Request, Response, and Status Codes
Explore the fundamentals of API requests and responses and the NestJS request life cycle.
We'll cover the following...
Request-response model
The request-response model is a communication pattern where a client sends an HTTP request to a server, and the server processes the request and returns an HTTP response containing the requested data. This model forms the core mechanism for client-server interactions in REST architecture, allowing clients to request resources or trigger actions on the server via well-defined API endpoints.
This lesson will explore the request-response model in the context of NestJS and RESTful API development.
Request
An HTTP request is a mechanism for a client to interact with the resources from the server. HTTP works based on the request-response model.
Below is a request and response example—a client app requests a to-do list from a RESTful API server, and the server returns a response with a list of to-do items in JSON format.
The request includes headers that provide additional information to the server, such as content type or authentication credentials.
Different HTTP request methods can perform different operations on the resources in RESTful APIs. They are listed below:
HTTP Request Method Operations
HTTP Method | Operation | Example |
GET | Read | GET /api/todo/1 |
POST | Create | POST /api/todo |
PUT | Update | PUT /api/todo/1 |
PATH | Update | PATCH /api/todo/1 |
DELETE | Delete | DELETE /api/todo/1 |