The vendored React bundle

What React is in devpage — React and react-dom bundled into one file that widgets run with in the browser — where it came from, its version and licence, how devpage serves it, and how to upgrade it. It is a mechanism page under the viewer, for someone about to replace the bundle; how to write a widget is in Widgets.

What is in the repository

The bundle is built from the npm packages react@19.3.0 and react-dom@19.3.0 (published 2026-09-09) with this entry module:

import * as React from "react";
export * from "react";
export default React;
export { jsx, jsxs, Fragment } from "react/jsx-runtime";
export { createRoot } from "react-dom/client";

How devpage uses it

src/server.rs compiles the file into the binary with include_str! and serves it at /__devpage/react.js — see built-in assets. Every page's import map points react, react/jsx-runtime and react-dom/client at it, so compiled widgets — whose JSX becomes react/jsx-runtime calls — and the page script's mounting code share one copy of React (Widgets).

Upgrading it