resolvers.js

const resolvers = {
  Query: {
    getFoo: (_, { id }, context) => 
      context.dataSources.myFoos.get(id, { ttlInSeconds: 60 })
  },
  Mutation: {
    updateFoo: async (_, { id, fields }, context) => {
      if (context.isAdmin) {
        context.dataSources.myFoos.updateFields(id, fields)
      }
    }
  }
}