please implement the `get_online_tag` method.")

    def reset_online_tag(self, recorder: Union[list, object]):
        """
        Offline all models and set the recorders to 'online'.

        Args:
            recorder (Union[list,object]):
                the recorder you want to reset to 'online'.

        """
        raise NotImplementedError(f"Please implement the `reset_online_tag` method.")

    def online_models(self) -> list:
        """
        Get current `online` models

        Returns:
            list: a list of `online` models.

View on GitHub (pinned to 79633dd950)

Solutions

1. Use OnlineToolR, which implements get_online_tag by reading the tag parameter from the recorder via R.get_recorder
2. Implement get_online_tag(self, recorder) -> str in your subclass, returning ONLINE_TAG or OFFLINE_TAG
3. Audit that every abstract method of OnlineTool (set_online_tag, get_online_tag, reset_online_tag, online_models, update_online_pred) has an override

Example fix

# before
class MyTool(OnlineTool):
    def set_online_tag(self, tag, recorder):
        ...
    # get_online_tag missing

# after
class MyTool(OnlineTool):
    def set_online_tag(self, tag, recorder):
        ...
    def get_online_tag(self, recorder) -> str:
        rec = R.get_recorder(recorder_id=rec.id)
        return rec.list_tags()[ONLINE_TAG]

from qlib.workflow.online.utils import OnlineTool

def assert_get_tag_implemented(tool):
    if type(tool).get_online_tag is OnlineTool.get_online_tag:
        raise TypeError(f'{type(tool).__name__} must implement get_online_tag')

from qlib.workflow.online.utils import OnlineTool

def has_get_online_tag(tool) -> bool:
    return type(tool).get_online_tag is not OnlineTool.get_online_tag

try:
    tag = tool.get_online_tag(rec)
except NotImplementedError:
    tag = 'offline'  # treat unknown as offline, or re-raise for strict flows

When it happens

Trigger: Calling OnlineTool().get_online_tag(recorder); running a custom OnlineTool subclass through OnlineManager flows that read tags (e.g. online_models implementations that delegate to get_online_tag); forgetting the override when porting OnlineToolR to another backend.

Common situations: Custom OnlineTool implementations for bespoke model registries; mixing base-class and recorder-based tool instances in one strategy; refactoring OnlineToolR and dropping a method.

Related errors

• Please implement the `set_online_tag` method.
• Please implement the `reset_online_tag` method.
• Please implement the `online_models` method.
• Please implement the `update_online_pred` method.
• Please implement the `get_all_stock` method

AI-assisted analysis of microsoft/qlib@79633dd950 (2026-08-15). Data as JSON: /api/errors/4733a2e806829586. Report an issue: GitHub.