Following are errors returned by the Hellō server when making a request, or when calling the introspection API.

Request Errors

If there is an issue with fulfilling the request (Step 3), the response (Step 4) will have an error query parameter set to one of the following string:

invalid_requestThe request is missing a required parameter, includes an invalid parameter value, includes a parameter more than once, or is otherwise malformed.
access_deniedThe user denied or cancelled the request.
invalid_scopeThe requested scope is invalid, unknown, or malformed.
server_errorThe Hellō server encountered an unexpected condition that prevented it from fulfilling the request. (This error code is equivalent to a 500 Internal Server Error HTTP status code.)
temporarily_unavailableThe Hellō server is currently unable to handle the request due to a temporary overloading or maintenance of the server. (This error code is equivalent to a 503 Service Unavailable HTTP status code.)


*NOTE: If the request contains an invalid client_id or request_uri, a response will not be sent and the user will be presented with an error message per RFC 6749 in new window

Introspection Errors

Following are the responses from the Token Introspection API

If the token is invalid in anyway, the API will return active set to false


If any of the parameters are missing you will receive an error

token_requiredThere was token parameter.
client_id_requiredThere was client_id parameter.
nonce_requiredThere was a nonce in the IT Token, and there was no nonce parameter.