diff --git a/Dockerfile b/Dockerfile
index 5b4a588..1751362 100755
--- a/Dockerfile
+++ b/Dockerfile
@@ -31,9 +31,7 @@ ENV FUNCTION_COMMAND="python"
 # Args to start the evaluation function with
 ENV FUNCTION_ARGS="-m,evaluation_function.main"
 
-# Use file-based communication interface instead of RPC
-# This handles larger payloads better (shimmy writes input to file, reads output from file)
-# shimmy will append input/output file paths as the last two arguments
-ENV FUNCTION_INTERFACE="file"
+# The transport to use for the RPC server
+ENV FUNCTION_RPC_TRANSPORT="ipc"
 
 ENV LOG_LEVEL="debug"
diff --git a/evaluation_function/main.py b/evaluation_function/main.py
index ae972f4..9375f86 100644
--- a/evaluation_function/main.py
+++ b/evaluation_function/main.py
@@ -1,127 +1,18 @@
-"""
-Main entry point for the FSA evaluation function.
-
-Supports two communication modes with shimmy:
-1. File-based (recommended for large payloads): shimmy passes input/output file paths as args
-2. RPC/IPC (default): Uses lf_toolkit's server for stdio/IPC communication
-"""
-
-import sys
-import json
-from typing import Any, Dict
 
 from lf_toolkit import create_server, run
-from lf_toolkit.evaluation import Params, Result as LFResult
 
 from .evaluation import evaluation_function
 from .preview import preview_function
 
-
-def handle_file_based_communication(input_path: str, output_path: str) -> None:
-    """
-    Handle file-based communication with shimmy.
-    
-    Reads input JSON from input_path, processes it, and writes result to output_path.
-    This is used when shimmy is configured with --interface file.
-    
-    Args:
-        input_path: Path to the input JSON file
-        output_path: Path to write the output JSON file
-    """
-    # Read input from file
-    with open(input_path, 'r', encoding='utf-8') as f:
-        input_data = json.load(f)
-    
-    # Extract command and request data
-    command = input_data.get('command', 'eval')
-    request_id = input_data.get('$id')
-    
-    # Build response structure
-    response_data: Dict[str, Any] = {}
-    if request_id is not None:
-        response_data['$id'] = request_id
-    response_data['command'] = command
-    
-    try:
-        if command == 'eval':
-            # Extract evaluation inputs
-            response = input_data.get('response')
-            answer = input_data.get('answer')
-            params_dict = input_data.get('params', {})
-            
-            # Create params object
-            params = Params(**params_dict) if params_dict else Params()
-            
-            # Call evaluation function
-            result = evaluation_function(response, answer, params)
-            
-            # Convert result to dict
-            if hasattr(result, 'to_dict'):
-                response_data['result'] = result.to_dict()
-            elif isinstance(result, dict):
-                response_data['result'] = result
-            else:
-                response_data['result'] = {'is_correct': False, 'feedback': str(result)}
-                
-        elif command == 'preview':
-            # Extract preview inputs
-            response = input_data.get('response')
-            params_dict = input_data.get('params', {})
-            
-            params = Params(**params_dict) if params_dict else Params()
-            
-            # Call preview function
-            result = preview_function(response, params)
-            
-            if hasattr(result, 'to_dict'):
-                response_data['result'] = result.to_dict()
-            elif isinstance(result, dict):
-                response_data['result'] = result
-            else:
-                response_data['result'] = {'preview': str(result)}
-                
-        else:
-            response_data['result'] = {
-                'is_correct': False,
-                'feedback': f'Unknown command: {command}'
-            }
-            
-    except Exception as e:
-        response_data['result'] = {
-            'is_correct': False,
-            'feedback': f'Error processing request: {str(e)}'
-        }
-    
-    # Write output to file
-    with open(output_path, 'w', encoding='utf-8') as f:
-        json.dump(response_data, f, ensure_ascii=False)
-
-
 def main():
+    """Run the IPC server with the evaluation and preview functions.
     """
-    Run the evaluation function.
-    
-    Detects communication mode based on command-line arguments:
-    - If 2+ args provided: File-based communication (last 2 args are input/output paths)
-    - Otherwise: RPC/IPC server mode using lf_toolkit
-    """
-    # Check for file-based communication
-    # shimmy passes input and output file paths as the last two arguments
-    if len(sys.argv) >= 3:
-        input_path = sys.argv[-2]
-        output_path = sys.argv[-1]
-        
-        # Verify they look like file paths (basic check)
-        if not input_path.startswith('-') and not output_path.startswith('-'):
-            handle_file_based_communication(input_path, output_path)
-            return
-    
-    # Fall back to RPC/IPC server mode
     server = create_server()
+
     server.eval(evaluation_function)
     server.preview(preview_function)
-    run(server)
 
+    run(server)
 
 if __name__ == "__main__":
     main()
\ No newline at end of file