docs/integrations/tools/playwright/

[giscus[bot]]

docs/integrations/tools/playwright/

Playwright is an open-source automation tool developed by Microsoft that allows you to programmatically control and automate web browsers. It is designed for end-to-end testing, scraping, and automating tasks across various web browsers such as Chromium, Firefox, and WebKit.

https://python.langchain.com/docs/integrations/tools/playwright/

[Giambapisasale]

This does not work "out of the box" because of this error:
\langchain_core\tools\base.py", line 446, in args
return self.get_input_schema().model_json_schema()["properties"]
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
\pydantic\json_schema.py", line 2277, in model_json_schema
raise AttributeError('model_json_schema() must be called on a subclass of BaseModel, not BaseModel itself.')

[Giambapisasale]

The toolkit is very buggy, the tools definitions are wrong, eg:
class CurrentWebPageTool(BaseBrowserTool):
"""Tool for getting the URL of the current webpage."""

name: str = "current_webpage"
description: str = "Returns the URL of the current page"
args_schema: Type[BaseModel] = BaseModel

args_schema CANNOT BE BaseModel, as per BaseTool definition:

class BaseTool(RunnableSerializable[Union[str, dict, ToolCall], Any]):
"""Interface LangChain tools must implement."""

def __init_subclass__(cls, **kwargs: Any) -> None:
    """Create the definition of the new tool class."""
    super().__init_subclass__(**kwargs)

    args_schema_type = cls.__annotations__.get("args_schema", None)

    if args_schema_type is not None and args_schema_type == BaseModel:
        # Throw errors for common mis-annotations.
        # TODO: Use get_args / get_origin and fully
        # specify valid annotations.
        typehint_mandate = """

class ChildTool(BaseTool):
...
args_schema: Type[BaseModel] = SchemaClass
..."""
name = cls.name
msg = (
f"Tool definition for {name} must include valid type annotations"
f" for argument 'args_schema' to behave as expected.\n"
f"Expected annotation of 'Type[BaseModel]'"
f" but got '{args_schema_type}'.\n"
f"Expected class looks like:\n"
f"{typehint_mandate}"
)
raise SchemaAnnotationError(msg)