langgraph basic use in tool inject

examples/qwen_langgraph_react.py

@@ -0,0 +1,65 @@
+"""
+Minimal LangGraph ReAct agent using Qwen3-Coder(-Flash) via OpenAI-compatible API.
+
+Prereqs:
+  pip install -U langgraph langchain langchain-openai
+
+Env:
+  export QWEN_API_KEY=sk-...
+  export QWEN_BASE_URL=https://dashscope-intl.aliyuncs.com/compatible-mode/v1  # or your gateway
+  export QWEN_MODEL=qwen3-coder-flash  # use console's actual model name
+"""
+import sys,os
+
+
+from typing import Optional
+
+from langgraph.prebuilt import create_react_agent
+from langchain_core.messages import HumanMessage
+
+try:
+    from langchain.tools import tool
+except Exception:  # older versions
+    from langchain_core.tools import tool  # type: ignore
+
+from langgraph_qwen import ChatQwenOpenAICompat, bind_qwen_tools
+
+
+@tool
+def get_time(_: str = "") -> str:
+    """Get current local time in ISO format."""
+    import datetime as _dt
+    return _dt.datetime.now().isoformat()
+
+
+@tool
+def add(x_and_y: str) -> str:
+    """Add two integers given as 'x y'."""
+    xs = [int(s) for s in x_and_y.strip().split()]
+    if len(xs) != 2:
+        return "Please provide two integers: 'x y'"
+    return str(xs[0] + xs[1])
+
+
+def main():
+    # Prefer the custom adapter to avoid extra deps (langchain_openai)
+    base = ChatQwenOpenAICompat(temperature=0)
+    model = bind_qwen_tools(base, [get_time, add], tool_choice="auto")
+
+    agent = create_react_agent(model, [get_time, add])
+
+    # A prompt that can trigger multiple tool calls
+    question = (
+        "现在是几点？然后把 7 和 35 相加，并把两者结果合并成一句简洁中文回答。"
+    )
+
+    result = agent.invoke({"messages": [HumanMessage(content=question)]})
+
+    # Unpack final message text
+    last = result["messages"][-1]
+    print("\n=== Agent Final Answer ===\n")
+    print(getattr(last, "content", last))
+
+
+if __name__ == "__main__":
+    main()