Customization of OIDC error response in RH-SSO

Issue

• How can I possibly customize an OIDC error response from Keycloak/RH-SSO ?

• Our client applications generally expect a specific error format depending on the context (eg. PSD2 API). We would like to customize the error depending on the RH-SSO usage and client application expectations. For example, in the context of PSD2 API (and in particular following STET specifications), this error should be formatted as:

  {
      "timestamp": "2019-04-08T16:06:06499+0000",
      "status": 400,
      "error": "Bad Request",
      "message": "Maximum allowed refresh token reuse exceeded",
      "path": "/v1/token"
  }
  

  instead of:

  HTTP/1.1 400 Bad Request
  {
      "error": "invalid_grant",
      "error_description": "Maximum allowed refresh token reuse exceeded"
  }
  

  Is this PSD2-context error response formatting something possible in Keycloak ?