nvim-dap-matlab

Main Demo

_2026_02_28_12_25_10_316.mp4

Use REPL, Watch / Detect error line

_2026_03_01_01_58_23_714.mp4

What for?

A DAP (Debug Adapter Protocol) adapter between nvim-dap and the MATLAB Language Server for debugging MATLAB code directly in Neovim.

The MATLAB Language Server has built-in debugging capabilities after v1.3.0, but they are only exposed through proprietary LSP notifications not through a standard DAP server. This plugin bridges that gap by creating a local TCP server that translates between nvim-dap's standard DAP protocol and the MATLAB LSP's custom notification-based debug interface.

✅ Windows supported

---

Features

• Pure Lua — no external runtimes, no Python scripts, no separate debug server
• Use the same matlab.exe instance which is spawned by matlab lsp to reduce memory
• To prevent crash, it blocks executing debug session while matlab lsp is loading
• Optional fidget.nvim integration for LSP connection progress display
• Supports some keymaps to manage file browser / workspace window.
• Use nvim-dap's repl to interact with matlab with lsp completion and syntax

---

Requirements

Dependency	Required	Notes
Neovim	required	0.10+ recommended (uses vim.uv)
MATLAB	required	R2021b+ (Tested at R2024b)
MATLAB Language Server	required	Running in --stdio mode
Jaehaks/nvim-dap	required	forked to fix empty breakpoints Problem mfussenegger/nvim-dap/#1592 until it s fixed in original repo
fidget.nvim	optional	Shows beautiful progress

---

Installation

lazy.nvim

{
  "Jaehaks/nvim-dap-matlab",
  dependencies = {
    "Jaehaks/nvim-dap",
  },
  ft = "matlab",
  opts = {}
}

---

Configuration

1) MATLAB LSP

The MATLAB Language Server must be running before you can start a debug session.

Caution

This plugin supports only one project per neovim yet. So you should setup like below code to avoid attaching additional lsp due to matlab library.

vim.lsp.config('matlab-ls', {
  root_dir = function (bufnr, cb)
    local bufname = vim.api.nvim_buf_get_name(bufnr)
    if string.match(bufname, 'toolbox[\\/]matlab') then -- avoid attaching to installed matlab library
      return
    end
    local root = vim.fs.root(bufnr, { '.git' }) or vim.fn.expand('%:p:h')
    cb(root)
  end,

  cmd = {'matlab-language-server', '--stdio'},
  filetypes = {'matlab'},
  settings = {
    matlab = {
      indexWorkspace = true,
      installPath = '<matlab path>'
      matlabConnectionTiming = 'onStart',
      telemetry = false, -- don't report about any problem
    },
  },
  single_file_support = false, -- if enabled, lsp(matlab.exe) attaches per file, too heavy
})

Tip

Recommend to set pwd to project folder.

2) nvim-dap

Below code is an example.

Tip

When You set conditional breakpoint, you need to input some condition without if word

{
  'Jaehaks/nvim-dap',
  ft = {'matlab'},
  config = function ()
    local dap = require('dap')

	-- nvim-dap-matlab configure its own dap setting. You don't need to setup in nvim-dap.

	-- set keymaps
	-- You can use all nvim-dap's functions to debug.
  end
}

3) nvim-dap-matlab

require("nvim-dap-matlab").setup({
  lsp_name = 'matlab-ls',                 -- lsp name which you set using vim.lsp
  gui_windows = {
    auto_open = {                         -- these windows are opened automatically when debug starts.
      workspace = false,
      filebrowser = false,
    },
    keymaps = {
      toggle_workspace = '<leader>dw',    -- toggle workspace window to see variable list in GUI
      toggle_filebrowser = '<leader>df',  -- toggle file browser window to see variable list in GUI
    },
  },
  repl = {
    filetype = {'dap-repl', 'dap-view'},  -- set filetypes to apply lsp autocompletion and syntax
    keymaps = {
      previous_command_histroy = '<C-k>', -- insert previous command history to repl
      next_command_history = '<C-j>',     -- insert next command history to repl
    },
  }
})

---

Usage

Quick Start

1. Open a .m file in Neovim — the MATLAB LSP will connect automatically.
2. Wait for the LSP to finish loading (fidget.nvim or vim.notify() will show progress if it is completed).
3. Set breakpoints with dap.toggle_breakpoint().
4. Start debugging with dap.continue().
5. When a breakpoint is hit, use Step Over / Step Into / Step Out / Continue as usual.

Recommended Keymaps

local dap = require("dap")

vim.keymap.set('n', '<F5>', function ()
  local session = dap.session()
  if session and not session.stopped_thread_id then
    dap.close() -- if debug run is completed but session is remaining
  end
  dap.continue()
end, {desc = '[nvim-dap] Debug Run/continue'})
vim.keymap.set('n', '<F10>', dap.step_over, {desc = '[nvim-dap] Debug Step Over'})
vim.keymap.set('n', '<F11>', dap.step_into, {desc = '[nvim-dap] Debug Step Into'})
vim.keymap.set('n', '<F12>', dap.step_out, {desc = '[nvim-dap] Debug Step Out'})
vim.keymap.set('n', '<leader>dp', dap.pause, {desc = '[nvim-dap] Debug Pause'})
vim.keymap.set('n', '<leader>ds', dap.terminate, {desc = '[nvim-dap] Terminate Session'})
vim.keymap.set('n', '<leader>du', dap.clear_breakpoints, {desc = '[nvim-dap] Clear all Breakpoints'})
vim.keymap.set('n', '<leader>db', dap.toggle_breakpoint, {desc = '[nvim-dap] Set Breakpoint '})
vim.keymap.set('n', '<leader>dB', function ()
  local condition = vim.fn.input('condition : ') -- insert condition without 'if' word.
  if condition and condition ~= '' then
    dap.toggle_breakpoint(condition)
  end
end, {desc = '[nvim-dap] Set conditional Breakpoint '})

---

License

GPL-3.0