範例

下列範例顯示 Python Lambda 函數，可同時處理 REQUEST 和 RESPONSE 攔截器類型。REQUEST 攔截器會記錄 MCP 方法並傳遞請求不變，而 RESPONSE 攔截器則會傳遞回應不變。

傳遞攔截器

此範例示範一個簡單的攔截器，記錄 REQUEST 攔截器的 MCP 方法，並透過不變的方式傳遞所有請求和回應：

import json
import logging

# Configure logging
logger = logging.getLogger()
logger.setLevel(logging.INFO)

def lambda_handler(event, context):
    """
    Lambda function that handles both REQUEST and RESPONSE interceptor types.

    For REQUEST interceptors: logs the MCP method and passes request through unchanged
    For RESPONSE interceptors: passes response through unchanged
    """
    # Extract the MCP data from the event
    mcp_data = event.get('mcp', {})

    # Check if this is a REQUEST or RESPONSE interceptor based on presence of gatewayResponse
    if 'gatewayResponse' in mcp_data and mcp_data['gatewayResponse'] != None:
        # This is a RESPONSE interceptor
        logger.info("Processing RESPONSE interceptor - passing through unchanged")

        # Pass through the original request and response unchanged
        response = {
          "interceptorOutputVersion": "1.0",
          "mcp": {
              "transformedGatewayResponse": {
                  "body": mcp_data.get('gatewayResponse', {}).get('body', {}),
                  "statusCode": mcp_data.get('gatewayResponse', {}).get('statusCode', 200)
              }
          }
        }
    else:
        # This is a REQUEST interceptor
        gateway_request = mcp_data.get('gatewayRequest', {})
        request_body = gateway_request.get('body', {})
        mcp_method = request_body.get('method', 'unknown')

        # Log the MCP method
        logger.info(f"Processing REQUEST interceptor - MCP method: {mcp_method}")

        # Pass through the original request unchanged
        response = {
          "interceptorOutputVersion": "1.0",
          "mcp": {
              "transformedGatewayRequest": {
                  "body": request_body,
              }
          }
        }

    return response

此 Lambda 函數可以同時設定為 REQUEST 和 RESPONSE 攔截器。當設定為 REQUEST 攔截器時，它會記錄來自傳入請求的 MCP 方法。設定為 RESPONSE 攔截器時，只會傳遞未變更的回應。這兩種攔截器類型都會在不修改的情況下傳回原始資料，使其成為「傳遞」攔截器。