> ## Documentation Index
> Fetch the complete documentation index at: https://apixo.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.
# Nano Banana Pro
> Professional Google image generation API with 4K output and multi-reference editing
## Overview
Nano Banana Pro is a Google image model for high-quality text-to-image generation and reference-guided image editing. Use this page when you are ready to call the API after trying the model in the APIXO playground.
| Capability | Value |
| ---------------- | ----------------------------------------------------------------------- |
| Model ID | `nano-banana-pro` |
| Modes | `text-to-image`, `image-to-image` |
| Prompt length | 1-5000 characters |
| Reference images | Up to 10 URLs for `image-to-image` |
| Aspect ratios | `1:1`, `4:3`, `3:4`, `3:2`, `2:3`, `4:5`, `5:4`, `9:16`, `16:9`, `21:9` |
| Resolution tiers | `1K`, `2K`, `4K` |
| Output formats | `png`, `jpg` |
## Endpoint and authentication
Base URL:
```text theme={null}
https://api.apixo.ai/api/v1
```
| Method | Endpoint | Purpose |
| ------ | --------------------------------------------- | ------------------------------------- |
| `POST` | `/generateTask/nano-banana-pro` | Submit a generation task |
| `GET` | `/statusTask/nano-banana-pro?taskId={taskId}` | Poll task status and retrieve results |
All requests require your APIXO API key:
```http theme={null}
Authorization: Bearer YOUR_API_KEY
```
Submit requests also require:
```http theme={null}
Content-Type: application/json
```
## Copy-paste async quickstart
This minimal request submits a text-to-image task and returns a `taskId`.
```bash theme={null}
curl -X POST "https://api.apixo.ai/api/v1/generateTask/nano-banana-pro" \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"request_type": "async",
"input": {
"mode": "text-to-image",
"prompt": "a cozy cyberpunk cafe with neon lights, ultra detailed",
"aspect_ratio": "3:2",
"resolution": "2K",
"output_format": "png"
}
}'
```
Successful response:
```json theme={null}
{
"code": 200,
"message": "success",
"data": {
"taskId": "task_12345678"
}
}
```
Save the `taskId`; you need it to poll for the final result.
## Poll for result
```bash theme={null}
curl -X GET "https://api.apixo.ai/api/v1/statusTask/nano-banana-pro?taskId=task_12345678" \
-H "Authorization: Bearer YOUR_API_KEY"
```
Processing response:
```json theme={null}
{
"code": 200,
"message": "success",
"data": {
"taskId": "task_12345678",
"state": "processing",
"createTime": 1767965610929
}
}
```
Success response:
```json theme={null}
{
"code": 200,
"message": "success",
"data": {
"taskId": "task_12345678",
"state": "success",
"resultJson": "{\"resultUrls\":[\"https://file.apixo.ai/xxx.png\"]}",
"createTime": 1767965610929,
"completeTime": 1767965652317,
"costTime": 41388
}
}
```
Failed response:
```json theme={null}
{
"code": 200,
"message": "success",
"data": {
"taskId": "task_12345678",
"state": "failed",
"failCode": "CONTENT_VIOLATION",
"failMsg": "Content does not meet safety guidelines",
"createTime": 1767965610929,
"completeTime": 1767965620132
}
}
```
Parse `resultJson` after `state` becomes `success`:
```javascript theme={null}
const payload = JSON.parse(data.resultJson);
const imageUrls = payload.resultUrls;
```
## Request body
### Text-to-image
```json theme={null}
{
"request_type": "async",
"input": {
"mode": "text-to-image",
"prompt": "a fox in watercolor style, crisp details",
"aspect_ratio": "16:9",
"resolution": "2K",
"output_format": "png"
}
}
```
### Image-to-image
```json theme={null}
{
"request_type": "async",
"input": {
"mode": "image-to-image",
"prompt": "combine these references into a futuristic cityscape",
"image_urls": [
"https://example.com/ref1.png",
"https://example.com/ref2.jpg"
],
"aspect_ratio": "16:9",
"resolution": "4K",
"output_format": "jpg"
}
}
```
## Parameters
Result delivery mode. Use `async` for polling with `statusTask`, or `callback` for webhook delivery.
Required when `request_type` is `callback`. Must be a public HTTPS URL that can receive the final task payload. See [Webhooks](/api-reference/webhooks).
Nano Banana Pro input parameters.
Generation mode. Supported values: `text-to-image`, `image-to-image`.
Text prompt describing the desired image or edit. Supports 1-5000 characters and cannot be empty after trimming whitespace.
Reference image URLs. Required for `image-to-image`. Supports up to 10 URLs; each item must be a non-empty string. Use public direct JPG, PNG, or WebP URLs. If sent with `text-to-image`, the URLs are validated but are not forwarded to the text generation route.
Output aspect ratio. Supported values: `1:1`, `4:3`, `3:4`, `3:2`, `2:3`, `4:5`, `5:4`, `9:16`, `16:9`, `21:9`.
Output resolution tier. Supported values: `1K`, `2K`, `4K`. Values are case-sensitive.
Output image format. Supported values: `png`, `jpg`. Default is `png`.
## Response format
### Submit task response
`POST /generateTask/nano-banana-pro` returns a task ID when the task is accepted:
API status code. `200` means the task was accepted.
Human-readable status message.
Unique task identifier used with the status endpoint.
### Status response fields
Unique task identifier.
Current task state: `pending`, `processing`, `success`, or `failed`.
JSON string containing the generated image URLs. Present when `state` is `success`.
Machine-readable failure code. Present when `state` is `failed`.
Human-readable failure message. Present when `state` is `failed`.
Task creation timestamp in Unix milliseconds.
Task completion timestamp in Unix milliseconds. Present after completion.
Processing duration in milliseconds. Nano Banana Pro normalizes provider timing to milliseconds.
## Webhook callback mode
Use callback mode when your backend should receive the final result automatically instead of polling.
```bash theme={null}
curl -X POST "https://api.apixo.ai/api/v1/generateTask/nano-banana-pro" \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"request_type": "callback",
"callback_url": "https://your-server.com/webhooks/apixo",
"input": {
"mode": "image-to-image",
"prompt": "create a polished advertising image while preserving the product shape",
"image_urls": [
"https://example.com/product.png"
],
"aspect_ratio": "1:1",
"resolution": "4K",
"output_format": "png"
}
}'
```
See [Webhooks](/api-reference/webhooks) for delivery requirements and retry behavior.
## Billing
Nano Banana Pro is billed per generated image. The selected `resolution` determines the unit price.
| Resolution | APIXO price | Market price |
| ----------- | --------------- | --------------- |
| `1K` / `2K` | `$0.08 / image` | `$0.15 / image` |
| `4K` | `$0.14 / image` | `$0.30 / image` |
For current route and market comparison pricing, see [Pricing](https://apixo.ai/pricing).
## Latency and polling
Actual latency may vary by prompt complexity, reference image availability, provider route, and current queue load.
| Resolution | Typical generation time | Recommended first poll | Poll interval |
| ---------- | ----------------------- | ----------------------- | ------------- |
| `1K` | 20s-30s | 20s after task creation | 3s |
| `2K` | 30s-45s | 20s after task creation | 3s |
| `4K` | 45s-60s | 20s after task creation | 3s-5s |
For high-concurrency production workloads, use callback mode to avoid frequent polling. Result URLs are valid for 15 days; download and store important outputs promptly.
Rate limits and concurrency can vary by account, API key, and route. If you receive `429`, slow down requests and retry with backoff. For account-level details, see [System APIs](/api-reference/system).
## Errors and troubleshooting
### HTTP errors
| Code | Meaning | What to do |
| ----- | ------------------------------------------------------------------ | ------------------------------------------------ |
| `400` | Invalid request body, mode, parameter, balance, or image URL shape | Fix the request before retrying |
| `401` | Missing or invalid API key | Check the `Authorization` header |
| `402` | Insufficient balance or quota | Add balance or switch account/key |
| `403` | Key or route cannot access the model | Check permissions and route strategy |
| `429` | Rate limit or concurrency limit reached | Retry with exponential backoff |
| `500` | Server error | Retry with backoff |
| `502` | Upstream provider error | Retry with backoff |
| `504` | Upstream timeout | Retry or use callback mode for long-running jobs |
### Task failure codes
| Fail code | Meaning | What to do |
| ---------------------- | ----------------------------------------------------- | --------------------------------------------------------------------------------------- |
| `CONTENT_VIOLATION` | Prompt or reference image failed safety checks | Change the prompt or input image |
| `INVALID_IMAGE_URL` | A reference image URL could not be fetched or decoded | Use a public, direct image URL |
| `INVALID_PARAMETER` | A model parameter is unsupported or malformed | Check `mode`, `prompt`, `aspect_ratio`, `resolution`, `image_urls`, and `output_format` |
| `INSUFFICIENT_BALANCE` | The account does not have enough balance for the task | Add balance before retrying |
| `UPSTREAM_ERROR` | Provider-side failure | Retry with backoff or try another route |
| `TIMEOUT` | Generation did not finish in time | Retry, reduce input complexity, or use callback mode |
### Parameter troubleshooting
| Symptom | Likely cause | Fix |
| ---------------------------------- | ------------------------------------------------------------------------ | --------------------------------------------- |
| `Invalid mode type` | `input.mode` is missing or unsupported | Use `text-to-image` or `image-to-image` |
| `aspect_ratio` validation error | The value is missing or not one of the supported ratios | Send an exact supported ratio, such as `16:9` |
| `resolution` validation error | The value is missing, lowercase, or unsupported | Send `1K`, `2K`, or `4K` exactly |
| `output_format` validation error | The format is unsupported or malformed | Use `png` or `jpg` |
| Image-to-image task fails upstream | `image_urls` is empty, unreachable, too large, or not a direct image URL | Use 1-10 public direct image URLs |
See [Error Codes](/api-reference/errors) for the full error reference.
## Related links
* [Generation API Overview](/models)
* [Generate Task](/api-reference/generate-task)
* [Status Task](/api-reference/status-task)
* [Webhooks](/api-reference/webhooks)
* [Error Codes](/api-reference/errors)
* [Parameter Specification](/api-reference/parameters)
* [Routing Strategies](/concepts/routing-strategies)
* [Pricing](https://apixo.ai/pricing)