Scalar Has a Free API — Beautiful API Documentation in Seconds

TL;DR Scalar is an open-source API reference generator that turns your OpenAPI/Swagger spec into beautiful, interactive documentation. It's free, customizable, and includes a built-in API client for testing endpoints. What Is Scalar? Scalar is a modern alternative to Swagger UI and Redoc: Beautiful by default — dark/light themes, clean typography Interactive API client — test endpoints right from the docs OpenAPI 3.x support — full spec compliance Multiple integrations — Express, Fastify, Hono, Next.js, NestJS Customizable — themes, layouts, authentication Free and open source — MIT license Quick Start with Express npm install @scalar/express-api-reference import express from "express"; import { apiReference } from "@scalar/express-api-reference"; const app = express(); app.use( "/docs", apiReference({ spec: { url: "/openapi.json", }, theme: "purple", }) ); app.get("/openapi.json", (req, res) => { res.json({ openapi: "3.1.0", info: { title: "My API", version: "1.0" }, paths: { "/use