type: object
description: |
    RFC 6749 §5.2 error response. Returned by the OAuth endpoints on
    invalid grants, bad credentials, or when the OAuth subsystem is
    disabled (`error: endpoint_disabled`, `501`).
required: [error]
properties:
    error:
        type: string
        description: Machine-readable error code (e.g. `invalid_grant`, `invalid_client`, `endpoint_disabled`).
    error_description: { type: string }
    error_uri: { type: string, format: uri }
example:
    error: invalid_grant
    error_description: "Authorization code expired."
