Event types - Monitor YT

Monitor YT creates feed events when it detects meaningful changes to tracked public data.

Video events

Feed label	API type	Meaning
New video	`video_published`	A public long-form upload was discovered.
Title changed	`title_changed`	The observed title moved from one value to another.
Thumbnail changed	`thumbnail_changed`	The served thumbnail image changed. Images are compared by content, not URL.
Title test	`title_ab_test`	Two or three title variants were observed returning in rotation.
Title result	`title_ab_test_concluded`	A title rotation remained quiet long enough to conclude on a final observed title.
Thumbnail test	`thumbnail_ab_test`	Two or three served thumbnail variants were observed returning in rotation.
Thumbnail result	`thumbnail_ab_test_concluded`	A thumbnail rotation remained quiet long enough to conclude on a final observed image.
Members-only flip	`members_only_changed`	A previously known video switched between public and members-only visibility.

A concluded A/B event reports the variant on which the observed rotation rested. Monitor YT cannot read the channel owner’s private YouTube Studio result, so the final variant is not proof of YouTube’s statistical winner.

Channel events

Feed label	API type	Meaning
Subscriber milestone	`subscriber_change`	The rounded public count crossed a 1,000-subscriber boundary below 1 million, or a 10,000-subscriber boundary at or above 1 million. Moves in either direction count.
Channel renamed	`channel_renamed`	The observed channel display name changed.
Avatar changed	`channel_avatar_changed`	The observed channel profile image changed.

Events reflect public observations. YouTube may round counts, limit what is publicly visible, or change data between collection runs. For the response fields associated with each API type, see the API event object guide.