✨ Fallback to a Completions API when Sampling is not available (#1145)

examples/sampling_fallback.py

@@ -0,0 +1,34 @@
+import asyncio
+import os
+
+from mcp.types import ContentBlock
+from openai import OpenAI
+
+from fastmcp import FastMCP
+from fastmcp.experimental.sampling.handlers.openai import OpenAISamplingHandler
+from fastmcp.server.context import Context
+
+
+async def async_main():
+    server = FastMCP(
+        name="OpenAI Sampling Fallback Example",
+        sampling_handler=OpenAISamplingHandler(
+            default_model=os.getenv("MODEL") or "gpt-4o-mini",  # pyright: ignore[reportArgumentType]
+            client=OpenAI(
+                api_key=os.getenv("API_KEY"),
+                base_url=os.getenv("BASE_URL"),
+            ),
+        ),
+    )
+
+    @server.tool
+    async def test_sample_fallback(ctx: Context) -> ContentBlock:
+        return await ctx.sample(
+            messages=["hello world!"],
+        )
+
+    await server.run_http_async()
+
+
+if __name__ == "__main__":
+    asyncio.run(async_main())