We're currently uploading each new version of our extension via https://addons.opera.com/developer/
Because we need to do similar tasks for Chrome and Firefox, the whole lot becomes tedious and error-prone. Is there a way to automate this, similar to the Chrome Store Publish API?
Opera Addons Dev here. This panel does operate using REST api.
You can see what requests are being made in the background and try to mimic them.
You need to be authenticated in order to do that though.
Any script that preserves cookies and does authentication in https://auth.opera.com should be fine.