Example server to expose a fetch tool and a fetch prompt

examples/servers/simple-tool/mcp_simple_tool/server.py

@@ -0,0 +1,102 @@
+import anyio
+import click
+import httpx
+import mcp.types as types
+from mcp.server import Server
+
+
+async def fetch_website(
+    url: str,
+) -> list[types.TextContent | types.ImageContent | types.EmbeddedResource]:
+    headers = {
+        "User-Agent": "MCP Test Server (github.com/modelcontextprotocol/python-sdk)"
+    }
+    async with httpx.AsyncClient(follow_redirects=True, headers=headers) as client:
+        response = await client.get(url)
+        response.raise_for_status()
+        return [types.TextContent(type="text", text=response.text)]
+
+
+@click.group()
+def cli():
+    pass
+
+
+@cli.command()
+@click.option("--port", default=8000, help="Port to listen on for SSE")
+@click.option(
+    "--transport",
+    type=click.Choice(["stdio", "sse"]),
+    default="stdio",
+    help="Transport type",
+)
+def main(port: int, transport: str) -> int:
+    return anyio.run(_amain, port, transport)
+
+
+async def _amain(port: int, transport: str) -> int:
+    app = Server("mcp-website-fetcher")
+
+    @app.call_tool()
+    async def fetch_tool(
+        name: str, arguments: dict
+    ) -> list[types.TextContent | types.ImageContent | types.EmbeddedResource]:
+        if name != "fetch":
+            raise ValueError(f"Unknown tool: {name}")
+        if "url" not in arguments:
+            raise ValueError("Missing required argument 'url'")
+        return await fetch_website(arguments["url"])
+
+    @app.list_tools()
+    async def list_tools() -> list[types.Tool]:
+        return [
+            types.Tool(
+                name="fetch",
+                description="Fetches a website and returns its content",
+                inputSchema={
+                    "type": "object",
+                    "required": ["url"],
+                    "properties": {
+                        "url": {
+                            "type": "string",
+                            "description": "URL to fetch",
+                        }
+                    },
+                },
+            )
+        ]
+
+    if transport == "sse":
+        from mcp.server.sse import SseServerTransport
+        from starlette.applications import Starlette
+        from starlette.routing import Route
+
+        sse = SseServerTransport("/messages")
+
+        async def handle_sse(scope, receive, send):
+            async with sse.connect_sse(scope, receive, send) as streams:
+                await app.run(
+                    streams[0], streams[1], app.create_initialization_options()
+                )
+
+        async def handle_messages(scope, receive, send):
+            await sse.handle_post_message(scope, receive, send)
+
+        starlette_app = Starlette(
+            debug=True,
+            routes=[
+                Route("/sse", endpoint=handle_sse),
+                Route("/messages", endpoint=handle_messages, methods=["POST"]),
+            ],
+        )
+
+        import uvicorn
+
+        uvicorn.run(starlette_app, host="0.0.0.0", port=port)
+    else:
+        from mcp.server.stdio import stdio_server
+
+        async with stdio_server() as streams:
+            await app.run(streams[0], streams[1], app.create_initialization_options())
+
+    return 0