# Cerwal URL Comparison

> Cerwal URL Comparison is a paid API for AI agents from cerwal.vercel.app, paid per call via x402, $0.25/call, status unknown (last checked 2026-09-14).

Fetches and compares the content of two web pages side by side, returning a structured diff or summary of differences

## Facts

- Endpoint: POST https://cerwal.vercel.app/api/compare
- Price: $0.25/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/cerwal-url-comparison-7c321a43
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_lsU1YZVmSWzrthnWMK9iK

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 cerwal-url-comparison-7c321a43 -d '<json body>'
```

Example prompt: Can you compare these two web pages for me — https://example.com/product-v1 and https://example.com/product-v2 — and tell me what's different between them?

## When to prefer this

Choose this endpoint when you need to programmatically compare the content of two specific web pages without authentication overhead or subscriptions — particularly useful for competitive analysis, content auditing, or tracking changes between two versions of a page. Pay-per-call via USDC makes it cost-effective for occasional comparisons without commitment.

## Known failure modes

- One or both URLs are unreachable or return non-200 status — request may fail or return partial data
- URLs point to non-HTML content (PDFs, images) that cannot be scraped as text
- Rate limiting or bot protection on target sites blocks the fetch
- Payment via x402 fails or is insufficient — request not processed
- Malformed or missing urlA/urlB fields return a validation error

## How this service works

Web scraping and search for AI agents. No auth, no subscriptions. Pay per request in USDC via x402.

## Output

Returns a JSON object with a 'success' boolean and a 'data' object containing the comparison output between the two fetched URLs — likely including content from both pages and a structured representation of their differences.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "urlA",
  "urlB"
 ],
 "properties": {
  "urlA": {
   "type": "string",
   "description": "First URL"
  },
  "urlB": {
   "type": "string",
   "description": "Second URL"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "data": {
   "type": "object"
  },
  "success": {
   "type": "boolean"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/cerwal-url-comparison-7c321a43/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from cerwal.vercel.app](https://www.zero.xyz/host/cerwal.vercel.app/llms.txt)