google/nano-banana-2.1/text-to-imageFrom 8 credits per image· Create Image

Nano Banana 2.1 is Google's update to Nano Banana 2 (Gemini 3.1 Flash Image), released on 6 October 2026. Google improved visual quality, prompt adherence, character consistency across edits and text rendering, and says it fixed the tiling seams on wide banners at 2K and 4K. It renders at 1K, 2K or 4K in fourteen shapes up to 8:1, edits with up to fourteen reference images and can search the web or reference pictures first.

Call it with the model name google/nano-banana-2.1/text-to-image on POST /jobs/createTask, from 8 credits per image ($0.08). New accounts get 30 free credits to try it in the Playground first.

  • Create Image
  • Edit Image
  • Up to 4K
  • Up to 14 reference images
  • 14 aspect ratios
Model namegoogle/nano-banana-2.1/text-to-image
EndpointPOST https://api.popnow.ai/api/v1/jobs/createTask
# 1. Create the task. Keep the Idempotency-Key if you retry after a network error.
export IDEMPOTENCY_KEY="$(uuidgen)"
curl -X POST https://api.popnow.ai/api/v1/jobs/createTask \
  -H "Authorization: Bearer $POPNOW_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $IDEMPOTENCY_KEY" \
  -d '{
  "model": "google/nano-banana-2.1/text-to-image",
  "input": {
    "prompt": "A ceramic teapot on a linen cloth, soft window light, muted palette",
    "aspect_ratio": "16:9",
    "resolution": "1k",
    "output_format": "png"
  }
}'

# 2. Copy data.taskId from the response, then poll until state is succeeded, failed, canceled or expired.
TASK_ID="TASK_ID_FROM_RESPONSE"
curl "https://api.popnow.ai/api/v1/jobs/recordInfo?taskId=$TASK_ID" \
  -H "Authorization: Bearer $POPNOW_API_KEY"

The input is built from the schema below, so it passes validation as written. Change the prompt and links to your own.

Price

OptionCredits per image≈ USD
resolution 1K7.2$0.072
resolution 2K10.8$0.11
resolution 4K24.3$0.24

1 credit = $0.01 · Every option and its price: GET /models/google/nano-banana-2.1/text-to-image

Each task is rounded up to whole credits, so one run at the lowest tier costs 8 credits per image ($0.08).

Limits

Resolutions
1K · 2K · 4K
Aspect ratios
1:1 · 3:2 · 2:3 · 3:4 · 4:3 · 4:5 +8
Prompt length (characters)
5,000

Parameters

These fields come from the same schema we check every request against. Fields that are not listed are rejected.

  • promptstringRequired

    Describe the image you want.

    Range
    1 – 5000 chars
  • aspect_ratiostringOptional

    The shape of the frame: wide, square or tall.

    Default
    "16:9"
    Allowed values
    "1:1""3:2""2:3""3:4""4:3""4:5""5:4""9:16""16:9""21:9""1:4""4:1""1:8""8:1"
  • resolutionstringOptionalChanges the price

    Output size. Bigger sizes look sharper and cost more.

    Default
    "1k"
    Allowed values
    "1k""2k""4k"
  • enable_web_searchbooleanOptionalChanges the price

    Checks the web first, for dates, places and current facts.

    Default
    false
  • enable_image_searchbooleanOptionalChanges the price

    Looks up real pictures of a place or product first.

    Default
    false
  • output_formatstringOptional

    File type of the result.

    Default
    "png"
    Allowed values
    "png""jpeg"
Raw JSON Schema
{
  "type": "object",
  "required": [
    "prompt"
  ],
  "properties": {
    "prompt": {
      "type": "string",
      "maxLength": 5000,
      "minLength": 1,
      "description": "Describe the image you want."
    },
    "resolution": {
      "enum": [
        "1k",
        "2k",
        "4k"
      ],
      "type": "string",
      "default": "1k",
      "description": "Output size tier."
    },
    "aspect_ratio": {
      "enum": [
        "1:1",
        "3:2",
        "2:3",
        "3:4",
        "4:3",
        "4:5",
        "5:4",
        "9:16",
        "16:9",
        "21:9",
        "1:4",
        "4:1",
        "1:8",
        "8:1"
      ],
      "type": "string",
      "default": "16:9",
      "description": "Output aspect ratio."
    },
    "output_format": {
      "enum": [
        "png",
        "jpeg"
      ],
      "type": "string",
      "default": "png",
      "description": "File format of the result."
    },
    "enable_web_search": {
      "type": "boolean",
      "default": false,
      "description": "Look up current facts on the web before drawing."
    },
    "enable_image_search": {
      "type": "boolean",
      "default": false,
      "description": "Look up reference pictures on the web before drawing."
    }
  },
  "additionalProperties": false
}

A real result from Nano Banana 2.1

Bubble Cape
PromptFashion editorial photograph in a sunlit Andalusian plaza with whitewashed walls: a Spanish woman in her forties with slicked-back dark hair wears a structured tangerine bolero jacket and wide cobalt trousers, and a huge cape made of iridescent soap-bubble film billows behind her like a sail, catching rainbow light. Hard sun, deep shadows, low angle, 35mm film grain, photorealistic, no text.
The same request through the API
{
  "model": "google/nano-banana-2.1/text-to-image",
  "input": {
    "prompt": "Fashion editorial photograph in a sunlit Andalusian plaza with whitewashed walls: a Spanish woman in her forties with slicked-back dark hair wears a structured tangerine bolero jacket and wide cobalt trousers, and a huge cape made of iridescent soap-bubble film billows behind her like a sail, catching rainbow light. Hard sun, deep shadows, low angle, 35mm film grain, photorealistic, no text.",
    "aspect_ratio": "16:9",
    "resolution": "1k",
    "output_format": "png"
  }
}

Responses, polling and callbacks

Every model works the same way: create a task, then poll it or wait for a callback.

Price it first

cURL
curl -X POST https://api.popnow.ai/api/v1/jobs/quote \
  -H "Authorization: Bearer $POPNOW_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "google/nano-banana-2.1/text-to-image",
  "input": {
    "prompt": "A ceramic teapot on a linen cloth, soft window light, muted palette",
    "aspect_ratio": "16:9",
    "resolution": "1k",
    "output_format": "png"
  }
}'

Same body as createTask. It returns the expected and the highest possible charge, and runs nothing.

Accepted

HTTP
HTTP/1.1 202 Accepted

{
  "code": 200,
  "msg": "success",
  "data": {
    "taskId": "task_01k3m8x9q2z4v7n5p6r8s0t1w3",
    "state": "queued"
  },
  "request_id": "req_example_create"
}

HTTP 202 means the task was accepted and the credits are held, not charged yet. The final charge never goes above the hold.

Check status

cURL
curl "https://api.popnow.ai/api/v1/jobs/recordInfo?taskId=$TASK_ID" \
  -H "Authorization: Bearer $POPNOW_API_KEY"

Poll every few seconds with backoff and stop once state is succeeded, failed, canceled or expired.

Finished task

JSON
{
  "code": 200,
  "msg": "success",
  "data": {
    "taskId": "task_01k3m8x9q2z4v7n5p6r8s0t1w3",
    "model": "google/nano-banana-2.1/text-to-image",
    "state": "succeeded",
    "output": {
      "assets": [
        {
          "url": "https://cdn.popnow.ai/tasks/task_01k3m8x9q2z4v7n5p6r8s0t1w3/output.png?signature=FROM_RESPONSE",
          "expiresAt": "2026-10-17T12:20:00Z",
          "mime": "image/png",
          "width": 1024,
          "height": 1024
        }
      ]
    },
    "settled": true
  },
  "request_id": "req_example_record"
}

Download from url before expiresAt. Need a fresh link later? Ask POST /common/download-url.

Verify a callback

Node.js
import { createHash, createHmac, timingSafeEqual } from "node:crypto";
import express from "express";

const app = express();
// express.raw keeps the exact bytes that were signed; express.json would not match.
app.post("/hooks/popnow", express.raw({ type: "application/json" }), (req, res) => {
  const timestamp = req.header("X-Webhook-Timestamp");
  const signature = req.header("X-Webhook-Signature") ?? "";
  const body = JSON.parse(req.body.toString("utf8"));
  const taskId = body.data?.taskId ?? body.task_id;
  const digest = createHash("sha256").update(req.body).digest("hex");
  const expected = createHmac("sha256", process.env.POPNOW_WEBHOOK_SECRET)
    .update(`${taskId}.${timestamp}.${digest}`)
    .digest("base64");
  const ok = expected.length === signature.length && timingSafeEqual(Buffer.from(expected), Buffer.from(signature));
  // Check the signature first, then reject anything older than five minutes.
  if (!ok || Math.abs(Date.now() / 1000 - Number(timestamp)) > 300) return res.status(401).end();
  res.status(200).end(); // answer fast, then fetch the task and store its files
});

With callBackUrl set, we post the finished task to you. Check the signature against the raw body before you trust it.

Send a local file

cURL
curl -X POST https://api.popnow.ai/api/v1/common/upload-url \
  -H "Authorization: Bearer $POPNOW_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"contentType": "image/png", "bytes": 482113}'

# PUT the file bytes to data.uploadUrl with every header in data.headers, then commit it:
curl -X POST https://api.popnow.ai/api/v1/files/$FILE_ID/commit \
  -H "Authorization: Bearer $POPNOW_API_KEY"
# The commit returns a popnow://f/... reference. Put it in any image, video or
# audio field of the task input instead of a public https URL.

Public https links work as they are. Local files go through upload-url and commit first.