Gemini 3.1 flash image preview shutdown: Sume model ids

Google's deprecations page lists gemini-3.1-flash-image-preview and gemini-3-pro-image-preview with a June 25, 2026 shutdown date, and names gemini-3.1-flash-image and gemini-3-pro-image as the replacements. Calls through Sume do not use those ids: you send a catalog id such as google/nano-banana-2.

What does Google's deprecations page say?

The page defines a shutdown as the model being completely turned off, with the endpoint no longer available. It lists the two preview image ids below.

Which id do I use on Sume?

Sume's image catalog lists google/nano-banana-2, and the bare router id nano-banana-2 is accepted as an alias for it. Sume serves every catalog model through a single sume endpoint in v1, and GET /v1/images/models shows what is available. See the Image API docs.

Do I have to migrate anything on Sume?

If your Sume code already sends a catalog id, nothing here names a preview id to change. If a script still carries a Gemini preview string in a model field, replace it with a catalog id from GET /v1/images/models. Related: the earlier Gemini 2.5 Flash Image shutdown.

What if I do not care which family runs?

model: "sume/auto" lets Sume pick the family and never discloses which one ran, so use a catalog id when you need a specific model.