Serverless Developer Guide
What is API Gateway?
Amazon API Gateway is an AWS service for creating, publishing, maintaining, monitoring, and 
securing REST, HTTP, and WebSocket APIs. API Gateway can transform inbound web requests into
events that are processed by Lambda functions, AWS services, and HTTP endpoints.
API Gateway can process many concurrent API calls and provides additional management 
capabilities, including:
• Authorization, authentication, and API Keys for access control
• Documentation and version control
• OpenAPI 3.0 import and export
Although similar in purpose, the REST API and HTTP API conﬁguration and management console 
experiences are quite diﬀerent. WebSocket APIs are included in the advanced section, as they are 
less frequently used when starting out.
• REST API conﬁguration models resources with Client, Method request, Integration Request, 
Integration endpoint, Integration Response, Method Response, return to Client.
• HTTP API conﬁguration models routes with a tree of HTTP methods and associated integration 
conﬁguration.
Important
Unless otherwise stated, REST APIs are discussed in the fundamentals.
Fundamentals
An API (Application Program Interface) is a collection of endpoints that connect to your application 
logic. You may already be familiar with creating APIs in traditional frameworks. This section will 
introduce how the concepts map to API Gateway.
Core Concepts
You can choose to get started with the core concepts in a workshop or tutorial, or read through the 
high level concepts here.
What is API Gateway? 62