Multi-Turn Chat

Build a streaming multi-turn chat with history management

Multi-Turn Chat

This guide shows how to build a stateful conversation with streaming output, history management, and proper turn lifecycle.

The History Pattern

SimpleLLMFunc agents are stateless by default — they don’t store conversation history internally. You pass history in, you get updated history back. This makes state management explicit and testable.

import asyncio
from SimpleLLMFunc import OpenAICompatible, llm_chat
from SimpleLLMFunc.hooks import is_response_yield, is_event_yield

models = OpenAICompatible.load_from_json_file("provider.json")
llm = models["openrouter"]["openai/gpt-4o"]


@llm_chat(llm_interface=llm, stream=True)
async def chat(message: str, history: list | None = None):
    """
    You are a concise, helpful assistant.
    Remember context from earlier in the conversation.
    """
    pass

The parameter named history (or chat_history) is special — the framework uses it to carry conversation state between turns.

Streaming Responses

async def main():
    history = []

    # Turn 1
    print("User: What is Python?")
    print("Assistant: ", end="")
    async for output in chat("What is Python?", history):
        if is_response_yield(output):
            print(output.response, end="")
            history = output.messages
    print("\n")

    # Turn 2 — the agent remembers turn 1
    print("User: What are its main features?")
    print("Assistant: ", end="")
    async for output in chat("What are its main features?", history):
        if is_response_yield(output):
            print(output.response, end="")
            history = output.messages
    print()


asyncio.run(main())

Each output.messages contains the full updated conversation. Pass it back for the next turn.

Event-Aware Consumption

For richer UX, handle individual events:

from SimpleLLMFunc.hooks import (
    LLMChunkArriveEvent,
    ToolCallStartEvent,
    ToolCallEndEvent,
    ReactEndEvent,
)


async def run_turn(message: str, history: list) -> list:
    async for output in chat(message, history):
        if is_event_yield(output):
            event = output.event
            if isinstance(event, LLMChunkArriveEvent):
                print(event.accumulated_content, end="", flush=True)
            elif isinstance(event, ToolCallStartEvent):
                print(f"\n[calling {event.tool_name}...]")
            elif isinstance(event, ToolCallEndEvent):
                print(f"[done: {event.tool_name}]")
            elif isinstance(event, ReactEndEvent):
                return event.final_messages
    return history

Non-Streaming Mode

For simpler use cases where you just want the final response:

@llm_chat(llm_interface=llm, stream=False)
async def simple_chat(message: str, history: list | None = None):
    """A helpful assistant."""
    pass


async def main():
    history = []
    async for output in simple_chat("Hello!", history):
        if is_response_yield(output):
            print(output.response)
            history = output.messages


asyncio.run(main())

Why History is External

This is a deliberate design choice:

• Testable — You can snapshot and replay any conversation state
• Flexible storage — Store in memory, Redis, disk, database — your choice
• Fork-friendly — Branch a conversation by copying the history list
• No hidden state — The agent has no memory you don’t control

For agents that need durable, self-modifying context (experiences, compaction, forking), see SelfRef.

What’s Next

Design Philosophy

Understand why the framework is designed this way.

Context Model

Learn how context is structured, mutated, and compiled.