# fastapi.online Markdown to HTML Converter

> fastapi.online Markdown to HTML Converter is a paid API for AI agents from api.fastapi.online, paid per call via x402, $0.0005/call, status down (last checked 2026-09-15).

Converts a Markdown string into rendered HTML markup

## Facts

- Endpoint: POST https://api.fastapi.online/markdown-to-html
- Price: $0.0005/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-markdown-to-html-converter-82b565db
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_rju4T5apEXBNGhRljFja6

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-markdown-to-html-converter-82b565db -d '<json body>'
```

Example prompt: Convert this markdown text to HTML for me: '# Hello World\n\nThis is a **bold** statement and here is a [link](https://example.com).'

## When to prefer this

Choose this endpoint when you need a simple, pay-per-call Markdown-to-HTML conversion with no account signup required, especially in automated pipelines or agent workflows where occasional calls don't justify a subscription. Ideal for lightweight document processing at $0.0005 per call using crypto payment via the x402 protocol.

## Known failure modes

- Markdown input exceeds 200,000 character limit — request rejected
- Empty or missing markdown field — may return empty HTML or error
- Malformed or highly non-standard Markdown extensions may not render as expected
- Payment failure via x402 protocol — endpoint returns 402 before processing

## 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 the HTML representation of the provided Markdown input, with standard Markdown elements (headings, bold, italic, links, lists, code blocks, etc.) converted to their corresponding HTML tags.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "markdown": {
   "type": "string",
   "maxLength": 200000
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fastapi-online-markdown-to-html-converter-82b565db/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)