Accessing Multiple Previous Steps

How to access multiple previous steps

Advanced workflows often require data from multiple previous steps beyond just the immediate predecessor. The StepInput object provides powerful methods to access any previous step’s output by name or retrieve all accumulated content.

Example

def create_comprehensive_report(step_input: StepInput) -> StepOutput:
    """
    Custom function that creates a report using data from multiple previous steps.
    This function has access to ALL previous step outputs and the original workflow message.
    """

    # Access original workflow input
    original_topic = step_input.workflow_message or ""

    # Access specific step outputs by name
    hackernews_data = step_input.get_step_content("research_hackernews") or ""
    web_data = step_input.get_step_content("research_web") or ""

    # Or access ALL previous content
    all_research = step_input.get_all_previous_content()

    # Create a comprehensive report combining all sources
    report = f"""
        # Comprehensive Research Report: {original_topic}

        ## Executive Summary
        Based on research from HackerNews and web sources, here's a comprehensive analysis of {original_topic}.

        ## HackerNews Insights
        {hackernews_data[:500]}...

        ## Web Research Findings  
        {web_data[:500]}...
    """

    return StepOutput(
        step_name="comprehensive_report", 
        content=report.strip(), 
        success=True
    )

# Use in workflow
workflow = Workflow(
    name="Enhanced Research Workflow",
    steps=[
        Step(name="research_hackernews", agent=hackernews_agent),
        Step(name="research_web", agent=web_agent),
        Step(name="comprehensive_report", executor=create_comprehensive_report),  # Accesses both previous steps
        Step(name="final_reasoning", agent=reasoning_agent),
    ],
)

Available Methods

• step_input.get_step_content("step_name") - Get content from specific step by name
• step_input.get_all_previous_content() - Get all previous step content combined
• step_input.workflow_message - Access the original workflow input message
• step_input.previous_step_content - Get content from immediate previous step

In case of Parallel step, when you do step_input.get_step_content("parallel_step_name"), it will return a dict with each key as individual_step_name for all the outputs from the steps defined in parallel. Example:

parallel_step_output = step_input.get_step_content("parallel_step_name")

parallel_step_output will be a dict with each key as individual_step_name for all the outputs from the steps defined in parallel.

{
    "individual_step_name_1": "output_from_individual_step_1",
    "individual_step_name_2": "output_from_individual_step_2",
}

Developer Resources

• Access Multiple Previous Steps Output