# mcpserver.nvim

A Neovim plugin that implements an MCP (Model Context Protocol) server, allowing external MCP clients to interact with Neovim through a Unix socket.

## Features

- **get_buffer_content**: Fetch the contents of the current buffer

## Installation

Using [lazy.nvim](https://github.com/folke/lazy.nvim):

```lua
{
  dir = "/path/to/mcpserver.nvim", -- Use your local path
  -- Server starts automatically on VimEnter
}
```

## Usage

### Neovim Plugin

#### Manual Control

Start the MCP server:
```vim
:MCPServerStart
```

Stop the MCP server:
```vim
:MCPServerStop
```

#### Get Socket Path

```lua
local mcpserver = require('mcpserver')
local socket_path = mcpserver.get_socket_path()
print(socket_path) -- e.g., "/tmp/nvim-mcp-server-12345.sock"
```

#### Socket Location

The server creates a unique Unix socket at `/tmp/nvim-mcp-server-<PID>.sock` where `<PID>` is the Neovim process ID. This allows multiple Neovim instances to run MCP servers simultaneously.

### Standalone MCP Server

For use with external MCP clients that communicate via stdio:

```bash
# Auto-detect running Neovim instance
lua standalone.lua

# Specify Neovim socket path
lua standalone.lua /tmp/nvim-mcp-server-12345.sock
```

The standalone server:
- Communicates via stdio (JSON-RPC over stdin/stdout)
- Auto-detects running Neovim MCP server sockets
- Forwards requests to the Neovim instance
- Works with any MCP client that supports stdio transport

### Available Tools

#### get_buffer_content

Returns JSON with:
- `filename`: Path to the current buffer file
- `content`: Full text content of the buffer
- `line_count`: Number of lines in the buffer

## MCP Client Usage

### Direct Socket Connection

Connect to the Unix socket at `/tmp/nvim-mcp-server-<PID>.sock` and use standard MCP protocol:

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "get_buffer_content",
    "arguments": {}
  }
}
```

### Stdio Connection

Use the standalone server for stdio-based MCP clients:

```bash
echo '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"get_buffer_content","arguments":{}}}' | lua standalone.lua
```

## Development

The plugin structure:
- `lua/mcpserver/init.lua`: Core MCP server implementation
- `lua/mcpserver/tools.lua`: Tool implementations  
- `plugin/mcpserver.lua`: Plugin setup and commands
- `standalone.lua`: Standalone MCP server for stdio communication

## Requirements

- Neovim with Lua support
- For standalone mode: `netcat` (nc) for Unix socket communication