282 lines
12 KiB
Python
282 lines
12 KiB
Python
"""OpenRouter chat-completions client (S2 seam).
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OpenAI-compatible direct client — zero heavy deps (httpx only). Key / base URL
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/ model all come from the environment; the client is injectable for tests
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(transport or a stub subclass). No call-quota logic by design (CONTRACT C3:
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no artificial limits on real calls; only ordinary robustness retries).
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"""
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from __future__ import annotations
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import json
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import logging
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import os
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import re
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import time
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from typing import Any, Callable
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import httpx
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logger = logging.getLogger("hvr.llm")
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DEFAULT_MODEL = "deepseek/deepseek-v4-flash-0731"
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DEFAULT_BASE_URL = "https://openrouter.ai/api/v1"
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_JSON_FENCE = re.compile(r"^```(?:json)?\s*|\s*```$")
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class LLMError(Exception):
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"""User-readable upstream failure (HTTP/network/parse-after-retry)."""
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def resolve_env(env: dict[str, str] | None = None) -> dict[str, str]:
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"""Resolve runtime config. Key stays external (CONTRACT C2)."""
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env = env or dict(os.environ)
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api_key = env.get("OPENROUTER_API_KEY") or env.get("PRODREAM_BACKEND_OPENROUTER_API_KEY") or ""
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base_url = (env.get("OPENROUTER_BASE_URL") or DEFAULT_BASE_URL).rstrip("/")
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# 正向代理（含 Basic Auth），如后端 .env 的 PRODREAM_BACKEND_OPENROUTER_PROXY_URL
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proxy_url = env.get("OPENROUTER_PROXY_URL") or env.get("PRODREAM_BACKEND_OPENROUTER_PROXY_URL") or ""
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model = env.get("HVR_LLM_MODEL") or DEFAULT_MODEL
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return {"api_key": api_key, "base_url": base_url, "proxy_url": proxy_url, "model": model}
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def _join_content_parts(content: Any) -> str:
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if isinstance(content, str):
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return content
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if isinstance(content, list):
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parts: list[str] = []
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for part in content:
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if isinstance(part, str):
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parts.append(part)
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elif isinstance(part, dict):
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parts.append(str(part.get("text") or ""))
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return "".join(parts)
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return ""
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def message_text(data: dict[str, Any]) -> str:
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"""Read assistant text from an OpenAI-compatible completion payload.
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DeepSeek V4 / OpenRouter reasoning models often put thinking in
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``reasoning`` / ``reasoning_content`` and leave ``content`` empty when
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the shared output budget is exhausted.
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"""
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try:
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choice = data["choices"][0]
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message = choice.get("message") or {}
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except (KeyError, IndexError, TypeError) as exc:
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raise LLMError("大模型响应缺少内容字段") from exc
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text = _join_content_parts(message.get("content"))
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if text.strip():
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return text
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finish = str(choice.get("finish_reason") or "")
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has_reasoning = bool(
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message.get("reasoning")
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or message.get("reasoning_content")
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or message.get("reasoning_details")
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)
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extra: list[str] = []
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if finish:
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extra.append(f"finish_reason={finish}")
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if has_reasoning:
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extra.append("思考过程占满了输出额度")
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suffix = "；".join(extra) if extra else "可能被截断或拒绝"
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raise LLMError(f"模型未返回内容（{suffix}）")
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def reasoning_config(disable_reasoning: bool = False) -> dict[str, Any]:
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"""OpenRouter rejects payloads that set both ``effort`` and ``max_tokens``."""
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if disable_reasoning:
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return {"effort": "none", "exclude": True}
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# 思考预算实测（2026-08-25 两次）：
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# 2048 → 单次 diagnose 309.8s，模型烧满全部思考 token；DeepSeek 思考
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# token 生成速度远慢于正文（约 1/10），5 分钟几乎全花在想。
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# 512 → 同文书同 prompt 实测 70.2s，输出完整合规（4 briefs / 5 patterns）。
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# 早期 2048→1024 曾因旧版冗长 prompt 引入 502（思考受限→输出不合规→校验
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# 失败）；prompt 压紧凑后 512 可行，JSON 校验失败仍有 complete_json 重试兜底。
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return {"max_tokens": 512}
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def extract_json(content: str | None) -> dict[str, Any]:
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"""Parse model output as JSON. Strips ```json fences and trims to the
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outermost balanced {...} region."""
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if not content or not content.strip():
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raise LLMError("模型未返回内容（可能被截断或拒绝）")
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text = _JSON_FENCE.sub("", content.strip()).strip()
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try:
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parsed = json.loads(text)
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if isinstance(parsed, dict):
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return parsed
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except json.JSONDecodeError:
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pass
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start = text.find("{")
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end = text.rfind("}")
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if start != -1 and end > start:
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try:
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parsed = json.loads(text[start : end + 1])
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if isinstance(parsed, dict):
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return parsed
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except json.JSONDecodeError:
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pass
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raise LLMError("模型输出不是有效的 JSON（解析失败）")
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def _readable_error(resp: httpx.Response) -> str:
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"""从上游错误响应提取一行用户可读信息（优先 error.message），
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不把完整 JSON body 甩给页面（PRD §11 失败兜底）。"""
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try:
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body = resp.json()
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if isinstance(body, dict):
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msg = (body.get("error") or {}).get("message", "") if isinstance(body.get("error"), dict) else ""
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if msg:
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return msg[:300]
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except Exception:
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pass
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return resp.text[:200]
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class LlmClient:
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"""Thin OpenAI-compatible client. `transport`/`client` injectable for tests."""
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def __init__(
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self,
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api_key: str | None = None,
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base_url: str | None = None,
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model: str | None = None,
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proxy: str | None = None,
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timeout: float = 180.0,
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# 实测（2026-08-25）：诊断正常输出 ~2.5k tokens（prompt 已压紧凑）；
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# 模型偶发啰嗦打满 16000 → 截断 → JSON 失败 → 重试又 258s，页面卡 5 分钟。
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# 8000 给正常输出 3 倍余量，打满时更快失败并走既有重试兜底。
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max_tokens: int = 8000,
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temperature: float = 0.3,
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transport: httpx.BaseTransport | None = None,
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) -> None:
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cfg = resolve_env()
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self.api_key = api_key or cfg["api_key"]
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self.base_url = base_url or cfg["base_url"]
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self.model = model or cfg["model"]
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self.proxy = proxy if proxy is not None else cfg["proxy_url"]
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self.timeout = timeout
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self.max_tokens = max_tokens
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self.temperature = temperature
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if not self.api_key:
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raise LLMError("缺少 OpenRouter Key：请通过 local_start.sh 启动（从 prodream_backend/.env 读取）")
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self._transport = transport
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# -- internal ----------------------------------------------------------
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def _post(self, payload: dict[str, Any]) -> httpx.Response:
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kwargs: dict[str, Any] = {"timeout": self.timeout}
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if self._transport is not None:
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kwargs["transport"] = self._transport
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# trust_env=False + 显式 proxy：直连配置的 base_url，不继承本机 Surge 等系统代理；
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# 区域代理（PRODREAM_BACKEND_OPENROUTER_PROXY_URL）作为正向代理传入
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with httpx.Client(trust_env=False, proxy=self.proxy or None, **kwargs) as client:
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resp = client.post(
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f"{self.base_url}/chat/completions",
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headers={
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"Authorization": f"Bearer {self.api_key}",
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"Content-Type": "application/json",
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},
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json=payload,
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)
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return resp
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def _complete(
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self,
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system: str,
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user: str,
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json_reminder: bool = False,
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disable_reasoning: bool = False,
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) -> str:
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messages = [{"role": "system", "content": system}]
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if json_reminder:
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messages.append(
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{"role": "system", "content": "只输出符合要求的 JSON，不要输出任何其它文字、解释或代码块标记。"}
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)
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messages.append({"role": "user", "content": user})
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payload: dict[str, Any] = {
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"model": self.model,
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"messages": messages,
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"temperature": self.temperature,
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"max_tokens": self.max_tokens,
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"response_format": {"type": "json_object"},
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}
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# DeepSeek V4 Flash 的思考 token 与正文共用输出额度；不限制时
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# diagnose 这类长 JSON 经常只返回空 content（页面上就是 502）。
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# OpenRouter：effort 与 max_tokens 只能二选一。
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payload["reasoning"] = reasoning_config(disable_reasoning)
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# 观测：每次 LLM 调用都打耗时 + usage，慢链路（同事反馈 diagnose 卡 5 分钟）靠它定位
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t0 = time.monotonic()
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try:
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resp = self._post(payload)
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except (httpx.HTTPError, ValueError, TypeError) as exc: # 网络/超时；代理 URL 或配置错误（如 .env 解析出整行变量名）
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dt = time.monotonic() - t0
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logger.warning("llm http-error dt=%.1fs %s", dt, exc.__class__.__name__)
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if isinstance(exc, httpx.HTTPError):
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raise LLMError(f"调用大模型失败（网络/超时）：{exc.__class__.__name__}") from exc
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# 2026-08-25 实测：代理 URL 带变量名前缀 → httpx 构造期 ValueError → 裸 500
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# （此前只捕 httpx.HTTPError）。配置类错误同样转可读 LLMError（PRD §11 失败兜底）
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raise LLMError(f"调用大模型失败（配置错误，请检查代理/地址设置）：{exc}") from exc
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dt = time.monotonic() - t0
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if resp.status_code != 200:
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logger.warning("llm http %s dt=%.1fs retry-hint=%s", resp.status_code, dt, resp.headers.get("retry-after", ""))
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raise LLMError(f"调用大模型失败（HTTP {resp.status_code}）：{_readable_error(resp)}")
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try:
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body = resp.json()
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except Exception as exc:
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raise LLMError("模型未返回内容（可能被截断或拒绝）") from exc
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usage = body.get("usage") or {}
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# uvicorn 默认只给 uvicorn.* logger 配 handler，root 的 info 会被吞；
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# 观测行用 warning 级别保证进入 stderr 日志（慢链路定位依据）
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logger.warning(
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"llm ok model=%s dt=%.1fs prompt=%s completion=%s reasoning=%s total_time_ms=%s",
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self.model, dt,
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usage.get("prompt_tokens"), usage.get("completion_tokens"),
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usage.get("reasoning_tokens"), usage.get("total_time"),
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)
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return message_text(body)
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# -- public ------------------------------------------------------------
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def complete_json(
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self,
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system: str,
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user: str,
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validate: Callable[[dict[str, Any]], str | None] | None = None,
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) -> dict[str, Any]:
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"""Structured completion with robustness retries (SEAMS default:
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any LLMError (parse failure / empty content / transient upstream
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failure) is retried once, the retry carrying a JSON-only reminder
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and turning reasoning off so the answer is not crowded out).
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No quota logic.
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`validate` is an optional semantic check on the parsed JSON: return
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None when acceptable, or a one-line Chinese explanation when not
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(e.g. per-paragraph arrays must match the input paragraph count).
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A failing check is treated exactly like a parse failure — logged,
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retried once, only surfaced after both attempts fail."""
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last_error: LLMError | None = None
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for attempt in range(2):
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try:
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content = self._complete(
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system,
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user,
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json_reminder=(attempt == 1),
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disable_reasoning=(attempt == 1),
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)
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parsed = extract_json(content)
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if validate is not None:
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problem = validate(parsed)
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if problem:
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raise LLMError(problem)
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if attempt == 1:
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logger.warning("llm retry succeeded after first failure: %s", last_error)
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return parsed
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except LLMError as exc:
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last_error = exc
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if attempt == 0:
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logger.warning("llm call failed, retrying once: %s", exc)
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assert last_error is not None
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logger.error("llm call failed after 2 attempts: %s", last_error)
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raise last_error
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