GitHub - bigcodegen/mcp-neovim-server: Control Neovim using Model Context Protocol (MCP) and the official neovim/node-client JavaScript library (original) (raw)

Neovim MCP Server

Connect Claude Desktop (or any Model Context Protocol client) to Neovim using MCP and the official neovim/node-client JavaScript library. This server leverages Vim's native text editing commands and workflows, which Claude already understands, to create a lightweight code or general purpose AI text assistance layer.

Version 0.5.2 - Now with comprehensive error handling, improved MCP compliance, and helpful workflow prompts!

Features

• Connects to your nvim instance if you expose a socket file, for example --listen /tmp/nvim, when starting nvim
• Views your current buffers and manages buffer switching
• Gets cursor location, mode, file name, marks, registers, and visual selections
• Runs vim commands and optionally shell commands through vim
• Can make edits using insert, replace, or replaceAll modes
• Search and replace functionality with regex support
• Project-wide grep search with quickfix integration
• Comprehensive window management
• Health monitoring and connection diagnostics

API

Resources

• nvim://session: Current neovim text editor session
• nvim://buffers: List of all open buffers in the current Neovim session with metadata including modified status, syntax, and window IDs

Tools

Core Tools

• vim_buffer
  • Get buffer contents with line numbers (supports filename parameter)
  • Input filename (string, optional) - Get specific buffer by filename
  • Returns numbered lines with buffer content
• vim_command
  • Send a command to VIM for navigation, spot editing, and line deletion
  • Input command (string)
  • Runs vim commands with nvim.replaceTermcodes. Multiple commands work with newlines
  • Shell commands supported with ! prefix when ALLOW_SHELL_COMMANDS=true
  • On error, 'nvim:errmsg' contents are returned
• vim_status
  • Get comprehensive Neovim status
  • Returns cursor position, mode, filename, visual selection, window layout, current tab, marks, registers, working directory, LSP client info, and plugin detection
• vim_edit
  • Edit lines using insert, replace, or replaceAll modes
  • Input startLine (number), mode ("insert" | "replace" | "replaceAll"), lines (string)
  • insert: insert lines at startLine
  • replace: replace lines starting at startLine
  • replaceAll: replace entire buffer contents
• vim_window
  • Manipulate Neovim windows (split, vsplit, close, navigate)
  • Input command (string: "split", "vsplit", "only", "close", "wincmd h/j/k/l")
• vim_mark
  • Set named marks at specific positions
  • Input mark (string: a-z), line (number), column (number)
• vim_register
  • Set content of registers
  • Input register (string: a-z or "), content (string)
• vim_visual
  • Create visual mode selections
  • Input startLine (number), startColumn (number), endLine (number), endColumn (number)

Enhanced Buffer Management

• vim_buffer_switch
  • Switch between buffers by name or number
  • Input identifier (string | number) - Buffer name or number
• vim_buffer_save
  • Save current buffer or save to specific filename
  • Input filename (string, optional) - Save to specific file
• vim_file_open
  • Open files into new buffers
  • Input filename (string) - File to open

Search and Replace

• vim_search
  • Search within current buffer with regex support
  • Input pattern (string), ignoreCase (boolean, optional), wholeWord (boolean, optional)
• vim_search_replace
  • Find and replace with advanced options
  • Input pattern (string), replacement (string), global (boolean, optional), ignoreCase (boolean, optional), confirm (boolean, optional)
• vim_grep
  • Project-wide search using vimgrep with quickfix list
  • Input pattern (string), filePattern (string, optional) - File pattern to search

Advanced Workflow Tools

• vim_macro
  • Record, stop, and play Vim macros
  • Input action ("record" | "stop" | "play"), register (string, a-z), count (number, optional)
• vim_tab
  • Complete tab management
  • Input action ("new" | "close" | "next" | "prev" | "first" | "last" | "list"), filename (string, optional)
• vim_fold
  • Code folding operations
  • Input action ("create" | "open" | "close" | "toggle" | "openall" | "closeall" | "delete"), startLine/endLine (numbers, for create)
• vim_jump
  • Jump list navigation
  • Input direction ("back" | "forward" | "list")

System Tools

• vim_health
  • Check Neovim connection health and socket status

Using this comprehensive set of 19 tools, Claude can peer into your neovim session, navigate buffers, perform searches, make edits, record macros, manage tabs and folds, and handle your complete development workflow with standard Neovim features.

Prompts

• neovim_workflow: Get contextual help and guidance for common Neovim workflows including editing, navigation, search, buffer management, window operations, and macro usage. Provides step-by-step instructions for accomplishing tasks with the available MCP tools.

Error Handling

The server implements comprehensive error handling with custom error classes and consistent error responses:

• NeovimConnectionError: Socket connection failures with detailed messages
• NeovimCommandError: Command execution failures with command context
• NeovimValidationError: Input validation failures

New in v0.5.2: All tools now include robust try-catch error handling that returns meaningful error messages in proper MCP format. Features include connection health monitoring, graceful error propagation, and actionable error messages to help diagnose issues.

Limitations

• May not interact well with complex neovim configurations or plugins
• Shell command execution is disabled by default for security
• Socket connection required - won't work with standard vim

Configuration

Environment Variables

• ALLOW_SHELL_COMMANDS: Set to 'true' to enable shell command execution (e.g. !ls). Defaults to false for security.
• NVIM_SOCKET_PATH: Set to the path of your Neovim socket. Defaults to '/tmp/nvim' if not specified.

Usage with Claude Desktop

Add this to your claude_desktop_config.json:

{ "mcpServers": { "MCP Neovim Server": { "command": "npx", "args": [ "-y", "mcp-neovim-server" ], "env": { "ALLOW_SHELL_COMMANDS": "true", "NVIM_SOCKET_PATH": "/tmp/nvim" } } } }

License

This MCP server is licensed under the MIT License. This means you are free to use, modify, and distribute the software, subject to the terms and conditions of the MIT License. For more details, please see the LICENSE file in the project repository.