Pika Video Studio's 50 references vs Sume's per-model limits

Pika's new Video Studio lets you attach up to 50 characters, products, settings and styles and @mention them in a prompt. Sume has no single 50-item library. Its limits belong to each model: Gemini Omni Flash 1.1 takes up to 10 reference images and up to 3 reference videos of 3 seconds or less, and the Genjutsu motion-transfer model takes 1 to 8 reference images.

Pika's number is from its September 17 post. Sume's are from Video Router, read 2026-10-01.

How does Pika describe its references?

The post says Video Studio attaches up to 50 characters, products, settings and styles, which you then @mention in the prompt to make a clip or a multi-shot video up to 30 seconds with sound. It does not say how many items each underlying model receives.

What are Sume's reference limits?

Limits are set per catalog model, so read capabilities from GET /v1/video-router/models instead of assuming one envelope.

How do I point at one reference in a prompt?

On Omni Flash, address media as <IMAGE_REF_0> and <VIDEO_REF_0>. The numbers are 0-based and follow list order, so the first image you send is <IMAGE_REF_0>. That is Sume's counterpart to an @mention, with positions instead of names. The Seedance form is covered in Seedance 2.5 @ tags.

What if I have more than 10 references?

Choose the ones that decide the shot. If a character appears in many images, send the clearest few. Splitting a long story into several shots, each with its own small reference set, also stays inside the caps. Send an Idempotency-Key on each request so a retry does not create a duplicate job.