> ## Documentation Index > Fetch the complete documentation index at: https://docs.agno.com/llms.txt > Use this file to discover all available pages before exploring further. # Router with Nested Choices HITL Example > Use HITL with nested step lists in Router choices. Use HITL with nested step lists in Router choices. When choices contain nested lists like \[step\_a, \[step\_b, step\_c]], the nested list becomes a Steps container that executes ALL steps in sequence when selected. ```python router_nested_choices.py theme={null} """ Router with Nested Choices HITL Example This example demonstrates how to use HITL with nested step lists in Router choices. When choices contain nested lists like [step_a, [step_b, step_c]], the nested list becomes a Steps container that executes ALL steps in sequence when selected. Use cases: - Pre-defined pipelines that user can choose from - "Packages" of processing steps (e.g., "Basic", "Standard", "Premium") - Workflow templates where user picks a complete flow Flow: 1. Receive input (automatic) 2. User selects a processing package (single step OR a sequence of steps) 3. Execute the selected package (if nested, all steps run in sequence) 4. Generate output (automatic) Key concept: - choices=[step_a, [step_b, step_c], step_d] - "step_a" -> executes just step_a - "steps_group_1" -> executes step_b THEN step_c (chained) - "step_d" -> executes just step_d """ from agno.db.sqlite import SqliteDb from agno.workflow.router import Router from agno.workflow.step import Step from agno.workflow.steps import Steps from agno.workflow.types import StepInput, StepOutput from agno.workflow.workflow import Workflow # ============================================================ # Step 1: Receive input (automatic) # ============================================================ def receive_input(step_input: StepInput) -> StepOutput: """Receive and validate input.""" user_query = step_input.input or "document" return StepOutput( content=f"Input received: '{user_query}'\n" "Ready for processing.\n\n" "Please select a processing package." ) # ============================================================ # Individual processing steps # ============================================================ def quick_scan(step_input: StepInput) -> StepOutput: """Quick scan - fast but basic.""" prev = step_input.previous_step_content or "" return StepOutput( content=f"{prev}\n\n[QUICK SCAN]\n" "- Surface-level analysis\n" "- Key points extracted\n" "- Processing time: 30 seconds" ) def deep_analysis(step_input: StepInput) -> StepOutput: """Deep analysis - thorough examination.""" prev = step_input.previous_step_content or "" return StepOutput( content=f"{prev}\n\n[DEEP ANALYSIS]\n" "- Comprehensive examination\n" "- Pattern detection applied\n" "- Processing time: 5 minutes" ) def quality_check(step_input: StepInput) -> StepOutput: """Quality check - verify results.""" prev = step_input.previous_step_content or "" return StepOutput( content=f"{prev}\n\n[QUALITY CHECK]\n" "- Results validated\n" "- Accuracy verified: 98%\n" "- Processing time: 1 minute" ) def format_output(step_input: StepInput) -> StepOutput: """Format output - prepare final results.""" prev = step_input.previous_step_content or "" return StepOutput( content=f"{prev}\n\n[FORMAT OUTPUT]\n" "- Results formatted\n" "- Report generated\n" "- Processing time: 30 seconds" ) def archive_results(step_input: StepInput) -> StepOutput: """Archive results - store for future reference.""" prev = step_input.previous_step_content or "" return StepOutput( content=f"{prev}\n\n[ARCHIVE]\n" "- Results archived\n" "- Backup created\n" "- Processing time: 15 seconds" ) # ============================================================ # Final step (automatic) # ============================================================ def finalize(step_input: StepInput) -> StepOutput: """Finalize and return results.""" results = step_input.previous_step_content or "No processing performed" return StepOutput( content=f"=== FINAL RESULTS ===\n\n{results}\n\n=== PROCESSING COMPLETE ===" ) # Define individual steps quick_scan_step = Step( name="quick_scan", description="Fast surface-level scan (30s)", executor=quick_scan ) # Define step sequences as Steps containers with descriptive names standard_package = Steps( name="standard_package", description="Standard processing: Deep Analysis + Quality Check (6 min)", steps=[ Step(name="deep_analysis", executor=deep_analysis), Step(name="quality_check", executor=quality_check), ], ) premium_package = Steps( name="premium_package", description="Premium processing: Deep Analysis + Quality Check + Format + Archive (8 min)", steps=[ Step(name="deep_analysis", executor=deep_analysis), Step(name="quality_check", executor=quality_check), Step(name="format_output", executor=format_output), Step(name="archive_results", executor=archive_results), ], ) # Create workflow with Router HITL # User can select: # - "quick_scan" -> runs just quick_scan # - "standard_package" -> runs deep_analysis THEN quality_check # - "premium_package" -> runs deep_analysis THEN quality_check THEN format_output THEN archive_results workflow = Workflow( name="package_selection_workflow", db=SqliteDb(db_file="tmp/workflow_router_nested.db"), steps=[ Step(name="receive_input", executor=receive_input), Router( name="package_selector", choices=[ quick_scan_step, # Single step standard_package, # Steps container (2 steps) premium_package, # Steps container (4 steps) ], requires_user_input=True, user_input_message="Select a processing package:", allow_multiple_selections=False, # Pick ONE package ), Step(name="finalize", executor=finalize), ], ) # Alternative: Using nested lists directly (auto-converted to Steps containers) # Note: Auto-generated names like "steps_group_0" are less descriptive workflow_with_nested_lists = Workflow( name="nested_list_workflow", db=SqliteDb(db_file="tmp/workflow_router_nested_alt.db"), steps=[ Step(name="receive_input", executor=receive_input), Router( name="package_selector", choices=[ Step( name="quick_scan", description="Fast scan (30s)", executor=quick_scan, ), # Nested list -> becomes "steps_group_1" Steps container [ Step(name="deep_analysis", executor=deep_analysis), Step(name="quality_check", executor=quality_check), ], # Nested list -> becomes "steps_group_2" Steps container [ Step(name="deep_analysis", executor=deep_analysis), Step(name="quality_check", executor=quality_check), Step(name="format_output", executor=format_output), Step(name="archive_results", executor=archive_results), ], ], requires_user_input=True, user_input_message="Select a processing option:", ), Step(name="finalize", executor=finalize), ], ) if __name__ == "__main__": print("=" * 60) print("Router with Nested Choices (Pre-defined Packages)") print("=" * 60) print("\nThis example shows how to offer 'packages' of steps.") print("Each package can be a single step or a sequence of steps.\n") run_output = workflow.run("quarterly report") # Handle HITL pauses while run_output.is_paused: # Handle Router requirements (user selection) for requirement in run_output.steps_requiring_route: print(f"\n[DECISION POINT] {requirement.step_name}") print(f"[HITL] {requirement.user_input_message}") # Show available packages print("\nAvailable packages:") for i, choice in enumerate(requirement.available_choices or [], 1): # Get description if available from the router's choices print(f" {i}. {choice}") print("\nPackage details:") print(" - quick_scan: Fast surface-level scan (30s)") print(" - standard_package: Deep Analysis + Quality Check (6 min)") print(" - premium_package: Full pipeline with archiving (8 min)") selection = input("\nEnter your choice: ").strip() if selection: requirement.select(selection) print(f"\n[HITL] Selected package: {selection}") for requirement in run_output.steps_requiring_confirmation: print( f"\n[HITL] {requirement.step_name}: {requirement.confirmation_message}" ) if input("Continue? (yes/no): ").strip().lower() in ("yes", "y"): requirement.confirm() else: requirement.reject() run_output = workflow.continue_run(run_output) print("\n" + "=" * 60) print(f"Status: {run_output.status}") print("=" * 60) print(run_output.content) ``` ## Run the Example ```bash theme={null} uv pip install -U agno cel-python fastapi sqlalchemy ``` Save the code above as `router_nested_choices.py`, then run: ```bash theme={null} python router_nested_choices.py ``` Full source: [cookbook/04\_workflows/08\_human\_in\_the\_loop/router/03\_router\_nested\_choices.py](https://github.com/agno-agi/agno/blob/main/cookbook/04_workflows/08_human_in_the_loop/router/03_router_nested_choices.py)