Midjourney

Overview

Midjourney is an async image model for high-quality text-to-image generation, reference-guided remixing, region editing, variation, and upscaling. Use this page when you are ready to call the API after trying Midjourney in the APIXO playground.

Capability	Value
Model ID	`midjourney`
Modes	`text-to-image`, `image-to-image`, `upload-paint`, `vary`, `upscale`
Prompt length	Non-empty. Route limits are up to 2000 characters or up to 6000 UTF-8 bytes; keep prompts under 2000 characters for portable requests.
Reference images	Use exactly 1 image for route-compatible `image-to-image` or `upload-paint` requests. Some routes can accept up to 2 images.
Aspect ratios	`1:1`, `1:2`, `2:1`, `2:3`, `3:2`, `3:4`, `4:3`, `5:6`, `6:5`, `9:16`, `16:9`
Speeds	`fast`, `turbo`; `relaxed` is accepted by validation but is not listed on public pricing
Result count	Usually 4 images for generation and variation, usually 1 image for upscale

Do not put Midjourney inline flags such as --ar, --style, or --sref inside prompt. The backend strips prompt text from the first -- onward. Use API fields such as aspect_ratio, stylization, variety, and weirdness instead.

Endpoint and authentication

Base URL:

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

Method	Endpoint	Purpose
`POST`	`/generateTask/midjourney`	Submit a Midjourney task
`GET`	`/statusTask/midjourney?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/midjourney" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "request_type": "async",
    "input": {
      "mode": "text-to-image",
      "prompt": "a cinematic product photo of a transparent speaker on black marble",
      "version": "7",
      "speed": "fast",
      "aspect_ratio": "16:9"
    }
  }'

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/midjourney?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://file.apixo.ai/img1.png\",\"https://file.apixo.ai/img2.png\",\"https://file.apixo.ai/img3.png\",\"https://file.apixo.ai/img4.png\"]}",
    "createTime": 1767965610929,
    "completeTime": 1767965652317,
    "costTime": 41388
  }
}

Failed response:

{
  "code": 200,
  "message": "success",
  "data": {
    "taskId": "task_12345678",
    "state": "failed",
    "failCode": "PromptInvalid",
    "failMsg": "Prompt is invalid or rejected by provider",
    "createTime": 1767965610929,
    "completeTime": 1767965620132,
    "costTime": 9203
  }
}

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": "text-to-image",
    "prompt": "a quiet library inside a glass greenhouse, soft morning light",
    "version": "7",
    "speed": "fast",
    "aspect_ratio": "16:9",
    "stylization": 100,
    "variety": 10,
    "weirdness": 0
  }
}

Image-to-image

{
  "request_type": "async",
  "input": {
    "mode": "image-to-image",
    "prompt": "a dog lying in a bright park with green grass and trees",
    "image_urls": [
      "https://example.com/dog-at-home.jpg"
    ],
    "version": "7",
    "speed": "fast",
    "aspect_ratio": "4:3"
  }
}

Upload-paint

Use upload-paint when you want to edit a specific region. If mask, canvas, and imgPos are omitted on compatible routes, the backend can auto-fill a full-image edit region from image_urls[0].

{
  "request_type": "async",
  "input": {
    "mode": "upload-paint",
    "prompt": "add a modern espresso machine on the counter",
    "image_urls": [
      "https://example.com/cafe.jpg"
    ],
    "version": "7",
    "speed": "fast",
    "mask": {
      "areas": [
        {
          "width": 1024,
          "height": 1024,
          "points": [320, 420, 700, 420, 700, 760, 320, 760]
        }
      ]
    },
    "canvas": {
      "width": 1024,
      "height": 1024
    },
    "imgPos": {
      "width": 1024,
      "height": 1024,
      "x": 0,
      "y": 0
    }
  }
}

Vary

{
  "request_type": "async",
  "input": {
    "mode": "vary",
    "taskId": "task_previous_midjourney",
    "imageIndex": 0,
    "type": 1,
    "remixPrompt": "more dramatic lighting and richer color contrast"
  }
}

Upscale

{
  "request_type": "async",
  "input": {
    "mode": "upscale",
    "taskId": "task_previous_midjourney",
    "imageIndex": 2,
    "type": 0
  }
}

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

Midjourney input parameters.

Show properties

mode

string

required

Operation mode. Supported values: text-to-image, image-to-image, upload-paint, vary, upscale.

prompt

string

Required for text-to-image, image-to-image, and upload-paint. Must be non-empty. Route limits are up to 2000 characters or up to 6000 UTF-8 bytes; keep prompts under 2000 characters for portable requests.

image_urls

string[]

Reference image URLs. Required for image-to-image and upload-paint. Use exactly 1 image for route-compatible requests; some routes can accept up to 2 images. URLs should be public, directly fetchable JPG, PNG, or WebP files.

version

string

Midjourney model version. Use 7, 6.1, 6, 5.2, 5.1, or niji6 for broad compatibility. Some routes also normalize values such as v7, v6.1, v6, niji 6, and niji 7.

speed

string

Required for text-to-image, image-to-image, and upload-paint. Supported values: relaxed, fast, turbo. Public pricing currently lists fast and turbo; use those for predictable billing.

aspect_ratio

string

Output aspect ratio. Supported values: 1:1, 1:2, 2:1, 2:3, 3:2, 3:4, 4:3, 5:6, 6:5, 9:16, 16:9. When omitted, the upstream default is used.

variety

integer

Midjourney chaos/variation control. Supported range: 0-100. One route defaults omitted values to 10; other routes omit the flag unless you set it.

stylization

integer

Artistic stylization strength. Supported range: 0-1000. One route defaults omitted values to 1; other routes omit the flag unless you set it.

weirdness

integer

Surreal or unconventional effect strength. Supported range: 0-3000. One route defaults omitted values to 1; other routes omit the flag unless you set it.

enableTranslation

boolean

Requests prompt translation to English. Translation behavior is route-dependent: some routes default to translation, while others only translate when the route is configured for it and this flag is true.

watermark

string

Optional watermark text. Supported on compatible routes.

taskId

string

Required for vary and upscale. Use the APIXO task ID from a previous successful Midjourney generation task.

imageIndex

integer

Required for vary and upscale. Selects one image from the previous result. Supported range: 0-3.

type

integer

default:"0"

Optional transform type. For vary, 0 means subtle variation and 1 means strong variation. For upscale, supported values are 0, 1, 2, and 3 on compatible routes.

remixPrompt

string

Optional text guidance for vary on compatible routes. For upload-paint, if remixPrompt is omitted, compatible routes reuse prompt.

mask

object

Optional for upload-paint. Use it when you need region-specific editing. If omitted on compatible routes, the backend can create a full-image mask from the source image.

Show properties

areas

object[]

Polygon edit regions. Each area can include width, height, and points. points is a flat coordinate array: [x1,y1,x2,y2,...].

url

string

Black/white mask image URL or base64 mask. White areas are regenerated. Use either areas or url, not both.

canvas

object

Optional for upload-paint. Canvas dimensions. If provided, width and height must be positive integers.

Show properties

width

integer

Canvas width in pixels.

height

integer

Canvas height in pixels.

imgPos

object

Optional for upload-paint. Source image position and size on the canvas.

Show properties

width

integer

Image width in pixels.

height

integer

Image height in pixels.

integer

Horizontal offset from the canvas top-left corner.

integer

Vertical offset from the canvas top-left corner.

Response format

Submit task response

POST /generateTask/midjourney 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 APIXO task identifier used with the status endpoint.

Status response fields

taskId

string

Unique APIXO task identifier.

state

string

Current task state: pending, 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 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/midjourney" \
  -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": "text-to-image",
      "prompt": "a premium watch on dark stone, macro photography, soft reflections",
      "version": "7",
      "speed": "fast",
      "aspect_ratio": "1:1"
    }
  }'

See Webhooks for delivery requirements and retry behavior.

Billing

Midjourney is billed per use. The selected speed determines the unit price. Public pricing currently lists fast and turbo.

Speed	APIXO price	Market comparison
`fast`	`$0.15 / use`	`$0.30 / use`
`turbo`	`$0.25 / use`	`$0.50 / use`

For current route and market comparison pricing, see Pricing.

Latency and polling

Actual latency may vary by prompt complexity, mode, selected route, and current queue load.

Mode or speed	Typical generation time	Recommended first poll	Poll interval
`turbo` generation	15s-25s	20s after task creation	3s-5s
`fast` generation	30s-45s	20s after task creation	3s-5s
`vary` or `upscale`	15s-60s	15s after task creation	3s-5s

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, mode, parameter, prompt, or 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	Check permissions and route strategy
`429`	Rate limit or concurrency limit reached	Retry with exponential backoff
`500`	Server error	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
`PromptInvalid`	Prompt is invalid or rejected by the provider	Rewrite the prompt and remove unsafe or malformed content
`MissingParameter`	Required request parameters are missing	Check `mode`, `prompt`, `speed`, `image_urls`, `taskId`, and `imageIndex`
`SensitiveContentDetected`	Input or output was flagged by safety checks	Change the prompt or source image
`InputOutputSensitiveContentDetected`	The input or output was flagged as sensitive	Try different inputs
`Upload error`	Image upload or image size validation failed	Use a public direct image URL and keep image files within supported limits
`Website TimeOut`	MidJourney official website did not respond after multiple attempts	Retry later or use callback mode
`Task TimeOut`	The upstream task became outdated or timed out	Retry the generation
`RateLimitExceeded`	Upstream or APIXO rate limit was reached	Retry with exponential backoff

Common fixes

Symptom	Fix
`Invalid mode type`	Use one of `text-to-image`, `image-to-image`, `upload-paint`, `vary`, or `upscale`.
Parameter is ignored	Use stable API field names: `aspect_ratio`, `variety`, `stylization`, and `weirdness`.
Prompt unexpectedly loses flags	Move Midjourney flags out of `prompt`; text after the first `--` is stripped by the backend.
`taskId` not found for `vary` or `upscale`	Use the APIXO task ID from a previous Midjourney result, not the upstream provider task ID.
Upload-paint fails to read image size	Use a public, directly fetchable source image URL. The backend reads `image_urls[0]` to fill default canvas and mask values.
`relaxed` fails billing or routing	Use `fast` or `turbo` unless your account has explicit `relaxed` pricing enabled.

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

Upload-paint

Vary

Upscale

Parameters

Response format

Submit task response

Status response fields

Webhook callback mode

Billing

Latency and polling

Errors and troubleshooting

HTTP errors

Task failure codes

Common fixes

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

​Upload-paint

​Vary

​Upscale

​Parameters

​Response format

​Submit task response

​Status response fields

​Webhook callback mode

​Billing

​Latency and polling

​Errors and troubleshooting

​HTTP errors

​Task failure codes

​Common fixes

​Related links

Overview

Endpoint and authentication

Copy-paste async quickstart

Poll for result

Request body

Text-to-image

Image-to-image

Upload-paint

Vary

Upscale

Parameters

Response format

Submit task response

Status response fields

Webhook callback mode

Billing

Latency and polling

Errors and troubleshooting

HTTP errors

Task failure codes

Common fixes

Related links