langchain/libs/community/langchain_community/agent_toolkits/json/base.py

"""Json agent."""
from __future__ import annotations

from typing import TYPE_CHECKING, Any, Dict, List, Optional

from langchain_core.callbacks import BaseCallbackManager
from langchain_core.language_models import BaseLanguageModel

from langchain_community.agent_toolkits.json.prompt import JSON_PREFIX, JSON_SUFFIX
from langchain_community.agent_toolkits.json.toolkit import JsonToolkit

if TYPE_CHECKING:
    from langchain.agents.agent import AgentExecutor


def create_json_agent(
    llm: BaseLanguageModel,
    toolkit: JsonToolkit,
    callback_manager: Optional[BaseCallbackManager] = None,
    prefix: str = JSON_PREFIX,
    suffix: str = JSON_SUFFIX,
    format_instructions: Optional[str] = None,
    input_variables: Optional[List[str]] = None,
    verbose: bool = False,
    agent_executor_kwargs: Optional[Dict[str, Any]] = None,
    **kwargs: Any,
) -> AgentExecutor:
    """Construct a json agent from an LLM and tools."""
    from langchain.agents.agent import AgentExecutor
    from langchain.agents.mrkl.base import ZeroShotAgent
    from langchain.chains.llm import LLMChain

    tools = toolkit.get_tools()
    prompt_params = (
        {"format_instructions": format_instructions}
        if format_instructions is not None
        else {}
    )
    prompt = ZeroShotAgent.create_prompt(
        tools,
        prefix=prefix,
        suffix=suffix,
        input_variables=input_variables,
        **prompt_params,
    )
    llm_chain = LLMChain(
        llm=llm,
        prompt=prompt,
        callback_manager=callback_manager,
    )
    tool_names = [tool.name for tool in tools]
    agent = ZeroShotAgent(llm_chain=llm_chain, allowed_tools=tool_names, **kwargs)
    return AgentExecutor.from_agent_and_tools(
        agent=agent,
        tools=tools,
        callback_manager=callback_manager,
        verbose=verbose,
        **(agent_executor_kwargs or {}),
    )