Are hooks applied to all Clients?

I’d like to create a hook to add extra claim information for a client. If I create a hook, can I assign it to one client, or API? Or does it execute on every client?

Hooks are still in Beta and at the moment only apply to [Database Connections] (Database Connections). They will apply to all clients, but you do have access to context.connection, so you might be able to filter by the connection.

If you want to add information to a tokens from a given client, you can use [rules] (https://manage.auth0.com/#/rules) with context.clientNamesuch as:

if (context.clientName === 'NameOfTheClient') {
  (...)
}

It sure would be nice to allow per client hooks.

Thanks a lot for providing that feedback!