From 6673ec7070c20f0ee4c151f17057a9aa6d068c2e Mon Sep 17 00:00:00 2001
From: Vadym Barda <vadym@langchain.dev>
Date: Thu, 6 Mar 2025 15:55:19 -0500
Subject: [PATCH] don't disable parallel tool calls for o3-mini (#53)

---
 langgraph_supervisor/supervisor.py | 26 +++++++++++++++++++++-----
 1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/langgraph_supervisor/supervisor.py b/langgraph_supervisor/supervisor.py
index 6318723..584944e 100644
--- a/langgraph_supervisor/supervisor.py
+++ b/langgraph_supervisor/supervisor.py
@@ -1,7 +1,7 @@
 import inspect
 from typing import Any, Callable, Literal, Type
 
-from langchain_core.language_models import LanguageModelLike
+from langchain_core.language_models import BaseChatModel, LanguageModelLike
 from langchain_core.tools import BaseTool
 from langgraph.graph import END, START, StateGraph
 from langgraph.prebuilt.chat_agent_executor import (
@@ -27,6 +27,25 @@
 """
 
 
+MODELS_NO_PARALLEL_TOOL_CALLS = {"o3-mini"}
+
+
+def _supports_disable_parallel_tool_calls(model: LanguageModelLike) -> bool:
+    if not isinstance(model, BaseChatModel):
+        return False
+
+    if hasattr(model, "model_name") and model.model_name in MODELS_NO_PARALLEL_TOOL_CALLS:
+        return False
+
+    if not hasattr(model, "bind_tools"):
+        return False
+
+    if "parallel_tool_calls" not in inspect.signature(model.bind_tools).parameters:
+        return False
+
+    return True
+
+
 def _make_call_agent(
     agent: Pregel,
     output_mode: OutputMode,
@@ -127,10 +146,7 @@ def create_supervisor(
     handoff_tools = [create_handoff_tool(agent_name=agent.name) for agent in agents]
     all_tools = (tools or []) + handoff_tools
 
-    if (
-        hasattr(model, "bind_tools")
-        and "parallel_tool_calls" in inspect.signature(model.bind_tools).parameters
-    ):
+    if _supports_disable_parallel_tool_calls(model):
         model = model.bind_tools(all_tools, parallel_tool_calls=False)
     else:
         model = model.bind_tools(all_tools)