From 0e0939bb321e480fccabcb8d3292ba659af80a0c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E2=80=9CNaeel=E2=80=9D?= <tazet@narod.ru>
Date: Wed, 24 Jun 2026 18:06:05 +0400
Subject: [PATCH] =?UTF-8?q?v1.0.176:=20spec=5Fevents=20=E2=80=94=20FOR=20U?=
 =?UTF-8?q?PDATE=20+=20transaction=20for=20seq=20race?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 deploy/db/spec_events.py | 26 ++++++++++++++++++++------
 1 file changed, 20 insertions(+), 6 deletions(-)

diff --git a/deploy/db/spec_events.py b/deploy/db/spec_events.py
index 8544724..b9e765a 100644
--- a/deploy/db/spec_events.py
+++ b/deploy/db/spec_events.py
@@ -1,6 +1,6 @@
 """spec_events — event sourcing: apply ops, reset contract."""
 import json, uuid
-from .connection import query, execute
+from .connection import query, execute, get_pool
 
 
 def reset(contract_id):
@@ -10,11 +10,25 @@ def reset(contract_id):
 
 
 def get_next_seq(contract_id):
-    rows = query(
-        "SELECT COALESCE(MAX(seq), 0) + 1 AS n FROM spec_events WHERE contract_id = %s",
-        (contract_id,),
-    )
-    return rows[0]["n"] if rows else 1
+    """Get next sequence number with row lock to prevent race conditions."""
+    pool = get_pool()
+    conn = pool.getconn()
+    try:
+        conn.autocommit = False
+        with conn.cursor() as cur:
+            cur.execute(
+                "SELECT COALESCE(MAX(seq), 0) + 1 FROM spec_events WHERE contract_id = %s FOR UPDATE",
+                (contract_id,),
+            )
+            seq = cur.fetchone()[0]
+        conn.commit()
+        return seq
+    except Exception:
+        conn.rollback()
+        raise
+    finally:
+        conn.autocommit = True
+        pool.putconn(conn)
 
 
 def apply_ops(contract_id, supplement_id, document_id, ops, prompt_id, raw_llm_response):