Six Nano Banana 2.1 start frames, six Wan 3.0 clips: a 3-min Short

Generate six vertical stills first, then pass each one as the first frame of a 30-second Wan 3.0 job. At 1K the stills are $0.60 ($0.10 each); six 30-second 720p clips are $22.50; the Timeline join is $0.30. Total: $23.40 for a 180-second Short, the maximum length (YouTube Help, read 2026-10-09).

The reason to start from stills is control. Nano Banana 2.1 went GA on 2026-10-06 with better multi-turn character consistency and new aspect ratios (Gemini API changelog, read 2026-10-09), so you can lock a character in the image step and let the video step animate it.

Budget

Sume's image catalog lists 9:16 in the aspect_ratio values and 1K or 2K as resolution tiers. Wan 3.0 accepts 2 to 30 seconds and first_frame / last_frame images.

The two requests

Step one asks for a vertical still. Step two passes the finished image URL as frame_images. When both frame_images and input_references are sent, frame_images decides and the job is image-to-video.

# 1) the still
curl -X POST https://api.sume.com/v1/images \
  -H "Authorization: Bearer $SUME_API_KEY" -H "Content-Type: application/json" \
  -d '{"model":"nano-banana-2.1","prompt":"Scene 3: ...","aspect_ratio":"9:16","resolution":"1K"}'

# 2) the clip, first frame = that image
curl -X POST https://api.sume.com/v1/videos \
  -H "Authorization: Bearer $SUME_API_KEY" -H "Content-Type: application/json" \
  -d '{"model":"wan-3.0","prompt":"Slow push-in, scene 3","aspect_ratio":"9:16","resolution":"720p","duration":30,
   "frame_images":[{"type":"image_url","image_url":{"url":"https://example.com/scene3.png"},"frame_type":"first_frame"}]}'

Gotchas

• Use the same character description in all six image prompts; the model does not remember the previous call unless you pass a reference.
• Each frame_images entry needs a frame_type of first_frame or last_frame.
• Import the six finished MP4s before the Timeline render; Timeline only accepts media.sume.com URLs from your workspace.
• Stills are billed even if you discard the video, so check each still before you submit the clip.