return {
  'stevearc/conform.nvim',
  dependencies = {
    'nvim-lua/plenary.nvim',
    'WhoIsSethDaniel/mason-tool-installer.nvim',
  },
  event = { 'BufReadPre', 'BufNewFile' },
  opts = {
    formatters = {
      juliaformatter = {
        command = 'julia',
        args = {
          '--project=' .. vim.fn.expand('~/.julia/environments/nvim-format'),
          '--startup-file=no',
          '--history-file=no',
          '-e',
          [[
            using JuliaFormatter
            print(format_text(read(stdin, String)))
          ]],
        },
        stdin = true,
      },
    },
    formatters_by_ft = {
      python = {
        'ruff_fix',
        'ruff_format',
        'ruff_organize_imports',
      },
      yaml = { 'yamlfmt' },
      sh = { 'shfmt' },
      sql = { 'sqlfluff' },
      lua = { 'stylua' },
      json = { 'jq' },
      julia = { 'juliaformatter' }, -- keep JuliaFormatter here
      markdown = { 'prettierd', 'prettier' },
      html = { 'prettierd' },
      css = { 'prettierd' },
      javascript = { 'prettierd' },
      typescript = { 'prettierd' },
    },

    -- Fallback setup
    format_on_save = function(bufnr)
      if vim.bo[bufnr].filetype == 'julia' then
        return
      end
      return {
        timeout_ms = 2000,
        lsp_fallback = true,
      }
    end,

    notify_on_error = true,
    async = true,
  },

  config = function(_, opts)
    -- Setup Conform
    require('conform').setup(opts)

    -- Auto-install formatters via Mason
    local all_formatters = {}
    for _, formatters in pairs(opts.formatters_by_ft) do
      for _, f in ipairs(formatters) do
        all_formatters[f] = true
      end
    end

    local exclude = {
      ruff_fix = true,
      ruff_format = true,
      ruff_organize_imports = true,
      juliaformatter = true, -- exclude JuliaFormatter from Mason (install via Julia)
    }

    local tools = vim.tbl_filter(function(tool)
      return not exclude[tool]
    end, vim.tbl_keys(all_formatters))

    require('mason-tool-installer').setup({
      ensure_installed = tools,
      auto_update = false,
      run_on_start = true,
    })
  end,
}