Apps talking to apps.
An API is a menu another system offers: send a request in the right shape, get data back. Five parts to recognise.
Anatomy Of A Request
Endpoint
The address you send the request to.
Method
GET reads, POST creates, PATCH updates, DELETE removes.
Key
Proves who's asking. A secret.
Response
The data back, usually as JSON.
Status code
The one-number verdict. See right.
Status Codes
200
All good
401
Not allowed: check the key
404
Wrong address
429
Too many requests
500
Their server broke
Source: MDN ↗
Know the address, the key and the limits.