Support loading config from XDG_CONFIG paths

aider/args.py

@@ -791,8 +791,8 @@ def get_parser(default_config_files, git_root):
         is_config_file=True,
         metavar="CONFIG_FILE",
         help=(
-            "Specify the config file (default: search for .aider.conf.yml in git root, cwd"
-            " or home directory)"
+            "Specify the config file (default: search for .aider.conf.yml in git root, cwd, home"
+            " dir, and for conf.yml in ~/.config/aider)"
         ),
     ).complete = shtab.FILE
     # This is a duplicate of the argument in the preparser and is a no-op by this time of

aider/args_formatter.py

@@ -93,7 +93,7 @@ def _format_text(self, text):
 ##########################################################
 # Sample .aider.conf.yml
 # This file lists *all* the valid configuration entries.
-# Place in your home dir, or at the root of your git repo.
+# Place in your home dir, git repo root, or $XDG_CONFIG_HOME/aider/conf.yml.
 ##########################################################
 
 # Note: You can only put OpenAI and Anthropic API keys in the YAML

aider/main.py

@@ -305,6 +305,17 @@ def parse_lint_cmds(lint_cmds, io):
 def generate_search_path_list(default_file, git_root, command_line_file):
     files = []
     files.append(Path.home() / default_file)  # homedir
+
+    xdg_config_home = os.environ.get("XDG_CONFIG_HOME")
+    if not xdg_config_home:
+        xdg_config_home = Path.home() / ".config"
+    else:
+        xdg_config_home = Path(xdg_config_home)
+    xdg_aider_dir = xdg_config_home / "aider"
+    files.append(xdg_aider_dir / default_file)
+    if default_file.startswith("."):
+        files.append(xdg_aider_dir / default_file[1:])
+
     if git_root:
         files.append(Path(git_root) / default_file)  # git root
     files.append(default_file)
@@ -465,15 +476,35 @@ def main(argv=None, input=None, output=None, force_git_root=None, return_coder=F
 
     default_config_files = []
     try:
-        default_config_files += [conf_fname.resolve()]  # CWD
+        default_config_files.append(conf_fname.resolve())  # CWD
     except OSError:
         pass
 
     if git_root:
         git_conf = Path(git_root) / conf_fname  # git root
         if git_conf not in default_config_files:
             default_config_files.append(git_conf)
-    default_config_files.append(Path.home() / conf_fname)  # homedir
+
+    xdg_config_home = os.environ.get("XDG_CONFIG_HOME")
+    if not xdg_config_home:
+        xdg_config_home = Path.home() / ".config"
+    else:
+        xdg_config_home = Path(xdg_config_home)
+    xdg_aider_dir = xdg_config_home / "aider"
+
+    # Non-dotted version, higher precedence
+    xdg_conf_no_dot = xdg_aider_dir / "conf.yml"
+    if xdg_conf_no_dot not in default_config_files:
+        default_config_files.append(xdg_conf_no_dot)
+
+    # Dotted version
+    xdg_conf_dot = xdg_aider_dir / conf_fname
+    if xdg_conf_dot not in default_config_files:
+        default_config_files.append(xdg_conf_dot)
+
+    home_conf = Path.home() / conf_fname
+    if home_conf not in default_config_files:
+        default_config_files.append(home_conf)  # homedir
     default_config_files = list(map(str, default_config_files))
 
     parser = get_parser(default_config_files, git_root)

aider/website/docs/config/aider_conf.md

@@ -6,14 +6,15 @@ description: How to configure aider with a YAML config file.
 
 # YAML config file
 
-Most of aider's options can be set in an `.aider.conf.yml` file.
-Aider will look for a this file in these locations:
+Most of aider's options can be set in a YAML config file.
+Aider will look for config files in these locations:
 
-- Your home directory.
-- The root of your git repo.
-- The current directory.
+- Your home directory (`~/.aider.conf.yml`).
+- Your XDG config home in `$XDG_CONFIG_HOME/aider/`. Aider will look for `conf.yml` and `.aider.conf.yml`. If `$XDG_CONFIG_HOME` is not set, it defaults to `~/.config`.
+- The root of your git repo (`.aider.conf.yml`).
+- The current directory (`.aider.conf.yml`).
 
-If the files above exist, they will be loaded in that order. Files loaded last will take priority.
+If the files above exist, they will be loaded in that order. Settings from files loaded later take priority.
 
 You can also specify the `--config <filename>` parameter, which will only load the one config file.
 

tests/basic/test_main.py

@@ -533,8 +533,18 @@ def test_yaml_config_file_loading(self):
             cwd_config = cwd / ".aider.conf.yml"
             named_config = git_dir / "named.aider.conf.yml"
 
+            # Create XDG config files
+            xdg_config_home = fake_home / ".config"
+            os.environ["XDG_CONFIG_HOME"] = str(xdg_config_home)
+            xdg_aider_dir = xdg_config_home / "aider"
+            xdg_aider_dir.mkdir(parents=True)
+            xdg_config_dot = xdg_aider_dir / ".aider.conf.yml"
+            xdg_config_no_dot = xdg_aider_dir / "conf.yml"
+
             cwd_config.write_text("model: gpt-4-32k\nmap-tokens: 4096\n")
             git_config.write_text("model: gpt-4\nmap-tokens: 2048\n")
+            xdg_config_no_dot.write_text("model: xdg-no-dot\nmap-tokens: 600\n")
+            xdg_config_dot.write_text("model: xdg-dot\nmap-tokens: 500\n")
             home_config.write_text("model: gpt-3.5-turbo\nmap-tokens: 1024\n")
             named_config.write_text("model: gpt-4-1106-preview\nmap-tokens: 8192\n")
 
@@ -555,8 +565,6 @@ def test_yaml_config_file_loading(self):
                 # Test loading from current working directory
                 main(["--yes", "--exit"], input=DummyInput(), output=DummyOutput())
                 _, kwargs = MockCoder.call_args
-                print("kwargs:", kwargs)  # Add this line for debugging
-                self.assertIn("main_model", kwargs, "main_model key not found in kwargs")
                 self.assertEqual(kwargs["main_model"].name, "gpt-4-32k")
                 self.assertEqual(kwargs["map_tokens"], 4096)
 
@@ -567,10 +575,24 @@ def test_yaml_config_file_loading(self):
                 self.assertEqual(kwargs["main_model"].name, "gpt-4")
                 self.assertEqual(kwargs["map_tokens"], 2048)
 
-                # Test loading from home directory
+                # Test loading from XDG (no dot)
                 git_config.unlink()
                 main(["--yes", "--exit"], input=DummyInput(), output=DummyOutput())
                 _, kwargs = MockCoder.call_args
+                self.assertEqual(kwargs["main_model"].name, "xdg-no-dot")
+                self.assertEqual(kwargs["map_tokens"], 600)
+
+                # Test loading from XDG (dot)
+                xdg_config_no_dot.unlink()
+                main(["--yes", "--exit"], input=DummyInput(), output=DummyOutput())
+                _, kwargs = MockCoder.call_args
+                self.assertEqual(kwargs["main_model"].name, "xdg-dot")
+                self.assertEqual(kwargs["map_tokens"], 500)
+
+                # Test loading from home directory
+                xdg_config_dot.unlink()
+                main(["--yes", "--exit"], input=DummyInput(), output=DummyOutput())
+                _, kwargs = MockCoder.call_args
                 self.assertEqual(kwargs["main_model"].name, "gpt-3.5-turbo")
                 self.assertEqual(kwargs["map_tokens"], 1024)