The COAP API return appropriate COAP status codes for every request.

2.01

Created

2.02

Deleted

2.03

Valid

2.04

Changed

2.05

Content

4.00

Bad Request

4.01

Unauthorized

4.03

Forbidden

4.04

Not Found

4.08

Request Entity Incomplete

4.12

Precondition Failed

4.13

Request Entity Too Large

5.00

Internal Server Error

5.02

Bad Gateway

5.03

Service Unavailable

5.04

Gateway Timeout