diff --git a/tests/test_config.py b/tests/test_config.py
new file mode 100644
index 0000000..6ad9291
--- /dev/null
+++ b/tests/test_config.py
@@ -0,0 +1,133 @@
+"""Tests for configuration module."""
+
+import os
+import tempfile
+from pathlib import Path
+
+import pytest
+
+from codexchange.config import (
+    ConfigSettings,
+    get_config_path,
+    load_config,
+    save_config,
+    get_config,
+)
+
+
+class TestConfigSettings:
+    """Tests for ConfigSettings model."""
+
+    def test_default_values(self):
+        """Test that ConfigSettings has correct default values."""
+        config = ConfigSettings()
+        assert config.ollama_host == "http://localhost:11434"
+        assert config.default_model == "codellama"
+        assert config.timeout == 300
+        assert config.verbose is False
+
+    def test_custom_values(self):
+        """Test that ConfigSettings accepts custom values."""
+        config = ConfigSettings(
+            ollama_host="http://ollama:11434",
+            default_model="llama2",
+            timeout=600,
+            verbose=True
+        )
+        assert config.ollama_host == "http://ollama:11434"
+        assert config.default_model == "llama2"
+        assert config.timeout == 600
+        assert config.verbose is True
+
+
+class TestConfigPath:
+    """Tests for configuration file path."""
+
+    def test_get_config_path(self):
+        """Test that config path is in home directory."""
+        config_path = get_config_path()
+        assert config_path.name == ".codexchange.yaml"
+        assert config_path.parent == Path.home()
+
+
+class TestLoadConfig:
+    """Tests for loading configuration."""
+
+    def test_load_default_config(self):
+        """Test loading config when file doesn't exist."""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            config_path = Path(tmpdir) / "nonexistent.yaml"
+            config = load_config(config_path)
+            
+            assert config.ollama_host == "http://localhost:11434"
+            assert config.default_model == "codellama"
+
+    def test_load_config_from_file(self):
+        """Test loading config from YAML file."""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            config_path = Path(tmpdir) / ".codexchange.yaml"
+            
+            yaml_content = """
+ollama_host: http://custom:11434
+default_model: mistral
+timeout: 600
+verbose: true
+"""
+            with open(config_path, "w") as f:
+                f.write(yaml_content)
+            
+            config = load_config(config_path)
+            
+            assert config.ollama_host == "http://custom:11434"
+            assert config.default_model == "mistral"
+            assert config.timeout == 600
+            assert config.verbose is True
+
+
+class TestSaveConfig:
+    """Tests for saving configuration."""
+
+    def test_save_config(self):
+        """Test saving config to YAML file."""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            config_path = Path(tmpdir) / ".codexchange.yaml"
+            config = ConfigSettings(
+                ollama_host="http://test:11434",
+                default_model="testmodel",
+                timeout=120
+            )
+            
+            save_config(config, config_path)
+            
+            assert config_path.exists()
+            
+            with open(config_path, "r") as f:
+                content = f.read()
+            
+            assert "http://test:11434" in content
+            assert "testmodel" in content
+            assert "120" in content
+
+
+class TestGetConfig:
+    """Tests for getting configuration with env overrides."""
+
+    def test_environment_override(self, monkeypatch):
+        """Test that environment variables override config."""
+        monkeypatch.setenv("CODEXCHANGE_OLLAMA_HOST", "http://env-host:11434")
+        monkeypatch.setenv("CODEXCHANGE_DEFAULT_MODEL", "env-model")
+        monkeypatch.setenv("CODEXCHANGE_TIMEOUT", "900")
+        
+        config = get_config()
+        
+        assert config.ollama_host == "http://env-host:11434"
+        assert config.default_model == "env-model"
+        assert config.timeout == 900
+
+    def test_invalid_timeout_env(self, monkeypatch):
+        """Test handling of invalid timeout environment variable."""
+        monkeypatch.setenv("CODEXCHANGE_TIMEOUT", "invalid")
+        
+        config = get_config()
+        
+        assert config.timeout == 300