# RealCite URL Verifier

> RealCite URL Verifier is a paid API for AI agents from goodsong.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Verifies a URL by checking if it resolves, its final HTTP status and redirect chain, whether it is archived on the Wayback Machine, and optionally whether expected text appears on the live page.

## Facts

- Endpoint: POST https://goodsong.dev/verify/url
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/realcite-url-verifier-3dab78a0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Ze56xLXFXWHt4XecwpoXT

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 realcite-url-verifier-3dab78a0 -d '<json body>'
```

Example prompt: Can you check whether https://example.com/research-paper is still live, confirm it's archived on the Wayback Machine around 2023-06-15, and verify the page contains the text 'climate change mitigation'?

## When to prefer this

Use this endpoint when you need to verify the live status and integrity of a specific URL — especially for citation checking, fact-checking pipelines, link validation before publishing, or confirming that a referenced source is both accessible and contains claimed content. Prefer it over generic HTTP checkers when you also need Wayback Machine archive confirmation or content-presence validation in a single call.

## Known failure modes

- URL is malformed or not http/https — returns validation error
- URL times out or is unreachable — reported as failed resolution
- Wayback Machine API is temporarily unavailable — archive check may return an error
- Expected content not found on page — returns a negative match result, not an error
- URL redirects to a completely different domain — reported in redirect chain but may surprise caller

## How this service works

Verify a URL: does it resolve, what's the final status and redirect chain, is it archived on the Wayback Machine, and (optionally) does expected text appear on the page. Checked via direct fetch and the Internet Archive.

## Output

Returns whether the URL resolves successfully, the final HTTP status code, the full redirect chain if any redirects occurred, whether a Wayback Machine snapshot exists (and details of the nearest archived snapshot if an expected date was provided), and whether the expected content text was found on the live page if specified.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "format": "uri",
   "description": "The URL to verify. Must be http or https."
  },
  "expected_date": {
   "type": "string",
   "description": "Optional ISO date (YYYY-MM-DD); checks for an archived snapshot near this date."
  },
  "expected_content": {
   "type": "string",
   "description": "Optional text that should appear on the page."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/realcite-url-verifier-3dab78a0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from goodsong.dev](https://www.zero.xyz/host/goodsong.dev/llms.txt)