# REST Standard
source: https://developer.mastercard.com/mastercard-processing-core/documentation/api-basics-section/rest-standard/index.md

The Mastercard Processing APIs follow Representational State Transfer (REST) principles. The APIs have predictable resource-oriented URLs, accept JavaScript Object Notation ([JSON](https://www.json.org/json-en.html)) request bodies, return JSON-encoded responses, and use standard Hypertext Transfer Protocol (HTTP) response codes, authentication, and verbs.

The Mastercard Processing APIs send `POST`, `GET`, `PUT`, and `PATCH` requests to endpoints (for example, `/cards`) to communicate and HTTP response codes to indicate status and errors.

The Mastercard Processing APIs use HTTPS to ensure data privacy, but HTTPS with TLS versions below v1.2 are not supported. All requests must include the header `Content-Type` of `application/json`, and the body must be a valid JSON object.