About Prefect Pony XL
Prefect Pony XL is a community anime checkpoint from the Pony XL lineage, published here as a single text-to-image endpoint. It takes a 5,000-character prompt, seven native SDXL sizes, an optional seed and a choice of JPEG, PNG or WebP.
Call it with the model name prefect/pony-xl/text-to-image on POST /jobs/createTask, from 3 credits per image ($0.03). New accounts get 30 free credits to try it in the Playground first.
Introduction
The endpoint takes a prompt of up to 5,000 characters, one of seven native SDXL sizes, an optional seed and JPEG, PNG or WebP output, and returns one image per call.
Key features
Keep an established tag workflow productive
Pony XL is a text-to-image option for creators who already work in deliberate, descriptive tag sequences. Put the subject, visual style, composition and lighting in a stable order so a prompt library remains understandable to the people maintaining it.
Iterate one creative decision at a time
Establish a composition that works, then change one meaningful visual idea per iteration: gesture, wardrobe, environment or lighting. Compare outputs side by side and retain the prompt version that preserves the intent, rather than treating every run as an unrelated concept.
Review suitability before publishing
Judge anatomy, composition, text rendering and visual consistency at the intended delivery resolution.
Request parameters
| Parameter | Required | Description |
|---|---|---|
seed | No | Reuse the same number to get a repeatable result. ≥ 0 · ≤ 2147483647 |
size | No | Output image size in pixels, written as width*height. All values are native SDXL shapes. 1024*1024 · 896*1152 · 1152*896 · 832*1216 · 1216*832 · 768*1344 · 1344*768 · Default: 1024*1024 |
prompt | Yes | Describe the image as comma-separated tags: quality tags first, then subject and wardrobe, then lighting and lens. |
output_format | No | File type of the result. png · jpeg · webp · Default: png |
Pricing
Prices are in credits, the same credits you use on the website (1 credit = $0.01). The hold is taken when the task is accepted and settled to the actual charge when it finishes; failed tasks are refunded.
| Option | Credits per image | ≈ USD |
|---|---|---|
| Standard | 2.25 | $0.023 |
Each task is rounded up to whole credits, so one run at the lowest tier costs 3 credits per image ($0.03).
For an exact number before you run, send the same body to POST /jobs/quote.
Use cases
Start from a written brief
Choose the size first — seven native SDXL shapes from 1024*1024 to 1344*768 — then build the prompt from quality tags, subject and wardrobe, and pin a seed once the pose works.
Fan art and social posts
The WebP option means the image can go straight into a page or a feed without a re-encode step in between.
Character sheets and references
Generate the same character across the seven shapes — square for an avatar, 2:3 for a full-body sheet, 16:9 for a banner — reusing the seed and swapping only the framing tags. It gives a consistent-enough reference set without a training run.
Prompt guide & pro tips
Pin the seed once a frame is worth keeping
Store the seed with the prompt. Without it, the exact frame cannot be rebuilt — a near-identical prompt on a fresh seed gives a different character, not a variation of the same one.
Lead with quality tags, then the subject
This lineage responds to the score/quality tag conventions of the Pony ecosystem far more than to descriptive sentences. Put those tags first, then subject and wardrobe, then lighting, lens and background. Prose still works, it just steers less.
Adapt the included example
Start with the published example using output_format: png, size: 1216*832. Replace the subject and creative direction while keeping the input contract for this mode intact.
score_9, score_8_up, 1girl, solo, silver twin tails, oversized varsity jacket, denim shorts, standing on a neon-lit city street at night, rain reflections, looking at viewer, cinematic lighting, detailed background
The wide shape and the neon are both in the prompt: this lineage reads lighting tags as readily as wardrobe tags.
Check the result before iterating
Four fields, no more: prompt, size, seed and output_format. There is no image input, no negative-prompt field, no step or guidance control, no LoRA slot and no batch count — the checkpoint's own sampler settings are fixed and not exposed. Sizes are limited to the seven native SDXL shapes; arbitrary width and height are not accepted. Output is a single image per call. Photoreal prompts will come back stylised: this is an anime merge, not a general-purpose model.
API quick start
Call the Prefect Pony XL API in three steps
- Create an API key. Sign in to PopNow and create a key in the API console. Keys start with sk-popnow- and use the same credits as the website.
- Send the request. POST /jobs/createTask with model prefect/pony-xl/text-to-image and an input object that follows the parameter table. The response returns a task ID straight away.
- Get the result. Poll GET /jobs/recordInfo with the task ID, or pass a callBackUrl and we post the result to it. Download the output links when the task succeeds.
# 1. Create the task. Keep the Idempotency-Key if you retry after a network error.
export IDEMPOTENCY_KEY="$(uuidgen)"
curl -X POST https://api.popnow.ai/api/v1/jobs/createTask \
-H "Authorization: Bearer $POPNOW_API_KEY" \
-H "Content-Type: application/json" \
-H "Idempotency-Key: $IDEMPOTENCY_KEY" \
-d '{
"model": "prefect/pony-xl/text-to-image",
"input": {
"prompt": "A ceramic teapot on a linen cloth, soft window light, muted palette",
"size": "1024*1024",
"output_format": "png"
}
}'
# 2. Copy data.taskId from the response, then poll until state is succeeded, failed, canceled or expired.
TASK_ID="TASK_ID_FROM_RESPONSE"
curl "https://api.popnow.ai/api/v1/jobs/recordInfo?taskId=$TASK_ID" \
-H "Authorization: Bearer $POPNOW_API_KEY"Replace the prompt and any links with your own. The API tab has the response, polling and callback reference.
Prefect Pony XL API questions
How much does the Prefect Pony XL API cost?
Prefect Pony XL costs 3 credits ($0.03) per image. Credits are the same as on the website (1 credit = $0.01), new accounts get 30 free credits, and failed tasks are refunded.
What is the model name for Prefect Pony XL in the API?
Put prefect/pony-xl/text-to-image for Create Image in the model field of POST /jobs/createTask.
How should I write prompts for it?
Tag-style, comma-separated, quality tags first. It was trained the way local SDXL checkpoints are trained, so the prompting habits from that ecosystem transfer directly. Long descriptive sentences work but steer more weakly than tags do.
Can I get the same image twice?
Yes — pass the same seed with the same prompt and the same size. Leave the seed out and each call returns a different frame. Store the seed alongside any frame you want to be able to rebuild.
Can I send a reference image?
No. This endpoint is text-to-image only; there is no image input, no inpainting and no ControlNet-style conditioning. For image-driven edits use one of the image-to-image endpoints in the catalog.
Which sizes are available and why these?
Seven sizes, all at SDXL's native pixel counts: 1024*1024, 896*1152, 1152*896, 832*1216, 1216*832, 768*1344 and 1344*768. Asking for an off-ratio size on an SDXL model is where anatomy tends to fall apart, so the endpoint exposes the trained shapes rather than an arbitrary width and height.
What are the limits of the Prefect Pony XL API?
Prompt length (characters): 5,000. Requests outside these limits are rejected before anything is charged.
Can I try Prefect Pony XL without writing code?
Yes. The Playground runs Prefect Pony XL on your PopNow credits, needs no API key, and shows the matching code for every run.
All Prefect Pony XL models
Anima Turbo is a newer anime model that also reads plain sentences and turns photos into anime.