Midjourney v8.2 API: Async Calls, 4-Image Jobs, --ar/--hd Sizes and Per-Image Cost
Midjourney v8.2 (model ID midjourney-v8-2 ) is now live on HopBase , submitted over the OpenAI-compatible POST /v1/images/generations endpoint and polled for results with GET /v1/video/tasks/{task_id} . The biggest difference from most image models is that every job returns a fixed set of 4 candida
Posted on Oct 28 • Originally published at hop-base.com
Midjourney v8.2 (model ID midjourney-v8-2 ) is now live on HopBase, submitted over the OpenAI-compatible POST /v1/images/generations endpoint and polled for results with GET /v1/video/tasks/{task_id}. The biggest difference from most image models is that every job returns a fixed set of 4 candidate images, and aspect ratio and quality are written into the prompt ( --ar sets the ratio, --hd renders at native 2K) instead of being passed as request fields. Billing follows the number of images actually returned: $0.0067 per image at 1K and $0.0108 per image at 2K. Check that your key can see it with GET /v1/models.
Midjourney prices officially by GPU time (0.8 GPU minutes for a standard job, 1.3 minutes with --hd ), and we convert that official rate into a per-image price. Billing follows the number of images actually returned, so a single call costs four images' worth — put that in your budget model rather than estimating from a one-image price. To compare against single-image models, multiply their per-image price by the number of candidates you would otherwise generate — see live pricing at https://hop-base.com/pricing. The console itemises the actual cost of every request.
Size is not a request field; it comes from --ar in the prompt, and adding --hd renders at native 2K. Measured values:
--ar only accepts integer ratios, so --ar 1.5:1 is rejected. The ceiling is 14:1, tightened to 4:1 once --hd is on.
We reject this set at submit time rather than forwarding it: some of these the model silently ignores (you pay and get nothing for it), and the rest only fail after the job has run for tens of seconds. The error message names the parameter and why it is not supported.
# 1. Submit; returns 202 plus a task ID curl https://api.hop-base.com/v1/images/generations \ -H "Authorization: Bearer sk-your-key" \ -H "Content-Type: application/json" \ -d '{"model":"midjourney-v8-2","prompt":"a red apple on a wooden table, studio light --ar 16:9"}' # 2. Poll with the id from the previous step; once completed, take the 4 links from outputs (valid 24 hours) curl https://api.hop-base.com/v1/video/tasks/YOUR_TASK_ID \ -H "Authorization: Bearer sk-your-key" Enter fullscreen mode Exit fullscreen mode FAQ Can I generate just one image?
No. Every Midjourney generation mode returns a fixed 2×2 grid of four candidate images. That is how the model itself works, not a restriction added on our side.
Neither the image-count field in the request nor --repeat changes the result, which is why we do not accept any value of n other than 4 — better to say so at submit time than to silently charge you for four.
In the prompt: --ar sets the ratio and --hd renders at native 2K. The quality field in the request body has no effect on this model and is rejected if you send it. The full size table is above.
Yes — at most 1, passed in the images field, with --iw (0-3) to tune how strongly it is followed; for style references, use --sref together with --sw. Note that v8.2 does not support --oref or --cref; Midjourney has replaced them with its new editing models.
No. Only jobs that actually produce images are billed; failed jobs cost nothing. If a prompt is stopped by content moderation the response gives an explicit failure reason, so you can rewrite it and retry.
PER_IMAGE = { " 1k ": 0.0067, " 2k ": 0.0108 } # official list price, USD per returned image def batch_cost ( jobs: int, tier: str = " 1k " ) -> float: return jobs * 4 * PER_IMAGE [ tier ] # every job returns 4 images print ( batch_cost ( 500 )) # 500 standard jobs -> ~$13.40 print ( batch_cost ( 500, " 2k " )) # 500 --hd jobs -> ~$21.60 Enter fullscreen mode Exit fullscreen mode Full parameter reference and error codes: Midjourney v8.2 docs. Live list prices for every model: hop-base.com/pricing. Originally published on the HopBase blog.