How to launch multiple Azure Functions apps on different ports

Turns out setting up Hosts.LocalHostPort via local.settings.json doesn't work (consistently at least, I keep getting semi-random Value cannot be null. (Parameter 'provider') errors on function startup), contrary to what the documentation says. If you override the command line args directly, via a launchSettings.json , it works consistently and I even get faster startup ¯_ (ツ)_/¯:

{
"profiles": {
"api": {
"commandName": "Project",
"commandLineArgs": "start --port 7072"
}
}
}

You might want to add a --pause-on-error in there too.