Use the --no-gitignore flag

https://docs.railway.com/reference/cli-api#up:~:text=to%20linked%20environment)-,%2D%2Dno%2Dgitignore,-Don%27t%20ignore%20paths-,%2D%2Dno%2Dgitignore,-Don%27t%20ignore%20paths)

Thanks! That would work if I wanted to un-ignore all the ignored files, but I only want to deploy a subset. My current workaround is just to use a script in my CI that removes that line from the .gitignore for deployment.

Add a .railwayignore file for any files you want only railway up to ignore, and then use the --no-gitignore flag so that the CLI will only ignore what you have set in your .railwayignore file.