Cheapest legal Wan 3.0 call: 2 s at 480p is $0.125, 15x less than 30 s

The cheapest legal Wan 3.0 call is 2 s at 480p: 2 x $0.0625 = $0.125. That is 15 times less than a 30 s clip at the same resolution ($1.875), which makes the 2 s call the right size for a key check or a smoke test.

Minimum versus maximum

Wan 3.0 accepts 2 to 30 s at 480p, 720p and 1080p, with per-second rates of $0.0625, $0.125 and $0.25. The OpenAPI request schema only says duration is an integer of at least 1, so a 1 s request passes the schema and is rejected by the model's own range. Check the length in your own code first.

The smallest request

This is the body to use for a first call or a health check. The response is a 202 with id, polling_url, status and model.

curl -X POST https://api.sume.com/v1/videos \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Idempotency-Key: $(uuidgen)" \
  -H "Content-Type: application/json" \
  -d '{"model":"wan-3.0","prompt":"A red ball rolls across a wooden floor","duration":2,"resolution":"480p"}'

Gotchas

Other models have different floors: Seedance 2.5 starts at 4 s, MiniMax H3 at 5 s, Gemini Omni Flash 1.1 at 3 s. Never hardcode 2; read supported_durations for the model you picked.

The request schema rejects unknown fields (additionalProperties is false), so do not add a seed or size to a test call: both return 400 unsupported_parameter on every model.