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.