Approved an avatar preview, now the hook changed: new preview

You cannot edit the script after approving a Sume avatar preview. POST /v1/avatar-video-previews/{id}/generate-video reuses the stored request, and the docs say the structural fields (script, video_inputs, avatar_handle, scene, aspect_ratio) still require a new preview. The only thing you can change at that step is the final render quality. So if the hook line changes, create a new preview for it.

This is from Sume's Avatar video previews page, read on 2026-10-02. A preview generates the first-frame still stage without starting the full render, so you approve composition before the full spend.

What can I change at each step?

The docs separate what each of the three preview calls accepts.

What is the practical hook workflow?

For a hook test, treat each opening line as its own preview. Create one preview per line, look at preview_image_url (and scene_previews[] for multi-scene), then call generate-video only on the previews you want. regenerate is for a different still of the same request, not a different line. With an empty body, generate-video keeps the quality chosen at preview create, and a quality override applies to the final render only. Preview stills are tier-independent and always reused, as the docs put it.

The duration window is the same as a direct render: an estimated 4 to 60 seconds inclusive. Media inputs such as product_image and scene.image_url are public HTTPS URLs.

Where do captions fit in?

Inline captions stored on preview create are applied at generate-video time. Preview stills are never caption-burned, so a still with no captions on it is normal. The docs also say a caption stage that fails can leave the avatar job succeeded with a clean primary video_url and captions.status=failed; the standalone Video captions endpoint can caption that clean file later.

What should I do next?

Three habits that follow from the docs:

• Keep one preview id per hook line, so you can map a result back to its text.
• Decide the aspect ratio before you preview: it is structural and cannot change later.
• Use approve first, then pick the quality tier when only the tier is undecided.