[md]core

mcp-core · JVM · Scala.js · Scala Native

The foundation. Defines the MCP protocol types (tools, resources, resource templates, prompts, capabilities), the Server[F] abstraction, the fluent builders (tool, resource, prompt, plus their contextual* variants), and the JSON Schema derivation machinery. Every other module depends on this.

libraryDependencies += "net.andimiller.mcp" %%% "mcp-core" % "0.10.0"

A taste of the surface — typed I/O case classes derive JSON Schema and circe codecs in one shot, and tool / resource / prompt are the fluent builders that produce values you hand to ServerBuilder:

import cats.effect.IO
import io.circe.{Decoder, Encoder}
import net.andimiller.mcp.core.schema.JsonSchema
import net.andimiller.mcp.core.server.*

case class Greet(name: String)    derives JsonSchema, Decoder
case class Greeting(text: String) derives JsonSchema, Encoder.AsObject

val greetTool: Tool.Resolved[IO] =
  tool.name("greet").in[Greet].out[Greeting]
    .run(req => IO.pure(Greeting(s"Hello, ${req.name}!")))

val server: IO[Server[IO]] =
  ServerBuilder[IO]("my-server", "1.0.0").withTool(greetTool).build

Most user docs live in Getting Started — start with Tools, Resources, and Prompts to see what the core builders look like in practice.