zio-ella

zio-ella is a framework for writing MCP (Model Context Protocol) servers using Scala 3 and ZIO with zio-http. In MCP terms, you define a set of capabilities and tools, where each Tool can accept arguments and return results. For example, a tool named get-time returns the current server time, while a tool named get-weather can accept a city as an argument and respond with a weather string. The example demonstrates how to define a Capabilities collection and expose a run method that starts the MCP server. The integration example shows wiring the server into a ZIO application, boot logging, and configuring the port from a config source. To use the tools, you interact with the Tool definitions and supply any required arguments (for instance, city for get-weather) and then consume the resulting response produced by the server.

Prerequisites:

• Docker installed and running (recommended for this MCP server in its current packaging approach).
• Optional local Scala/Java development environment if you intend to build from source (Java 17+ JDK, sbt, Scala 3).

Installation options:

1. Run with Docker (recommended):

   • Ensure Docker is running.
   • Pull and run the image: docker run -i otobrglez/zio-ella
   • The container will start the MCP server exposed on the container's port (adjust as needed with port mappings).

2. Build from source (if you have a Scala 3 environment):

   • Install prerequisites: Java 17+, sbt.
   • Clone the repository: git clone https://github.com/otobrglez/zio-ella.git
   • Navigate to the project directory: cd zio-ella
   • Build the project: sbt package
   • Run the server (example, adapt to your setup): java -jar target/scala-3.x.x/zio-ella.jar

Notes:

• The project is in early development; expect rapid changes and evolving APIs. Check the repository for the latest build and run instructions.
• If you plan to deploy, consider containerizing with Docker for consistency across environments.

Tips and considerations:

• The server exposes tools defined in the Capabilities; add or modify Tools to extend functionality (e.g., new endpoints or data sources).
• For local development, keep an eye on port configuration and ensure the port your MCP server listens on is accessible to clients.
• Since the project is under active development, consult the project’s issue tracker or docs for any breaking changes or migration notes when updating versions.
• If you plan to run outside Docker, ensure you have a compatible Java/Scala toolchain and the necessary dependencies wired into your build.
• Environment variables can be used to customize runtime behavior (e.g., ports, endpoints, or feature flags).