API Gateway Concepts

Used for creating, publishing, maintaining, monitoring, and securing REST and WebSocket APIs at any scale.
Create APIs to access AWS or other web services
create APIs for use in client applications
Also, make APIs available to third-party developers.
Support for stateful or WebSocket and stateless or REST APIs.
Authentication by AWS IAM policies, Lambda authorizer functions, and Amazon Cognito user pools.
Developer portal for publishing your APIs.
Canary release deployments for safely rolling out changes.
Integrate with CloudTrail logging and monitoring of API usage and API changes.
Support for custom domain names.
Create REST APIs that:
- Are HTTP-based.
- Adhere to the REST protocol, which enables stateless client-server communication.
- Implement standard HTTP methods such as GET, POST, PUT, PATCH and DELETE.
create WebSocket APIs
- Adhere to the WebSocket protocol, which enables stateful, full-duplex communication between client and server.
- Route incoming messages and based on message content.

Architecture

API Gateway handles accepting and processing up to hundreds of thousands of concurrent API calls,
It manages
- traffic management
- authorization
- access control
- monitoring
- API version management

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