First, create a custom route directory to your root. Originally I added my custom route files under
core/server/, but since it is going to be overwritten by updates on Ghost, it might be preferrable to make them agnostic about the core directory altogether.
Then, define your own custom routes in whatever way you want. Add routes, controllers, or middlewares, etc...
core/server/middleware/index.js and just after the line
blogApp.use('/ghost', adminApp);, import your own custom route files and add the routes there.
var customRoutes = require("../../../customRoutes/index.js"); customRoutes(blogApp);
And it should be done. Test it out in your own blog.