Error Node | Vellum | Documentation

1 from vellum.workflows import BaseWorkflow 2 from vellum.workflows.nodes import ErrorNode 3 from vellum.workflows.inputs.base import BaseInputs 4 from vellum.workflows.state import BaseState 5 6 class Inputs(BaseInputs): 7 threshold: int 8 9 class StartNode(BaseNode): 10 class Ports(BaseNode.Ports): 11 success = Port.on_if(Inputs.threshold.greater_than(10)) 12 fail = Port.on_else() 13 14 class SuccessNode(BaseNode): 15 class Outputs(BaseNode.Outputs): 16 result = Inputs.threshold 17 18 class FailNode(ErrorNode): 19 error = "Input threshold was too low" 20 21 class BasicErrorNodeWorkflow(BaseWorkflow[Inputs, BaseState]): 22 graph = { 23 StartNode.Ports.success >> SuccessNode, 24 StartNode.Ports.fail >> FailNode, 25 } 26 class Outputs(BaseWorkflow.Outputs): 27 final_value = SuccessNode.Outputs.result

vellum.workflows.nodes.ErrorNode

Used to raise an error to reject the surrounding Workflow and return custom error messages.

Attributes

error

Union[str, VellumError]Required

The error to raise. Can be either:

A string message
A VellumError object with a message and error code

Outputs

This node doesn’t produce outputs. However, Workflows that invoke this node will error and the error message will appear in the Vellum UI.