Action (Upscale, Variation, Reroll, Zoom)

Use CometAPI POST /mj/submit/action to apply Midjourney actions—upscale, variation, reroll, zoom, and more—on images generated via imaging.

POST /mj/submit/action

Create a Midjourney follow-up action task

cURL

curl --request POST \
  --url https://api.cometapi.com/mj/submit/action \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "customId": "MJ::JOB::variation::3::example",
  "taskId": "1773314942177684"
}
'

200

{
  "code": 123,
  "description": "<string>",
  "result": "<string>",
  "properties": {
    "numberOfQueues": 123,
    "discordInstanceId": "<string>",
    "discordChannelId": "<string>"
  }
}

Use this endpoint after a Midjourney task returns action buttons. It starts a new downstream task such as upscale, variation, reroll, zoom, or pan.

You need two values

• taskId from the original or most recent Midjourney task
• customId from the latest buttons array returned by Fetch Single Task

customId is not stable. Never hardcode it. Always read it from the latest polling response.

Common actions

• U1 to U4: upscale one image from the grid
• V1 to V4: generate variations from one image position
• Reroll: regenerate the full grid
• Zoom and Pan: extend the existing composition

After you submit an action

1. Create the follow-up task

   Send taskId and customId, then store the new returned task id.

2. Poll the new task

   Query Fetch Single Task again until the action finishes.

3. Handle modal-only actions

   If the new task reaches MODAL, continue with Modal to supply the extra input.

Authorizations

Authorization · string · header · required

Bearer token authentication. Use your CometAPI key.

Body

application/json

customId · string · required

Action id taken from the latest buttons array returned by the fetch endpoint.

taskId · string · required

Midjourney task id you want to continue from.

state · string

Custom state string. Returned as-is in the task result and webhook callback for your own tracking.

enableRemix · boolean

Whether to force remix mode when the current action supports it.

chooseSameChannel · boolean

Whether to prefer the same channel account used by the current task.

Response

200 - application/json

Action task accepted.

code · integer · required

description · string · required

result · string · required

New Midjourney task id created for the action.

properties · object

Show child attributes