How to add a Swagger summary to ServiceStack.GetAccessToken

[mythz]

Please don’t try to re-register or otherwise interfere with the registration of internal services, they’re not overridable. Any customizations should be done using the filters in OpenApiFeature which I’ve provided an example of in one of your earlier questions:

How to exclude HTTP methods from Swagger, Metadata and OpenAPI

The HTTP methods are limited by your Route definition, e.g: [Route("/myservice", "GET POST")] But this isn’t possible to annotate for built-in Services which are unspecified and default to allow “ANY” method. So you’ll basically need to modify the Open API schema by removing the HTTP methods you don’t want on selected paths, e.g: Plugins.Add(new OpenApiFeature { ApiDeclarationFilter = api => { foreach (var path in new[] {api.Paths["/auth"], api.Paths["/auth/{provider}"]}) …

e.g.

Plugins.Add(new OpenApiFeature
{
    ApiDeclarationFilter = api =>
    {
        api.Paths["/access-token"].Get.Summary = "My GetAccessToken Summary";
    },
});