Qiita API v2 does NOT support user-contributions officially. This API scrapes user-contributions on Qiita.
$ curl https://us-central1-charismatic-web-161410.cloudfunctions.net/qiita-contributions-api?user=takeo-asai{
"id": "takeo-asai",
"contributions": "303"
}cloud-functions-emulator is needed for test on a local machine
$ functions start
$ functions deploy qiitaContributions --trigger-http$ curl http://localhost:8010/qiitaContributions/us-central1/qiitaContributions?user=takeo-asai