@o76923 as much as I can tell, emojos.in just uses the mastodon-standard endpoint for emoji for literally anything:
void.rehab would be https://void.rehab/api/v1/custom_emojis
let mut url = Url::from_str("https://host.invalid/api/v1/custom_emojis").unwrap();
if url.set_host(Some(&instance)).is_err() {
return Err(InstanceError::from_kind(Kind::NotFound, instance));
}
...
Kind::NotFound => {
"Not a fediverse instance, or does not support the Mastodon custom emoji API"
}