If for some reason you want to know when a project was added to CircleCI, you can do the following.
With API auth configured (a token, or no token required via a logged in browser),
jq, you can run the following:
curl "https://circleci.com/api/v1.1/project/github/<org>/<repo>/1" | jq .steps.actions.start_time # Replace <org> with your GitHub org and # replace <repo> with your project's repository name.
For example, for my person website Feliciano.Tech (which is open source) you can run:
curl "https://circleci.com/api/v1.1/project/github/felicianotech/www.feliciano.tech/1" | jq .steps.actions.start_time % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 100 20160 100 20160 0 0 146k 0 --:--:-- --:--:-- --:--:-- 146k "2016-12-18T23:15:03.450Z"
My website’s first CircleCI build was December 18th, 2016 at 11:15pm UTC.