> ## Documentation Index > Fetch the complete documentation index at: https://docs.modellix.ai/llms.txt > Use this file to discover all available pages before exploring further. # Imagen 4.0 Fast > [Core Function] Imagen 4.0 Fast is a high-speed text-to-image model optimized for rapid visual generation. [Strengths] It offers incredible generation speed (approximately 2.7 seconds) and high cost-effectiveness while maintaining excellent text rendering inside images. [Best For] Highly recommended for rapid prototyping, quick design iteration, high-volume image generation, social media thumbnails, blog hero images, and UI mockups. [Limitations] Do NOT use this model if you require 2K resolution (it does not support the imageSize parameter) or the absolute highest cinematic fidelity and strict prompt alignment. Does not support negative prompts or native image editing. [Routing] Choose this model when the user emphasizes 'fast', 'quick', 'rapid', or needs high-volume, low-latency generation. ## OpenAPI ````yaml /model-api/google/google-t2i.json post /google/imagen-4.0-fast-generate-001 openapi: 3.1.0 info: description: The text-to-image models API from Google (Gemini and Imagen series). version: 1.0.0 contact: name: Modellix Support email: support@modellix.ai title: Google Text-to-Image Models API servers: - url: https://api.modellix.ai/api/v1 description: The text-to-image models API from Google. security: - bearerAuth: [] paths: /google/imagen-4.0-fast-generate-001: post: summary: Imagen 4.0 Fast description: >- [Core Function] Imagen 4.0 Fast is a high-speed text-to-image model optimized for rapid visual generation. [Strengths] It offers incredible generation speed (approximately 2.7 seconds) and high cost-effectiveness while maintaining excellent text rendering inside images. [Best For] Highly recommended for rapid prototyping, quick design iteration, high-volume image generation, social media thumbnails, blog hero images, and UI mockups. [Limitations] Do NOT use this model if you require 2K resolution (it does not support the imageSize parameter) or the absolute highest cinematic fidelity and strict prompt alignment. Does not support negative prompts or native image editing. [Routing] Choose this model when the user emphasizes 'fast', 'quick', 'rapid', or needs high-volume, low-latency generation. operationId: imagen40FastGenerate001Async requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/ImagenFastRequest' examples: fast_gen: summary: Fast image generation value: prompt: >- Watercolor illustration of a Japanese pagoda surrounded by cherry blossoms batch_fast: summary: Batch fast generation value: prompt: Flat design icon of a smartphone with colorful apps sampleCount: 4 aspectRatio: '1:1' responses: '200': description: Task submitted successfully content: application/json: schema: $ref: '#/components/schemas/AsyncTaskResponse' example: code: 0 message: success data: status: pending task_id: task-pqr678 model_id: google/imagen-4.0-fast-generate-001 get_result: method: GET url: https://api.modellix.ai/api/v1/tasks/task-pqr678 '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '429': $ref: '#/components/responses/TooManyRequests' '500': $ref: '#/components/responses/InternalServerError' components: schemas: ImagenFastRequest: type: object required: - prompt description: >- Imagen 4.0 Fast request schema. Supports `prompt`, `sampleCount`, `aspectRatio`, and `personGeneration`. properties: prompt: type: string description: Image description text minLength: 1 example: >- Watercolor illustration of a Japanese pagoda surrounded by cherry blossoms sampleCount: type: integer description: Number of images to generate per request default: 1 minimum: 1 maximum: 4 example: 1 aspectRatio: type: string description: Image aspect ratio default: '1:1' enum: - '1:1' - '3:4' - '4:3' - '9:16' - '16:9' example: '1:1' personGeneration: type: string description: Person generation policy default: allow_all enum: - dont_allow - allow_adult - allow_all example: allow_all AsyncTaskResponse: type: object required: - code - message - data properties: code: type: integer description: Response code, 0 indicates success example: 0 message: type: string description: Response message example: success data: type: object required: - status - task_id - model_id properties: status: type: string enum: - pending - processing description: Task status example: pending task_id: type: string description: Unique task identifier for polling example: task-abc123 model_id: type: string description: Model ID in `provider/model` format example: google/nano-banana get_result: type: object description: API information to query the task result properties: method: type: string description: HTTP method example: GET url: type: string description: Full URL to query the task result example: https://api.modellix.ai/api/v1/tasks/task-abc123 description: Detailed data about the submitted asynchronous task. ErrorResponse: type: object required: - code - message properties: code: type: integer description: Error code (equals HTTP status code) example: 400 message: type: string description: 'Error message in format ''Category: detail''' example: 'Invalid parameters: parameter ''prompt'' is required' responses: BadRequest: description: Invalid request parameters content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: code: 400 message: 'Invalid parameters: parameter ''prompt'' is required' Unauthorized: description: Unauthorized - Invalid or missing API Key content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: code: 401 message: 'Authentication failed: invalid API key' TooManyRequests: description: Too many requests - Rate limit exceeded headers: X-RateLimit-Limit: description: Maximum requests per minute schema: type: integer example: 100 X-RateLimit-Remaining: description: Remaining quota in current window schema: type: integer example: 0 X-RateLimit-Reset: description: Rate limit window reset time (Unix timestamp) schema: type: integer example: 1704067260 content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: code: 429 message: >- Rate limit exceeded: 100 requests per minute, retry after 60 seconds InternalServerError: description: Internal server error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: code: 500 message: Internal server error securitySchemes: bearerAuth: type: http scheme: bearer description: 'API Key authentication. Format: `Bearer YOUR_API_KEY`.' ````