It seems like

http4k-contract

generates a

servers

section like this if you don't specify any servers:

"servers": [
    {
      "url": "/",
      "description": null
    }
  ]

It would make more sense to not generate any

servers

section in this case.

from the open api docs:

An array of Server Objects, which provide connectivity information to a target server. If the servers property is not provided, or is an empty array, the default value would be a Server Object with a url value of /.

Right, then it is valid if the

"description": null

is removed.

that's valid anyway