iApp Image Generation

Generates an image from a Thai or English description, with the text you supply rendered in the picture exactly as written.

POST/v3/store/image-generation/iapp-image-generation/generateTry it

Price1.5 ICper request
Capacity1,000 images/hour
Served8.9Kcalls

v1.1.3-20260904
Active

Input

prompt: การ์ดอวยพรวันเกิดสีพาสเทล มีเค้กและลูกโป่ง ลายเส้นน่ารักแบบภาพประกอบ
text: สุขสันต์วันเกิด
font: itim
size: 1024x1024

OutputPOST /v3/store/image-generation/iapp-image-generation/generate

A pastel birthday card with a cake and balloons, the words สุขสันต์วันเกิด set in the itim typeface

status: success
id: 20260902-054442-f26467
width: 1024
height: 1024
font: itim
text: สุขสันต์วันเกิด
mime_type: image/png
time: translate: 3.1 generate: 8.6 total: 11.8
iapp: images: 1 version: 1.0.0-20260902

Every field, under Response

Made with this API

Generated by v1.1.0 on 3 September 2026, unedited. Click a picture to see it full size.

ก๋วยเตี๋ยวเรือ อร่อยมากtypeface kanit-bold

Request

curl -X POST https://api.iapp.co.th/v3/store/image-generation/iapp-image-generation/generate \
  -H "apikey: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ \
    "prompt": "การ์ดอวยพรวันเกิดสีพาสเทล มีเค้กและลูกโป่ง ลายเส้นน่ารักแบบภาพประกอบ", \
    "text": "สุขสันต์วันเกิด", \
    "font": "itim", \
    "size": "1024x1024" \
  }'

Response

200OK. The fields are explained under Response.

{
  "status": "success",
  "id": "20260902-054442-f26467",
  "width": 1024,
  "height": 1024,
  "font": "itim",
  "text": ["สุขสันต์วันเกิด"],
  "mime_type": "image/png",
  "image_base64": "iVBORw0KGgoAAAANSUhEUgAABAAAAAQACAIAAADwf7zU...",
  "time": { "translate": 3.1, "generate": 8.6, "total": 11.8 },
  "iapp": { "images": 1, "version": "1.0.0-20260902" }
}

Request

JSON, one image per request; a failed or rejected request is free. 1.5 IC per image during the preview; the list price of 3 IC applies when the preview ends, announced at least 14 days ahead.

Headers

apikeystringrequired

Your API key, created under API Keys in the control panel.

Body

promptstringrequired

The scene, in Thai or English, up to 1,500 characters; text in double quotes is rendered exactly too. Say where the text sits, the setting, the light and the style: two sentences give a designed picture, five words a plain one.

textstring | array

The text that must appear, one line per item or a string with line breaks, up to 4 lines of 120 characters. Thai in prompt but not in text is not guaranteed.

fontstring

A typeface id from the list below. Default kanit-bold.

sizestring

1024x1024, the default, 1280x768, 768x1280, 1536x1024 or 1024x1536.

stylestring

A style hint appended to the prompt: photorealistic, flat vector, watercolor.

seedinteger

Fixes the random seed, for a reproducible image.

reference_imagestring

A PNG, JPEG or WebP as Base64, a data: prefix accepted, up to 6 MB. The picture keeps this image's subject, look and style and follows the prompt for the rest.

personsarray

Up to two ids of Thai public figures, left to right, from the people search below: the reliable way to put a specific person in the picture, since a name typed in the prompt is an ordinary word.

person_referencestring

off, the default, or auto, which scans the prompt for well-known Thai people written with their exact full name or official position. Prefer persons.

text_scalenumber

The text block's width as a share of the image, 0.2 to 0.9. Default 0.55.

Endpoint	Does	Price
`POST /v3/store/image-generation/iapp-image-generation/generate`	Makes one image	3 IC per image, 1.5 IC in preview
`GET …/fonts`	Lists the typefaces	Free
`GET …/persons?q=`	Searches Thai public figures by name	Free
`GET …/persons/portrait?id=`	A portrait thumbnail of a person	Free
`POST …/persons/detect`	The people recognised in a description, for a confirmation step	Free

The 19 typefaces

All published under the SIL Open Font License. kanit-bold, the default, and kanit, prompt-bold, prompt: modern. sarabun-bold, sarabun: formal, for documents. mitr: rounded. chakrapetch-bold: technical, geometric. athiti-bold: compact. k2d-bold: display. notosans: neutral sans-serif. pridi, taviraj, notoserif: serif. itim: playful. mali, sriracha: handwriting. charm: cursive handwriting. srisakdi: decorative.

People: search, portrait, detect

The demo's @ picker uses these free endpoints, which share a limit of 20 requests per second per key.

Search, GET …/persons?q=<name>&limit=<n>: a Thai or Latin name, full or partial; an empty q returns the most requested. limit is 1 to 24, default 12. Each result has a stable id, the Thai name, name_en and, for office holders, a role.
Portrait, GET …/persons/portrait?id=<id>&size=<px>: a square JPEG, size 48 to 320, default 128, cached 24 hours; 404 when there is none.
Detect, POST …/persons/detect with {"prompt": "…"}: up to four people recognised in the description, each with id, name, name_en, role, the matched text and its kind (role, full or short). It never adds anyone: use it to ask the user who should get a real face, then send the confirmed ids in persons.

Response

The image as Base64 in image_base64, with its mime_type, width and height; the font, text and seed used; time, split into translate, generate and total; and text_check, whose result of ok, duplicate, missing or extra says whether the text came out exactly once. Every success carries the header iapp-input-images: 1.

Status codes

Code	Meaning
400	An invalid `size`, `font` or field; the message names it
422	Rejected by the content safety filter, `prompt_rejected` before generation or `content_rejected` after the image check; not charged
503	The model is starting; retry after 60 seconds

Details

Measured

Measure	Result
Thai text rendered exactly, gallery run of 34 prompts, 3 Sep 2026	32 of 34, 94%
Thai text letter-perfect, acceptance set of 11 prompts, 2 Sep 2026	11 of 11
Generation time, 1024 × 1024	20 to 45 s
Serving capacity	About 17 images per minute, 1,000 per hour; beyond that, requests queue

Limits

Rate limits per key: 2 per second, 30 per minute, 600 per hour.
Text keeps the shape of the chosen typeface; effects such as neon glow or chalk texture are applied only partially.
Prompts describing sexual content, sexual content involving minors or extreme gore are rejected before generation, and every image is screened after it; with a real person in the picture, through persons or reference_image, any sexual cue is rejected, swimwear included.

Data handling

Prompts and text are used only to make the requested image, which is returned inline and deleted within 24 hours. The model runs on iApp's own GPUs, and no prompt or image goes to a third party. The service is GDPR and PDPA compliant.

Changelog

Version	Date	Changes
v1.1.3-20260904	4 Sep 2026	Thai cultural knowledge grown from 31 to 791 concepts drawn from Thai Wikipedia, recognised in Thai or English on word boundaries and never where a word means something else, with all 50 test descriptions passing.
v1.1.2-20260904	4 Sep 2026	Thai subjects named in a description, such as uniforms, Songkran, ordination, Muay Thai, khon, spirit houses and dishes, come out the way they look: of 12 Thai-culture prompts, 5 were wrong before and all 12 are right now.
v1.1.1-20260904	4 Sep 2026	The content safety filter before and after generation, name detection limited to full names, official positions and first names of well-known people, and `POST …/persons/detect`, with the person endpoints limited to 20 requests per second.
v1.1.0-20260903	3 Sep 2026	Text placed as a physical part of the scene, `text_check` in the response, `reference_image`, and more than 4,000 Thai public figures through `persons`, from the iApp Thai Famous People dataset.
v1.0.0-20260902	2 Sep 2026	Preview release: Thai and English prompts, exact Thai text in 19 typefaces, five sizes, 1.5 IC per image.

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