Google - imagen4-fast

This page is generated from the upstream official OpenAPI documentation. Endpoints, parameters and examples match the official docs; brand and API domain are replaced with ModelFold.

Endpoint

POST /jobs/createTask

Full URL: https://ai.modelfold.online/v1/jobs/createTask

Authentication: every request must include the Authorization: Bearer <API_KEY> header.

Image generation by Google imagen4-fast

Query Task Status

After submitting a task, use the unified query endpoint to check progress and retrieve results:

• Get Task Details — Learn how to query task status and retrieve generation results

TIP

For production use, we recommend using the callBackUrl parameter to receive automatic notifications when generation completes, rather than polling the status endpoint.

Related Resources

• Market Overview — Explore all available models
• Common API — Check credits and account usage

Request Parameters

Body (application/json)

Parameter	Type	Required	Description
model	string	Yes	The model name to use for generation. Required field. - Must be google/imagen4-fast for this endpoint Default："google/imagen4-fast"。 Allowed values：google/imagen4-fast。 示例：google/imagen4-fast。
callBackUrl	string	No	The URL to receive generation task completion updates. Optional but recommended for production use. - System will POST task status and results to this URL when generation completes - Callback includes generated content URLs and task information - Your callback endpoint should accept POST requests with JSON payload containing results - Alternatively, use the Get Task Details endpoint to poll task status - To ensure callback security, see Webhook Verification Guide for signature verification implementation 示例：https://your-domain.com/api/callback。
input	object	No	Input parameters for the generation task
input.prompt	string	Yes	The text prompt describing what you want to see (Max length: 5000 characters) 示例：Create a cinematic, photorealistic medium shot capturing the nostalgic warmth of a late 90s indie film. The focus is a young woman with brightly dyed pink hair (slightly faded) and freckled skin, looking directly and intently into the camera lens with a hopeful yet slightly uncertain smile. She wears an oversized, vintage band t-shirt (slightly worn, with the faintly cracked white text “ModelFold AI” across the chest) layered over a long-sleeved striped top, along with simple silver stud earrings. The lighting is soft, golden hour sunlight streaming through a slightly dusty window, creating lens flare and illuminating dust motes in the air. The background shows a blurred, cluttered bedroom with posters on the wall and fairy lights, rendered with a shallow depth of field. Natural film grain, a warm, slightly muted color palette, and sharp focus on her expressive eyes enhance the intimate, authentic feel.。
input.negative_prompt	string	No	A description of what to discourage in the generated images (Max length: 5000 characters) 示例：``。
input.aspect_ratio	string	Yes	Required. Aspect ratio of the output image: 1:1, 16:9, 9:16, 3:4, 4:3 or auto. Allowed values：1:1 / 16:9 / 9:16 / 3:4 / 4:3 / auto。 示例：16:9。
input.seed	integer	No	Random seed for reproducible generation

Request Example

curl -X POST "https://ai.modelfold.online/v1/jobs/createTask" \
  -H "Authorization: Bearer $MODELFOLD_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "google/imagen4-fast",
  "callBackUrl": "https://your-domain.com/api/callback",
  "input": {
    "prompt": "Create a cinematic, photorealistic medium shot capturing the nostalgic warmth of a late 90s indie film. The focus is a young woman with brightly dyed pink hair (slightly faded) and freckled skin, looking directly and intently into the camera lens with a hopeful yet slightly uncertain smile. She wears an oversized, vintage band t-shirt (slightly worn, with the faintly cracked white text “ModelFold AI” across the chest) layered over a long-sleeved striped top, along with simple silver stud earrings. The lighting is soft, golden hour sunlight streaming through a slightly dusty window, creating lens flare and illuminating dust motes in the air. The background shows a blurred, cluttered bedroom with posters on the wall and fairy lights, rendered with a shallow depth of field. Natural film grain, a warm, slightly muted color palette, and sharp focus on her expressive eyes enhance the intimate, authentic feel.",
    "negative_prompt": "",
    "aspect_ratio": "16:9"
  }
}'

{
  "model": "google/imagen4-fast",
  "callBackUrl": "https://your-domain.com/api/callback",
  "input": {
    "prompt": "Create a cinematic, photorealistic medium shot capturing the nostalgic warmth of a late 90s indie film. The focus is a young woman with brightly dyed pink hair (slightly faded) and freckled skin, looking directly and intently into the camera lens with a hopeful yet slightly uncertain smile. She wears an oversized, vintage band t-shirt (slightly worn, with the faintly cracked white text “ModelFold AI” across the chest) layered over a long-sleeved striped top, along with simple silver stud earrings. The lighting is soft, golden hour sunlight streaming through a slightly dusty window, creating lens flare and illuminating dust motes in the air. The background shows a blurred, cluttered bedroom with posters on the wall and fairy lights, rendered with a shallow depth of field. Natural film grain, a warm, slightly muted color palette, and sharp focus on her expressive eyes enhance the intimate, authentic feel.",
    "negative_prompt": "",
    "aspect_ratio": "16:9"
  }
}

Response

200 — Request successful

{
  "code": 200,
  "msg": "success",
  "data": {
    "taskId": "task_google_1765172332800"
  }
}

500 — Server error.

参数	类型	必填	说明
code	integer	是	Response status code - 200: Success - Request has been processed successfully - 401: Unauthorized - Authentication credentials are missing or invalid - 402: Insufficient Credits - Account does not have enough credits to perform the operation - 404: Not Found - The requested resource or endpoint does not exist - 408: Timeout - No result has been returned for over 10 minutes. - 422: Validation Error - The request parameters failed validation checks - 429: Rate Limited - Request limit has been exceeded for this resource - 455: Service Unavailable - System is currently undergoing maintenance - 500: Server Error - An unexpected error occurred while processing the request - 501: Generation Failed - Content generation task failed - 505: Feature Disabled - The requested feature is currently disabled
msg	string	是	Response message, error description when failed
data	object	是	—

{
  "code": 500,
  "msg": "Server Error - An unexpected error occurred while processing the request",
  "data": null
}

Callback

onImageGenerated

Callback URL: {$request.body#/callBackUrl} (the callBackUrl in the request body).

Sent when the task succeeds or fails.

Callback body parameters

参数	类型	必填	说明
code	integer	否	200: success. 501: failure; see data.failCode and data.failMsg. Allowed values：200 / 501。 示例：200。
msg	string	否	Status message 示例：Playground task completed successfully.。
data	object	否	—
data.completeTime	integer	否	Task completion time, represented as a Unix timestamp in milliseconds 示例：1786427040000。
data.costTime	integer	否	Processing time in seconds. Present on both success and failure callbacks. 示例：48。
data.createTime	integer	否	Task creation time, represented as a Unix timestamp in milliseconds 示例：1786426989000。
data.creditsConsumed	number	否	Credits consumed by the task; 0 for failed tasks. 示例：4。
data.model	string	否	Image generation model used for the task 示例：google/imagen4-fast。
data.param	string	否	Parameters submitted when creating the task, in JSON string format 示例：{"input":"{\"aspect_ratio\":\"16:9\",\"prompt\":\"Create a cinematic, photorealistic medium shot with the nostalgic warmth of a late-1990s independent film. The subject is a young girl with bright pink hair showing slight fading and a face covered in freckles. She looks directly at the camera with a focused gaze and a hopeful yet slightly nervous smile. She wears a loose vintage band T- shirt with slight wear and distressed white lettering reading ‘ModelFold AI’ across the chest, layered over a striped long-sleeve shirt, with simple silver stud earrings. Use soft golden-hour sunlight streaming through a dusty window, creating lens flare and illuminating floating dust particles. The background is a blurred, messy bedroom with posters on the walls and string lights, rendered with a shallow depth of field. Add natural film grain, warm, soft, slightly desaturated colors, and sharp focus on the girl's expressive eyes to create an intimate and authentic feel.\"}","callBackUrl":"https://your-domain.com/api/callback","model":"google/imagen4-fast"}。
data.resultJson	string	否	Image generation result in JSON string format. resultUrls contains the list of generated image URLs. Present only when state is success. 示例：{"resultUrls":["https://tempfile.aiquickdraw.com/workers/images/image_90b6bf4499a80b74a2b5ee640b7aaf70.webp"]}。
data.state	string	否	Task status Allowed values：success / fail。 示例：success。
data.taskId	string	否	Task ID 示例：4543535251c1fac47c367fd1c193010e。
data.updateTime	integer	否	Use completeTime as the completion time; updateTime may equal createTime. 示例：1786427040000。
data.failCode	string	否	Failure code, a numeric string such as "400" or "500". Present only when state is fail. 示例：500。
data.failMsg	string	否	Failure reason. Present only when state is fail. 示例：<error detail>。

Success

{
  "code": 200,
  "msg": "Playground task completed successfully.",
  "data": {
    "taskId": "4543535251c1fac47c367fd1c193010e",
    "model": "google/imagen4-fast",
    "state": "success",
    "param": "{\"input\":\"{\\\"aspect_ratio\\\":\\\"16:9\\\",\\\"prompt\\\":\\\"Create a cinematic, photorealistic medium shot with the nostalgic warmth of a late-1990s independent film. The subject is a young girl with bright pink hair showing slight fading and a face covered in freckles. She looks directly at the camera with a focused gaze and a hopeful yet slightly nervous smile. She wears a loose vintage band T- shirt with slight wear and distressed white lettering reading ‘ModelFold AI’ across the chest, layered over a striped long-sleeve shirt, with simple silver stud earrings. Use soft golden-hour sunlight streaming through a dusty window, creating lens flare and illuminating floating dust particles. The background is a blurred, messy bedroom with posters on the walls and string lights, rendered with a shallow depth of field. Add natural film grain, warm, soft, slightly desaturated colors, and sharp focus on the girl's expressive eyes to create an intimate and authentic feel.\\\"}\",\"callBackUrl\":\"https://your-domain.com/api/callback\",\"model\":\"google/imagen4-fast\"}",
    "resultJson": "{\"resultUrls\":[\"https://tempfile.aiquickdraw.com/workers/images/image_90b6bf4499a80b74a2b5ee640b7aaf70.webp\"]}",
    "completeTime": 1786427040000,
    "createTime": 1786426989000,
    "costTime": 48,
    "creditsConsumed": 4,
    "updateTime": 1786427040000
  }
}

Failure

{
  "code": 501,
  "msg": "Playground task failed.",
  "data": {
    "taskId": "4543535251c1fac47c367fd1c193010e",
    "model": "google/imagen4-fast",
    "state": "fail",
    "param": "{\"input\":\"{\\\"aspect_ratio\\\":\\\"16:9\\\",\\\"prompt\\\":\\\"Create a cinematic, photorealistic medium shot with the nostalgic warmth of a late-1990s independent film. The subject is a young girl with bright pink hair showing slight fading and a face covered in freckles. She looks directly at the camera with a focused gaze and a hopeful yet slightly nervous smile. She wears a loose vintage band T- shirt with slight wear and distressed white lettering reading ‘ModelFold AI’ across the chest, layered over a striped long-sleeve shirt, with simple silver stud earrings. Use soft golden-hour sunlight streaming through a dusty window, creating lens flare and illuminating floating dust particles. The background is a blurred, messy bedroom with posters on the walls and string lights, rendered with a shallow depth of field. Add natural film grain, warm, soft, slightly desaturated colors, and sharp focus on the girl's expressive eyes to create an intimate and authentic feel.\\\"}\",\"callBackUrl\":\"https://your-domain.com/api/callback\",\"model\":\"google/imagen4-fast\"}",
    "failCode": "500",
    "failMsg": "<error detail>",
    "completeTime": 1786427040000,
    "createTime": 1786426989000,
    "costTime": 48,
    "creditsConsumed": 0,
    "updateTime": 1786427040000
  }
}