diff --git a/tests/test_cli.py b/tests/test_cli.py
index c339b8d..e773f03 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -1,32 +1,565 @@
+import json
+import os
+import tempfile
+from pathlib import Path
+from unittest.mock import MagicMock, patch
+
 import pytest
 from click.testing import CliRunner
-from src.cli import main
+
+from src.cli import main, serve, generate, validate, search
 
 
-@pytest.fixture
-def runner():
-    return CliRunner()
+class TestCLIMain:
+    """Test cases for the main CLI entry point."""
+
+    def test_main_help(self):
+        """Test that main command shows help."""
+        runner = CliRunner()
+        result = runner.invoke(main, ["--help"])
+
+        assert result.exit_code == 0
+        assert "LocalAPI Docs" in result.output
+        assert "serve" in result.output
+        assert "generate" in result.output
+        assert "validate" in result.output
+        assert "search" in result.output
+
+    def test_main_verbose_flag(self):
+        """Test verbose flag parsing."""
+        runner = CliRunner()
+        result = runner.invoke(main, ["--help"])
+
+        assert result.exit_code == 0
 
 
-def test_cli_help(runner):
-    result = runner.invoke(main, ['--help'])
-    assert result.exit_code == 0
-    assert 'LocalAPI Docs' in result.output
+class TestValidateCommand:
+    """Test cases for the validate command."""
+
+    def test_validate_valid_spec(self):
+        """Test validating a valid OpenAPI spec."""
+        spec = {
+            "openapi": "3.0.0",
+            "info": {
+                "title": "Test API",
+                "version": "1.0.0"
+            },
+            "paths": {}
+        }
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".json", delete=False) as f:
+            json.dump(spec, f)
+            f.flush()
+
+            runner = CliRunner()
+            result = runner.invoke(validate, [f.name])
+
+            assert result.exit_code == 0
+            assert "valid" in result.output.lower()
+
+            os.unlink(f.name)
+
+    def test_validate_invalid_spec(self):
+        """Test validating an invalid OpenAPI spec."""
+        spec = {
+            "openapi": "3.0.0",
+            "info": {
+                "title": "Test API"
+            }
+        }
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".json", delete=False) as f:
+            json.dump(spec, f)
+            f.flush()
+
+            runner = CliRunner()
+            result = runner.invoke(validate, [f.name])
+
+            assert result.exit_code == 1
+            assert "invalid" in result.output.lower() or "error" in result.output.lower()
+
+            os.unlink(f.name)
+
+    def test_validate_missing_file(self):
+        """Test validating a non-existent file."""
+        runner = CliRunner()
+        result = runner.invoke(validate, ["nonexistent.json"])
+
+        assert result.exit_code != 0
+        assert "not found" in result.output.lower() or "error" in result.output.lower()
+
+    def test_validate_yaml_spec(self):
+        """Test validating a YAML spec file."""
+        spec_content = """
+openapi: 3.0.0
+info:
+  title: Test API
+  version: 1.0.0
+paths: {}
+"""
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".yaml", delete=False) as f:
+            f.write(spec_content)
+            f.flush()
+
+            runner = CliRunner()
+            result = runner.invoke(validate, [f.name])
+
+            assert result.exit_code == 0
+
+            os.unlink(f.name)
+
+    def test_validate_json_output(self):
+        """Test validate command with JSON output."""
+        spec = {
+            "openapi": "3.0.0",
+            "info": {
+                "title": "Test API",
+                "version": "1.0.0"
+            },
+            "paths": {}
+        }
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".json", delete=False) as f:
+            json.dump(spec, f)
+            f.flush()
+
+            runner = CliRunner()
+            result = runner.invoke(validate, [f.name, "--json"])
+
+            assert result.exit_code == 0
+            assert "valid" in result.output.lower()
+
+            os.unlink(f.name)
 
 
-def test_cli_serve(runner, tmp_path, sample_spec):
-    result = runner.invoke(main, ['serve', str(sample_spec)])
-    assert result.exit_code == 0
+class TestGenerateCommand:
+    """Test cases for the generate command."""
+
+    def test_generate_html(self):
+        """Test generating HTML documentation."""
+        spec = {
+            "openapi": "3.0.0",
+            "info": {
+                "title": "Test API",
+                "version": "1.0.0",
+                "description": "A test API"
+            },
+            "paths": {
+                "/users": {
+                    "get": {
+                        "summary": "List users",
+                        "description": "Get a list of users",
+                        "responses": {
+                            "200": {
+                                "description": "Success"
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".json", delete=False) as f:
+            json.dump(spec, f)
+            f.flush()
+
+            runner = CliRunner()
+            with runner.isolated_filesystem():
+                result = runner.invoke(generate, [f.name, "--format", "html"])
+
+                assert result.exit_code == 0
+                assert "api-docs.html" in result.output.lower() or "generated" in result.output.lower()
+
+            os.unlink(f.name)
+
+    def test_generate_markdown(self):
+        """Test generating Markdown documentation."""
+        spec = {
+            "openapi": "3.0.0",
+            "info": {
+                "title": "Test API",
+                "version": "1.0.0"
+            },
+            "paths": {}
+        }
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".json", delete=False) as f:
+            json.dump(spec, f)
+            f.flush()
+
+            runner = CliRunner()
+            with runner.isolated_filesystem():
+                result = runner.invoke(generate, [f.name, "--format", "markdown"])
+
+                assert result.exit_code == 0
+
+            os.unlink(f.name)
+
+    def test_generate_json(self):
+        """Test generating JSON documentation."""
+        spec = {
+            "openapi": "3.0.0",
+            "info": {
+                "title": "Test API",
+                "version": "1.0.0"
+            },
+            "paths": {}
+        }
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".json", delete=False) as f:
+            json.dump(spec, f)
+            f.flush()
+
+            runner = CliRunner()
+            with runner.isolated_filesystem():
+                result = runner.invoke(generate, [f.name, "--format", "json"])
+
+                assert result.exit_code == 0
+
+            os.unlink(f.name)
+
+    def test_generate_with_output_path(self):
+        """Test generating with custom output path."""
+        spec = {
+            "openapi": "3.0.0",
+            "info": {
+                "title": "Test API",
+                "version": "1.0.0"
+            },
+            "paths": {}
+        }
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".json", delete=False) as f:
+            json.dump(spec, f)
+            f.flush()
+
+            runner = CliRunner()
+            with runner.isolated_filesystem():
+                result = runner.invoke(generate, [f.name, "--format", "html", "--output", "custom.html"])
+
+                assert result.exit_code == 0
+                assert os.path.exists("custom.html")
+
+            os.unlink(f.name)
+
+    def test_generate_with_all_formats(self):
+        """Test generating all output formats."""
+        spec = {
+            "openapi": "3.0.0",
+            "info": {
+                "title": "Test API",
+                "version": "1.0.0"
+            },
+            "paths": {}
+        }
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".json", delete=False) as f:
+            json.dump(spec, f)
+            f.flush()
+
+            runner = CliRunner()
+            with runner.isolated_filesystem():
+                result = runner.invoke(generate, [f.name, "--format", "all"])
+
+                assert result.exit_code == 0
+
+            os.unlink(f.name)
 
 
-def test_cli_generate(runner, tmp_path, sample_spec):
-    output = tmp_path / "output.html"
-    result = runner.invoke(main, ['generate', str(sample_spec), '-o', str(output)])
-    assert result.exit_code == 0
-    assert output.exists()
+class TestSearchCommand:
+    """Test cases for the search command."""
+
+    def test_search_basic(self):
+        """Test basic search functionality."""
+        spec = {
+            "openapi": "3.0.0",
+            "info": {
+                "title": "Test API",
+                "version": "1.0.0"
+            },
+            "paths": {
+                "/users": {
+                    "get": {
+                        "summary": "List all users",
+                        "description": "Get a list of all users in the system",
+                        "responses": {
+                            "200": {"description": "Success"}
+                        }
+                    }
+                }
+            }
+        }
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".json", delete=False) as f:
+            json.dump(spec, f)
+            f.flush()
+
+            runner = CliRunner()
+            result = runner.invoke(search, [f.name, "users"])
+
+            assert result.exit_code == 0
+
+            os.unlink(f.name)
+
+    def test_search_no_results(self):
+        """Test search with no results."""
+        spec = {
+            "openapi": "3.0.0",
+            "info": {
+                "title": "Test API",
+                "version": "1.0.0"
+            },
+            "paths": {
+                "/users": {
+                    "get": {
+                        "summary": "List users",
+                        "responses": {"200": {"description": "Success"}}
+                    }
+                }
+            }
+        }
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".json", delete=False) as f:
+            json.dump(spec, f)
+            f.flush()
+
+            runner = CliRunner()
+            result = runner.invoke(search, [f.name, "nonexistentendpoint12345"])
+
+            assert result.exit_code == 0
+            assert "no results" in result.output.lower()
+
+            os.unlink(f.name)
+
+    def test_search_json_output(self):
+        """Test search with JSON output."""
+        spec = {
+            "openapi": "3.0.0",
+            "info": {
+                "title": "Test API",
+                "version": "1.0.0"
+            },
+            "paths": {
+                "/users": {
+                    "get": {
+                        "summary": "List users",
+                        "responses": {"200": {"description": "Success"}}
+                    }
+                }
+            }
+        }
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".json", delete=False) as f:
+            json.dump(spec, f)
+            f.flush()
+
+            runner = CliRunner()
+            result = runner.invoke(search, [f.name, "users", "--json"])
+
+            assert result.exit_code == 0
+            assert "query" in result.output.lower() or "results" in result.output.lower()
+
+            os.unlink(f.name)
+
+    def test_search_with_limit(self):
+        """Test search with result limit."""
+        spec = {
+            "openapi": "3.0.0",
+            "info": {
+                "title": "Test API",
+                "version": "1.0.0"
+            },
+            "paths": {
+                "users": {
+                    "get": {
+                        "summary": "List users",
+                        "responses": {"200": {"description": "Success"}}
+                    }
+                }
+            }
+        }
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".json", delete=False) as f:
+            json.dump(spec, f)
+            f.flush()
+
+            runner = CliRunner()
+            result = runner.invoke(search, [f.name, "users", "--limit", "5"])
+
+            assert result.exit_code == 0
+
+            os.unlink(f.name)
 
 
-def test_cli_validate(runner, sample_spec):
-    result = runner.invoke(main, ['validate', str(sample_spec)])
-    assert result.exit_code == 0
-    assert 'valid' in result.output.lower()
+class TestServeCommand:
+    """Test cases for the serve command."""
+
+    def test_serve_invalid_spec(self):
+        """Test serve command with invalid spec."""
+        spec = {"invalid": "spec"}
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".json", delete=False) as f:
+            json.dump(spec, f)
+            f.flush()
+
+            runner = CliRunner()
+            result = runner.invoke(serve, [f.name, "--port", "9999", "--no-browser"])
+
+            assert result.exit_code == 1
+            assert "error" in result.output.lower() or "invalid" in result.output.lower()
+
+            os.unlink(f.name)
+
+    def test_serve_missing_file(self):
+        """Test serve command with missing file."""
+        runner = CliRunner()
+        result = runner.invoke(serve, ["nonexistent.json"])
+
+        assert result.exit_code == 1
+
+    def test_serve_with_custom_host_port(self):
+        """Test serve command with custom host and port."""
+        spec = {
+            "openapi": "3.0.0",
+            "info": {
+                "title": "Test API",
+                "version": "1.0.0"
+            },
+            "paths": {}
+        }
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".json", delete=False) as f:
+            json.dump(spec, f)
+            f.flush()
+
+            runner = CliRunner()
+            with runner.isolated_filesystem():
+                result = runner.invoke(serve, [f.name, "--host", "0.0.0.0", "--port", "9998", "--no-browser"])
+
+                assert result.exit_code != 0 or "9998" in result.output or "running" in result.output.lower()
+
+            os.unlink(f.name)
+
+
+class TestCLIIntegration:
+    """Integration tests for CLI commands."""
+
+    def test_full_parse_and_generate(self):
+        """Test complete parse and generate workflow."""
+        spec = {
+            "openapi": "3.0.0",
+            "info": {
+                "title": "Pet Store API",
+                "version": "1.0.0",
+                "description": "A sample pet store API"
+            },
+            "paths": {
+                "/pets": {
+                    "get": {
+                        "summary": "List all pets",
+                        "description": "Returns a list of all pets",
+                        "tags": ["pets"],
+                        "parameters": [
+                            {
+                                "name": "limit",
+                                "in": "query",
+                                "schema": {"type": "integer"},
+                                "description": "Maximum number of pets to return"
+                            }
+                        ],
+                        "responses": {
+                            "200": {
+                                "description": "A list of pets",
+                                "content": {
+                                    "application/json": {
+                                        "schema": {
+                                            "type": "array",
+                                            "items": {"type": "object"}
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    },
+                    "post": {
+                        "summary": "Create a pet",
+                        "tags": ["pets"],
+                        "requestBody": {
+                            "required": True,
+                            "content": {
+                                "application/json": {
+                                    "schema": {"type": "object"}
+                                }
+                            }
+                        },
+                        "responses": {
+                            "201": {"description": "Pet created"}
+                        }
+                    }
+                },
+                "/pets/{petId}": {
+                    "get": {
+                        "summary": "Get a pet",
+                        "tags": ["pets"],
+                        "parameters": [
+                            {
+                                "name": "petId",
+                                "in": "path",
+                                "required": True,
+                                "schema": {"type": "string"}
+                            }
+                        ],
+                        "responses": {
+                            "200": {"description": "Pet found"},
+                            "404": {"description": "Pet not found"}
+                        }
+                    },
+                    "delete": {
+                        "summary": "Delete a pet",
+                        "tags": ["pets"],
+                        "parameters": [
+                            {
+                                "name": "petId",
+                                "in": "path",
+                                "required": True,
+                                "schema": {"type": "string"}
+                            }
+                        ],
+                        "responses": {
+                            "204": {"description": "Pet deleted"}
+                        }
+                    }
+                }
+            },
+            "components": {
+                "schemas": {
+                    "Pet": {
+                        "type": "object",
+                        "properties": {
+                            "id": {"type": "string"},
+                            "name": {"type": "string"},
+                            "type": {"type": "string"}
+                        }
+                    }
+                }
+            }
+        }
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".json", delete=False) as f:
+            json.dump(spec, f)
+            f.flush()
+
+            runner = CliRunner()
+
+            validate_result = runner.invoke(validate, [f.name])
+            assert validate_result.exit_code == 0
+
+            with runner.isolated_filesystem():
+                generate_result = runner.invoke(generate, [f.name, "--format", "html"])
+                assert generate_result.exit_code == 0
+
+                search_result = runner.invoke(search, [f.name, "pet"])
+                assert search_result.exit_code == 0
+
+            os.unlink(f.name)