> ## Documentation Index > Fetch the complete documentation index at: https://docs.poyo.ai/llms.txt > Use this file to discover all available pages before exploring further. # Nano Banana 2.1 Image Generation > Create and edit images with Nano Banana 2.1 1. After submission, a `task_id` will be returned. If you provided a `callback_url`, a POST request will be sent when the task status becomes `finished` or `failed`. 2. You can also retrieve the result through [Query Task Status](/api-manual/task-management/status). # Nano Banana 2.1 Image Generation Use `nano-banana-2.1` for text-to-image generation. Add `image_urls` to edit one or more reference images with the same model ID. The model supports up to 10 reference images. ## Available Models * **nano-banana-2.1** - Text-to-image and image-to-image generation The default `resolution` is `1K`. For text-to-image generation, `size` defaults to `1:1`. When `image_urls` are provided, `size` defaults to `auto`, allowing the model to choose an aspect ratio from the reference images. You can also select a supported ratio explicitly. The `auto` option is only available for image editing. ## OpenAPI ````yaml api-manual/image-series/nano-banana-2-1.json POST /api/generate/submit openapi: 3.0.0 info: title: PoYo AI - Nano Banana 2.1 API description: Create and edit images with Nano Banana 2.1 version: 1.0.0 servers: - url: https://api.poyo.ai description: Production server security: - BearerAuth: [] paths: /api/generate/submit: post: tags: - Nano Banana 2.1 summary: Submit Nano Banana 2.1 Generation Task description: Create images from a prompt or edit up to 10 reference images operationId: submitNanoBanana21Task requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/SubmitRequest' examples: text-to-image: summary: Text-to-image generation value: model: nano-banana-2.1 callback_url: https://your-domain.com/callback input: prompt: A warm sunlit studio portrait of an orange cat size: '1:1' resolution: 1K image-to-image: summary: Reference-image editing value: model: nano-banana-2.1 input: prompt: >- Keep the subject and replace the background with a watercolor garden image_urls: - https://example.com/reference.png size: auto resolution: 2K responses: '200': description: Task submitted successfully content: application/json: schema: $ref: '#/components/schemas/SubmitResponse' '400': description: Invalid request parameters content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: code: 400 error: message: Invalid request parameters type: invalid_request_error '401': description: Unauthorized - Invalid API key content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: code: 401 error: message: Unauthorized - Invalid API key type: authentication_error components: schemas: SubmitRequest: type: object required: - model - input properties: model: type: string description: Nano Banana 2.1 model identifier enum: - nano-banana-2.1 callback_url: type: string format: uri description: Webhook callback URL for result notifications example: https://your-domain.com/callback input: type: object required: - prompt additionalProperties: false description: Image generation or editing parameters. properties: prompt: type: string description: Describe the image to create or how to edit reference images. minLength: 1 maxLength: 20000 example: An orange cat sitting by a window image_urls: type: array items: type: string format: uri minItems: 1 maxItems: 10 description: >- Optional reference image URLs for image editing. When provided, pass an array of 1 to 10 HTTP(S) URLs. example: - https://example.com/reference.png size: type: string description: >- Output aspect ratio. Defaults to auto when image_urls are provided, otherwise 1:1. auto is only supported for image editing and lets the model choose a ratio from the reference images. enum: - auto - '1:1' - '2:3' - '3:2' - '3:4' - '4:3' - '4:5' - '5:4' - '9:16' - '16:9' - '21:9' example: '16:9' resolution: type: string description: Output resolution. enum: - 1K - 2K - 4K default: 1K example: 2K SubmitResponse: type: object required: - code - data properties: code: type: integer example: 200 description: HTTP status code data: type: object required: - task_id - status - created_time properties: task_id: type: string example: task-unified-1757165031-uyujaw3d description: Unique task identifier for status tracking status: type: string enum: - not_started example: not_started description: Initial task status created_time: type: string format: date-time example: '2026-10-08T10:30:00' description: ISO 8601 timestamp when the task was created ErrorResponse: type: object required: - code - error properties: code: type: integer example: 400 description: HTTP status code error: type: object required: - message - type properties: message: type: string example: Invalid request parameters description: Error message describing what went wrong type: type: string example: invalid_request_error description: Error type identifier securitySchemes: BearerAuth: type: http scheme: bearer bearerFormat: API Key description: >- All API endpoints require Bearer Token authentication Get your API Key: Visit the [API Key Management Page](https://poyo.ai/dashboard/api-key) to get your API Key Add it to the request header: ``` Authorization: Bearer YOUR_API_KEY ``` ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.