fix(graph): use SDK in-process ASGI transport for thread metadata writes

cockpit/chat/a2ui/python/src/graph.py

@@ -782,7 +782,11 @@ async def generate_title(state: MessagesState, config) -> dict:
     thread_id = (config.get("configurable") or {}).get("thread_id")
     if not thread_id:
         return {}
-    sdk_url = os.environ.get("LANGGRAPH_API_URL", "http://localhost:2024")
+    # url=None lets the SDK use its in-process ASGI transport when the
+    # call originates from inside a LangGraph server graph (always the
+    # case here). The old fallback to localhost:2024 forced an HTTP
+    # round-trip that fails on the prod runtime container. See PR #493.
+    sdk_url = os.environ.get("LANGGRAPH_API_URL")
     try:
         client = get_client(url=sdk_url)
         thread = await client.threads.get(thread_id)

cockpit/chat/threads/python/src/graph.py

@@ -44,7 +44,12 @@ async def generate_title(state: MessagesState, config) -> dict:
     thread_id = (config.get("configurable") or {}).get("thread_id")
     if not thread_id:
         return {}
-    sdk_url = os.environ.get("LANGGRAPH_API_URL", "http://localhost:2024")
+    # url=None lets the SDK use its in-process ASGI transport when the
+    # call originates from inside a LangGraph server graph (always the
+    # case here). The old fallback to localhost:2024 forced an HTTP
+    # round-trip that fails on the prod runtime container. See PR #492
+    # for the diagnosis trail.
+    sdk_url = os.environ.get("LANGGRAPH_API_URL")
     try:
         client = get_client(url=sdk_url)
         thread = await client.threads.get(thread_id)

examples/chat/python/src/graph.py

@@ -97,7 +97,15 @@ async def _maybe_write_thread_title(state: "State", config: RunnableConfig) -> d
     """
     global _threads_client
     thread_id = (config.get("configurable") or {}).get("thread_id")
-    sdk_url = os.environ.get("LANGGRAPH_API_URL", "http://localhost:2024")
+    # url=None lets the SDK use its in-process ASGI transport when the
+    # call originates from inside a LangGraph server graph (which is
+    # always the case here). The old fallback to http://localhost:2024
+    # PREVENTED that path: it always forced an HTTP round-trip to a
+    # port that doesn't exist on the prod runtime container (it does
+    # locally because `langgraph dev` listens on 2024 — which is why
+    # this only broke in prod). LANGGRAPH_API_URL is only honoured
+    # when explicitly set, e.g. for cross-process callbacks.
+    sdk_url = os.environ.get("LANGGRAPH_API_URL")
     if not isinstance(thread_id, str) or not thread_id:
         return {"skipped": "no thread_id in config"}