Client profiles

A client profile describes a known kind of YouTube application, such as web, iOS, or an embedded TV client. It bundles a client name, version, user agent, headers, and public Innertube API key.

It is not a generated API key, user account, or authentication credential.

Keep the default first

The default profile is WEB. For player metadata, the SDK can try a small set of endpoint-appropriate fallbacks when one client identity is refused.

Most applications should leave client unset so that built-in behavior can do its job.

Override only for a reason

You can choose a default for one client instance:

import { YouTube, type ClientType } from 'just-yt';

const client: ClientType = 'IOS';
const yt = new YouTube({ client });

Or override a single video or transcript call:

const video = await yt.video('dQw4w9WgXcQ', {
  client: 'TV_EMBEDDED',
});

A per-call override is useful while diagnosing an endpoint-specific response or when a controlled integration has tested a particular profile. When you force one profile, the normal player fallback chain is not used for that call.

What a profile cannot promise

Different identities can receive different response shapes or playability decisions, but no profile guarantees access. It cannot make private content public or bypass age, member, regional, and anti-abuse controls.

Use the exported CLIENT_TYPES list and ClientType type rather than inventing profile names. The exact exports are listed in the API reference.