auto dark/light theme (from darkman)

.claude/settings.local.json

@@ -0,0 +1,8 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(NVIM_APPNAME=nvchad-test nvim:*)",
+      "Bash(darkman get:*)"
+    ]
+  }
+}

.nvimlog

@@ -0,0 +1 @@
+WRN 2026-02-16T16:29:54.587 ?.8        server_start:199: Failed to start server: read-only file system: /run/user/1000/nvim.8.0

init.lua

@@ -35,3 +35,9 @@ require "nvchad.autocmds"
 vim.schedule(function()
   require "mappings"
 end)
+
+-- Start theme sync with system (darkman)
+vim.schedule(function()
+  local theme_sync = require "theme-sync"
+  theme_sync.watch()
+end)

lua/chadrc.lua

@@ -2,6 +2,19 @@
 -- https://github.com/NvChad/ui/blob/v2.5/lua/nvconfig.lua
 -- Please read that file to know all available options :(
 
+-- Get system theme from darkman
+local function get_system_theme()
+  local handle = io.popen("darkman get 2>/dev/null")
+  if handle then
+    local result = handle:read("*a")
+    handle:close()
+    if result and result:match("light") then
+      return "onenord_light"
+    end
+  end
+  return "onenord"  -- default dark theme
+end
+
 ---@type ChadrcConfig
 local M = {
   ui = {
@@ -10,7 +23,7 @@ local M = {
     },
   },
   base46 = {
-    theme = "onenord",
+    theme = get_system_theme(),
   },
 
   nvdash = {

lua/options.lua

@@ -21,3 +21,9 @@ vim.g.neovide_scroll_animation_length = 0.15
 vim.g.neovide_cursor_animation_length = 0.11
 
 vim.o.swapfile = false
+
+-- Command to manually sync theme with system
+vim.api.nvim_create_user_command("ThemeSync", function()
+  require("theme-sync").sync()
+  vim.notify("Theme synced with system", vim.log.levels.INFO)
+end, { desc = "Sync theme with system (darkman)" })

lua/theme-sync.lua

@@ -0,0 +1,61 @@
+-- Sync Neovim theme with system (darkman)
+
+local M = {}
+
+-- Theme mappings
+M.themes = {
+  light = "onenord_light",
+  dark = "onenord",        -- Change to your preferred dark theme
+}
+
+-- Get current system theme from darkman
+function M.get_system_mode()
+  local handle = io.popen("darkman get 2>/dev/null")
+  if handle then
+    local result = handle:read("*a")
+    handle:close()
+    result = result and result:gsub("%s+$", "") or nil
+    if result == "light" then
+      return "light"
+    end
+  end
+  return "dark"
+end
+
+-- Apply theme based on mode (mirrors NvChad's toggle_theme logic)
+function M.apply_theme(mode)
+  local theme = M.themes[mode] or M.themes.dark
+  local opts = require("nvconfig").base46
+
+  -- Update in-memory config so base46.compile() picks up the new theme
+  opts.theme = theme
+
+  -- Bust chadrc cache, read old theme from file, then replace it
+  package.loaded.chadrc = nil
+  local old_theme = require("chadrc").base46.theme
+  require("nvchad.utils").replace_word('theme = "' .. old_theme, 'theme = "' .. theme)
+
+  require("base46").load_all_highlights()
+end
+
+-- Sync with system theme
+function M.sync()
+  local mode = M.get_system_mode()
+  M.apply_theme(mode)
+end
+
+-- Watch for theme changes (checks periodically)
+function M.watch()
+  local timer = vim.loop.new_timer()
+  local last_mode = M.get_system_mode()
+
+  timer:start(0, 5000, vim.schedule_wrap(function()
+    local current_mode = M.get_system_mode()
+    if current_mode ~= last_mode then
+      M.apply_theme(current_mode)
+      last_mode = current_mode
+    end
+  end))
+end
+
+return M