# PapaCasper Broken Link Checker

> PapaCasper Broken Link Checker is a paid API for AI agents from papacasper.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Crawls a website starting from a given URL and reports all broken links found on same-origin pages, with optional external link checking.

## Facts

- Endpoint: POST https://papacasper.com/mcp/pay/broken_link_check
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/papacasper-broken-link-checker-9283b3b8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_AfKqXtN7aLlZ_A6Zo8EiD

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 papacasper-broken-link-checker-9283b3b8 -d '<json body>'
```

Example prompt: Can you crawl my website at https://myblog.com and find all broken links, checking up to 30 pages and including external links too?

## When to prefer this

Choose this endpoint when you need to systematically discover broken links across multiple pages of a website in a single call, especially when you want both internal and external link coverage. Ideal for pre-launch QA, SEO auditing, and routine site maintenance workflows. Prefer over single-URL link extractors when multi-page crawling is needed.

## Known failure modes

- Invalid or unreachable starting URL returns an error
- maxPages cap of 50 is enforced — values above this are clamped
- Timeout on slow or large sites may result in incomplete crawl
- Non-HTTP URLs (e.g. mailto:, javascript:) may be skipped or flagged differently
- Sites blocking crawlers via robots.txt may return limited results
- Payment failure (x402) prevents execution

## How this service works

A hosted MCP server exposing utility tools any AI agent can call over HTTP — page-to-markdown, SEO audits, robots/sitemap checks, and more.

## Output

Returns a structured object containing broken links discovered during the crawl, including the source page where each broken link was found, the broken link URL, and the HTTP status code or error reason. May also include a summary count of pages crawled and total links checked.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "url"
 ],
 "properties": {
  "url": {
   "type": "string",
   "description": "Starting URL to crawl"
  },
  "maxPages": {
   "type": "number",
   "description": "Max same-origin pages to crawl (default 20, capped at 50)"
  },
  "checkExternal": {
   "type": "boolean",
   "description": "Also check links pointing off-site (default true; crawling never follows off-site links)"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/papacasper-broken-link-checker-9283b3b8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from papacasper.com](https://www.zero.xyz/host/papacasper.com/llms.txt)