🎉 v4.0.0

[ravitemer]

We're excited to announce MCPHub v4.0.0 (PR #40), focusing on making the plugin more accessible and powerful with zero configuration support and Lua native MCP servers! There are no Breaking Changes.

✨ Zero Configuration Support

MCPHub now works out of the box with minimal setup:

require("mcphub").setup({})  

• Default port: 37373
• Default config: ~/.config/mcphub/servers.json (auto-created)
• No manual configuration needed

Installation Improvements:

• Default Installation (Global npm):
  • Continues to work with npm install -g mcp-hub
  • No additional configuration needed

Bundled Installation (No global npm access needed):

{
    "ravitemer/mcphub.nvim",
    dependencies = { "nvim-lua/plenary.nvim" },
    build = "bundled_build.lua",  -- Local installation
    config = function()
        require("mcphub").setup({
            use_bundled_binary = true
        })
    end
}

• Auto-updates with plugin updates
• No global npm permissions required

See our Installation Guide for more options.

🎨 UI Window Customization

ui = {
    window = {
        width = 0.8,    -- 0-1 (ratio); "50%" (percentage); 50 (raw number)
        height = 0.8,   -- 0-1 (ratio); "50%" (percentage); 50 (raw number)
        border = "rounded", -- "none", "single", "double", "rounded", "solid", "shadow"
        relative = "editor",
        zindex = 50,
    },
}

Example with width = 0.7 and height = 0.8:

📊 Lualine Integration

require('lualine').setup {
    sections = {
        lualine_x = {
            {require('mcphub.extensions.lualine')},
        },
    },
}

When connecting show warning state:

When idle shows total number of connected servers:

When a tool or resources is being called, shows spinner:

See Lualine Integration Guide for more details.

📝 Server Prompt Preview

With gd or <cr> on breadcrumb in the Hub view, can preview the Active Servers prompt that is being sent to the llm. This gives you a better idea of how the servers are represented in text:

🎉 Lua Native MCP Servers

Why Use Native MCP Servers?

The Challenge

Many Neovim chat plugins like Avante and CodeCompanion already provide ways to add custom tools:

-- Avante's custom tools
require("avante").setup({
    custom_tools = {
        get_weather = {
            name,
            description,
            param,
            returns,
            func
        }
    }
})
-- CodeCompanion's tools 
require("codecompanion").setup({
    chat = {
        tools = {
            get_weather = {
                 name,
                 description,
                 cmds,
                 schema,
                 output,
            }
        }
    }
})

This leads to several limitations:

Feature	Regular tools	MCPHub Native Servers
Implementation	Needs reimplementing for each plugin	Write once, works everywhere
Api	Needs plugin specific docs	Intuitive chained api res:text():image():send()
Instructions	Can't have long schema.description	Tools,Resources converted to system prompt, instructions in one place
Resources Support	No built-in resource handling	Full URI-based resource system
Response Types	No standard types	MCP standard types (text, images, blobs)
State Management	Per-plugin implementation	Centralized lifecycle management
Plugin Updates	May break tool implementations	Tools isolated from plugin changes

MCPHub Solution

MCPHub solves these problems by providing a standardized protocol (MCP) and a central hub for tools and resources:

Option 1: Static Definition

native_servers = { 
    weather = {
        name = "weather",
        capabilities = {
            tools = {
                {
                    name = "get_weather",
                    description = "Get current weather for a city",
                    inputSchema = { ... },
                    handler = function(req, res)
                        res:text("Weather: ☀️ 22°C"):send()
                    end
                }
            },
            resources = { ... },
            resourceTemplates = { ... }
        }
    }
}

Option 2: Dynamic Registration

local mcphub = require("mcphub")

mcphub.add_tool("weather", {
    name = "get_weather",
    description = "Get current weather for a city",
    inputSchema = { ... },
    handler = function(req, res)
        res:text("Weather: ☀️ 22°C"):send()
    end
})

Preview:

See Native Servers Guide and Example Servers for more details.

🔧 Built-in Neovim Server

The built-in Neovim server has some common utility tools and resources that are already available with common chat plugins. You can always enable or disable a particular tool just like regular MCP servers. Neovim server is built to show what's possible with native servers.

Interactive File Operations

The current write-to-file tools among chat plugins doesn't open the file in the editor and doesn't show what's being written. If we made some changes to the file we need to send these changes in our next conversation. The new write_file tool in native neovim is designed to address these. Once the LLM calls write_file on neovim server , the file is opened in the editor area with a diff view. The tool will only resolve once the user either accepts (by saving the file with :w or ga to accept the changes) or rejects (by closing the buffer or gr to reject the changes. Any changes made by the user or the formatter will be sent as a diff to the LLM so the user doesn't need to manually explain changes. This is something similar to how the vscode diff editor works. Please provide any suggestions you have. Depending on the user needs we can send the whole file content after any formatting or with any diagnostics. I am thinking of writing a similar edit_file tool that works similar to this.

write_file_demo.mp4

🔌 Extension Improvements

Tool Approvals

Better tool approval requests

• Tool approval request shows arguments as well
• use config.extensions.avante.auto_approve_mcp_tool_calls = true auto approve mcp tool for
  avante
• use gta in chat or vim.g.codecompaion_auto_tool_mode=true for
  codecompanion

CodeCompanion Integration

Configure chat variables and tool results:

require("mcphub").setup({
    extensions = {
        codecompanion = {
            show_result_in_chat = true,  -- Show tool results in chat
            make_vars = true,  -- Create chat variables from MCP resources
        },
    },
})

require("codecompanion").setup({
    strategies = {
        chat = {
            tools = {
                ["mcp"] = {
                    callback = function() 
                        return require("mcphub.extensions.codecompanion") 
                    end,
                    description = "Call tools and resources from MCP Servers",
                    opts = {
                        requires_approval = true,
                    }
                }
            }
        }
    }
})

• Currently supports codecompanion. Avante support will also be added soon.

• Whenever the servers are updated, the variables will also be updated in realtime
  

• E.g LSP current file diagnostics
  

Check our CodeCompanion Guide for setup.

Avante Integration

Configure auto-approve behavior:

require("mcphub").setup({
    extensions = {
        avante = {
            auto_approve_mcp_tool_calls = true,
        }
    },
})

require("avante").setup({
    system_prompt = function()
        local hub = require("mcphub").get_hub_instance()
        return hub:get_active_servers_prompt()
    end,
    custom_tools = function()
        return {
            require("mcphub.extensions.avante").mcp_tool(),
        }
    end,
})

See Avante Integration Guide for more.

🎯 Other Improvements

• Enhanced UI features:

  • Syntax highlighting for config view and markdown
  • Multiline input textarea with 'o' keymap
  • Enhanced help view
  • Server prompt preview with breadcrumbs
  • Real-time configuration updates

• Auto-generate Native MCP Servers using LLMs

• Configure tool results display in chat plugins

• New write_file tool with interactive diff view

📚 Resources

• Installation Guide
• Configuration Guide
• Native Servers Guide
• Troubleshooting Guide
• API Reference

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