01 Hello Agent#

Script: example/01_hello_agent.py.

This is the smallest OpenRath program: build a flow.Agent, pass it a Session, and receive an updated session.

python example/01_hello_agent.py

Concept	API
Agent as module	`flow.Agent(system_prompt, provider, on_event=...)`
Session as runtime value	`Session.from_user_message(...).to("local")`
Streaming callback	`on_event=stream_to_stdout()`
Usage accounting	`out.cumulative_usage`

Needs an OpenAI-compatible key or llm.default_provider config.