How to know if the deployment was triggered manually from netlify site

I’ve created a build plugin that compares changes in projects to minimize deployment costs.

so sometimes users need to redeploy their site and my plugin blocked them.
I am wondering what is the trigger that can help to proceed with the deployment if it can by Netlify UI.

for further information
plugin link

Hey @f22hd,

This won’t be possible when triggering the build manually from the UI. There is no information in a plugin that would allow it to determine the source of the build. A plugin can read environment variables, but you’d have to add that variable each time you wish to deploy a change. Not sure if you want to go down that path.

Finally, you can use build hooks to trigger builds that could have some environment information attached to them.