[md]Dice MCP server

modules/example-dice-mcp · Stdio · JVM / JS / Native

A cross-platform stdio MCP server demonstrating tools, resources, prompts, and form elicitation.

• Tools: roll_dice — roll dice using standard notation (e.g., 2d20 + 5); roll_interactive — build a dice expression by repeatedly asking the client for (face, count) choices via elicitation
• Resources: dice://rules/standard (static reference), dice://history (recent rolls)
• Prompt: explain_notation — explains dice notation to the user

Uses IOApp.Simple, ServerBuilder, and StdioTransport.run with a SessionContext-aware factory so each session gets its own Random, history ref, and ElicitationClient.

Build and run (JVM)

sbt exampleDiceJVM/run

Build a Scala Native binary

# Requires clang/llvm (e.g. via nix-shell)
sbt exampleDiceNative/nativeLink
./modules/example-dice-mcp/native/target/scala-3.3.4/example-dice-mcp-out

Note: the native binary must be re-linked any time the server changes — sbt exampleDiceJVM/run is the fastest feedback loop during development.

Configure in Claude Code

.mcp.json:

{
  "mcpServers": {
    "dice": {
      "command": "sbt",
      "args": ["exampleDiceJVM/run"]
    }
  }
}

Or with a pre-built Native binary:

{
  "mcpServers": {
    "dice": {
      "command": "./modules/example-dice-mcp/native/target/scala-3.3.4/example-dice-mcp-out"
    }
  }
}