Nano Banana 2 API: Google Text-to-Image & Editing

Overview

Nano Banana 2 is a high-quality image generation model for text-to-image creation and reference-guided image generation. 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-2`
Modes	`text-to-image`, `image-to-image`
Prompt length	1-20000 characters
Reference images	Required for `image-to-image`; up to 14 URLs
Aspect ratios	`auto`, `1:1`, `1:4`, `4:1`, `1:8`, `3:2`, `2:3`, `3:4`, `4:3`, `4:5`, `5:4`, `8:1`, `9:16`, `16:9`, `21:9`
Resolution tiers	`1k`, `2k`, `4k`
Output formats	`png`, `jpeg`, `jpg`

Endpoint and authentication

Base URL:

https://api.apixo.ai/api/v1

Method	Endpoint	Purpose
`POST`	`/generateTask/nano-banana-2`	Submit a generation task
`GET`	`/statusTask/nano-banana-2?taskId={taskId}`	Poll task status and retrieve results

All requests require your APIXO API key:

Authorization: Bearer YOUR_API_KEY

Submit requests also require:

Content-Type: application/json

Copy-paste async quickstart

This minimal request submits a text-to-image task and returns a taskId.

curl -X POST "https://api.apixo.ai/api/v1/generateTask/nano-banana-2" \
  -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 and rain-soaked streets",
      "aspect_ratio": "3:2",
      "resolution": "2k"
    }
  }'

Successful response:

{
  "code": 200,
  "message": "success",
  "data": {
    "taskId": "task_12345678"
  }
}

Save the taskId; you need it to poll for the final result.

Poll for result

curl -X GET "https://api.apixo.ai/api/v1/statusTask/nano-banana-2?taskId=task_12345678" \
  -H "Authorization: Bearer YOUR_API_KEY"

Processing response:

{
  "code": 200,
  "message": "success",
  "data": {
    "taskId": "task_12345678",
    "state": "processing",
    "createTime": 1767965610929
  }
}

Success response:

{
  "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:

{
  "code": 200,
  "message": "success",
  "data": {
    "taskId": "task_12345678",
    "state": "failed",
    "failCode": "SensitiveContent",
    "failMsg": "Content violates safety policy, please adjust the prompt",
    "createTime": 1767965610929,
    "completeTime": 1767965620132
  }
}

Parse resultJson after state becomes success:

const payload = JSON.parse(data.resultJson);
const imageUrls = payload.resultUrls;

Request body

Text-to-image

{
  "request_type": "async",
  "input": {
    "mode": "text-to-image",
    "prompt": "a fox in watercolor style",
    "aspect_ratio": "16:9",
    "resolution": "2k",
    "output_format": "png",
    "google_search": false
  }
}

Image-to-image

{
  "request_type": "async",
  "input": {
    "mode": "image-to-image",
    "prompt": "make this scene look like sunrise with warm golden light",
    "image_urls": [
      "https://example.com/source.png"
    ],
    "aspect_ratio": "4:5",
    "resolution": "4k",
    "output_format": "jpeg",
    "google_search": false
  }
}

Parameters

string

default:"async"

required

Result delivery mode. Use async for polling with statusTask, or callback for webhook delivery.

string

Required when request_type is callback. Must be a public HTTPS URL that can receive the final task payload. See Webhooks.

object

required

Nano Banana 2 input parameters.

Show properties

string

required

Generation mode. Supported values: text-to-image, image-to-image.

string

required

Text prompt describing the desired image or edit. Leading and trailing whitespace is ignored for validation. Supports 1-20000 characters.

string[]

Reference image URLs. Required for image-to-image; provide 1-14 public, directly fetchable image URLs.

string

required

Output aspect ratio. Supported values: auto, 1:1, 1:4, 4:1, 1:8, 3:2, 2:3, 3:4, 4:3, 4:5, 5:4, 8:1, 9:16, 16:9, 21:9.

string

required

Output resolution tier. Supported values: 1k, 2k, 4k. The API accepts either lowercase or uppercase values and normalizes them for processing.

string

default:"png"

Output image format. Supported values: png, jpeg, jpg. Use jpeg for the JPEG format; jpg is accepted as an alias.

boolean

default:"false"

Enables web search context when supported by the active route. Defaults to false.

aspect_ratio and resolution are required. auto is accepted for aspect_ratio; automatic framing is used when supported.

Response format

Submit task response

POST /generateTask/nano-banana-2 returns a task ID when the task is accepted:

integer

API status code. 200 means the task was accepted.

string

Human-readable status message.

string

Unique task identifier used with the status endpoint.

Status response fields

string

Unique task identifier.

string

Current task state: processing, success, or failed.

string

JSON string containing the generated image URLs. Present when state is success.

string

Machine-readable failure code. Present when state is failed.

string

Human-readable failure message. Present when state is failed.

integer

Task creation timestamp in Unix milliseconds.

integer

Task completion timestamp in Unix milliseconds. Present after completion.

integer

Processing duration in milliseconds. Present after successful completion when available.

Webhook callback mode

Use callback mode when your backend should receive the final result automatically instead of polling.

curl -X POST "https://api.apixo.ai/api/v1/generateTask/nano-banana-2" \
  -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": "turn this product photo into a polished studio ad",
      "image_urls": [
        "https://example.com/product.png"
      ],
      "aspect_ratio": "1:1",
      "resolution": "2k",
      "output_format": "png"
    }
  }'

See Webhooks for delivery requirements and retry behavior.

Billing

New non-LLM requests use 1 credit = $0.001. Calculate the full amount, including billable quantity and add-ons, apply the applicable account discount, then round the request total upward to the next whole credit. Agreed fixed unit prices retain their precision and replace the standard price and discount; final rounding still applies. See credit conversion and rounding. Nano Banana 2 is billed per generated image. The selected resolution determines the unit price.

Resolution	APIXO price
`1k`	`$0.05 / image`
`2k`	`$0.08 / image`
`4k`	`$0.12 / image`

For current API rates in USD, see API pricing.

Latency and polling

Actual latency may vary by prompt complexity, reference image accessibility, selected resolution, route health, and current queue load. The backend returns costTime in milliseconds after completion when timing data is available.

Stage	Guidance
First poll	Wait 10s-20s after task creation before the first status request
Poll interval	Poll every 10s while `state` is `processing`
Production delivery	Use callback mode for high-concurrency workloads

Result URLs are available for 15 days by default. 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.

Errors and troubleshooting

HTTP errors

Code	Meaning	What to do
`400`	Invalid request body, mode, parameter, 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 or unknown task failure	Retry with backoff
`502`	Service error	Retry with backoff
`504`	Service timeout	Retry or use callback mode for long-running jobs

Task failure codes

Fail code	Meaning	What to do
`PromptInvalid`	Prompt was invalid or rejected	Revise the prompt
`SensitiveContent`	Prompt or output violated safety policy	Change the prompt or reference image
`ImageFormatIncorrect`	A reference image could not be accepted	Use a public, direct image URL in a common image format
`MissingParameter`	A required parameter was missing	Check `mode`, `prompt`, `aspect_ratio`, `resolution`, and `image_urls`
`RateLimited`	A rate limit was reached	Retry with backoff
`Timeout`	The task timed out	Retry, reduce input complexity, or use callback mode
`Unknown error`	An unknown task failure occurred	Retry with backoff or contact support with the `taskId`

See Error Codes for the full error reference.

MCP integration

The complete model schema declares result decoding in mcp.result and supported file bindings in mcp.attachments. These are client integration metadata, not generation input parameters. Attachment paths: image_urls. Preserve the user’s file order. Model parameter validation remains on the API.

​Overview

​Endpoint and authentication

​Copy-paste async quickstart

​Poll for result

​Request body

​Text-to-image

​Image-to-image

​Parameters

​Response format

​Submit task response

​Status response fields

​Webhook callback mode

​Billing

​Latency and polling

​Errors and troubleshooting

​HTTP errors

​Task failure codes

​MCP integration

​Related links

Overview

Endpoint and authentication

Copy-paste async quickstart

Poll for result

Request body

Text-to-image

Image-to-image

Parameters

Response format

Submit task response

Status response fields

Webhook callback mode

Billing

Latency and polling

Errors and troubleshooting

HTTP errors

Task failure codes

MCP integration

Related links