Gemini Omni edit returns 400: the five field mistakes on Sume

If a Gemini Omni Flash 1.1 edit on Sume returns 400, one of five things is almost always in the body: an aspect_ratio, generate_audio: false, a bitrate_mode, reference_audio_urls, or another media field next to video_url. Remove it and resubmit. The edit takes only prompt, video_url and an optional resolution.

The refused fields

Sume treats an edit as its own input shape on the single gemini-omni-flash-1.1 id. The Video Router docs spell out what the shape does not accept, and the API refuses those fields loudly rather than dropping them, because a silent drop would bill you for something you did not ask for.

Two near-misses

Two more points catch people. First, duration is not an error with video_url, but it is only a hint for the credit reserve and does not trim the output. Second, /v1/videos does not carry the edit field at all: the edit mode is a Video Router field, so send it to /v1/video-router/generate.

Also check the resolution value. The edit-capable row lists 360p, 720p, 1080p and 4K, so 480p and 768p are not valid for it.

When the 400 is not a field

Use the poll or /v1/jobs/{id}/status response, not a raw provider message, to read why a job failed after it was accepted. An unreachable video_url is reported as a public-network error without revealing the URL, so first check that the clip opens in a private browser window.