Application Programming Interfaces (API)

An API is a way for a computer program to communicate directly with another program

CRUD

• Create
• Read
• Update
• Delete

HTTP methods

• GET - retrieves data from an object
• PUT - adds information to an object
• POST - creates an object
• DELETE - removes an object
• PATCH - applies partial modifications to an object

REST Is an architecture, not a protocol. It gives guidelines for the structure and organization of an API.
It supports any transport and data format.
HTTP(S) transport and JSON or XML data formats are commonly used.
It typically has faster performance and is easier to work with than SOAP.

• It should be a client-server architecture: the client sends a request, the server sends a response
• Uniform interface: provides simplicity
• Statelessness: no client context is stored on the server between request
• Cacheability: responses must define themselves
• Layered system: any intermediary devices such as load balancers must be transparent to the client and server
• Code on demand (optional): server can temporarily extend or customize the functionality of a client by transferring executable code

REST Authentication Types

• No auth
• Basic Authentication: Username and password sent in plain text
• API Key: Uses encrypted tokens, usually created in admin portal. The same user can request tokens with different permission. The server must check the API key permissions on every client request.
• Bearer Token: Basic or API Key authentication user request encrypted Bearer Token which is the automatically included in other requests. Permissions are embedded in the token so it puts less load on server than API Key.

REST Request URL

https://demo.app.com|/api/running/aaa/users/pablo|?dryrun

1xx: Informational
2xx: Success
200: OK
201: Created
204: No Content (deleted)
3xx: Redirection

4xx: Client Error
400: Bad request
401: Unauthorized
403: Forbidden
404: Not Found

5xx: Server Error
500: Internal Server Error