This line assumes that every schema it operates on will be {type: string}, {type: object} or soforth, and fails to support the type combinators anyOf, oneOf and allOf when they occur at the top level. While I appreciate that providing a meaningful rendering of such types is challenging, it'd be awesome if the openapi plugin could at least fail gracefully and let a user know what killed it.

  File "sphinxcontrib/openapi/openapi30.py", line 262, in _httpresource
    type=param['schema']['type'],
KeyError: 'type'

isn't a great UX and hunting down what part of my spec was killing Sphinx took a hot second.