Fast MCP Scala

🚀 Fast MCP-Scala

A high-level, developer-friendly Scala 3 library for building Model Context Protocol (MCP) servers.

🚀 Quick Start

Fast MCP-Scala is an advanced library designed to simplify the process of building MCP servers using Scala 3. It offers a range of features to enhance development efficiency and flexibility.

✨ Features

• ZIO-based effect handling and asynchronous support.
• Annotation-driven API (@Tool, @Resource, @Prompt).
• Automatic JSON Schema and handler generation via Scala 3 macros.
• Seamless integration with the Java MCP SDK.

📦 Installation

Using sbt

Add the following to your build.sbt (default for Scala 3.6.4):

libraryDependencies += "com.tjclp" %% "fast-mcp-scala" % "0.1.0"

Using Scala CLI

You can use the following commands:

//> using scala 3.6.4
//> using dep com.tjclp::fast-mcp-scala:0.1.0
//> using options "-Xcheck-macros" "-experimental"

💻 Usage Examples

Basic Usage

//> using scala 3.6.4
//> using dep com.tjclp::fast-mcp-scala:0.1.0
//> using options "-Xcheck-macros" "-experimental"

import com.tjclp.fastmcp.core.{Tool, ToolParam, Prompt, PromptParam, Resource}
import com.tjclp.fastmcp.server.FastMcpServer
import com.tjclp.fastmcp.macros.RegistrationMacro.*
import zio.*

// Define annotated tools, prompts, and resources
object Example:
  @Tool(name = Some("add"), description = Some("Add two numbers"))
  def add(
      @ToolParam("First operand") a: Double,
      @ToolParam("Second operand") b: Double
    ): Double = a + b

  @Prompt(name = Some("greet"), description = Some("Generate a greeting message"))
  def greet(@PromptParam("Name to greet") name: String): String =
    s"Hello, $name!"

  // Note: Resource templates (templated URIs) are not yet supported;
  // Will be implemented when the MCP Java SDK adds template support.
  @Resource(uri = "file://test", description = Some("Test resource"))
  def test(): String = "This is a test"

object ExampleServer extends ZIOAppDefault:
  override def run =
    for
      server <- ZIO.succeed(FastMcpServer("ExampleServer"))
      _      <- ZIO.attempt(server.scanAnnotations[Example.type])
      _      <- server.runStdio()
    yield ()

Running the Example

The above example can be run from the root directory of the repository using scala-cli scripts/quickstart.scala. You can run the server using the MCP inspector with the following command:

npx @modelcontextprotocol/inspector scala-cli <path_to_repo>/scripts/quickstart scala

You can also run the example directly from the command line:

scala-cli \
    -e '//> using dep com.tjclp::fast-mcp-scala:0.1.0'
    //> using options "-Xcheck-macros" "-experimental"

📚 Documentation

Integration with Claude Desktop

You can create a file in ~/.config/claude with the following content:

export Claude=$((To be implemented))

📄 License

This project is released under the MIT License.