[md]Modules
scala-mcp is a multi-module library — pick the modules you need for the transports and features your server uses. Core types and the stdio transport are tiny; HTTP, Redis, and OpenAPI support layer on top.
| Module | Platforms | Description |
|---|---|---|
| core | JVM, JS, Native | Protocol types, server abstraction, schema derivation, JSON codecs |
| stdio | JVM, JS, Native | stdin/stdout transport for subprocess-based servers |
| http4s | JVM, JS, Native | Streamable HTTP + SSE transport via http4s Ember; bundles the Explorer UI |
| openapi | JVM, JS, Native | OpenAPI 3.x schema model + tool-builder helpers |
| redis | JVM | Redis-backed SessionStore / SessionRefs / StateRef / notification sink |
| tapir | JVM | Bridge that turns any sttp.tapir.Schema[A] into a JsonSchema[A] |
| golden-munit | JVM, JS, Native | Golden testing framework for MCP server specs (munit) |
| explorer | JS | Browser-based UI for exploring and testing MCP servers (consumed via http4s) |