rclnodejs v2.1.0-beta.0 (2026-06-11)

First beta of the 2.1 line. The headline is a full ES Module migration: rclnodejs is now a native ESM package that ships both ESM and CommonJS from a single artifact, so import and require consumers — and TypeScript under NodeNext — all resolve the right entry automatically.

This is a pre-release. Everything from 2.0.0 carries over unchanged; the dual-format packaging is the main thing to validate before 2.1.0 final. If you upgrade from 2.0.0, nothing breaks — require('rclnodejs') keeps working, and you can now also import it without a shim or interop wrapper.

The migration landed in three staged phases (rename CJS-only tooling → convert the library and tests to native ESM → add the dual build), so the git history stays bisectable and each step is reviewable on its own.

📣 Important Notes

• rclnodejs is now "type": "module". The package publishes a tsup-built dist/ that emits both an ESM (import) and a CommonJS (require) entry for every public surface, selected at resolution time through package.json exports conditions — covering the root entry plus the rclnodejs/web, rclnodejs/web/server, and rclnodejs/rosocket subpaths.
• CommonJS consumers are unaffected. const rclnodejs = require('rclnodejs') continues to work exactly as before, including the rclnodejs/web and rclnodejs/rosocket subpaths under the require condition.
• ESM consumers can now import rclnodejs from 'rclnodejs' and use top-level await directly, with no createRequire shim.
• TypeScript projects on module/moduleResolution: NodeNext get correct types for both module systems; the rclnodejs/rosocket subpath now ships its own .d.ts/.d.cts so it types cleanly under import and require.
• Build-time and message-generation tooling (e.g. the message generator and JSDoc tooling) remain CommonJS and are kept on .cjs extensions; this is internal and does not affect consumers.
• Downstream code that reached into undocumented lib/ internals via deep relative paths should switch to the published exports/subpath entry points.
• Minimum Node.js remains 20.20.2. The same Linux x64 / arm64 N-API prebuilds run unchanged on every Node.js ≥ 20.20.2 (including 24.x and 26.x) across Humble, Jazzy, Kilted, Lyrical, and Rolling.

✨ Highlights

ESM migration — dual ESM + CommonJS package

• Phase 1 — rename CJS-only build and generator files to .cjs, isolating tooling that must stay CommonJS from the soon-to-be-ESM runtime (#1529)
• Phase 2 — convert lib/, index.js, and the full test suite to native ES modules (#1530)
• Phase 3 — dual ESM + CommonJS build via tsup, wired through package.json exports conditions so each consumer resolves the right artifact (#1531)
• Add type declarations for the rclnodejs/rosocket subpath — ships .d.ts/.d.cts so the WebSocket gateway types cleanly under both module systems (#1533)
• Modernize tsconfig.json for Node.js (NodeNext) module resolution (#1528)
• Modernize the bundled TypeScript demos to NodeNext + ES2022 (#1534)

API and types

• Add enable_logger_service option for runtime log-level control (#1522)
• Add publisher/subscription event_type_is_supported checks (#1520)
• Infer concrete types from constructor TypeClass forms for sharper type inference (#1526)

🔧 Maintenance

• Pump commander to 15.0.0 (#1524)

Getting Started with ESM

// ESM
import rclnodejs from 'rclnodejs';

await rclnodejs.init();
const node = new rclnodejs.Node('publisher_example_node');
const publisher = node.createPublisher('std_msgs/msg/String', 'topic');
publisher.publish('Hello ROS 2 from rclnodejs');
node.spin();

// CommonJS — still supported, unchanged
const rclnodejs = require('rclnodejs');

rclnodejs.init().then(() => {
  const node = new rclnodejs.Node('publisher_example_node');
  const publisher = node.createPublisher('std_msgs/msg/String', 'topic');
  publisher.publish('Hello ROS 2 from rclnodejs');
  node.spin();
});

The rclnodejs/web and rclnodejs/rosocket subpaths resolve under both module systems:

import { connect } from 'rclnodejs/web';        // ESM
const { connect } = require('rclnodejs/web');    // CommonJS

npm i rclnodejs@2.1.0-beta.0

Full Changelog: 2.0.0...2.1.0-beta.0