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POST
/
api
/
v1
/
client
/
job
/
CreateTask
flux 2 flex image generation or editing.
curl --request POST \
  --url https://api.crun.ai/api/v1/client/job/CreateTask \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '
{
  "model": "replicate/flux-2-flex",
  "callback_url": "https://your-domain.com/api/callback",
  "input": {
    "prompt": "An ethereal forest with glowing flora, captured in a macro photography style.",
    "img_urls": [
      "https://example.com/macro_reference.png"
    ],
    "prompt_upsampling": true,
    "steps": 40,
    "guidance": 6,
    "aspect_ratio": "4:3",
    "resolution": "2K",
    "output_format": "png"
  }
}
'
{
  "code": 200,
  "message": "success",
  "data": {
    "task_id": "task_12345678"
  }
}

​
Query Task Status

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

Get Task Info

Learn how to query task status and retrieve generation results
For production use, we recommend using the callback_url parameter to receive automatic notifications when generation completes, rather than polling the status endpoint.

Models Overview

Explore all available models

Common API

Check credits and account usage

Authorizations

​
x-api-key
string
header
required

All APIs require authentication via API Key.

Get API Key:

  1. Visit API Key Management Page to get your API Key

Usage: Add to request header:

x-api-key: YOUR_API_KEY

Note:

  • Keep your API Key secure and do not share it with others
  • If you suspect your API Key has been compromised, reset it immediately in the management page

Body

application/json
​
model
enum<string>
required

The model name to use for generation. Required field.

  • Must be flux-2-flex for this endpoint
Available options:
flux-2-flex
​
input
object
required

Input parameters for the Flux 2 Flex model, offering granular control over inference steps, guidance, and multi-image referencing.

​
callback_url
string<uri>

Optional. Callback URL for receiving task completion notifications.

  • System will POST task status and results to this URL when generation completes
  • Callback payloads structure is consistent with the data object returned by the task status query
  • Your callback endpoint should accept POST requests with JSON payload containing results
  • It returns an HTTP 200 status code upon successful receipt
Example:

"https://your-domain.com/api/callback"

Response

Request successful

​
code
enum<integer>

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
  • 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
Available options:
200,
401,
402,
404,
422,
429,
455,
500,
501,
505
​
message
string

Response message, error description when failed

Example:

"success"

​
data
object