How to pass a command from PHP to NodeJS and vice versa?

Question

PHP

Background
Previously, the site used only PHP and all requests went through Ajax. Now NodeJS for WebSockets (socket.io) has been added.
Question
How to transfer data array from PHP to NodeJS?
On the example of a chat: on some events, the server sends a message to the chat to the user (adds an entry to the database), at this moment you need to send this message to the user from NodeJS.

Answer 1

You need a data bus. Arm yourself with message queues (ZeroMQ, RabbitMQ, ActiveMQ, etc.)

Answer 2

I also struggled with this issue, eventually installed Ratchet and used WebSocket in PHP.
Works great!