People's legs and feet on a racetrack. They're about to begin running at the same time.

If you’ve ever used the package concurrently to run more than one thing at the same time while developing, you probably have seen how the logs are a little jumbled together. All output is logged to the console, by default, with a number representing the process that created the output. As an example, here’s a Vite frontend and a toy websocket server in the backend that logs every message received from the FE:

[0]   VITE v7.3.0  ready in 220 ms
[0] 
[0]   ➜  Local:   http://localhost:5174/
[0]   ➜  Network: use --host to expose
[1] received: { 'message': 'hi' }

This is…fine? But it’s easy to miss the [0] or [1], it’s just one number and honestly if you’re not looking for it it just sort of fades into the background.

But by passing the --names flag in you can call your processes anything you want.

concurrently --names frontend,backend 'vite' 'node src/server.js' turns the above output into:

[frontend]   VITE v7.3.0  ready in 220 ms
[frontend] 
[frontend]   ➜  Local:   http://localhost:5174/
[frontend]   ➜  Network: use --host to expose
[backend] received: { 'message': 'hi' }

And of course you can use more descriptive names, although these are plenty for me.

I wasn’t able to find the official documentation on this, although there is documentation on how to interact programmatically with concurrently and pass in the names options. I’m not sure how to incorporate that into a development pipeline but that’s a me problem. For now, the command-line flag is all I need.