I'm trying to use Trello API to create cards on our boards. But i cannot really bypass authentication programmatically, because a user prompt always appears asking for authentication in trello.
The idea is i create a system user on trello, add it to the boards, then use its API key to create the cards. I'm following this approach because I used Zapier to generate cards from Freshdesk, and wondering how Zapier bypass OAuth to do this.
You simply cannot bypass the authentication of the API, however what you can do is to generate the valid oAuth tokens for your "System User" and use them for authentication.
I'm not aware of the complete Auth process of trello, but most oAuth providers give you the possiblity to create tokens which last quite long (refresh tokens). You could use these in your code to call the api without any additional auth process.
You could also store the normal auth tokens and re-validate them from time to time using the prompt.
Best solution depends on what you are trying to achieve...