> ## Documentation Index
> Fetch the complete documentation index at: https://docs.crun.ai/llms.txt
> Use this file to discover all available pages before exploring further.
# Flux 2 Pro
> Flux 2 Pro is an image generation and editing model by Black Forest Labs. It creates high-quality images from text prompts and can edit existing images using natural language instructions. The model handles complex text rendering, photorealistic details, and maintains consistent characters or styles across multiple reference images.
## Query Task Status
After submitting a task, use the unified query endpoint to check progress and retrieve results:
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.
## Related Resources
Explore all available models
Check credits and account usage
## OpenAPI
````yaml models/flux/flux-2-pro.json post /api/v1/client/job/CreateTask
openapi: 3.0.0
info:
title: Crun Flux 2 Pro API
description: crun.ai Flux 2 Pro API Documentation
version: 1.0.0
contact:
name: Technical Support
email: support@crun.ai
servers:
- url: https://api.crun.ai
description: API Server
security:
- ApiKeyAuth: []
paths:
/api/v1/client/job/CreateTask:
post:
summary: flux 2 pro image generation or editing.
operationId: flux-2-pro
requestBody:
required: true
content:
application/json:
schema:
type: object
required:
- model
- input
properties:
model:
type: string
enum:
- flux-2-pro
description: |-
The model name to use for generation. Required field.
- Must be `flux-2-pro` for this endpoint
callback_url:
type: string
format: uri
description: >-
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
input:
type: object
description: >-
Input parameters for the Flux 2 Pro model, supporting
high-fidelity image generation and multi-image reference.
properties:
prompt:
type: string
description: >-
Text prompt for image generation. Highly descriptive
prompts yield better results.
minLength: 1
maxLength: 5000
example: >-
A cinematic portrait of a cyberpunk wanderer in a
rain-slicked neon street, highly detailed armor, 8k.
img_urls:
type: array
description: >-
List of input image URLs for image-to-video or
image-to-image generation. Maximum 8 images. Supported
formats: jpeg, png, gif, webp.
items:
type: string
format: uri
maxItems: 8
example:
- https://example.com/reference-1.jpg
aspect_ratio:
type: string
description: >-
Aspect ratio for the generated image. Use
'match_input_image' to inherit the ratio from the first
reference image.
enum:
- '1:1'
- '2:3'
- '3:2'
- '3:4'
- '4:3'
- '4:5'
- '5:4'
- '9:16'
- '16:9'
- match_input_image
default: match_input_image
example: '16:9'
resolution:
type: string
description: >-
Resolution in megapixels. Up to 4 MP is possible, but 2
MP or below is recommended. The maximum image size is
2048x2048, which means that high-resolution images may
not respect the resolution if aspect ratio is not 1:1.
enum:
- 1K
- 2K
- 4K
default: 1K
example: 1K
safety_tolerance:
type: integer
description: >-
Safety filter sensitivity. 1 is most strict (heavy
filtering), 5 is most permissive.
minimum: 1
maximum: 5
default: 2
example: 2
seed:
type: integer
description: Random seed for reproducible generation.
example: 42
output_format:
type: string
description: File format of the generated image.
enum:
- png
- jpg
- webp
default: webp
example: webp
output_quality:
type: integer
description: >-
Quality when saving the output images, from 0 to 100.
100 is best quality, 0 is lowest quality. Not relevant
for `png` outputs
minimum: 0
maximum: 100
default: 80
example: 90
required:
- prompt
example:
model: flux-2-pro
callback_url: https://your-domain.com/api/callback
input:
prompt: >-
An oil painting of a futuristic garden where flowers are made
of glowing fiber optics, vibrant colors.
aspect_ratio: '3:2'
resolution: 2K
safety_tolerance: 3
output_format: jpg
output_quality: 95
seed: 555
responses:
'200':
description: Request successful
content:
application/json:
schema:
allOf:
- $ref: '#/components/schemas/ApiResponse'
- type: object
properties:
data:
type: object
properties:
task_id:
type: string
description: >-
Task ID, can be used with Get Task Details
endpoint to query task status
example: task_12345678
example:
code: 200
message: success
data:
task_id: task_12345678
'422':
description: Validation Error
content:
application/json:
schema:
allOf:
- $ref: '#/components/schemas/ApiResponse'
- type: object
properties:
errors:
type: array
description: Detailed validation error messages
items:
type: string
example:
- specific error field message
example:
code: 422
message: Missing Params or Type Error
errors:
- specific error field message
'500':
$ref: '#/components/responses/Error'
components:
schemas:
ApiResponse:
type: object
properties:
code:
type: integer
enum:
- 200
- 401
- 402
- 404
- 422
- 429
- 455
- 500
- 501
- 505
description: >-
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
message:
type: string
description: Response message, error description when failed
example: success
responses:
Error:
description: Server Error
securitySchemes:
ApiKeyAuth:
type: apiKey
in: header
name: x-api-key
description: >-
All APIs require authentication via API Key.
Get API Key:
1. Visit [API Key Management Page](https://crun.ai/user-api-key) 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
````