feat: add stealth mode and enhance undetected browser support

- Add playwright-stealth integration with enable_stealth parameter in BrowserConfig
- Merge undetected browser strategy into main async_crawler_strategy.py using adapter pattern
- Add browser adapters (BrowserAdapter, PlaywrightAdapter, UndetectedAdapter) for flexible browser switching
- Update install.py to install both playwright and patchright browsers automatically
- Add comprehensive documentation for anti-bot features (stealth mode + undetected browser)
- Create examples demonstrating stealth mode usage and comparison tests
- Update pyproject.toml and requirements.txt with patchright>=1.49.0 and other dependencies
- Remove duplicate/unused dependencies (alphashape, cssselect, pyperclip, shapely, selenium)
- Add dependency checker tool in tests/check_dependencies.py

Breaking changes: None - all existing functionality preserved

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: unclecode

crawl4ai/__init__.py

@@ -88,6 +88,13 @@
     ErrorDetail
 )
 
+# Browser Adapters
+from .browser_adapter import (
+    BrowserAdapter,
+    PlaywrightAdapter,
+    UndetectedAdapter
+)
+
 from .utils import (
     start_colab_display_server,
     setup_colab_environment
@@ -173,6 +180,10 @@
     "CompilationResult",
     "ValidationResult",
     "ErrorDetail",
+    # Browser Adapters
+    "BrowserAdapter",
+    "PlaywrightAdapter", 
+    "UndetectedAdapter",
 ]
 
 

crawl4ai/async_configs.py

@@ -383,6 +383,8 @@ class BrowserConfig:
         light_mode (bool): Disables certain background features for performance gains. Default: False.
         extra_args (list): Additional command-line arguments passed to the browser.
                            Default: [].
+        enable_stealth (bool): If True, applies playwright-stealth to bypass basic bot detection.
+                              Cannot be used with use_undetected browser mode. Default: False.
     """
 
     def __init__(
@@ -423,6 +425,7 @@ def __init__(
         extra_args: list = None,
         debugging_port: int = 9222,
         host: str = "localhost",
+        enable_stealth: bool = False,
     ):
         self.browser_type = browser_type
         self.headless = headless 
@@ -463,6 +466,7 @@ def __init__(
         self.verbose = verbose
         self.debugging_port = debugging_port
         self.host = host
+        self.enable_stealth = enable_stealth
 
         fa_user_agenr_generator = ValidUAGenerator()
         if self.user_agent_mode == "random":
@@ -494,6 +498,13 @@ def __init__(
         # If persistent context is requested, ensure managed browser is enabled
         if self.use_persistent_context:
             self.use_managed_browser = True
+            
+        # Validate stealth configuration
+        if self.enable_stealth and self.use_managed_browser and self.browser_mode == "builtin":
+            raise ValueError(
+                "enable_stealth cannot be used with browser_mode='builtin'. "
+                "Stealth mode requires a dedicated browser instance."
+            )
 
     @staticmethod
     def from_kwargs(kwargs: dict) -> "BrowserConfig":
@@ -530,6 +541,7 @@ def from_kwargs(kwargs: dict) -> "BrowserConfig":
             extra_args=kwargs.get("extra_args", []),
             debugging_port=kwargs.get("debugging_port", 9222),
             host=kwargs.get("host", "localhost"),
+            enable_stealth=kwargs.get("enable_stealth", False),
         )
 
     def to_dict(self):
@@ -564,6 +576,7 @@ def to_dict(self):
             "verbose": self.verbose,
             "debugging_port": self.debugging_port,
             "host": self.host,
+            "enable_stealth": self.enable_stealth,
         }