> ## Documentation Index > Fetch the complete documentation index at: https://evolink.ai/docs/llms.txt > Use this file to discover all available pages before exploring further. # Nanobanana 2.1 Image Generation > - Nano Banana 2.1 (gemini-nano-banana-2.1) model supports text-to-image, image-to-image, image editing, multi-image composition and other generation modes, with output at `1K`, `2K` or `4K` - Asynchronous processing mode, use the returned task ID to [query](https://evolink.ai/docs/en/api-manual/task-management/get-task-detail) - Generated image links are valid for 24 hours, please save them promptly - Billing: output images are billed by resolution tier, input images per image, web search and image search by the actual number of searches, and prompt text, text output and thinking by tokens; the final charge is the `usage` returned by the task query ## OpenAPI ````yaml /en/api-manual/image-series/nanobanana-2.1/nanobanana-2.1-image-generate.json POST /v1/images/generations openapi: 3.1.0 info: title: Nano Banana 2.1 Interface description: >- Create image generation tasks using AI models, supporting various models and parameter configurations license: name: MIT version: 1.0.0 servers: - url: https://api.evolink.ai description: Production environment security: - bearerAuth: [] tags: - name: Image Generation description: AI image generation related APIs paths: /v1/images/generations: post: tags: - Image Generation summary: Nano Banana 2.1 Interface description: >- - Nano Banana 2.1 (gemini-nano-banana-2.1) model supports text-to-image, image-to-image, image editing, multi-image composition and other generation modes, with output at `1K`, `2K` or `4K` - Asynchronous processing mode, use the returned task ID to [query](https://evolink.ai/docs/en/api-manual/task-management/get-task-detail) - Generated image links are valid for 24 hours, please save them promptly - Billing: output images are billed by resolution tier, input images per image, web search and image search by the actual number of searches, and prompt text, text output and thinking by tokens; the final charge is the `usage` returned by the task query operationId: createImageGenerationNanoBanana21 requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/ImageGenerationRequest' examples: text_to_image: summary: Text to Image value: model: gemini-nano-banana-2.1 prompt: A cat playing on the grass size: '16:9' quality: 2K image_edit: summary: Image to Image / Image Editing value: model: gemini-nano-banana-2.1 prompt: >- Replace the cat in the image with a Shiba Inu, keeping the background and lighting unchanged quality: 2K image_urls: - https://example.com/image1.png web_search: summary: Generate after Web Search value: model: gemini-nano-banana-2.1 prompt: >- A weather infographic for Tokyo this weekend, flat style, clear and readable text size: '16:9' quality: 2K model_params: web_search: true responses: '200': description: Image generation task created successfully content: application/json: schema: $ref: '#/components/schemas/ImageGenerationResponse' '400': description: Invalid request parameters content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: code: invalid_request message: Invalid request parameters type: invalid_request_error '401': description: Unauthenticated, invalid or expired token content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: code: unauthorized message: Invalid or expired token type: authentication_error '402': description: Insufficient quota, recharge required content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: code: insufficient_quota message: Insufficient quota. Please top up your account. type: insufficient_quota '403': description: Access denied content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: code: model_access_denied message: >- Token does not have access to model: gemini-nano-banana-2.1 type: invalid_request_error '429': description: Rate limit exceeded content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: code: rate_limit_exceeded message: Too many requests, please try again later type: rate_limit_error '500': description: Internal server error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: code: internal_error message: Internal server error type: api_error components: schemas: ImageGenerationRequest: type: object required: - model - prompt properties: model: type: string description: >- Image generation model name, official channel, better stability and controllability, suitable for commercial scenarios example: gemini-nano-banana-2.1 enum: - gemini-nano-banana-2.1 default: gemini-nano-banana-2.1 prompt: type: string description: >- Prompt describing the image to be generated, or describing how to edit the input image, up to `4000` tokens example: A cat playing in the grass size: type: string description: Aspect ratio of the generated image, default is `auto` enum: - auto - '1:1' - '1:4' - '4:1' - '1:8' - '8:1' - '2:3' - '3:2' - '3:4' - '4:3' - '4:5' - '5:4' - '9:16' - '16:9' - '21:9' default: auto quality: type: string description: |- Resolution tier of the generated image, default is `2K` **Note:** - Different tiers have different pricing; the output image is billed by the selected tier, so pass it explicitly enum: - 1K - 2K - 4K default: 2K image_urls: type: array description: >- Reference image URL list for image-to-image, image editing and multi-image composition **Note:** - Maximum number of input images per request: `14` - Image size: not exceeding `20MB` - Supported file formats: `.jpeg`, `.jpg`, `.png`, `.webp` - Image URLs must be directly accessible by the server, or the image URL should directly download when accessed (typically these URLs end with image file extensions, such as `.png`, `.jpg`) - Input images are billed per image items: type: string format: uri maxItems: 14 example: - https://example.com/image1.png - https://example.com/image2.png model_params: type: object description: Model extension parameters properties: web_search: type: boolean description: >- Whether to enable web search, defaults to `false`. When enabled, the model looks up current information on the web before generating **Note:** - Billed by the actual number of searches the model runs; one request may search several times default: false example: true image_search: type: boolean description: >- Whether to enable image search, defaults to `false`. When enabled, the model retrieves images from the web as visual references before generating **Note:** - Billed by the actual number of searches the model runs; one request may search several times default: false example: true thinking_level: type: string description: >- Thinking level, controls the depth of reasoning the model performs before generating images, defaults to `auto` - `auto`: Not specified, the model decides - `min`: Minimal reasoning, fastest - `medium`: Balanced reasoning - `high`: Deep reasoning **Note:** - Tokens produced by thinking are billed as text output enum: - auto - min - medium - high default: auto example: medium callback_url: type: string description: >- HTTPS callback address after task completion **Callback Timing:** - Triggered when task is completed, failed, or cancelled - The callback may omit `usage.credits_used` while billing is pending; verify final billing with the task API **Security Restrictions:** - Only HTTPS protocol is supported - Callback to internal IP addresses is prohibited (127.0.0.1, 10.x.x.x, 172.16-31.x.x, 192.168.x.x, etc.) - URL length must not exceed `2048` UTF-8 bytes **Callback Mechanism:** - Timeout: `10` seconds - Maximum `3` retries on failure (retries after `1` second/`2` seconds/`4` seconds) - Callback response body format is consistent with the task query API response format - Callback address returning 2xx status code is considered successful, other status codes will trigger retry format: uri example: https://your-domain.com/webhooks/image-task-completed ImageGenerationResponse: type: object properties: created: type: integer description: Task creation timestamp example: 1757165031 id: type: string description: Task ID example: task-unified-1757165031-uyujaw3d model: type: string description: Actual model name used example: gemini-nano-banana-2.1 object: type: string enum: - image.generation.task description: Specific task type progress: type: integer description: Task progress percentage (0-100) minimum: 0 maximum: 100 example: 0 status: type: string description: Task status enum: - pending - processing - completed - failed example: pending task_info: $ref: '#/components/schemas/TaskInfo' description: Asynchronous task information type: type: string enum: - text - image - audio - video description: Task output type example: image usage: $ref: '#/components/schemas/Usage' description: Usage and billing information ErrorResponse: type: object properties: error: type: object properties: code: type: string description: Error code identifier message: type: string description: Error description type: type: string description: Error type TaskInfo: type: object properties: can_cancel: type: boolean description: Whether the task can be cancelled example: true estimated_time: type: integer description: Estimated completion time (seconds) minimum: 0 example: 45 Usage: type: object description: Usage and billing information properties: billing_rule: type: string description: Billing rule enum: - per_call - per_token - per_second - per_image example: per_image credits_reserved: type: number description: Estimated credits consumed minimum: 0 example: 3.0845 user_group: type: string description: User group category enum: - default - vip example: default securitySchemes: bearerAuth: type: http scheme: bearer description: >- ##All APIs require Bearer Token authentication## **Get API Key:** Visit [API Key Management Page](https://evolink.ai/dashboard/keys) to get your API Key **Add to request header:** ``` Authorization: Bearer YOUR_API_KEY ``` ```` > ## Documentation Index > Fetch the complete documentation index at: https://evolink.ai/docs/llms.txt > Use this file to discover all available pages before exploring further. # Query Task Status > Query the status, progress, and result information of asynchronous tasks by task ID ## OpenAPI ````yaml en/api-manual/task-management/get-task-detail.json get /v1/tasks/{task_id} openapi: 3.1.0 info: title: Get Task Details API description: >- Query the status, progress, and result information of asynchronous tasks by task ID license: name: MIT version: 1.0.0 servers: - url: https://api.evolink.ai description: Production environment security: - bearerAuth: [] tags: - name: Task Management description: Asynchronous task management related APIs paths: /v1/tasks/{task_id}: get: tags: - Task Management summary: Query Task Status description: >- Query the status, progress, and result information of asynchronous tasks by task ID operationId: getTaskDetail parameters: - name: task_id in: path required: true schema: type: string description: >- Task ID, ignore {} when querying, append the id from the async task response body at the end of the path example: task-unified-1756817821-4x3rx6ny responses: '200': description: Task status details content: application/json: schema: $ref: '#/components/schemas/TaskDetailResponse' '400': description: Request parameter error, format error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: code: invalid_task_id message: Invalid task ID format, must start with 'task-unified-' type: invalid_request_error param: task_id '401': description: Unauthenticated, token invalid or expired content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: code: unauthorized message: Authentication required type: authentication_error '402': description: Insufficient quota, recharge required content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: code: quota_exceeded message: Insufficient quota. Please top up your account. type: insufficient_quota '403': description: No permission to access content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: code: permission_denied message: You don't have permission to access this task type: invalid_request_error '404': description: Resource does not exist content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: code: task_not_found message: The requested task could not be found type: invalid_request_error '429': description: Request rate limit exceeded content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: code: rate_limit_exceeded message: Rate limit exceeded type: evo_api_error '500': description: Internal server error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: code: internal_error message: Failed to retrieve task status type: api_error components: schemas: TaskDetailResponse: type: object properties: created: type: integer description: Task creation timestamp example: 1756817821 id: type: string description: Task ID example: task-unified-1756817821-4x3rx6ny model: type: string description: Model used example: gemini-nano-banana-2.1 object: type: string description: Task type enum: - image.generation.task - video.generation.task - audio.generation.task example: image.generation.task progress: type: integer minimum: 0 maximum: 100 description: Task progress percentage example: 100 results: type: array items: type: string format: uri description: Task result list (provided when completed) example: - http://example.com/image.jpg status: type: string description: Task status enum: - pending - processing - completed - failed example: completed error: type: object nullable: true description: >- Error information when the task fails (only present when status is "failed"). Note: error.code here is a string-type business error code, different from HTTP status codes. See the Error Codes Reference for the complete list. properties: code: type: string description: Business error code (string type) example: content_policy_violation message: type: string description: User-friendly error description with troubleshooting tips example: |- Content policy violation. Your request was blocked by safety filters. type: type: string description: Error type identifier, always "task_error" example: task_error task_info: type: object description: Task detailed information properties: can_cancel: type: boolean description: Whether the task can be cancelled example: false type: type: string description: Task type enum: - image - video - audio - text example: image ErrorResponse: type: object properties: error: type: object properties: code: type: string description: Error code (string type) example: invalid_task_id message: type: string description: Error description message example: Invalid task ID format type: type: string description: Error type example: invalid_request_error param: type: string description: Related parameter name example: task_id securitySchemes: bearerAuth: type: http scheme: bearer description: >- ##All APIs require Bearer Token authentication## **Get API Key:** Visit [API Key Management Page](https://evolink.ai/dashboard/keys) to get your API Key **Add to request header:** ``` Authorization: Bearer YOUR_API_KEY ``` ````