Seedance 2.5 Draft mode on Runway: 480p proofs, and 480p on Sume

Runway's changelog for October 2 lists a Seedance 2.5 Draft mode in Agent that renders 480p drafts. On Sume, seedance-2.5 accepts resolution: 480p as a normal API parameter, so a draft is just a cheaper request. On Sume no v1 model accepts a seed, so the 1080p render is a new take.

What Runway announced

The changelog names Seedance 2.5 Draft mode inside Runway's Agent, aimed at cheap proofs before a final. Runway's API pricing page lists seedance2_5 at 20 to 68 credits per second plus input fees, which is $0.20 to $0.68 at $0.01 a credit. The page I read does not tie the Draft mode to a specific credit rate.

What Sume does

Sume's seedance-2.5 accepts 4 to 30 seconds at 480p, 720p and 1080p and bills per 1,000 video tokens, with list times 1.25. You can read the price per 1,000 tokens in the pricing_skus field from GET /v1/videos/models. I found no separate Draft mode in the Sume docs; a draft is a 480p call.

A draft-then-final loop

• Submit the shot at 480p and a short duration; review the motion.
• If it is good, resubmit with the same prompt and frames at 1080p. This is a new generation, not an upscale of the draft.
• Keep the first frame fixed with frame_images to hold composition between the two renders.

How to run the same idea via the Sume API

A 480p draft loop has three things to hold fixed: the prompt, the first frame and the duration. Send the draft with resolution: 480p and a short duration, review it, then repeat with resolution: 1080p. Because no v1 model takes a seed, the two takes may differ in motion even with identical inputs; use a first frame in frame_images to hold the composition.

Seedance 2.5 is billed per 1,000 video tokens, so the saving from drafting at 480p comes from fewer tokens per clip. I do not publish the token count per second here, because it is not in the docs I read. Run one 480p and one 1080p test and read usage.cost for each.