Early Stop a Workflow

Stop a running workflow from any step by returning StepOutput with stop=True.

Any step can stop the workflow early by returning a StepOutput with stop=True. Here, a validation step checks the incoming data and halts the workflow before the processing steps run if the data is bad.

When to use: When you need safety mechanisms, quality gates, or validation checkpoints that should prevent downstream processing if conditions aren’t met. Ideal for data validation pipelines, security checks, quality assurance workflows, or any process where continuing with invalid inputs could cause problems.

Install dependencies:

uv pip install agno openai

early_stop_workflow_with_agents.py

from agno.agent import Agent
from agno.models.openai import OpenAIResponses
from agno.workflow import Workflow
from agno.workflow.types import StepInput, StepOutput

# Create agents with more specific validation criteria
data_validator = Agent(
    name="Data Validator",
    model=OpenAIResponses(id="gpt-5.2"),
    instructions=[
        "You are a data validator. Analyze the provided data and determine if it's valid.",
        "For data to be VALID, it must meet these criteria:",
        "- user_count: Must be a positive number (> 0)",
        "- revenue: Must be a positive number (> 0)",
        "- date: Must be in a reasonable date format (YYYY-MM-DD)",
        "",
        "Return exactly 'VALID' if all criteria are met.",
        "Return exactly 'INVALID' if any criteria fail.",
        "Also briefly explain your reasoning.",
    ],
)

data_processor = Agent(
    name="Data Processor",
    model=OpenAIResponses(id="gpt-5.2"),
    instructions="Process and transform the validated data.",
)

report_generator = Agent(
    name="Report Generator",
    model=OpenAIResponses(id="gpt-5.2"),
    instructions="Generate a final report from processed data.",
)


def early_exit_validator(step_input: StepInput) -> StepOutput:
    """
    Custom function that checks data quality and stops workflow early if invalid
    """
    # Get the validation result from previous step
    validation_result = step_input.previous_step_content or ""

    if "INVALID" in validation_result.upper():
        return StepOutput(
            content="Data validation failed. Workflow stopped early to prevent processing invalid data.",
            stop=True,  # Stop the entire workflow here
        )
    else:
        return StepOutput(
            content="Data validation passed. Continuing with processing...",
            stop=False,  # Continue normally
        )


# Create workflow with conditional early termination
workflow = Workflow(
    name="Data Processing with Early Exit",
    description="Process data but stop early if validation fails",
    steps=[
        data_validator,  # Step 1: Validate data
        early_exit_validator,  # Step 2: Check validation and possibly stop early
        data_processor,  # Step 3: Process data (only if validation passed)
        report_generator,  # Step 4: Generate report (only if processing completed)
    ],
)

if __name__ == "__main__":
    print("\n=== Testing with INVALID data ===")
    workflow.print_response(
        input="Process this data: {'user_count': -50, 'revenue': 'invalid_amount', 'date': 'bad_date'}"
    )

    print("=== Testing with VALID data ===")
    workflow.print_response(
        input="Process this data: {'user_count': 1000, 'revenue': 50000, 'date': '2024-01-15'}"
    )