I found one other way to use types across modules. /* @flow */ var Person; type Person = {name: {first: string; last: string;}; isActive: boole

I found one other way to use types across modules. /* @flow */ var Person; type Person = {name: {first: string; last: string;}; isActive: boolean;} module.exports.Person = Person Just by writing that var you can use the type across modules.