diff --git a/lua/jj_mini_diff/init.lua b/lua/jj_mini_diff/init.lua
index cf5731b..dec0100 100644
--- a/lua/jj_mini_diff/init.lua
+++ b/lua/jj_mini_diff/init.lua
@@ -107,13 +107,36 @@ local function _place_signs_in_buffer()
   end
 end
 
+-- Check if current buffer's file is in a jj repo
+local function _is_jj_repo()
+  local file_path = vim.api.nvim_buf_get_name(0)
+  if file_path == "" then
+    return false
+  end
+  local dir = vim.fn.fnamemodify(file_path, ":h")
+  while dir ~= "" and dir ~= "/" do
+    if vim.fn.isdirectory(dir .. "/.jj") == 1 then
+      return true
+    end
+    dir = vim.fn.fnamemodify(dir, ":h")
+  end
+  return false
+end
+
 
 function M.setup(opts)
   opts = opts or {}
   _define_signs() -- Call to define signs
-  -- TODO: Implement configuration options
+
+  -- Autocommands to update signs
+  vim.api.nvim_create_autocmd({ "BufReadPost", "BufWritePost", "CursorHold" }, {
+    group = vim.api.nvim_create_augroup("JjMiniDiff", { clear = true }),
+    callback = function()
+      if _is_jj_repo() then
+        _place_signs_in_buffer()
+      end
+    end,
+  })
 end
 
--- TODO: Implement core logic for Git signs
-
 return M