Flux 2

Overview

Flux 2 is a Black Forest Labs image model for high-quality text-to-image generation and reference-guided image editing. Use this page when you are ready to call the API after trying Flux 2 in the APIXO playground.

Capability	Value
Model ID	`flux-2`
Modes	`pro-text-to-image`, `pro-image-to-image`, `flex-text-to-image`, `flex-image-to-image`
Prompt length	3-5000 characters
Reference images	1-8 URLs for image-to-image modes
Aspect ratios	`1:1`, `4:3`, `3:4`, `3:2`, `2:3`, `16:9`, `9:16`, `auto`
Resolution tiers	`1K`, `2K`

Endpoint and authentication

Base URL:

https://api.apixo.ai/api/v1

Method	Endpoint	Purpose
`POST`	`/generateTask/flux-2`	Submit a generation task
`GET`	`/statusTask/flux-2?taskId={taskId}`	Poll task status and retrieve results

All requests require your APIXO API key:

Authorization: Bearer YOUR_API_KEY

Submit requests also require:

Content-Type: application/json

Copy-paste async quickstart

This minimal request submits a text-to-image task and returns a taskId.

curl -X POST "https://api.apixo.ai/api/v1/generateTask/flux-2" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "request_type": "async",
    "input": {
      "mode": "pro-text-to-image",
      "prompt": "a cozy cyberpunk cafe with neon signs and rain on the windows",
      "aspect_ratio": "16:9",
      "resolution": "1K"
    }
  }'

Successful response:

{
  "code": 200,
  "message": "success",
  "data": {
    "taskId": "task_12345678"
  }
}

Save the taskId; you need it to poll for the final result.

Poll for result

curl -X GET "https://api.apixo.ai/api/v1/statusTask/flux-2?taskId=task_12345678" \
  -H "Authorization: Bearer YOUR_API_KEY"

Processing response:

{
  "code": 200,
  "message": "success",
  "data": {
    "taskId": "task_12345678",
    "state": "processing",
    "createTime": 1767965610929
  }
}

Success response:

{
  "code": 200,
  "message": "success",
  "data": {
    "taskId": "task_12345678",
    "state": "success",
    "resultJson": "{\"resultUrls\":[\"https://r2.apixo.ai/xxx.png\"]}",
    "createTime": 1767965610929,
    "completeTime": 1767965652317,
    "costTime": 41388
  }
}

Failed response:

{
  "code": 200,
  "message": "success",
  "data": {
    "taskId": "task_12345678",
    "state": "failed",
    "failCode": "SensitiveContent",
    "failMsg": "Content violates provider policy, please adjust the prompt",
    "createTime": 1767965610929,
    "completeTime": 1767965620132
  }
}

Parse resultJson after state becomes success:

const payload = JSON.parse(data.resultJson);
const imageUrls = payload.resultUrls;

Request body

Text-to-image

{
  "request_type": "async",
  "input": {
    "mode": "pro-text-to-image",
    "prompt": "a minimal poster for a jazz night, with crisp readable typography",
    "aspect_ratio": "3:4",
    "resolution": "1K"
  }
}

Image-to-image

{
  "request_type": "async",
  "input": {
    "mode": "flex-image-to-image",
    "prompt": "turn this product photo into a polished studio campaign image",
    "image_urls": [
      "https://example.com/source.png"
    ],
    "aspect_ratio": "1:1",
    "resolution": "2K"
  }
}

Parameters

request_type

string

default:"async"

required

Result delivery mode. Use async for polling with statusTask, or callback for webhook delivery.

callback_url

string

Required when request_type is callback. Must be a public HTTPS URL that can receive the final task payload. See Webhooks.

input

object

required

Flux 2 input parameters.

Show properties

mode

string

required

Generation mode. Supported values: pro-text-to-image, pro-image-to-image, flex-text-to-image, flex-image-to-image.

prompt

string

required

Text prompt describing the desired image or edit. Supports 3-5000 characters.

image_urls

string[]

Reference image URLs. Required for pro-image-to-image and flex-image-to-image. Supports 1-8 URLs. Use public, directly reachable JPG, PNG, or WebP files under 10 MB each for best upstream compatibility.

aspect_ratio

string

required

Output aspect ratio. Supported values: 1:1, 4:3, 3:4, 3:2, 2:3, 16:9, 9:16, auto.

resolution

string

required

Output resolution tier. Supported values: 1K, 2K. Values are case-sensitive.

Mode options

Mode	Use case
`pro-text-to-image`	Pro text-to-image generation
`pro-image-to-image`	Pro image-to-image editing with reference images
`flex-text-to-image`	Flex text-to-image generation
`flex-image-to-image`	Flex image-to-image editing with reference images

Response format

Submit task response

POST /generateTask/flux-2 returns a task ID when the task is accepted:

code

integer

API status code. 200 means the task was accepted.

message

string

Human-readable status message.

data.taskId

string

Unique task identifier used with the status endpoint.

Status response fields

taskId

string

Unique task identifier.

state

string

Current task state: processing, success, or failed.

resultJson

string

JSON string containing the generated image URLs. Present when state is success.

failCode

string

Machine-readable failure code. Present when state is failed.

failMsg

string

Human-readable failure message. Present when state is failed.

createTime

integer

Task creation timestamp in Unix milliseconds.

completeTime

integer

Task completion timestamp in Unix milliseconds. Present after completion.

costTime

integer

Processing duration in milliseconds. Present after successful completion.

Webhook callback mode

Use callback mode when your backend should receive the final result automatically instead of polling.

curl -X POST "https://api.apixo.ai/api/v1/generateTask/flux-2" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "request_type": "callback",
    "callback_url": "https://your-server.com/webhooks/apixo",
    "input": {
      "mode": "pro-text-to-image",
      "prompt": "a premium coffee bag label with exact readable brand typography",
      "aspect_ratio": "1:1",
      "resolution": "2K"
    }
  }'

See Webhooks for delivery requirements and retry behavior.

Billing

Flux 2 is billed per generated image. The selected mode tier and resolution determine the unit price.

Mode tier	Resolution	APIXO Value price	Official price	Market price
`pro-*`	`1K`	`$0.035 / image`	`$0.045 / image`	`$0.045 / image`
`pro-*`	`2K`	`$0.05 / image`	`$0.07 / image`	`$0.07 / image`
`flex-*`	`1K`	`$0.10 / image`	`$0.12 / image`	`$0.12 / image`
`flex-*`	`2K`	`$0.16 / image`	`$0.22 / image`	`$0.22 / image`

For current route and market comparison pricing, see Pricing.

Latency and polling

Actual latency may vary by prompt complexity, reference image count, provider route, and current queue load.

Typical generation time	Recommended first poll	Poll interval
About 30 seconds	20 seconds after task creation	3-10 seconds

For high-concurrency production workloads, use callback mode to avoid frequent polling.

Rate limits and concurrency can vary by account, API key, and route. If you receive 429, slow down requests and retry with backoff. For account-level details, see System APIs.

Errors and troubleshooting

HTTP errors

Code	Meaning	What to do
`400`	Invalid request body, missing parameter, unsupported value, prompt length issue, or inaccessible image URL	Fix the request before retrying
`401`	Missing or invalid API key	Check the `Authorization` header
`402`	Insufficient balance or quota	Add balance or switch account/key
`403`	Key or route cannot access the model, or provider rejected the content	Check permissions and adjust the prompt or images
`429`	Rate limit or concurrency limit reached	Retry with exponential backoff
`500`	Server error or unknown upstream failure	Retry with backoff
`502`	Upstream provider error	Retry with backoff
`504`	Upstream timeout	Retry or use callback mode for long-running jobs

Task failure codes

Fail code	Meaning	What to do
`SensitiveContent`	Prompt, input image, or output was flagged by provider safety checks	Change the prompt or reference image
`ProhibitedContentDetected`	Provider rejected the task for prohibited content	Adjust the prompt or input image
`ImageNotAccess`	A reference image URL could not be fetched	Use a public, direct image URL
`PromptInvalid`	Prompt was invalid or rejected by the provider	Rewrite the prompt
`MissingParameter`	One or more required parameters were missing	Check `mode`, `prompt`, `aspect_ratio`, `resolution`, and `image_urls`
`RateLimited`	Provider or account rate limit was reached	Retry with backoff
`Timeout`	Provider timed out	Retry, reduce input complexity, or use callback mode
`Unknown error`	Upstream failure did not match a known error rule	Retry with backoff or contact support if it persists

See Error Codes for the full error reference.

Getting Started

Image Models

Video Models

Audio Models

Overview

Endpoint and authentication

Copy-paste async quickstart

Poll for result

Request body

Text-to-image

Image-to-image

Parameters

Mode options

Response format

Submit task response

Status response fields

Webhook callback mode

Billing

Latency and polling

Errors and troubleshooting

HTTP errors

Task failure codes

Getting Started

Image Models

Video Models

Audio Models

Documentation Index

​Overview

​Endpoint and authentication

​Copy-paste async quickstart

​Poll for result

​Request body

​Text-to-image

​Image-to-image

​Parameters

​Mode options

​Response format

​Submit task response

​Status response fields

​Webhook callback mode

​Billing

​Latency and polling

​Errors and troubleshooting

​HTTP errors

​Task failure codes

​Related links

Overview

Endpoint and authentication

Copy-paste async quickstart

Poll for result

Request body

Text-to-image

Image-to-image

Parameters

Mode options

Response format

Submit task response

Status response fields

Webhook callback mode

Billing

Latency and polling

Errors and troubleshooting

HTTP errors

Task failure codes

Related links