PraisonAI/examples/python/workflows/workflow_early_stop.py

"""
Workflow Early Stop Example

Demonstrates how to stop a workflow early using custom handler
functions that return StepResult with stop_workflow=True.
"""

from praisonaiagents import (
    AgentFlow, Task, WorkflowContext, StepResult
)

# Custom validator that can stop the workflow
def validate_data(context: WorkflowContext) -> StepResult:
    """Check if data is valid and stop workflow if not."""
    data = context.variables.get("data", {})
    
    if data.get("value", 0) < 0:
        return StepResult(
            output="❌ Validation failed: negative value detected. Stopping workflow.",
            stop_workflow=True  # This stops the entire workflow
        )
    
    return StepResult(
        output="✅ Validation passed: data is valid.",
        stop_workflow=False  # Continue to next step
    )

# Create workflow with early stop capability
workflow = AgentFlow(
    name="Data Processing",
    description="Process data with validation gate",
    variables={
        "data": {"value": -5}  # Invalid data - will trigger early stop
    },
    steps=[
        Task(
            name="validate",
            handler=validate_data  # Custom function
        ),
        Task(
            name="process",
            action="Process the validated data."  # Won't run if validation fails
        ),
        Task(
            name="report",
            action="Generate final report."  # Won't run if validation fails
        )
    ]
)

if __name__ == "__main__":
    print("=== Testing with invalid data ===")
    result = workflow.run("", llm="gpt-4o-mini", verbose=True)
    for step in result.get("steps", []):
        print(f"  {step.get('step', 'step')}: {step.get('output', step.get('status'))}")

    print("\n=== Testing with valid data ===")
    workflow.variables["data"] = {"value": 42}
    result = workflow.run("", llm="gpt-4o-mini", verbose=True)
    for step in result.get("steps", []):
        print(f"  {step.get('step', 'step')}: {step.get('status', 'completed')}")