Quick start

feTS Client is a fully type safe HTTP Client that uses OpenAPI (opens in a new tab) specification. It automatically infers types from the document and gives you a type safe API to interact with your API.

Installation

yarn add fets

Usage

First, you need to create a TypeScript file that exports your OpenAPI document. Due to the limitations in TypeScript, we cannot import types from JSON files directly. See this issue (opens in a new tab). Just copy and paste the content of the OpenAPI file inside the TypeScript file, and export it with as const modifier.

export default { openapi: '3.0.0' /* ... */ } as const

Then, you can create a client instance by passing the OpenAPI document to the createClient function.

import { createClient, Mutable } from 'fets'
import openapi from './openapi'
 
const client = createClient<Mutable<typeof openapi>>()
 
const response = await client['/pets'].get()
 
const pets = await response.json()
console.log(pets)

Infer types from feTS Server

If you are using feTS Server and share the types of your router instance. You can infer types from there directly.

import { createClient } from 'fets'
// Don't forget to add `type` to get the types only.
import type { router } from './router'
 
const client = createClient<typeof router>({
  endpoint: 'http://localhost:3000'
})
 
const response = await client['/pets'].get()
const pets = await response.json()
console.log(pets)