tamagui.config.ts

import { config } from "@tamagui/config"

import { createTamagui } from "tamagui"
const tamaguiConfig = createTamagui(config)
// this makes typescript properly type everything based on the config

type Conf = typeof tamaguiConfig

declare module "tamagui" {
  interface TamaguiCustomConfig extends Conf {}
}
export default tamaguiConfig
// depending on if you chose tamagui, @tamagui/core, or @tamagui/web

// be sure the import and declare module lines both use that same name