API


A	Application
P	Programming
I	Interface

Allows other programs or application to use functionality that you expose:

Functions
Protocols
Objects

Weather Data Example

Request:

GET https://www.7timer.info/bin/astro.php
?lon=15.593063
&lat=48.411018
&ac=0
&unit=metric
&output=json

Response:

HTTP/1.1 200 OK
Content-Type: application/json

{
  "product": "civil",
  "init": "2023070206",
  "dataseries": [
    {
      "cloudcover": 7,
      "temp2m": 21,
      "rh2m": "63%",
      "wind10m": {
      "direction": "W",
      "speed": 3
    },
    ...
  ]
}

API Use-Cases

Frontend - Backend Communication
Component Comunication
- e.g. One Service calls another service
DaaS

Frontend-Backend

API_Frontend_Backend Using APIs, you can link any software parts, potentially using different technologies, as long as they support the same protocol.

Component Communication

API_Component_Communication

Protocols

There are several common protocols used in APIs.

API_Communication_Protocols

Attributes of protocols

Protocols …

allow exchange of messages and information between 2 processes.
- Processes don’t need to be on the same physical machine. Can be distributed and communicate over network.
are open to any technology or programming language.
have a clear specification.