# fastapi.online — Concept Art Generator

> fastapi.online — Concept Art 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 concept art images from a text description using self-hosted AI image generation models, with optional seed for reproducibility.

## Facts

- Endpoint: POST https://api.fastapi.online/generate-concept-art
- 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-concept-art-generator-43fb9912
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_m5WoMC1xMy2SA7mtVAZe0

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-concept-art-generator-43fb9912 -d '<json body>'
```

Example prompt: Generate concept art of a dark fantasy dragon perched on a ruined castle at dusk, use seed 42 for reproducibility.

## When to prefer this

Choose this endpoint when you need quick, pay-per-call AI concept art generation without signing up for a full account. It's ideal for agents or developers who want reproducible image outputs via a seed parameter and prefer crypto micro-payments (USDC) over subscription billing. Prefer this over larger cloud image APIs when cost-per-call economics matter and no API key setup is desired.

## Known failure modes

- Description too short (minLength:1) or too long (maxLength:300) returns validation error
- Invalid seed type (non-integer) causes schema validation failure
- Payment failure or insufficient USDC balance results in 402 Payment Required
- Model overload or server timeout may return 503 or timeout error
- Empty or nonsensical description may produce low-quality or abstract outputs

## 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 concept art image based on the provided text description. The seed parameter allows reproducible outputs — using the same seed and description will yield the same image. The image is delivered as a response payload (likely base64-encoded or a URL), suitable for creative, game, or design workflows.

## Request schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fastapi-online-concept-art-generator-43fb9912/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)