Wan 3.0 thinking mode: why document and web page input needs it

Wan 3.0's thinking mode is the setting that lets it read a document or a public web page as input. fal's Wan 3 page says thinking is required for those two inputs; Alibaba's API reference names the matching parameter prompt_extend, which must be true whenever a file or a link is provided. Sume's wan-3.0 does not expose either input, so there is no thinking setting to turn on.

Read 2026-09-29 on fal's Wan 3 page and Alibaba Cloud's API reference; the Sume side is from the model catalog and Video generation.

What does each vendor call it?

The two pages use different words for what may be the same switch, and neither page says they are identical, so treat them as separate settings.

What does prompt extension do to my prompt?

Alibaba says a language model rewrites the input prompt, that this significantly improves quality for shorter prompts, and that it increases latency. If you need the words you wrote to stay exactly as written, that is a trade to know about on any route that turns it on.

Is there a thinking switch on Sume?

No. The catalog constraints for wan-3.0 say file_url, web_url and enable_thinking are not exposed in v1. The fields you can send are prompt, duration, resolution, aspect_ratio, generate_audio, frame_images and input_references.

How do I write a good prompt without it?

Say who or what is in frame, what moves, how the camera moves, and the light, in one clear paragraph. That gives the model the content a document parse would otherwise supply. For a long source, summarize it into scenes yourself first.