diff --git a/tests/test_cli.py b/tests/test_cli.py
new file mode 100644
index 0000000..540b27f
--- /dev/null
+++ b/tests/test_cli.py
@@ -0,0 +1,110 @@
+"""Unit tests for CLI interface."""
+
+import os
+import tempfile
+from pathlib import Path
+from unittest.mock import patch, MagicMock
+
+import pytest
+from click.testing import CliRunner
+
+from dev_env_sync.cli.main import cli, get_default_config_path, load_config
+from dev_env_sync import __version__
+
+
+class TestCLI:
+    """Tests for CLI interface."""
+    
+    @pytest.fixture
+    def runner(self):
+        """Create a CLI runner."""
+        return CliRunner()
+    
+    def test_version_command(self, runner):
+        """Test version command."""
+        result = runner.invoke(cli, ["version"])
+        
+        assert result.exit_code == 0
+        assert __version__ in result.output
+    
+    def test_platforms_command(self, runner):
+        """Test platforms command."""
+        result = runner.invoke(cli, ["platforms"])
+        
+        assert result.exit_code == 0
+        assert "Current Platform" in result.output
+        assert "Supported Platforms" in result.output
+        assert "Linux" in result.output
+        assert "macOS" in result.output
+        assert "WSL" in result.output
+    
+    def test_status_command_no_config(self, runner):
+        """Test status command without configuration."""
+        result = runner.invoke(cli, ["status"])
+        
+        assert result.exit_code == 0
+        assert "Platform:" in result.output
+    
+    def test_sync_command_no_config(self, runner):
+        """Test sync command without configuration."""
+        result = runner.invoke(cli, ["sync"])
+        
+        assert result.exit_code != 0
+        assert "No configuration file found" in result.output
+    
+    def test_init_command(self, runner, temp_dir):
+        """Test init command."""
+        output_file = temp_dir / "test-config.yml"
+        
+        result = runner.invoke(cli, ["init", "-o", str(output_file)])
+        
+        assert result.exit_code == 0
+        assert "Sample configuration written to" in result.output
+        assert output_file.exists()
+    
+    def test_verbose_flag(self, runner):
+        """Test verbose flag."""
+        result = runner.invoke(cli, ["--verbose", "version"])
+        
+        assert result.exit_code == 0
+    
+    def test_dry_run_flag(self, runner, temp_dir):
+        """Test dry-run flag with config."""
+        config_file = temp_dir / ".dev-env-sync.yml"
+        config_file.write_text('version: "1.0"\nname: "Test"')
+        
+        with patch('dev_env_sync.cli.main.get_default_config_path', return_value=str(config_file)):
+            result = runner.invoke(cli, ["--dry-run", "status"])
+        
+        assert result.exit_code == 0
+        assert "DRY-RUN MODE" in result.output
+
+
+class TestConfigPathResolution:
+    """Tests for configuration path resolution."""
+    
+    def test_get_default_config_path_env(self, temp_dir, monkeypatch):
+        """Test getting config path from environment variable."""
+        config_file = temp_dir / "test-config.yml"
+        config_file.write_text("version: '1.0'")
+        
+        monkeypatch.setenv("DEV_ENV_SYNC_CONFIG", str(config_file))
+        
+        path = get_default_config_path()
+        
+        assert path == str(config_file)
+    
+    def test_load_config_success(self, sample_config_yaml, temp_dir):
+        """Test loading configuration successfully."""
+        config_file = temp_dir / "config.yml"
+        config_file.write_text(sample_config_yaml)
+        
+        config = load_config(str(config_file))
+        
+        assert config is not None
+        assert config.version == "1.0"
+    
+    def test_load_config_nonexistent(self):
+        """Test loading nonexistent configuration."""
+        with pytest.raises(Exception):
+            load_config("/nonexistent/config.yml")