Cartoon image API

What it is for

The cartoon model is a full Krea 2 finetune tuned for western comics and cartoons: bold clean outlines, flat or cel-shaded colour, readable expressions and poses, on a 12B model that follows sentence-length prompts closely.

Nothing is prepended to your prompt on this model. Image-to-image and inpainting run on a Pony SDXL companion checkpoint under the same model id, which does use its native score-tag prefix.

• Stylised character art and cartoon scenes
• Image to image for restyling an existing frame
• Inpainting to fix or replace a region
• Trained characters from the characters API, on the same family

Generate an image

curl https://api.fastgencloud.com/v1/images/generations \
  -H "Authorization: Bearer $FASTGEN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
      "model": "cartoon",
      "prompt": "a cheerful barista cartoon character behind an espresso machine, bold outlines, flat colour, expressive pose",
      "size": "1024x1024"
    }'

Parameters

model

cartoon

prompt

plain-language prompt, 1–2000 characters, verbatim

negative_prompt

optional, verbatim — only has an effect when guidance is above 1

size

1024x1024, 832x1216, 1216x832, 896x1152, 1152x896

n

1–4 images per request

seed

optional integer for reproducible output

steps / guidance

defaults 8 / 1 (turbo-distilled); steps 4–24, guidance 1–8

How the API works

Every generation is a job. The POST returns 202 with a job id immediately, so your request thread is never blocked on a GPU. You then either poll GET /v1/jobs/{id} or register a webhook_url and receive a signed callback when the job finishes.

Send an Idempotency-Key header and a retried request replays the original job instead of charging you twice. Your wallet is debited when the job is submitted and refunded automatically if it fails.

curl https://api.fastgencloud.com/v1/jobs/$JOB_ID \
  -H "Authorization: Bearer $FASTGEN_API_KEY"

Pricing and billing

Pricing is prepaid and usage-based: you top the wallet up with a card and each job debits it. There is no subscription, no per-seat cost, and no monthly minimum.

Images above 1 megapixel are billed pro rata by pixel count — a 1.5 MP image costs 1.5x the listed rate. Failed jobs are refunded in full, automatically.