@nicolas-chaulet/openapi-typescript-codegen

OpenAPI TypeScript Codegen

✨ Turn your OpenAPI specification into a beautiful TypeScript client

Table of Contents

• Table of Contents
• About
• Features
• Quick Start
• Installation
• Configuration
  • Formatting
  • Linting
  • Enums
  • Config API
• Contributing

About

This is an opinionated fork of the openapi-typescript-codegen package. We created it after the original project became unmaintained because we wanted to support OpenAPI v3.1 introduced in the FastAPI v0.99.0 release. We plan to resolve the most pressing issues in the original project – open an issue if you'd like to prioritise your use case!

Features

• generate TypeScript clients from OpenAPI v2.0, v3.0, and v3.1 specifications
• support JSON or YAML input files
• handle external references using JSON Schema $Ref Parser
• generate Fetch, Node-Fetch, Axios, Angular, or XHR HTTP clients
• can be used with CLI, Node.js, or npx
• abortable requests through cancellable promise pattern

Quick Start

The fastest way to use openapi-ts is via npx

npx @nicolas-chaulet/openapi-typescript-codegen -i path/to/openapi.json -o src/client

Congratulations on creating your first client! 🎉

Installation

npm install @nicolas-chaulet/openapi-typescript-codegen --save-dev

or

yarn add @nicolas-chaulet/openapi-typescript-codegen -D

If you want to use openapi-ts with CLI, add a script to your package.json file

"scripts": {
  "openapi-ts": "openapi-ts"
}

You can also generate your client programmatically by importing openapi-ts in a .ts file.

import { createClient } from '@nicolas-chaulet/openapi-typescript-codegen'

createClient({
  input: 'path/to/openapi.json',
  output: 'src/client',
})

⚠️ You need to be running Node.js v18 or newer

Configuration

openapi-ts supports loading configuration from a file inside your project root directory. You can either create a openapi-ts.config.cjs file

/** @type {import('@nicolas-chaulet/openapi-typescript-codegen').UserConfig} */
module.exports = {
  input: 'path/to/openapi.json',
  output: 'src/client',
}

or openapi-ts.config.mjs

/** @type {import('@nicolas-chaulet/openapi-typescript-codegen').UserConfig} */
export default {
  input: 'path/to/openapi.json',
  output: 'src/client',
}

Alternatively, you can use openapi-ts.config.js and configure the export statement depending on your project setup.

Formatting

By default, openapi-ts will automatically format your client according to your project configuration. To disable automatic formatting, set format to false

/** @type {import('@nicolas-chaulet/openapi-typescript-codegen').UserConfig} */
export default {
  format: false,
  input: 'path/to/openapi.json',
  output: 'src/client',
}

You can also prevent your client from being processed by formatters by adding your output path to the tool's ignore file (e.g. .prettierignore).

Linting

For performance reasons, openapi-ts does not automatically lint your client. To enable this feature, set lint to true

/** @type {import('@nicolas-chaulet/openapi-typescript-codegen').UserConfig} */
export default {
  input: 'path/to/openapi.json',
  lint: true,
  output: 'src/client',
}

You can also prevent your client from being processed by linters by adding your output path to the tool's ignore file (e.g. .eslintignore).

Enums

We do not generate TypeScript enums because they are not standard JavaScript and pose typing challenges. If you want to iterate through possible field values without manually typing arrays, you can export enums by running

/** @type {import('@nicolas-chaulet/openapi-typescript-codegen').UserConfig} */
export default {
  enums: true,
  input: 'path/to/openapi.json',
  output: 'src/client',
}

This will export your enums as plain JavaScript objects. For example, Foo will generate the following

export const FooEnum = {
  FOO: 'foo',
  BAR: 'bar',
} as const;

Config API

$ openapi-ts --help

  Usage: openapi-ts [options]

  Options:
    -V, --version             output the version number
    -i, --input <value>       OpenAPI specification, can be a path, url or string content (required)
    -o, --output <value>      Output directory (required)
    -c, --client <value>      HTTP client to generate [fetch, xhr, node, axios, angular] (default: "fetch")
    --name <value>            Custom client class name
    --useOptions <value>      Use options instead of arguments (default: false)
    --base <value>            Manually set base in OpenAPI config instead of inferring from server value
    --enums                   Generate JavaScript objects from enum definitions (default: false)
    --exportCore <value>      Write core files to disk (default: true)
    --exportServices <value>  Write services to disk [true, false, regexp] (default: true)
    --exportModels <value>    Write models to disk [true, false, regexp] (default: true)
    --exportSchemas <value>   Write schemas to disk (default: true)
    --format                  Process output folder with formatter?
    --no-format               Disable processing output folder with formatter
    --lint                    Process output folder with linter?
    --no-lint                 Disable processing output folder with linter
    --no-operationId          Use path URL to generate operation ID
    --postfixServices         Service name postfix (default: "Service")
    --postfixModels           Model name postfix
    --request <value>         Path to custom request file
    --useDateType <value>     Output Date instead of string for the format "date-time" in the models (default: false)
    -h, --help                display help for command

Contributing

Please refer to the contributing guide for how to install the project for development purposes.