Steps containers.
nested_choices.py
"""
Nested Choices
==============
Demonstrates nested lists in router choices, which are converted into sequential `Steps` containers.
"""
from typing import List, Union
from agno.agent.agent import Agent
from agno.models.openai import OpenAIChat
from agno.workflow.router import Router
from agno.workflow.step import Step
from agno.workflow.types import StepInput
from agno.workflow.workflow import Workflow
# ---------------------------------------------------------------------------
# Create Agents
# ---------------------------------------------------------------------------
step_a = Agent(name="step_a", model=OpenAIChat(id="gpt-4o-mini"), instructions="Step A")
step_b = Agent(name="step_b", model=OpenAIChat(id="gpt-4o-mini"), instructions="Step B")
step_c = Agent(name="step_c", model=OpenAIChat(id="gpt-4o-mini"), instructions="Step C")
# ---------------------------------------------------------------------------
# Define Router Selector
# ---------------------------------------------------------------------------
def nested_selector(
step_input: StepInput,
step_choices: list,
) -> Union[str, Step, List[Step]]:
user_input = step_input.input.lower()
if "single" in user_input:
return step_choices[0]
return step_choices[1]
# ---------------------------------------------------------------------------
# Create Workflow
# ---------------------------------------------------------------------------
workflow = Workflow(
name="Nested Choices Routing",
steps=[
Router(
name="Nested Router",
selector=nested_selector,
choices=[step_a, [step_b, step_c]],
),
],
)
# ---------------------------------------------------------------------------
# Run Workflow
# ---------------------------------------------------------------------------
if __name__ == "__main__":
workflow.print_response("Run the sequence", stream=True)
Run the Example
1
Set up your virtual environment
uv venv --python 3.12
source .venv/bin/activate
uv venv --python 3.12
.venv\Scripts\activate
2
Install dependencies
uv pip install -U agno fastapi openai
3
Export your OpenAI API key
export OPENAI_API_KEY="your_openai_api_key_here"
$Env:OPENAI_API_KEY="your_openai_api_key_here"
4
Run the example
Save the code above as
nested_choices.py, then run:python nested_choices.py