OpenBB-finance/OpenBB · error · AttributeError

Error: The app file '{app_path}' does not contain an '{name}

Error message

Error: The app file '{app_path}' does not contain an '{name}' instance

What it means

AttributeError raised after the app module was successfully imported/loaded, but it has no attribute with the requested name (default 'app', or the part after ':' in 'module:attr' notation, or the --name value). The importer then cannot retrieve the FastAPI instance to serve.

Source

Thrown at openbb_platform/extensions/mcp_server/openbb_mcp_server/utils/app_import.py:74

                raise FileNotFoundError(  # pylint: disable=raise-missing-from
                    f"Error: Neither module '{module_path}' could be imported nor file '{file_path}' exists"
                )

            module = _load_module_from_file_path(file_path)

    # Case 2: File path (e.g., "main.py" or "my_app/main.py")
    else:
        if not Path(app_path).is_absolute():
            cwd = Path.cwd()
            app_path = str(cwd.joinpath(app_path).resolve())

        if not Path(app_path).exists():
            raise FileNotFoundError(f"Error: The app file '{app_path}' does not exist")

        module = _load_module_from_file_path(app_path)

    if not hasattr(module, name):
        raise AttributeError(
            f"Error: The app file '{app_path}' does not contain an '{name}' instance"
        )

    app_or_factory = getattr(module, name)

    # Here we use the same approach as uvicorn to handle factory functions.
    # This prevents us from relying on explicit type annotations.
    # See: https://github.com/encode/uvicorn/blob/master/uvicorn/config.py
    try:
        app = app_or_factory()
        if not factory:
            print(  # noqa: T201
                "\n\n[WARNING]   "
                "App factory detected. Using it, but please consider setting the --factory flag explicitly.\n"
            )
    except TypeError:
        if factory:
            raise TypeError(  # pylint: disable=raise-missing-from

View on GitHub (pinned to 3e071fcc2c)

Solutions

Match the name: use colon notation --app main.py:application or pass --name application
Or add 'app = application' (an alias) in the module so the default name works
For factories, export the factory function by its exact name and add --factory

Example fix

# before
# main.py:  application = FastAPI()
openbb-mcp --app ./main.py            # looks for 'app'

# after
openbb-mcp --app ./main.py:application

Defensive patterns

Strategy: validation

Validate before calling

import runpy  # or import the module explicitly
mod = importlib.import_module(module_name) if module_importable else runpy.run_path(file_path)
if not hasattr(mod, attr_name):
    available = [n for n in dir(mod) if isinstance(getattr(mod, n), FastAPI)]
    raise ValueError(f"no '{attr_name}' attr; FastAPI instances found: {available}")

Type guard

def module_exposes_app(module, name: str) -> bool:
    return hasattr(module, name)

Try / catch

try:
    app = import_app("./main.py", "app")
except AttributeError as e:
    if "does not contain" in str(e):
        import runpy
        mod = runpy.run_path("./main.py")
        candidates = [n for n, v in mod.items() if isinstance(v, FastAPI)]
        app = import_app(f"./main.py:{candidates[0]}", candidates[0])
    else:
        raise

Prevention

Standardize on the variable name 'app' across your services
Use colon notation main.py:application to state the name explicitly in the command
Lint for 'app = FastAPI(' in the entry module during CI

When it happens

Trigger: --app main.py where main.py creates the app under a different variable (e.g. 'application' or 'api'); --app my_app.main:create_app without that function existing; --name app when the file names it 'fastapi_app'. The check is a plain hasattr on the loaded module.

Common situations: Following a tutorial whose variable name differs from your project's, refactoring that renames the app variable, using a factory function name that was misspelled, assuming 'app' is exported by a package's __init__ when it is defined in a submodule.

Related errors

AI-assisted analysis of OpenBB-finance/OpenBB@3e071fcc2c (2026-08-14). Data as JSON: /api/errors/78d8b09616622b15. Report an issue: GitHub.