Первый коммит

app/modules/shared/checkpointer.py

@@ -0,0 +1,30 @@
+from __future__ import annotations
+
+import threading
+
+import psycopg
+from langgraph.checkpoint.postgres import PostgresSaver
+from psycopg.rows import dict_row
+
+from app.modules.shared.db import database_url
+
+_CHECKPOINTER: PostgresSaver | None = None
+_LOCK = threading.Lock()
+
+
+def _conn_string() -> str:
+    url = database_url()
+    if url.startswith("postgresql+psycopg"):
+        return url.replace("postgresql+psycopg", "postgresql", 1)
+    return url
+
+
+def get_checkpointer() -> PostgresSaver:
+    global _CHECKPOINTER
+    with _LOCK:
+        if _CHECKPOINTER is None:
+            conn = psycopg.connect(_conn_string(), autocommit=True, row_factory=dict_row)
+            cp = PostgresSaver(conn)
+            cp.setup()
+            _CHECKPOINTER = cp
+        return _CHECKPOINTER