diff --git a/ra_aid/__main__.py b/ra_aid/__main__.py
index cf4fdb8..cbe7f75 100644
--- a/ra_aid/__main__.py
+++ b/ra_aid/__main__.py
@@ -298,95 +298,6 @@ def run_research_subtasks(base_task: str, config: dict, model, expert_enabled: b
         run_agent_with_retry(subtask_agent, subtask_prompt, config)
 
 
-def validate_environment(args):
-    """Validate required environment variables and dependencies.
-    
-    Args:
-        args: The parsed command line arguments
-        
-    Returns:
-        (expert_enabled, missing_expert_info): Tuple of bool indicating if expert is enabled, and list of missing expert info
-    """
-    missing = []
-    provider = args.provider
-    expert_provider = args.expert_provider
-
-    # Check API keys based on provider
-    if provider == "anthropic":
-        if not os.environ.get('ANTHROPIC_API_KEY'):
-            missing.append('ANTHROPIC_API_KEY environment variable is not set')
-    elif provider == "openai":
-        if not os.environ.get('OPENAI_API_KEY'):
-            missing.append('OPENAI_API_KEY environment variable is not set')
-    elif provider == "openrouter":
-        if not os.environ.get('OPENROUTER_API_KEY'):
-            missing.append('OPENROUTER_API_KEY environment variable is not set')
-    elif provider == "openai-compatible":
-        if not os.environ.get('OPENAI_API_KEY'):
-            missing.append('OPENAI_API_KEY environment variable is not set')
-        if not os.environ.get('OPENAI_API_BASE'):
-            missing.append('OPENAI_API_BASE environment variable is not set')
-
-    expert_missing = []
-    # Check expert provider keys with fallback
-    if expert_provider == "anthropic":
-        expert_key_missing = not os.environ.get('EXPERT_ANTHROPIC_API_KEY')
-        fallback_available = expert_provider == provider and os.environ.get('ANTHROPIC_API_KEY')
-        if expert_key_missing and fallback_available:
-            os.environ['EXPERT_ANTHROPIC_API_KEY'] = os.environ['ANTHROPIC_API_KEY']
-            expert_key_missing = False
-        if expert_key_missing:
-            expert_missing.append('EXPERT_ANTHROPIC_API_KEY environment variable is not set')
-
-    elif expert_provider == "openai":
-        expert_key_missing = not os.environ.get('EXPERT_OPENAI_API_KEY')
-        fallback_available = expert_provider == provider and os.environ.get('OPENAI_API_KEY')
-        if expert_key_missing and fallback_available:
-            os.environ['EXPERT_OPENAI_API_KEY'] = os.environ['OPENAI_API_KEY']
-            expert_key_missing = False
-        if expert_key_missing:
-            expert_missing.append('EXPERT_OPENAI_API_KEY environment variable is not set')
-
-    elif expert_provider == "openrouter":
-        expert_key_missing = not os.environ.get('EXPERT_OPENROUTER_API_KEY')
-        fallback_available = expert_provider == provider and os.environ.get('OPENROUTER_API_KEY')
-        if expert_key_missing and fallback_available:
-            os.environ['EXPERT_OPENROUTER_API_KEY'] = os.environ['OPENROUTER_API_KEY']
-            expert_key_missing = False
-        if expert_key_missing:
-            expert_missing.append('EXPERT_OPENROUTER_API_KEY environment variable is not set')
-
-    elif expert_provider == "openai-compatible":
-        expert_key_missing = not os.environ.get('EXPERT_OPENAI_API_KEY')
-        fallback_available = expert_provider == provider and os.environ.get('OPENAI_API_KEY')
-        if expert_key_missing and fallback_available:
-            os.environ['EXPERT_OPENAI_API_KEY'] = os.environ['OPENAI_API_KEY']
-            expert_key_missing = False
-        if expert_key_missing:
-            expert_missing.append('EXPERT_OPENAI_API_KEY environment variable is not set')
-            
-        expert_base_missing = not os.environ.get('EXPERT_OPENAI_API_BASE')
-        base_fallback_available = expert_provider == provider and os.environ.get('OPENAI_API_BASE')
-        if expert_base_missing and base_fallback_available:
-            os.environ['EXPERT_OPENAI_API_BASE'] = os.environ['OPENAI_API_BASE']
-            expert_base_missing = False
-        if expert_base_missing:
-            expert_missing.append('EXPERT_OPENAI_API_BASE environment variable is not set')
-
-
-    # If main keys missing, we must exit immediately
-    if missing:
-        print_error("Missing required dependencies:")
-        for item in missing:
-            print_error(f"- {item}")
-        sys.exit(1)
-
-    # If expert keys missing, we disable expert tools instead of exiting
-    expert_enabled = True
-    if expert_missing:
-        expert_enabled = False
-
-    return expert_enabled, expert_missing
 
 def main():
     """Main entry point for the ra-aid command line tool."""