LangChatEngine

from langchat.core.engine import LangChatEngine

LangChatEngine(
    *,
    llm,
    vector_db,
    db,
    reranker=None,
    prompt_template=None,
    standalone_question_prompt=None,
    verbose=False,
    max_chat_history=20,
)

async def chat(
    self,
    query: str,
    user_id: str,
    platform: str = "default",
    standalone_question: str | None = None,
) -> dict

{
    "response": str,           # AI response text
    "user_id": str,            # echoed user_id
    "timestamp": str,          # ISO 8601 UTC
    "status": "success"|"error",
    "response_time": float,    # seconds
    "error": str | None,       # error message on failure
}

def get_session(
    self,
    user_id: str,
    platform: str = "default",
) -> UserSession

# Pre-process the question yourself
standalone = f"Question about Acme Corp: {user_query}"

result = await lc.engine.chat(
    query=user_query,
    user_id="alice",
    standalone_question=standalone,
)

from langchat.core.engine import set_api_server_mode
set_api_server_mode(True)   # called automatically by create_app()