Files
api/services/chat/app/llm.py
Roberto Musso 0d5fa3e569 feat(chat): integrate Langfuse tracing, prompt management & generation tracking
- shared/config.py: add LANGFUSE_SECRET_KEY, LANGFUSE_PUBLIC_KEY, LANGFUSE_HOST
- services/chat/app/tracing.py: new module — Langfuse client singleton,
  create_trace(), get_langfuse_callback(), get_prompt(), link_prompt_to_trace(),
  score_trace(), flush/shutdown helpers. Gracefully no-ops when keys are missing.
- services/chat/app/llm.py: add callbacks param to get_llm() for LangChain
  callback handler injection
- services/chat/app/deep_agent.py: accept langfuse_handler in all run_* and
  _run_single_agent* functions, pipe callbacks to LLM calls, fetch managed
  prompts from Langfuse with fallback to hardcoded system prompts
- services/chat/app/redis_consumer.py: create Langfuse trace per request
  (home_request/floating_request), pass callback handler to deep_agent,
  link prompt name to trace, attach output preview, flush after each request
- services/chat/app/main.py: shutdown Langfuse client in lifespan teardown
- services/chat/requirements.txt: add langfuse>=2.0.0

Langfuse prompt names: 'home_system', 'floating_system' — create these in
the Langfuse dashboard to manage prompts. Without them, hardcoded defaults
are used transparently.
2026-03-22 23:15:04 +01:00

73 lines
2.0 KiB
Python

"""LLM factory — centralised model instantiation via LiteLLM.
Adapted from app/core/llm.py for the Chat Service.
Uses shared.config.settings instead of app.config.settings.
"""
from __future__ import annotations
import os
import warnings
from openai import AsyncOpenAI
import litellm
from langchain_openai import ChatOpenAI
from langchain_litellm import ChatLiteLLM
from shared.config import settings
litellm.drop_params = True
warnings.filterwarnings(
"ignore",
message=r"PydanticSerializationUnexpectedValue\(Expected `ResponseAPIUsage`",
category=UserWarning,
)
def _api_key_for_model(model: str) -> str | None:
if model.startswith("anthropic/"):
return settings.ANTHROPIC_API_KEY or None
if model.startswith("gemini/") or model.startswith("google/"):
return settings.GOOGLE_API_KEY or None
if model.startswith("cerebras/"):
return settings.CEREBRAS_API_KEY or None
if model.startswith("github_copilot/"):
return None
return settings.OPENAI_API_KEY or None
def get_llm(
*,
model: str | None = None,
temperature: float = 0,
callbacks: list | None = None,
) -> ChatOpenAI | ChatLiteLLM:
model = model or settings.LLM_MODEL
if settings.GITHUB_COPILOT_TOKEN_DIR:
os.environ.setdefault("GITHUB_COPILOT_TOKEN_DIR", settings.GITHUB_COPILOT_TOKEN_DIR)
if "/" in model:
return ChatLiteLLM(model=model, temperature=temperature, callbacks=callbacks)
return ChatOpenAI(
model=model,
temperature=temperature,
api_key=_api_key_for_model(model),
callbacks=callbacks,
)
async def embed(text: str) -> list[float]:
model = settings.LLM_EMBED_MODEL
if model.startswith("github_copilot/") or "/" in model:
response = await litellm.aembedding(model=model, input=[text])
return response.data[0]["embedding"]
client = AsyncOpenAI(api_key=settings.OPENAI_API_KEY)
response = await client.embeddings.create(model=model, input=text)
return response.data[0].embedding