标签：#httpapi

There is common point of confusion. what's the different between REST API vs. HTTP API in AWS and what's the different between them and a traditional Rest API you write with e.g express in node in the broader software world, a "REST API" is just an architectural pattern built on top of HTTP requests. The confusion comes entirely from AWS-specific marketing terminology . When you are inside the AWS ecosystem, Amazon API Gateway is a specific managed service, and AWS chose to split that service into two different flavors (or software products): one called "REST API" and one called "HTTP API." Here is exactly how they work under the hood, how they differ internally, and how it compares to traditional servers. 1. How It Works: REST API vs. HTTP API (AWS Architecture) Think of Amazon API Gateway as a reverse proxy or a "front door" that sits in front of your Lambda functions. AWS REST API (The Heavyweight) When a request hits an AWS REST API, AWS passes that request through a massive feature pipeline before it ever touches your Lambda code. [Client Request] ──> [Authentication (Cognito/IAM)] ──> [Request Validation] ──> [Data Transformation (VTL)] ──> [Your Lambda] What happens: AWS decrypts the request, validates the JSON schema, checks API keys, runs any custom request transformations using a complex mapping language called VTL, and then invokes your Lambda function. Why it costs more: You are paying AWS for all that computing power happening inside the API Gateway layer itself. AWS HTTP API (The Express Lane) When a request hits an AWS HTTP API, AWS strips out almost the entire middle pipeline. [Client Request] ──> [JWT/OAuth2 Authorization Only] ──> [Your Lambda] What happens: The HTTP API acts as a lightning-fast router. It optionally checks a standard JWT token, converts the incoming HTTP request directly into a clean JSON object, and throws it straight into your Lambda function. Why it costs less: Because AWS is doing almost zero processing or data manipulation. Y