When building an application that exposes a REST API, it's crucial to support the full set of HTTP methods - GET, POST, PUT, PATCH, and DELETE. While it may be tempting to only implement a subset for simplicity, doing so severely limits the functionality and flexibility of your API. Here's why you need all 5:

GET - For Retrieving Data The GET method is the foundation of any REST API. It allows clients to retrieve representations of resources, such as fetching a list of products or getting the details of a specific order. GET requests should be idempotent, meaning multiple identical requests should return the same data.

POST - For Creating New Resources To create new resources on the server, the POST method is essential. A POST request contains all data necessary for creating the new resource in the request body. Common use cases include creating a new user account or placing a new order.

PUT - For Updating Resources (Entire Representation) The PUT method allows clients to update an existing resource by replacing its entire representation. When issuing a PUT request, the entire updated resource representation is included in the request body. This method guarantees that the resource on the server matches the client's state after a successful request.

PATCH - For Partial Updates While PUT is great for complete representations, PATCH offers a way to update partial resource data. With PATCH, clients only need to send the properties that actually changed, making API calls more efficient. PATCH requests help reduce bandwidth usage and simplify the client-side code for handling updates.

DELETE - For Removing Resources As its name implies, the DELETE method allows clients to remove or delete a resource identified by a URI. Implementing DELETE ensures your API provides complete transparency and functionality to consumers when resources need to be removed from the system.

By supporting all five HTTP methods, your REST API enables complete Create, Read, Update, and Delete (CRUD) operations. This flexibility empowers API consumers to build full-featured clients that can comprehensively interact with resources on your server.

Neglecting any of these methods hamstrings your API capabilities. For instance, without PUT or PATCH, updating resources would be extremely limited. Without DELETE, you'd have no way to remove resources through the API. And of course, without GET or POST, reading or creating data would be impossible.

In summary, embracing GET, POST, PUT, PATCH, and DELETE unlocks the true power of REST APIs. It enables intuitive and consistent resource management while aligning with best practices and principles of RESTful design. For any API striving to be comprehensive and consumer-friendly, robust HTTP method support is essential.