Example translating user named Nice to v5 ID:
https://api.twitch.tv/kraken/users?login=nice
You get:
{
"_total": 1,
"users": [
{
"display_name": "Nice",
"_id": "204416",
"name": "nice",
"type": "user",
"bio": "ChubzyKik: ScaredPsn: Xur \/ Scared",
"created_at": "2007-12-17T21:45:33.839812Z",
"updated_at": "2016-12-09T01:45:44.344078Z",
"logo": "https:\/\/static-cdn.jtvnw.net\/jtv_user_pictures\/nice-profile_image-9e639b1dc2ede357-300x300.jpeg"
}
]
}
But from USERS endpoint you get:
{
"error": "Unprocessable Entity",
"status": 422,
"message": "User \"204416\" is unavailable"
}
So it’s a bit inconsistent and also allows to get users which are banned (?).
Also unrelated but funny, the user Undefined actually exists and it’s chat is just like you would expect.