We don’t entirely support typescript currently, and it’s something we are looking into. For the moment we don’t really have any suggestions on implementing it at a project level.
See:
https://github.com/strapi/strapi/issues/630
Some have already tried/started to implement it:
https://github.com/strapi/strapi/pull/8652
https://github.com/strapi/strapi/pull/7803
https://github.com/strapi/strapi/pull/6550
But we are still doing some internal discussion and right now it’s not a priority for us. We would rather do it -right- than -fast-