Add Memory Gateway agent plugin

plugins/memory-gateway-agent/memory_gateway_plugin/trace.py

@@ -0,0 +1,45 @@
+from __future__ import annotations
+
+import json
+import os
+from datetime import datetime, timezone
+from pathlib import Path
+from typing import Any
+
+from .output import redact, short_id
+
+
+def trace_enabled() -> bool:
+    return os.environ.get("MEMORY_GATEWAY_PLUGIN_TRACE_HOOKS", "").strip().lower() in {"1", "true", "yes", "on"}
+
+
+def trace_path() -> Path:
+    return Path(__file__).resolve().parents[1] / ".tmp" / "hook_trace.log"
+
+
+def trace_hook(
+    hook_name: str,
+    *,
+    session_id: str = "",
+    gateway_action: str = "",
+    gateway_called: bool = False,
+    ok: bool | None = None,
+    audit_delta: int | None = None,
+    reason: str = "",
+) -> None:
+    if not trace_enabled():
+        return
+    path = trace_path()
+    path.parent.mkdir(parents=True, exist_ok=True)
+    payload: dict[str, Any] = {
+        "timestamp": datetime.now(timezone.utc).isoformat(),
+        "hook": hook_name,
+        "session_id": short_id(session_id),
+        "gateway_action": gateway_action,
+        "gateway_called": gateway_called,
+        "ok": ok,
+        "audit_delta": audit_delta,
+        "reason": reason[:160] if reason else "",
+    }
+    with path.open("a", encoding="utf-8") as handle:
+        handle.write(json.dumps(redact(payload), ensure_ascii=False, default=str) + "\n")