Commit Graph

8 Commits (73da8f863cff5ef6af358ec173572a1a8495baef)

Author SHA1 Message Date
Nuno Campos 9cbf14dec2
Fetch runnable config from context var inside runnable lambda and runnable generator (#15334)
- easier to write custom logic/loops with automatic tracing
- if you don't want to streaming support write a regular function and
pass to RunnableLambda
- if you do want streaming write a generator and pass it to
RunnableGenerator

```py
import json
from typing import AsyncIterator

from langchain_core.messages import BaseMessage, FunctionMessage, HumanMessage
from langchain_core.agents import AgentAction, AgentFinish
from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder
from langchain_core.runnables import Runnable, RunnableGenerator, RunnablePassthrough
from langchain_core.tools import BaseTool

from langchain.agents.output_parsers import OpenAIFunctionsAgentOutputParser
from langchain.chat_models import ChatOpenAI
from langchain.tools.render import format_tool_to_openai_function


def _get_tavily():
    from langchain.tools.tavily_search import TavilySearchResults
    from langchain.utilities.tavily_search import TavilySearchAPIWrapper

    tavily_search = TavilySearchAPIWrapper()
    return TavilySearchResults(api_wrapper=tavily_search)


async def _agent_executor_generator(
    input: AsyncIterator[list[BaseMessage]],
    *,
    max_iterations: int = 10,
    tools: dict[str, BaseTool],
    agent: Runnable[list[BaseMessage], BaseMessage],
    parser: Runnable[BaseMessage, AgentAction | AgentFinish],
) -> AsyncIterator[BaseMessage]:
    messages = [m async for mm in input for m in mm]
    for _ in range(max_iterations):
        next_message = await agent.ainvoke(messages)
        yield next_message
        messages.append(next_message)

        parsed = await parser.ainvoke(next_message)
        if isinstance(parsed, AgentAction):
            result = await tools[parsed.tool].ainvoke(parsed.tool_input)
            next_message = FunctionMessage(name=parsed.tool, content=json.dumps(result))
            yield next_message
            messages.append(next_message)
        elif isinstance(parsed, AgentFinish):
            return


def get_agent_executor(tools: list[BaseTool], system_message: str):
    llm = ChatOpenAI(model="gpt-4-1106-preview", temperature=0, streaming=True)
    prompt = ChatPromptTemplate.from_messages(
        [
            ("system", system_message),
            MessagesPlaceholder(variable_name="messages"),
        ]
    )
    llm_with_tools = llm.bind(
        functions=[format_tool_to_openai_function(t) for t in tools]
    )

    agent = {"messages": RunnablePassthrough()} | prompt | llm_with_tools
    parser = OpenAIFunctionsAgentOutputParser()
    executor = RunnableGenerator(_agent_executor_generator)
    return executor.bind(
        tools={tool.name for tool in tools}, agent=agent, parser=parser
    )


agent = get_agent_executor([_get_tavily()], "You are a very nice agent!")


async def main():
    async for message in agent.astream(
        [HumanMessage(content="whats the weather in sf tomorrow?")]
    ):
        print(message)


if __name__ == "__main__":
    import asyncio

    asyncio.run(main())
```

results in this trace
https://smith.langchain.com/public/fa17f05d-9724-4d08-8fa1-750f8fcd051b/r
8 months ago
Nuno Campos 99000c612e
Propagate context vars in all classes/methods (#15329)
- Any direct usage of ThreadPoolExecutor or asyncio.run_in_executor
needs manual handling of context vars

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9 months ago
Nuno Campos 4e4b119614 Fix executor 9 months ago
chyroc 7ce338201c
Patch: improve check openai version (#15301) 9 months ago
Nuno Campos f7313adf2a old py compat 9 months ago
Nuno Campos eb5e250188 Propagate context vars in all classes/methods
- Any direct usage of ThreadPoolExecutor or asyncio.run_in_executor needs manual handling of context vars
9 months ago
joshy-deshaw bf5385592e
core, community: propagate context between threads (#15171)
While using `chain.batch`, the default implementation uses a
`ThreadPoolExecutor` and run the chains in separate threads. An issue
with this approach is that that [the token counting
callback](https://python.langchain.com/docs/modules/callbacks/token_counting)
fails to work as a consequence of the context not being propagated
between threads. This PR adds context propagation to the new threads and
adds some thread synchronization in the OpenAI callback. With this
change, the token counting callback works as intended.

Having the context propagation change would be highly beneficial for
those implementing custom callbacks for similar functionalities as well.

---------

Co-authored-by: Nuno Campos <nuno@langchain.dev>
9 months ago
Harrison Chase d82cbf5e76
Separate out langchain_core package (#13577)
Co-authored-by: Nuno Campos <nuno@boringbits.io>
Co-authored-by: Bagatur <baskaryan@gmail.com>
Co-authored-by: Erick Friis <erick@langchain.dev>
10 months ago