# fastapi.online — API Code Generator

> fastapi.online — API Code Generator is a paid API for AI agents from api.fastapi.online, paid per call via x402, $0.006/call, status down (last checked 2026-10-22).

Generates boilerplate API code for a specified framework based on a natural-language description of what the API should do

## Facts

- Endpoint: POST https://api.fastapi.online/generate-api?utm_source=zero.xyz
- Price: $0.006/call
- Payment: x402
- Status: down
- Last checked: 2026-10-22
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fastapi-online-api-code-generator-2b5f7a52
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_CI8wALzrdljKtrKJLjFMh

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-api-code-generator-2b5f7a52 -d '<json body>'
```

Example prompt: Generate me a boilerplate Express API that handles user login and JWT authentication — just give me the starter code I can drop into my project.

## When to prefer this

Choose this endpoint when you need quick, no-signup API scaffolding code generated on demand and paid per-call with USDC crypto — ideal for agents automating developer workflows without committing to a subscription service. Prefer this over general-purpose LLM APIs when you want a specialized, cost-controlled code generation call billed at a flat $0.006 per request.

## Known failure modes

- Description too vague or missing — returns generic or empty output
- Unsupported or misspelled framework name — may default to Express or produce incorrect code
- Description exceeds 2000 character limit — request rejected
- Payment not completed via x402 protocol — 402 response returned
- Server-side model error — may return 500 with no code generated

## 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 generated API source code (boilerplate/scaffold) tailored to the specified framework and description, ready to be used as a starting point for development.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "framework": {
   "type": "string",
   "maxLength": 300,
   "description": "target framework (default Express)"
  },
  "description": {
   "type": "string",
   "maxLength": 2000,
   "minLength": 2,
   "description": "what the API should do"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fastapi-online-api-code-generator-2b5f7a52/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)