Is your feature request related to a problem? Please describe.

When I'm consuming hydra APIs I would like to know which fields in the response json can be optional/null/absent, so that I can model my types properly on the consumer side.

For some responses there is a proper description of the fields in the documentation.
For example for login request responses there are already helpful comments

{
    // Skip, if true, let's us know that ORY Hydra has successfully authenticated the user and we should not show any UI
    "skip": true|false,

    // The user-id of the already authenticated user - only set if skip is true
    "subject": "user-id",

    ...
}

This information lets me model this as

type Subject = string

type HydraLoginContinuation =
| Skip of Subject
| Continue

type HydraLoginRequest = {
    Continuation: HydraLoginContinuation
    ...
}

otherwise it would look like this:

type HydraLoginRequest = {
    Skip: bool option
    Subject: string option
    ...
}

That is all great, but I would like this information for all fields in all response objects.
After the sample json in the documentation it says

For a full documentation on all available keys, please head over to the API documentation (make sure to select the right API version).

But the API documentation doesn't give me the information I need:
https://www.ory.sh/docs/hydra/sdk/api#loginrequest

Describe various solutions you'd like

This information belongs in the API documentation.
Possible solutions:
a. Right now there is "Required" column that always seems to be false. We could use that value to indicate that a field will always be present in the response and that it has a non-null value.
b. We could postfix Name or Type values with "(optional)"
c. We could prefix Description value with "(optional)"

More opinions

I think this should apply to at least all endpoints of all ory services that are not supposed to be consumed by a standard library (like oauth2/token etc)