Eclipse IDE integrations with Coding Agents over ACP and MCP

NOTE: This code base is a work in progress and is a pre-release. It is being shared at this time for communication and co-ordination purposes

This feature adds an open-source Coding Agent chat experience to Eclipse, built atop two open protocols:

• Model Context Protocol
  • Standardizes communication between agents and external resources, tools and prompts.
• Agent Client Protocol
  • Standardizes communication between IDEs and coding agents.

Model Context Protocol services for Eclipse IDE

This feature runs a Model Context Protocol server within the Eclipse IDE VM enabling interactivity between Eclipse based experiences and LLM-powered Agentic experiences running within or outside of the Eclipse IDE. Features include:

• An MCP server using the mcp java sdk running inside the workbench that can serve over HTTP
• A set of built-in platform services including:
  • Access to workspace, editors, consoles, markers, annotations, …
  • Resource templates with variables and content assist
• An extension point for plugins to contribute MCP tools and resources to the Eclipse MCP server
  • Contribute MCP resources using annotated functions via MCP Annotations and Jackson Annotations
• Centralized preferences, tracing, capabilities

MCP Integrations

• Eclipse MCP services can be consumed by any MCP client such as:
  • Desktop Apps such as Claude Desktop
  • Terminal CLIs such as Gemini and Claude Code
• IDEs such as Eclipse and VS Code
  • Within Eclipse using Copilot for Eclipse
  • Run a CLI inside an Eclipse terminal
  • The Agent Client Protocol powered chat described below

Agent Client Protocol (ACP) Services for Eclipse IDE

• The Agent Client Protocol formalizes an IDE to Coding Agent protocol
  • A "Coding Agent" is a local app, typically a CLI, that can access files, run approved terminal commands, serve as an MCP client, and use LLMs to perform complex tasks as prompted by the end user.
• Existing implementations include:
  • Editor Implementations
    • Zed
    • emacs
    • neovim
    • marimo notebook
  • Agent Implementations
    • Gemini
    • Claude Code
    • Goose
• Features of the protocol include:
  • Chat Session Lifecycle
  • User Prompt Lifecycle
  • Client can forward list of MCP Servers to Agent
  • Tool Use Confirmation
  • API for read/write file/editor buffers
  • Embedded and referenced resources
  • / # @ commands

Screenshots

Enable the internal MCP Server to run on an HTTP port

Prompt the Coding Agent to write code and run tools

Prompt for sample code

Prompt for explanations

Demonstrations

• Coding Agent developing SQL
• HTML and Markdown display, Code Blocks, Resource Links
• Claude Conversation with Eclipse MCP: What's wrong with my java project

Installation

• Download a recent version of Eclipse J2EE package that has this plugins dependencies built-in.
• Clone this repositority locally
• From Eclipse navigate to Help > Install New Software...
• Click "Add..." > "Archive..." and navigate to the org.eclipse.mcp.update folder, then click "Open"
• Uncheck "Group items by category"
• Toggle the checkbox for the feature that shows up in the view
• Click "Next" until "Finish"
• Click "OK" to the security warning and allow the patch to install
• When prompted to restart, click "Yes"

To connect the built-in MCP server to an external MCP client

• Navigate to preference page "Coding Agents/Agent Contexts"
• Select the "Enable MCP HTTP Server" checkbox and apply the changes.
• Use the "Copy to clipboard" button to copy the MCP's SSE Endpoint to the clipboard.
• Add the HTTP SSE MCP endpoint to your MCP client of choice.

To use the Coding Agent view with Google Gemini CLI

• Install the Google Gemini CLI locally
• Start up gemini in a terminal and log in using google.
• In Eclipse navigate to preference page "Coding Agents/Agent CLIs".
• Enter in a valid location for your node executable and the gemini cli js file
  • while we await improvements on automatically finding gemini files...
    • use where node and where gemini in a terminal to find locations
    • you can use quotes if either contains a space
    • on windows you may find the gemini js file somewhere like
      • C:\Users<user>\AppData\Roaming\npm\node_modules@google\gemini-cli\dist\index.js
• Open the Coding Agent view
• Select Coding Agent: Gemini CLI
• Type into the chat input, press enter to submit prompt