Files
cluster-knaster/core/src/knaster/llm.py
T

72 lines
2.4 KiB
Python

"""Chat-Client für das OpenAI-kompatible API von LiteLLM."""
from __future__ import annotations
from dataclasses import dataclass, field
from typing import Any, Protocol
import httpx
from .problems import is_context_overflow_message
class LLMError(Exception):
"""Basisklasse; `infra=True` bedeutet: Endpunkt/Netz, nicht Modellqualität."""
infra = True
class EndpointError(LLMError):
pass
class ContextOverflowError(LLMError):
pass
@dataclass
class ChatResult:
content: str
finish_reason: str | None = None
usage: dict[str, Any] = field(default_factory=dict)
model: str | None = None
class ChatClient(Protocol):
def chat(self, model: str, messages: list[dict[str, str]], *, max_tokens: int | None = None,
temperature: float | None = None) -> ChatResult: ...
class OpenAIChatClient:
def __init__(self, base_url: str, api_key: str = "", timeout: float = 120.0,
client: httpx.Client | None = None):
self.base_url = base_url.rstrip("/")
self.headers = {"Authorization": f"Bearer {api_key}"} if api_key else {}
self.client = client or httpx.Client(timeout=timeout)
def chat(self, model: str, messages: list[dict[str, str]], *, max_tokens: int | None = None,
temperature: float | None = None) -> ChatResult:
body: dict[str, Any] = {"model": model, "messages": messages}
if max_tokens is not None:
body["max_tokens"] = max_tokens
if temperature is not None:
body["temperature"] = temperature
try:
resp = self.client.post(f"{self.base_url}/v1/chat/completions", json=body, headers=self.headers)
except httpx.HTTPError as exc:
raise EndpointError(f"{type(exc).__name__}: {exc}") from exc
if resp.status_code == 400 and is_context_overflow_message(resp.text):
raise ContextOverflowError(resp.text[:500])
if resp.status_code == 429 or resp.status_code >= 500:
raise EndpointError(f"HTTP {resp.status_code}: {resp.text[:300]}")
if resp.status_code >= 400:
raise EndpointError(f"HTTP {resp.status_code}: {resp.text[:300]}")
data = resp.json()
choice = data["choices"][0]
return ChatResult(
content=choice["message"].get("content") or "",
finish_reason=choice.get("finish_reason"),
usage=data.get("usage") or {},
model=data.get("model"),
)