Anthropic Basic Reasoning Stream

Stream reasoning events from Claude with extended thinking enabled.

basic_reasoning_stream.py
"""
Basic Reasoning Stream
======================

Demonstrates this reasoning cookbook example.
"""

from agno.agent import Agent
from agno.models.anthropic import Claude
from agno.run.agent import RunEvent  # noqa


# ---------------------------------------------------------------------------
# Create Example
# ---------------------------------------------------------------------------
def run_example() -> None:
    # Create an agent with reasoning enabled
    agent = Agent(
        reasoning_model=Claude(
            id="claude-sonnet-4-5",
            thinking={"type": "enabled", "budget_tokens": 1024},
        ),
        instructions="Think step by step about the problem.",
    )

    prompt = "What is 25 * 37? Show your reasoning."

    agent.print_response(prompt, stream=True, stream_events=True)

    # # or you can capture the event using
    # for run_output_event in agent.run(
    #     prompt,
    #     stream=True,
    #     stream_events=True,
    # ):
    #     if run_output_event.event == RunEvent.run_started:
    #         print(f"\nEVENT: {run_output_event.event}")

    #     elif run_output_event.event == RunEvent.reasoning_started:
    #         print(f"\nEVENT: {run_output_event.event}")
    #         print("Reasoning started...\n")

    #     elif run_output_event.event == RunEvent.reasoning_content_delta:
    #         # This is the NEW streaming event for reasoning content
    #         # It streams the raw content as it's being generated
    #         print(run_output_event.reasoning_content, end="", flush=True)

    #     elif run_output_event.event == RunEvent.run_content:
    #         if run_output_event.content:
    #             print(run_output_event.content, end="", flush=True)

    #     elif run_output_event.event == RunEvent.run_completed:
    #         print(f"\n\nEVENT: {run_output_event.event}")


# ---------------------------------------------------------------------------
# Run Example
# ---------------------------------------------------------------------------
if __name__ == "__main__":
    run_example()

Run the Example

Set up your virtual environment

uv venv --python 3.12
source .venv/bin/activate

Install dependencies

uv pip install -U agno anthropic openai

Export your API keys

export ANTHROPIC_API_KEY="your_anthropic_api_key_here"
export OPENAI_API_KEY="your_openai_api_key_here"

Run the example

Save the code above as basic_reasoning_stream.py, then run:

python basic_reasoning_stream.py

Full source: cookbook/10_reasoning/models/anthropic/basic_reasoning_stream.py