# fastapi.online T-Shirt Design Generator

> fastapi.online T-Shirt Design Generator is a paid API for AI agents from api.fastapi.online, paid per call via x402, $0.012/call, status down (last checked 2026-09-15).

Generates a creative t-shirt design concept based on a theme and optional random seed

## Facts

- Endpoint: POST https://api.fastapi.online/generate-tshirt-design
- Price: $0.012/call
- Payment: x402
- Status: down
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fastapi-online-t-shirt-design-generator-25b2f555
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_5Rl2Ftnuz_crOdaNbKHjW

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability fastapi-online-t-shirt-design-generator-25b2f555 -d '<json body>'
```

Example prompt: Generate a t-shirt design with a 'retro space exploration' theme using seed 42 so I can reproduce the same result later.

## When to prefer this

Choose this endpoint when you need a quick, low-cost AI-generated t-shirt design concept without signup, billed per call via crypto. It's ideal for agents automating merchandise ideation, apparel store workflows, or creative brainstorming pipelines where reproducibility via seed is useful.

## Known failure modes

- Theme string too long (exceeds 300 characters) — validation error
- Theme string is empty or missing — 422 Unprocessable Entity
- Payment not provided or insufficient — 402 Payment Required
- Model inference timeout — 5xx error
- Invalid seed type (non-integer) — validation error

## How this service works

Chat, embeddings, OCR, speech-to-text, image editing, image understanding (captioning/Q&amp;A), text-to-speech, translation, writing tools, classification tools, developer tools, local utilities, format/checksum validators, encoding &amp; crypto utilities, date/time calculators, geo/coordinate math, math &amp; finance calculators, novelty tools, and business/social writing generators — 179 endpoints in all, across multiple specialized self-hosted models. Pay per call with crypto — no signup — or get an API key.

## Output

Returns a generated t-shirt design concept — likely including a design description, visual concept, or rendered design artifact — based on the provided theme string and optional seed for reproducibility.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "seed": {
   "type": "integer"
  },
  "theme": {
   "type": "string",
   "maxLength": 300,
   "minLength": 1,
   "description": "the design theme"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fastapi-online-t-shirt-design-generator-25b2f555/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.fastapi.online](https://www.zero.xyz/host/api.fastapi.online/llms.txt)