set_youtube_thumbnail

io.github.hermoso-ai/hermoso · Verify this server

Set the CUSTOM THUMBNAIL on a video already on the connected channel, using a Hermoso image — a make_thumbnail render, a generated image, or a frame. The thumbnail is the single biggest lever on YouTube click-through and YouTube otherwise auto-picks a frame, so a published video without one is leaving reach on the table. It changes ONLY the thumbnail — video, title and privacy are untouched — but it is public and immediate, so show the user which image is going on which video and get a yes first. Custom thumbnails require a VERIFIED YouTube channel (a phone number at youtube.com/verify); without it YouTube refuses and the error says so. Images over YouTube’s 2MB cap are compressed automatically. The image must be Hermoso-HOSTED, which is not the same as Hermoso-GENERATED: the user’s own artwork works, put it through upload_file first and pass the URL that returns. An arbitrary external host is refused. 0 credits. Needs a connected YouTube channel.