chore: import upstream snapshot with attribution

examples/integrations/langgraph-python/serve.py

@@ -0,0 +1,59 @@
+"""
+Thin wrapper to serve the LangGraph agent via AG-UI protocol.
+Used in Docker where langgraph-cli dev (which needs Docker) is unavailable.
+The original main.py and all agent code remain unmodified.
+"""
+
+import os
+import sys
+
+# Add the agent directory to the path so imports work
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), "agent"))
+
+import uvicorn
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from langgraph.checkpoint.memory import MemorySaver
+
+# Import the original graph from the unmodified agent code
+from main import graph
+
+# The create_agent() graph may not have a checkpointer (it's normally
+# provided by the LangGraph Platform server). Add one for standalone serving.
+if not hasattr(graph, "checkpointer") or graph.checkpointer is None:
+    # Recompile with a checkpointer
+    graph = graph.copy()
+    graph.checkpointer = MemorySaver()
+
+# Use copilotkit's LangGraphAGUIAgent to serve via AG-UI
+from copilotkit import LangGraphAGUIAgent
+from ag_ui_langgraph import add_langgraph_fastapi_endpoint
+
+app = FastAPI()
+
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+
+@app.get("/health")
+async def health():
+    return {"status": "ok"}
+
+
+add_langgraph_fastapi_endpoint(
+    app=app,
+    agent=LangGraphAGUIAgent(
+        name="sample_agent",
+        description="LangGraph Python starter agent",
+        graph=graph,
+    ),
+    path="/",
+)
+
+if __name__ == "__main__":
+    port = int(os.getenv("AGENT_PORT", "8123"))
+    uvicorn.run(app, host="0.0.0.0", port=port)