示例

以下示例显示了一个可以同时处理请求和响应拦截器类型的 Python Lambda 函数。REQUEST 拦截器记录 MCP 方法并原封不动地传递请求，而 RESPONSE 拦截器则原封不动地传递响应。

Pass-through 拦截器

此示例演示了一个简单的拦截器，该拦截器记录请求拦截器的 MCP 方法，并未更改地传递所有请求和响应：

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

可以将此 Lambda 函数配置为请求和响应拦截器。当配置为请求拦截器时，它将记录来自传入请求的 MCP 方法。当配置为 RESPONSE 拦截器时，它只会原封不动地传递响应。两种拦截器类型均不加修改地返回原始数据，这使其成为 “直通” 拦截器。