diff --git a/README.md b/README.md
index e90abe8..3a0f1d2 100644
--- a/README.md
+++ b/README.md
@@ -65,12 +65,32 @@ use {
 }
 ```
 
+## Multiple Gitlab Repositories
+
 By default, the tool will look for and interact with MRs against a "main" branch. You can configure this by passing in the `base_branch` option:
 
 ```lua
 require('gitlab').setup({ project_id = 3, base_branch = 'master' })
 ```
 
+By default, the plugin will read the `project_id` provided in the setup call. However, if you add a `.gitlab.nvim` file to the root of your directory, the plugin will read that and use it as the project_id instead. The file should only contain the ID of the project:
+
+```
+112415
+```
+
+Which is effectively like calling the setup function like this:
+
+```lua
+require('gitlab').setup({ project_id = 112415, base_branch = 'master' })
+```
+
+If you are using `main` as your branch and you add a `.gitlab.nvim` configuration file, you can call an empty setup function and the plugin will work:
+
+```lua
+require('gitlab').setup()
+```
+
 ## Usage
 
 First, check out the branch that you want to review locally. Then open Neovim and the reviewer will be initialized. The `project_id` you specify in your configuration must match the project_id of the Gitlab project your terminal is inside of.
diff --git a/lua/gitlab/init.lua b/lua/gitlab/init.lua
index ddd646e..86b951d 100644
--- a/lua/gitlab/init.lua
+++ b/lua/gitlab/init.lua
@@ -41,6 +41,7 @@ M.setup             = function(args, build_only)
   state.BIN_PATH = parent_dir
   state.BIN = parent_dir .. "/bin"
 
+  if args == nil then args = {} end
   if args.dev == true then
     M.build(args)
   end
@@ -62,7 +63,15 @@ M.setup             = function(args, build_only)
 
   if build_only then return end
 
+  -- Override project_id in setup call if configuration file is present
+  local config_file_path = vim.fn.getcwd() .. "/.gitlab.nvim"
+  local config_file_content = read_file(config_file_path)
+  if config_file_content ~= nil then
+    args.project_id = config_file_content
+  end
+
   if args.project_id == nil then
+    args.project_id = u.read_file(state.BIN_PATH .. "/.gitlab/project_id")
     error("No project ID provided!")
   end
 
diff --git a/lua/gitlab/utils/init.lua b/lua/gitlab/utils/init.lua
index 1de1d61..94333c3 100644
--- a/lua/gitlab/utils/init.lua
+++ b/lua/gitlab/utils/init.lua
@@ -204,7 +204,16 @@ M.merge_tables = function(defaults, overrides)
   return result
 end
 
-
+function read_file(file_path)
+  local file = io.open(file_path, "r")
+  if file == nil then
+    return nil
+  end
+  local file_contents = file:read("*all")
+  file:close()
+  file_contents = string.gsub(file_contents, "\n", "")
+  return file_contents
+end
 
 M.get_relative_file_path = get_relative_file_path
 M.get_current_line_number = get_current_line_number