完善 MCP/会话上下文治理并补齐搜索与诊断能力。

补充历史压缩与会话诊断链路，强化 tool pairing 与空响应兜底观测；完善 Admin MCP 导入/绑定与相关前端展示；新增 web_search_fast/web_fetch_clean 及多项测试与文档更新，并同步技能安装与角色绑定策略改进。

Made-with: Cursor

runtime/chat/session_context_diagnostics.py

@@ -0,0 +1,105 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+from typing import Any
+
+
+@dataclass(frozen=True)
+class SessionContextStats:
+    session_id: str
+    total_messages: int
+    sampled_messages: int
+    last_n: int
+
+    last_n_total_chars: int
+    last_n_tool_total_chars: int
+    last_n_max_msg_chars: int
+    last_n_max_tool_chars: int
+    last_n_max_user_chars: int
+
+    empty_assistant_text_in_sampled: int
+    empty_assistant_text_ids: tuple[int, ...]
+
+    max_content_chars_in_sampled: int
+    max_tool_chars_in_sampled: int
+
+
+def compute_session_context_stats(
+    *,
+    store: Any,
+    session_id: str,
+    sample_n: int = 120,
+    last_n: int = 80,
+) -> SessionContextStats:
+    """Compute lightweight DB-backed stats for diagnosing context overflow vs empty responses.
+
+    This intentionally only inspects DB text lengths (not token counts).
+    """
+    sid = str(session_id or "").strip()
+    if not sid:
+        raise ValueError("session_id required")
+    sample_n = max(1, min(int(sample_n or 120), 2000))
+    last_n = max(1, min(int(last_n or 80), 2000))
+
+    total = 0
+    sampled_rows: list[tuple[int, str, str, int]] = []
+    last_rows: list[tuple[int, str, str, int]] = []
+    try:
+        # Prefer raw SQL to avoid store-level object hydration overhead.
+        with store._connect() as conn:  # noqa: SLF001
+            cur = conn.execute("select count(1) from chat_message where session_id=?", (sid,))
+            total = int((cur.fetchone() or [0])[0] or 0)
+            cur = conn.execute(
+                "select id, role, event_type, coalesce(length(content),0) as n "
+                "from chat_message where session_id=? order by id desc limit ?",
+                (sid, int(sample_n)),
+            )
+            sampled_rows = [(int(r[0]), str(r[1] or ""), str(r[2] or ""), int(r[3] or 0)) for r in (cur.fetchall() or [])]
+            cur = conn.execute(
+                "select id, role, event_type, coalesce(length(content),0) as n "
+                "from chat_message where session_id=? order by id desc limit ?",
+                (sid, int(last_n)),
+            )
+            last_rows = [(int(r[0]), str(r[1] or ""), str(r[2] or ""), int(r[3] or 0)) for r in (cur.fetchall() or [])]
+    except Exception:
+        # Fallback path via store API if direct SQL fails for any reason.
+        msgs = list(store.get_messages(session_id=sid, limit=int(sample_n)))
+        total = len(msgs)
+        sampled_rows = [
+            (int(getattr(m, "id", 0) or 0), str(getattr(m, "role", "") or ""), str(getattr(m, "event_type", "") or ""), len(str(getattr(m, "content", "") or "")))
+            for m in msgs
+        ]
+        last_rows = sampled_rows[: int(last_n)]
+
+    empty_ids = tuple(sorted([mid for mid, role, ev, n in sampled_rows if role == "assistant" and ev == "assistant_text" and int(n) == 0]))
+    max_content = max([n for *_rest, n in sampled_rows] or [0])
+    max_tool = max([n for _mid, role, _ev, n in sampled_rows if role == "tool"] or [0])
+
+    last_total = sum(int(n) for *_rest, n in last_rows)
+    last_tool_total = sum(int(n) for _mid, role, _ev, n in last_rows if role == "tool")
+    last_max = max([int(n) for *_rest, n in last_rows] or [0])
+    last_tool_max = max([int(n) for _mid, role, _ev, n in last_rows if role == "tool"] or [0])
+    last_user_max = max([int(n) for _mid, role, _ev, n in last_rows if role == "user"] or [0])
+
+    return SessionContextStats(
+        session_id=sid,
+        total_messages=int(total),
+        sampled_messages=len(sampled_rows),
+        last_n=int(last_n),
+        last_n_total_chars=int(last_total),
+        last_n_tool_total_chars=int(last_tool_total),
+        last_n_max_msg_chars=int(last_max),
+        last_n_max_tool_chars=int(last_tool_max),
+        last_n_max_user_chars=int(last_user_max),
+        empty_assistant_text_in_sampled=len(empty_ids),
+        empty_assistant_text_ids=empty_ids,
+        max_content_chars_in_sampled=int(max_content),
+        max_tool_chars_in_sampled=int(max_tool),
+    )
+
+
+__all__ = [
+    "SessionContextStats",
+    "compute_session_context_stats",
+]
+