axigen

Generate typed Axios client functions from your OpenAPI / Swagger spec — in one command.

Overview

axigen reads your OpenAPI (or Swagger) spec and generates fully-typed Axios wrapper functions, so you never have to write boilerplate API calls by hand again.

• ✅ Supports OpenAPI 3.x and Swagger 2.x (YAML or JSON)
• ✅ Generates typed request/response interfaces
• ✅ Works with your own Axios instance
• ✅ TypeScript and JavaScript output
• ✅ JSDoc comments from your spec's summaries
• ✅ Filter endpoints by tag
• ✅ Zero runtime dependencies in generated code

Installation

npm install -D axigen
# or
pnpm add -D axigen
# or
yarn add -D axigen

Quick Start

1. Create a config file:

npx axigen init

2. Edit axigen.config.js:

/** @type {import('axigen').AxigenConfig} */
module.exports = {
  // Path to your OpenAPI spec (YAML or JSON)
  input: "./openapi.yaml",

  output: {
    // Generated Axios client functions
    client: "./src/api/client.ts",
    // Generated TypeScript types
    types: "./src/api/types.ts",
  },

  // Import path to your Axios instance inside your project
  axiosInstancePath: "../lib/axios",
  axiosInstanceExport: "axiosInstance",

  language: "ts",
  jsdoc: true,
  functionName: {
    transforms: [{ match: "-([a-zA-Z])", flags: "g", replacement: "upper:$1" }],
    appendMethod: ["post", "put", "delete", "patch", "get", "head", "options"],
  },
};

3. Run:

npx axigen generate
# or simply:
npx axigen

Example

Given this OpenAPI spec:

paths:
  /users:
    get:
      operationId: getUsers
      summary: Get user list
      tags: [users]
      parameters:
        - name: page
          in: query
          schema:
            type: integer
        - name: limit
          in: query
          schema:
            type: integer
      responses:
        "200":
          description: OK
          content:
            application/json:
              schema:
                type: object
                properties:
                  data:
                    type: array
                    items:
                      $ref: "#/components/schemas/User"
                  total:
                    type: integer

  /users/{userId}:
    get:
      operationId: getUserById
      summary: Get user by ID
      tags: [users]
      parameters:
        - name: userId
          in: path
          required: true
          schema:
            type: string
      responses:
        "200":
          description: OK
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/User"

axigen generates:

// This file is auto-generated by axigen. DO NOT EDIT.
// Generated at: 2026-06-26T11:56:19.002Z

import type { AxiosRequestConfig, AxiosResponse } from "axios";
import { axiosInstance } from "../lib/axios";
import type { GetUserByIdPathParams, GetUserByIdResponse, GetUsersQueryParams, GetUsersResponse } from "./types";

/**
 * Get user list
 * `GET /users`
 * @tags users
 */
export async function getGetUsers(
  params?: GetUsersQueryParams,
  config?: AxiosRequestConfig,
  options?: AxiosRequestConfig,
): Promise<AxiosResponse<GetUsersResponse>> {
  const mergedConfig: AxiosRequestConfig = { ...config, params: { ...params, ...config?.params } };
  return axiosInstance({ method: "GET", url: "/users", ...mergedConfig }, options);
}

/**
 * Get user by ID
 * `GET /users/{userId}`
 * @tags users
 */
export async function getGetUserById(
  userId: GetUserByIdPathParams["userId"],
  config?: AxiosRequestConfig,
  options?: AxiosRequestConfig,
): Promise<AxiosResponse<GetUserByIdResponse>> {
  return axiosInstance({ method: "GET", url: `/users/${userId}`, ...config }, options);
}

Configuration

| Option | Type | Default | Description | | --------------------------- | -------------- | --------------- | ------------------------------------------------------------------------ | | input | string | — | Path to your OpenAPI spec file (YAML or JSON) | | output.client | string | — | Output path for the generated client functions | | output.types | string | — | Output path for generated TypeScript types (optional) | | axiosInstancePath | string | — | Import path to your Axios instance | | axiosInstanceExport | string | axiosInstance | Named export of your Axios instance | | language | 'ts' \| 'js' | 'ts' | Output language | | jsdoc | boolean | true | Add JSDoc comments to generated functions | | tags | string[] | — | Only generate endpoints matching these tags | | functionName | object | — | Control generated function name transforms and method suffix (see below) | | functionName.transforms | Transform[] | [] | Array of regex transform rules applied to the operationId | | functionName.appendMethod | string[] | [] | HTTP methods whose name is appended as a suffix to the function name |

Axios Instance

axigen does not create an Axios instance for you — it imports the one you already have in your project. The generated functions expect your instance to follow this call signature:

axiosInstance(config: AxiosRequestConfig, options?: AxiosRequestConfig): Promise<AxiosResponse>

This is intentional: it lets you intercept or merge options at the instance level (e.g. passing per-request auth headers or timeout overrides as a second argument), keeping generated code decoupled from your instance's internal logic.

A typical instance looks like this:

// src/lib/axios.ts
import axios, { type AxiosRequestConfig } from "axios";

const instance = axios.create({
  baseURL: "https://api.example.com/v1",
  headers: {
    "Content-Type": "application/json",
  },
});

export const axiosInstance = (config: AxiosRequestConfig, options?: AxiosRequestConfig) => instance({ ...config, ...options });

Then in your config:

axiosInstancePath: '../lib/axios',
axiosInstanceExport: 'axiosInstance', // default, can be omitted

Note: If you use a plain axios.create() instance without the two-argument wrapper, the options parameter passed by generated functions will be ignored. The wrapper pattern above is the recommended approach.

CLI

# Generate client from config (default command)
axigen generate [--config <path>] [--cwd <path>]

# Create a starter config file
axigen init

# Show version
axigen --version

# Show help
axigen --help

Programmatic Usage

You can also use axigen directly in Node.js scripts:

import { generate, loadConfig } from "axigen";

const config = await loadConfig(process.cwd());
const result = await generate(config, process.cwd());

console.log(`✓ Generated ${result.endpointCount} endpoints`);
console.log(`  client → ${result.clientPath}`);
console.log(`  types  → ${result.typesPath}`);

License

MIT