Google Nano Banana Pro Text To Image Multi API Documentation

Google Nano Banana Pro Text To Image Multi API Documentation

Playground

Try it on WaveSpeedAI!

Google’s Nano Banana Pro (Gemini 3.0 Pro Image) is a next-generation text-to-image model capable of generating multiple high-quality images in a single run. Extremely low cost — only $0.07 per image. Ready-to-use REST inference API, best performance, no coldstarts, affordable pricing.

Features

Nano Banana Pro Text-to-Image Multi (Gemini 3.0 Pro Image) is Google’s next-generation text-to-image model with true multi-image generation. One prompt generates two images in a single run, perfect for rapid exploration, A/B testing, and storyboard creation. On WaveSpeedAI, this endpoint costs $0.07 per image, or $0.14 per request for two images.


🌟 Why it stands out

  • True multi-image generation Generate two images from one prompt in a single request. num_images is fixed at 2.

  • Two-image output Each request returns two images, with controls for aspect ratio and output format.

  • Powerful prompt understanding Handles detailed, editorial-style prompts with nuanced control over subject, composition, lighting, and mood.

  • Aspect ratio and format flexibility Supports 3:2, 2:3, 3:4, and 4:3 aspect ratios, with png or jpeg output.

  • Fast and affordable at scale Batched generation plus a flat per-image price makes it ideal for campaigns, design sprints, and large creative pipelines.


⚙️ Capabilities

  • Input: one natural-language text prompt.
  • Output: two images per request.
  • num_images: fixed at 2; each request generates two images.
  • aspect_ratio: 3:2, 2:3, 3:4, or 4:3. Default: 3:2.
  • output_format: png or jpeg. Default: png.

Example use cases:

  • Generate two fashion shots from one art-direction prompt.
  • Produce multiple thumbnail variants for a single YouTube or e-commerce listing.
  • Create quick moodboard frames that share the same style but differ in composition.

💰 Pricing

  • $0.07 per image × 2 images = $0.14 per request.

💡 Best Use Cases

  • A/B testing ad creatives Produce multiple variations of a campaign visual, then pick the best-performing one.

  • Thumbnail and banner exploration Generate two layout and color options for social posts, storefronts, and landing pages.

  • Storyboards and keyframes Create multiple frames from a shared prompt to sketch out sequences for video, animation, or presentations.

  • Brand style development Lock in a consistent stylistic direction while exploring slight changes in pose, background, or framing.

  • Concept art and moodboards Batch-generate different interpretations of a scene to speed up early-stage visual ideation.


📝 Notes

  • Prompts must comply with Google’s safety policies. If a request fails or content is removed, review the prompt for restricted material and rephrase accordingly.
  • Each request generates two images. num_images cannot be changed to another value.
  • Avoid conflicting instructions inside a single prompt (for example, “night” and “bright midday sun” together), as this can reduce quality or coherence.
  • Higher-level, descriptive prompts usually work better than extremely short or keyword-only inputs.

🌏 Where Nano Banana Pro Fits In

Use Google Nano Banana Pro Text-to-Image Multi when:

  • You want two image options from a single prompt in one run.
  • You are iterating on creative direction and need fast, low-cost visual diversity.
  • You are building tools that benefit from batched image generation for performance and pricing reasons.

For complementary workflows on WaveSpeedAI:

  • Nano Banana Pro Text-to-Image Ultra – for maximum resolution and detail on individual hero images.
  • Nano Banana Pro Edit – for object-level or style edits on existing assets.
  • FLUX series – for cinematic, high-impact visuals and experimental aesthetics.
  • Seedream series – for cost-effective, style-consistent illustration and multi-image set generation.
  • Qwen Image series – for strong LoRA support, flexible style transfer, and advanced controllability.

Authentication

For authentication details, please refer to the Authentication Guide.

API Endpoints

Submit Task & Query Result

set -euo pipefail

export WAVESPEED_API_KEY="your-api-key"

REQUEST_BODY=$(cat <<'JSON'
{
  "prompt": "A cinematic ocean wave at sunrise, highly detailed",
  "aspect_ratio": "3:2",
  "num_images": 2,
  "output_format": "png"
}
JSON
)

# 1. Submit the prediction once. Never retry this request automatically:
# a retry after an unclear failure can create a second, billed task.
CHECK='The task may already exist. Check History or the predictions list before submitting again.'
if ! SUBMIT_RESPONSE=$(curl --silent --show-error --fail-with-body \
  --connect-timeout 10 --max-time 60 \
  -X POST "https://api.wavespeed.ai/api/v3/google/nano-banana-pro/text-to-image-multi" \
  -H "Authorization: Bearer ${WAVESPEED_API_KEY}" \
  -H "Content-Type: application/json" \
  -d "${REQUEST_BODY}"); then
  printf 'Submit failed. %s\n' "${CHECK}" >&2
  exit 1
fi

TASK=$(printf '%s' "${SUBMIT_RESPONSE}" | jq 'if type == "object" and has("data") then .data else . end')
PREDICTION_ID=$(printf '%s' "${TASK}" | jq -r '.id // empty')
if [ -z "${PREDICTION_ID}" ]; then
  printf 'Submission response did not contain a prediction id. %s\n' "${CHECK}" >&2
  exit 1
fi
RESULT_URL="https://api.wavespeed.ai/api/v3/predictions/${PREDICTION_ID}/result"

# 2. Poll until the prediction reaches a final status.
BODY_FILE=$(mktemp)
trap 'rm -f "${BODY_FILE}"' EXIT
while true; do
  # Transient errors (429, 5xx) are retried, honoring Retry-After.
  HTTP_CODE=$(curl --silent --show-error --fail-with-body \
    --connect-timeout 10 --max-time 60 --retry 5 --retry-delay 2 \
    --output "${BODY_FILE}" --write-out '%{http_code}' \
    "${RESULT_URL}" \
    -H "Authorization: Bearer ${WAVESPEED_API_KEY}" || true)
  case "${HTTP_CODE}" in
    2??) ;;
    000|429|5??)  # dropped connection or temporary error: keep polling
      printf 'Task %s: HTTP %s, polling again in 10s\n' "${PREDICTION_ID}" "${HTTP_CODE}" >&2
      sleep 10; continue ;;
    *) printf 'Task %s: HTTP %s\n' "${PREDICTION_ID}" "${HTTP_CODE}" >&2
      cat "${BODY_FILE}" >&2; exit 1 ;;
  esac
  RESULT=$(jq 'if type == "object" and has("data") then .data else . end' "${BODY_FILE}")
  STATUS=$(printf '%s' "${RESULT}" | jq -r '.status // empty')

  case "${STATUS}" in
    completed) printf '%s\n' "${RESULT}" | jq '.outputs'; break ;;
    failed|cancelled|timeout|deleted)
      printf 'Task %s ended with status %s\n' "${PREDICTION_ID}" "${STATUS}" >&2
      printf '%s\n' "${RESULT}" | jq . >&2; exit 1 ;;
    *) sleep 2 ;;
  esac
done

Retry temporary errors only while polling, never the submit request. Errors, retries and timeouts

Parameters

Task Submission Parameters

Request Parameters

ParameterTypeRequiredDefaultRangeDescription
promptstringYes-The positive prompt for the generation.
aspect_ratiostringYes3:23:2, 2:3, 3:4, 4:3The aspect ratio of the generated image. Defaults to 3:2.
num_imagesintegerNo22The number of images to generate.
output_formatstringNopngpng, jpegThe format of the output image.

Every model also accepts the global request options enable_sync_mode and enable_base64_output; see their pages for details.

Response Parameters

ParameterTypeDescription
codeintegerHTTP status code (e.g., 200 for success)
messagestringStatus message (e.g., “success”)
data.idstringUnique identifier for the prediction, Task Id
data.modelstringModel ID used for the prediction
data.outputsarrayOutput values, usually URL strings; some models return text strings or structured result objects (empty when status is not completed)
data.urlsobjectObject containing related API endpoints
data.statusstringTask status. completed is successful; failed, cancelled, timeout, and deleted are failure terminal statuses.
data.created_atstringISO timestamp of when the request was created (e.g., “2023-04-01T12:34:56.789Z”)
data.errorstringError message (empty if no error occurred)
data.timingsobjectObject containing timing details
data.timings.inferenceintegerInference time in milliseconds

Result Request Parameters

ParameterTypeRequiredDefaultDescription
idstringYes-Task ID

Result Response Parameters

ParameterTypeDescription
codeintegerHTTP status code (e.g., 200 for success)
messagestringStatus message (e.g., “success”)
dataobjectThe prediction data object containing all details
data.idstringUnique identifier for the prediction
data.modelstringModel ID used for the prediction
data.outputsarray<string | object>Array of generated outputs (empty when status is not completed). Items are usually URL strings, but may be text strings or structured result objects, depending on the model.
data.urlsobjectObject containing related API endpoints
data.statusstringStatus: completed is successful; failed, cancelled, timeout, and deleted are failure terminal statuses
data.created_atstringISO timestamp of when the request was created
data.errorstringError message (empty if no error occurred)
data.timingsobjectObject containing timing details
data.timings.inferenceintegerInference time in milliseconds
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