To have all the upcoming contests from all or codechef , codeforces , atcoder just put get request on the belowe url:

1. All Sites Data: https://backend-api-project.vercel.app/all
2. Codechef: https://backend-api-project.vercel.app/codechef
3. Codeforces: https://backend-api-project.vercel.app/codeforces
4. Atcoder: https://backend-api-project.vercel.app/atcoder

You will get data having following format:

1. name : string
2. url : string
3. start_time :string
4. end_time : string