14 Jan 2024
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Building a Secure API Gateway: A Step-by-Step Guide

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By Tyrone Showers
Co-Founder Taliferro


The API Gateway plays a pivotal role as the gatekeeper to your APIs. It acts as a reverse proxy, routing requests from clients to various microservices. More importantly, it ensures these interactions are secure and efficient. In this guide, we'll walk you through the steps to build a secure API Gateway, which is crucial for safeguarding your data and services.

1. Understanding the API Gateway

Before diving into the setup, it's important to understand what an API Gateway does. It manages request routing, composition, and protocol translation, often providing security, monitoring, and load balancing as well.

2. Setting Up Your API Gateway

The first step in building an API Gateway is to set it up on your preferred platform, such as AWS, Azure, or Google Cloud.

  • Create a REST API

    aws apigateway create-rest-api --name 'MyAPI' --description 'My First API Gateway'

  • Get the Root Resource ID

    aws apigateway get-resources --rest-api-id <restApiId>

  • Create a New Resource (e.g., /myresource)

    aws apigateway create-resource --rest-api-id <restApiId> --parent-id <rootResourceId> --path-part myresource

  • Create a GET Method on the New Resource

    aws apigateway put-method --rest-api-id <restApiId> --resource-id <resourceId> --http-method GET --authorization-type NONE

  • Set the Lambda Function as the GET Method's Integration

    aws apigateway put-integration --rest-api-id <restApiId> --resource-id <resourceId> --http-method GET --type AWS_PROXY --integration-http-method POST --uri 'arn:aws:apigateway:<region>:lambda:path/2015-03-31/functions/<lambdaFunctionArn>/invocations'

  • Deploy the API

    aws apigateway create-deployment --rest-api-id <restApiId> --stage-name dev

3. Enabling Cross-Origin Resource Sharing (CORS)

Once your gateway is up, the next step is to configure CORS if your API is to be accessed from different domains. This is crucial for web applications that interact with APIs hosted on different domains.

  • Enable CORS on a Specific Resource

    aws apigateway put-method --rest-api-id <restApiId> --resource-id <resourceId> --http-method OPTIONS --authorization-type NONE --request-parameters method.request.header.Access-Control-Request-Headers=false,method.request.header.Access-Control-Request-Method=false

  • Set Up the Mock Integration for the OPTIONS Method

    aws apigateway put-integration --rest-api-id <restApiId> --resource-id <resourceId> --http-method OPTIONS --type MOCK --request-templates '{"application/json": "{\"statusCode\": 200}" }'

  • Add the Necessary Response Headers

    aws apigateway put-method-response --rest-api-id <restApiId> --resource-id <resourceId> --http-method OPTIONS --status-code 200 --response-parameters method.response.header.Access-Control-Allow-Headers=false,method.response.header.Access-Control-Allow-Methods=false,method.response.header.Access-Control-Allow-Origin=false

    aws apigateway put-integration-response --rest-api-id <restApiId> --resource-id <resourceId> --http-method OPTIONS --status-code 200 --response-templates '{"application/json": ""}' --response-parameters method.response.header.Access-Control-Allow-Headers="'Content-Type,X-Amz-Date,Authorization,X-Api-Key,X-Amz-Security-Token'",method.response.header.Access-Control-Allow-Methods="'GET,POST,OPTIONS'",method.response.header.Access-Control-Allow-Origin="'*'"

  • Deploy the API

    aws apigateway create-deployment --rest-api-id <restApiId> --stage-name dev

4. Securing with API Keys

API keys are a simple yet effective way to control access to your API Gateway. They help in identifying the clients using your API and can be used to implement throttling and quota limits.

5. Implementing Rate Limiting

To protect your API from overuse and potential DDoS attacks, rate limiting is essential. It controls the number of requests a user can make in a given period.

  • Create a Usage Plan

    aws apigateway create-usage-plan --name 'MyUsagePlan' --description 'Usage plan with rate limit' --throttle "burstLimit=100, rateLimit=50"

  • Associate the Usage Plan with a Specific API Stage

    aws apigateway update-usage-plan --usage-plan-id <usagePlanId> --patch-operations op='add',path='/apiStages',value='<restApiId>:<stageName>'

  • Create API Keys (Optional)

    aws apigateway create-api-key --name 'ClientApiKey' --enabled

  • Associate API Key with the Usage Plan

    aws apigateway create-usage-plan-key --usage-plan-id <usagePlanId> --key-id <apiKeyId> --key-type 'API_KEY'

  • Deploy the API

    aws apigateway create-deployment --rest-api-id <restApiId> --stage-name dev

6. OAuth Integration for User Authentication

For APIs that require user-specific data, OAuth provides a secure and efficient way to authenticate and authorize users. It delegates user authentication to the service hosting the user account.

7. Logging and Monitoring

Monitoring your API Gateway is vital for security and performance optimization. Logging each request and response helps in identifying patterns, potential threats, and areas for improvement.

  • Create or Identify an IAM Role for Logging

    aws iam create-role --role-name 'ApiGatewayLogsRole' --assume-role-policy-document file://TrustPolicyForAPIGateway.json

  • Attach Policy to IAM Role

    aws iam attach-role-policy --role-name 'ApiGatewayLogsRole' --policy-arn 'arn:aws:iam::aws:policy/service-role/AmazonAPIGatewayPushToCloudWatchLogs'

  • Enable Access Logging on API Gateway Stage

    aws apigateway update-stage --rest-api-id  --stage-name  --patch-operations op='replace',path='/accessLogSettings/destinationArn',value='arn:aws:logs:::log-group:',op='replace',path='/accessLogSettings/format',value='$context.identity.sourceIp - $context.identity.caller - [$context.requestTime] "$context.httpMethod $context.resourcePath $context.protocol" $context.status $context.responseLength $context.requestId'

  • Enable Execution Logging (Optional)

    aws apigateway update-stage --rest-api-id <restApiId> --stage-name <stageName> --patch-operations op='replace',path='/*/*/logging/loglevel',value='INFO'

  • Create a CloudWatch Log Group (If Not Already Exists)

    aws logs create-log-group --log-group-name <logGroupName>

  • Deploy the API

    aws apigateway create-deployment --rest-api-id <restApiId>

    Replace `<restApiId>` and `<stageName>` with your API ID and the stage name respectively.

    This setup will enable both access logging and execution logging for your API Gateway, directing the logs to the specified CloudWatch log group. Access logging provides basic information about each request, such as the requester's IP and request/response size, while execution logging offers more detailed insight into each step of the API execution process.
    Remember, effective logging and monitoring are key to maintaining a secure and efficient API. These logs can be invaluable for diagnosing issues, analyzing user behavior, and detecting anomalies that might indicate security threats. With AWS CloudWatch, you also have the option to set up alarms and notifications based on specific log patterns or metrics, further enhancing your monitoring capabilities.

8. Custom Error Handling

Good error handling improves the reliability of your API Gateway. It should provide clear, informative error messages to the client in case of failures.

9. Regularly Update and Maintain

The world of web security is always evolving. Regular updates and maintenance are crucial for ensuring your API Gateway remains secure against new vulnerabilities.

10. Testing Your API Gateway

Once everything is set up, thorough testing is essential. Ensure all security measures work as intended, and the gateway efficiently manages the load.


Building a secure API Gateway is a nuanced process that plays a critical role in the protection and efficiency of your web services. By following these steps and implementing the recommended security measures, you can create a robust and reliable gateway for your API. This gateway will not only safeguard your data but also enhance the overall user experience by ensuring smooth, secure, and efficient interactions with your APIs.

Remember, security is an ongoing process. Regularly updating your API Gateway, monitoring its performance, and adapting to new security threats are key to maintaining a secure digital environment. As you implement these steps, keep in mind the evolving nature of web technologies and cybersecurity threats. Stay informed and be ready to adapt, ensuring your API Gateway remains a strong link in your cybersecurity chain.

In summary, a secure API Gateway is essential for any modern web application dealing with sensitive data or requiring controlled access. By taking these steps, you'll be well on your way to creating a gateway that not only meets current security standards but is also prepared for future challenges. Embrace these best practices, and ensure your API Gateway is a testament to your commitment to security and excellence in the digital realm.

Tyrone Showers