interface User {
  // Model inteface--could be imported from another file
  email: string
  name: string
  gender: 'Male' | 'Female' | 'Other'
}

export interface MySocialAPI {
  '/users': {
    // Route name (without prefix, if you have one)
    GET: {
      // Any valid HTTP method
      query: {
        // Query string params (e.g. /me?includeProfilePics=true)
        includeProfilePics?: boolean
      }
      response: User[] // JSON response
    }
  }

  '/user/:id/send-message': {
    POST: {
      params: {
        // Inline route params
        id: string
      }
      body: {
        // JSON request body
        message: string
      }
      response: {
        // JSON response
        success: boolean
      }
    }
  }
}

export interface FoodDeliveryAPI {
  '/me/orders': {
    POST: {
      body: {
        foodItemIds: number[]
        address: string
        paymentMethod: 'card' | 'cash'
      }
      response: {
        success: boolean
        eta?: string
      }
    }
  }

  // ...other routes...
}

import RestypedRouter from 'restyped-express-async'
import { FoodDeliveryAPI } from './food-delivery-api'
import * as express from 'express'

const app = express()

const apiRouter = express.Router()
app.use('/api', apiRouter)

const router = RestypedRouter<FoodDeliveryAPI>(apiRouter)

router.post('/me/orders', async req => {
  // Will not compile if you attempt to access an invalid body property
  const {
    foodItemIds, // number[]
    address, // string
    paymentMethod // 'card' | 'cash'
  } = req.body

  const success = await OrderModel.order(foodItemIds, address, paymentMethod)

  // Will not compile if returned value is not of type {success: boolean}
  return { success }
})

import axios from 'restyped-axios'
import { FoodDeliveryAPI } from './food-delivery-api'

const api = axios.create<FoodDeliveryAPI>({
  baseURL: 'https://fooddelivery.com/api/'
})

async function order() {
  // Will not compile if you pass incorrectly typed body params
  const res = await api.post('/me/orders', {
    foodItemIds: [142, 788],
    address: '1601 Market St, Phiadelphia, PA 19103',
    paymentMethod: 'cash'
  })

  // TypeScript knows that res.data is of type {success: boolean, eta?: string}
  const { success, eta } = res.data
}