MCP Hub

MCP Hub is an extension that integrates the Model Context Protocol (MCP) with CodeCompanion. It allows you to leverage MCP tools and resources directly within your chat interactions.

Features

• Access MCP tools via the @mcp tool in the chat buffer.
• Utilize MCP resources as context variables using the # prefix (e.g., #resource_name).
• Execute MCP prompts directly using /mcp:prompt_name slash commands.
• Receive real-time updates in CodeCompanion when MCP servers change.

Installation

First, install the MCP Hub Neovim plugin:

{
  "ravitemer/mcphub.nvim",
  build = "npm install -g mcp-hub@latest",
  config = function()
    require("mcphub").setup()
  end
}

For detailed MCP Hub configuration options, please refer to the documentation.

Next, register MCP Hub as an extension in your CodeCompanion configuration:

require("codecompanion").setup({
  extensions = {
    mcphub = {
      callback = "mcphub.extensions.codecompanion",
      opts = {
        show_result_in_chat = true,  -- Show mcp tool results in chat
        make_vars = true,            -- Convert resources to #variables
        make_slash_commands = true,  -- Add prompts as /slash commands
      }
    }
  }
})

Usage

Once configured, you can interact with MCP Hub within the CodeCompanion chat buffer:

• Tool Access: Type @mcp to add available MCP servers to the system prompt, enabling the LLM to use registered MCP tools.
• Resources as Variables: If make_vars = true, MCP resources become available as variables prefixed with #. You can include these in your prompts (e.g., Summarize the issues in #mcp:lsp:get_diagnostics):

Example: Accessing LSP diagnostics:

Prompts as Slash Commands: If make_slash_commands = true, MCP prompts are available as slash commands (e.g., /mcp:prompt_name). Arguments are handled via vim.ui.input.

Example: Using an MCP prompt via slash command:

Auto-approvals

MCP tool requests can be automatically approved, bypassing the confirmation prompt, if any of the following are true:

1. MCP Hub configuration:

require("mcphub").setup({
  config = { auto_approve = true }
})

2. Global MCP Hub variable: vim.g.mcphub_auto_approve = true
3. CodeCompanion auto tool mode: vim.g.codecompanion_auto_tool_mode = true (toggled via gta in the chat buffer)

Additional Resources

• MCP Hub Documentation
• Model Context Protocol Website
• Guide on Creating Lua Native MCP Servers