Codeforces
Get access to Codeforces data
Programming · API key · HTTPS
Programming APIs
5 API records with directory-reported descriptions, access facts, and source links.
Hackerearth
For compiling and running code in several languages
Programming · API key · HTTPS
Judge0 CE
Online code execution system
Programming · API key · HTTPS
KONTESTS
For upcoming and ongoing competitive coding contests
Programming · No auth · HTTPS
Mintlify
For programmatically generating documentation for code
Programming · API key · HTTPS