dummy mcp server / published by https://github.com/dacr/code-examples-manager #dd4efaa5-f30c-4bb2-98bd-df2ace4601c1/d40b8baf304b3c0e54701a77793c2bc2db018f63

fastmcp-hello-mcp-server.sc

// summary : dummy mcp server
// keywords : artificial-intelligence, generative-ai, llm, ai, mcp, mcp-server, @testable
// publish : gist
// authors : David Crosson
// license : Apache License Version 2.0 (https://www.apache.org/licenses/LICENSE-2.0.txt)
// id : dd4efaa5-f30c-4bb2-98bd-df2ace4601c1
// created-on : 2025-07-18T14:52:24+02:00
// managed-by : https://github.com/dacr/code-examples-manager
// run-with : scala-cli $file

//> using scala 3.7.1
//> using dep org.slf4j:slf4j-api:2.0.17
//> using dep org.slf4j:slf4j-simple:2.0.17
//> using dep com.tjclp::fast-mcp-scala:0.1.1
//> using options -Xcheck-macros -experimental

/*
{"jsonrpc":"2.0","id":0,"method":"initialize","params":{"protocolVersion": "2024-11-05"}}
{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"hello"}}
*/

import com.tjclp.fastmcp.core.*
import com.tjclp.fastmcp.macros.RegistrationMacro.*
import com.tjclp.fastmcp.server.{FastMcpServer, FastMcpServerSettings}
import zio.*

object ExampleServer extends ZIOAppDefault {
  object Example {
    @Tool(name = Some("hello"), description = Some("Say hello"))
    def hello(): String = "Hello, world!"
  }

  override def run = {
    val settings = FastMcpServerSettings(
      debug=true,
      logLevel="DEBUG",
    )
    for {
      server  <- ZIO.succeed(FastMcpServer(name = "hello-mcp-server", settings = settings))
      _       <- ZIO.attempt(server.scanAnnotations[Example.type])
      _       <- ZIO.log("Starting stdio server...")
      _       <- server
        .runStdio()
        .tapError(error => ZIO.log(s"Error running stdio: $error"))
        .onInterrupt(ZIO.log("Server interrupted"))
    } yield ()
  }
}

ExampleServer.main(args)