✨ Add MCP client demo for SSE (#598)

Author: Vinisha-projects

examples/client_demo.py

@@ -0,0 +1,45 @@
+import asyncio
+from typing import AsyncGenerator
+
+from fastapi import FastAPI
+from starlette.responses import StreamingResponse
+import uvicorn
+from threading import Thread
+import httpx
+from mcp.client.sse import aconnect_sse
+
+# Mock SSE server using FastAPI
+app = FastAPI()
+
+@app.get("/sse")
+async def sse_endpoint() -> StreamingResponse:
+    async def event_stream() -> AsyncGenerator[str, None]:
+        for i in range(3):
+            yield f"data: Hello {i+1}\n\n"
+            await asyncio.sleep(0.1)
+    return StreamingResponse(event_stream(), media_type="text/event-stream")
+
+def run_mock_server() -> None:
+    uvicorn.run(app, host="127.0.0.1", port=8012, log_level="warning")
+
+# MCP client demo to connect to the mock SSE server
+async def run_demo() -> None:
+    server_thread = Thread(target=run_mock_server, daemon=True)
+    server_thread.start()
+    await asyncio.sleep(1)
+
+    messages = []
+
+    async with httpx.AsyncClient() as client:
+        async with aconnect_sse(client, "GET", "http://127.0.0.1:8012/sse") as event_source:
+            async for event in event_source.aiter_sse():
+                if event.data:
+                    print("Event received:", event.data)
+                    messages.append(event.data)
+                if len(messages) == 3:
+                    break
+
+    print("\nClient demo finished. Messages received:", messages)
+
+if __name__ == "__main__":
+    asyncio.run(run_demo())