Exceptions

WeaverletException

class WeaverletException(Exception):
    pass

The base exception raised by Weaverlet itself. All framework-originated errors subclass Exception directly via this class (Weaverlet doesn't define more specific exception subclasses).

from weaverlet import WeaverletException

When it's raised

Site	Trigger
SimpleRouterComponent._resolve_prefix	use_prefix=True but context["prefix"] is missing.
AuthRouterComponent._resolve_prefix	Same. use_prefix=True without a prefix in context.
RedirectComponent.get_layout	Component constructed with use_prefix=True but context["prefix"] is missing.
StoreComponent.input_signal dispatch	An op-dict with an unknown op value (anything other than STORE, MERGE, CLEAN).

Catching it

from weaverlet import WeaverletException

try:
    wapp = WeaverletApp(root_component=root)
except WeaverletException as e:
    print(f"Weaverlet setup error: {e}")

The errors are usually configuration-time (raised when the layout is first built), not runtime. If WeaverletApp(...) succeeds, you're past the danger zone.

Not in the hierarchy

Weaverlet doesn't catch or remap Dash errors. DuplicateIdError, callback exceptions, etc. surface as their underlying Dash types. WeaverletApp(jupyter_mode=True) specifically raises TypeError, not WeaverletException, to match Python's standard practice for invalid-kwarg signaling.

See also

• WeaverletComponent
• WeaverletApp