diff --git a/tests/test_cli.py b/tests/test_cli.py
new file mode 100644
index 0000000..8331227
--- /dev/null
+++ b/tests/test_cli.py
@@ -0,0 +1,191 @@
+"""Tests for CLI interface."""
+import pytest
+import json
+from click.testing import CliRunner
+from unittest.mock import patch
+
+
+class TestCLI:
+    """Test cases for CLI commands."""
+
+    @pytest.fixture
+    def runner(self):
+        return CliRunner()
+
+    @pytest.fixture
+    def sample_json_file(self, tmp_path):
+        data = {"name": "Test", "value": 42}
+        file_path = tmp_path / "sample.json"
+        file_path.write_text(json.dumps(data))
+        return file_path
+
+    @pytest.fixture
+    def invalid_json_file(self, tmp_path):
+        file_path = tmp_path / "invalid.json"
+        file_path.write_text("{invalid json}")
+        return file_path
+
+    def test_cli_main_help(self, runner):
+        from json_to_openapi.cli import main
+        result = runner.invoke(main, ["--help"])
+        assert result.exit_code == 0
+        assert "JSON to OpenAPI Generator" in result.output
+
+    def test_cli_convert_basic(self, runner, sample_json_file, tmp_path):
+        from json_to_openapi.cli import main
+        output_file = tmp_path / "output.yaml"
+
+        result = runner.invoke(main, [
+            "convert",
+            str(sample_json_file),
+            "-o", str(output_file),
+            "-f", "yaml",
+            "-t", "Test API",
+            "-v", "1.0.0"
+        ])
+
+        assert result.exit_code == 0
+        assert output_file.exists()
+
+    def test_cli_convert_invalid_file(self, runner, tmp_path):
+        from json_to_openapi.cli import main
+        non_existent = tmp_path / "nonexistent.json"
+
+        result = runner.invoke(main, [
+            "convert",
+            str(non_existent)
+        ])
+
+        assert result.exit_code != 0
+        assert "Error" in result.output
+
+    def test_cli_info(self, runner):
+        from json_to_openapi.cli import main
+        result = runner.invoke(main, ["info"])
+        assert result.exit_code == 0
+        assert "JSON to OpenAPI Generator" in result.output
+
+    @patch('json_to_openapi.cli.click.prompt')
+    def test_cli_validate_valid_spec(self, mock_prompt, runner, tmp_path):
+        from json_to_openapi.cli import main
+
+        spec_content = """
+openapi: 3.0.3
+info:
+  title: Test API
+  version: 1.0.0
+paths: {}
+"""
+        spec_file = tmp_path / "valid.yaml"
+        spec_file.write_text(spec_content)
+
+        result = runner.invoke(main, ["validate", str(spec_file)])
+
+        assert result.exit_code == 0
+        assert "Validation passed" in result.output
+
+    @patch('json_to_openapi.cli.click.prompt')
+    def test_cli_validate_invalid_spec(self, mock_prompt, runner, tmp_path):
+        from json_to_openapi.cli import main
+
+        spec_content = """
+invalid: content
+"""
+        spec_file = tmp_path / "invalid.yaml"
+        spec_file.write_text(spec_content)
+
+        result = runner.invoke(main, ["validate", str(spec_file)])
+
+        assert result.exit_code != 0
+        assert "Validation failed" in result.output
+
+    def test_cli_batch_no_files(self, runner, tmp_path):
+        from json_to_openapi.cli import main
+
+        result = runner.invoke(main, [
+            "batch",
+            str(tmp_path / "*.json")
+        ])
+
+        assert result.exit_code != 0
+        assert "No files found" in result.output
+
+    def test_cli_batch_single_file(self, runner, sample_json_file, tmp_path):
+        from json_to_openapi.cli import main
+        output_dir = tmp_path / "output"
+        output_dir.mkdir()
+
+        result = runner.invoke(main, [
+            "batch",
+            str(sample_json_file),
+            "-o", str(output_dir),
+            "-f", "yaml"
+        ])
+
+        assert result.exit_code == 0
+        assert "Successfully processed" in result.output
+
+    @patch('json_to_openapi.cli.click.prompt')
+    @patch('json_to_openapi.cli.click.confirm')
+    def test_cli_interactive(self, mock_confirm, mock_prompt, runner, sample_json_file, tmp_path):
+        from json_to_openapi.cli import main
+
+        mock_confirm.return_value = False
+
+        mock_prompt.side_effect = [
+            str(sample_json_file),
+            "/items",
+            "get",
+            "Get Items",
+            "",
+            "yaml",
+            str(tmp_path / "output.yaml")
+        ]
+
+        result = runner.invoke(main, ["interactive"])
+
+        assert result.exit_code == 0
+
+    def test_cli_verbose_flag(self, runner, sample_json_file, tmp_path):
+        from json_to_openapi.cli import main
+        output_file = tmp_path / "output.yaml"
+
+        result = runner.invoke(main, [
+            "-v",
+            "convert",
+            str(sample_json_file),
+            "-o", str(output_file)
+        ])
+
+        assert result.exit_code == 0
+        assert "[DEBUG]" in result.output
+
+    def test_cli_quiet_flag(self, runner, sample_json_file, tmp_path):
+        from json_to_openapi.cli import main
+        output_file = tmp_path / "output.yaml"
+
+        result = runner.invoke(main, [
+            "-q",
+            "convert",
+            str(sample_json_file),
+            "-o", str(output_file)
+        ])
+
+        assert result.exit_code == 0
+        assert "Generated:" not in result.output
+
+    def test_cli_convert_json_format(self, runner, sample_json_file, tmp_path):
+        from json_to_openapi.cli import main
+        output_file = tmp_path / "output.json"
+
+        result = runner.invoke(main, [
+            "convert",
+            str(sample_json_file),
+            "-o", str(output_file),
+            "-f", "json"
+        ])
+
+        assert result.exit_code == 0
+        content = output_file.read_text()
+        parsed = json.loads(content)
+        assert parsed["openapi"] == "3.0.3"