Gemini Interactions API image output vs Sume /v1/images

With the Gemini API's Interactions API you read the generated image from the interaction.output_image property. On Sume you call POST /v1/images and read data[].url, a Sume-hosted signed URL; if the render outlasts 30 seconds the call returns 202 and a job envelope instead.

Gemini facts are from Google's image generation page; Sume facts from the Image API docs, read 2026-10-01.

How does Gemini return the image?

Google's page shows client.interactions.create with model gemini-3.1-flash-image and says you retrieve generated image data with the interaction.output_image property, which returns the last generated image block. The Python sample base64-decodes output_image.data and writes it to a file.

How does Sume return it?

The result payload is data[].url (Sume-hosted, signed) rather than inline base64, which keeps responses small. The Google image family is in the catalog as google/nano-banana-2, and the bare router id nano-banana-2 is accepted as an alias.

What if the response is 202?

POST /v1/images blocks for up to 30 seconds and returns 200 with the images. If generation is still running, or you send mode: "async", you get 202 with status_url and result_url. The docs are explicit: check the status code, not the body shape. Then poll GET /v1/jobs/{id}/status and fetch GET /v1/jobs/{id}/result; see Jobs and results.

const res = await fetch("https://api.sume.com/v1/images", {
  method: "POST",
  headers: {
    Authorization: "Bearer " + process.env.SUME_API_KEY,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    model: "google/nano-banana-2",
    prompt: "a nano banana dish in a fancy restaurant",
  }),
});
const body = await res.json();
if (res.status === 200) console.log(body.data[0].url);
else if (res.status === 202) console.log(body.data.result_url);

Which model id do I send?

Use the Sume catalog id, not the Gemini id. Sume serves every catalog model through a single sume endpoint in v1. For a similar comparison on the video side, see previous interaction id vs a job per request.