# unprice Canonical URL Extractor

> unprice Canonical URL Extractor is a paid API for AI agents from volkov.evgeny.m2.fvds.ru, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-18).

Fetches a webpage and extracts its canonical URL and Open Graph URL metadata via a pay-per-request API using USDC on Base.

## Facts

- Endpoint: GET https://volkov.evgeny.m2.fvds.ru/pay/canonical?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-18
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/unprice-canonical-url-extractor-3c116a59
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_SaBSrMwfEok21D-R8hyWO

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 unprice-canonical-url-extractor-3c116a59
```

Example prompt: Can you fetch the canonical URL for https://example.com/some-page and tell me what the canonical link tag and og:url point to?

## When to prefer this

Choose this endpoint when you need to programmatically extract the canonical URL or og:url metadata from any publicly accessible webpage in a pay-per-use model without a subscription. It is ideal for one-off SEO checks, URL normalization in data pipelines, or deduplication tasks where you need the authoritative URL a page declares for itself.

## Known failure modes

- URL not accessible or returns non-200 status — canonical and ogUrl fields may be empty or null
- Page has no canonical tag — canonical field returns empty string
- Payment fails or USDC balance insufficient — 402 response, request not processed
- Invalid or malformed URL input — request rejected with validation error
- Timeout fetching slow or unresponsive pages — empty or partial response

## How this service works

Tiny paid web services for agents. Pay per request with USDC on Base via x402, plus non-x402 Base USDC tx-hash checkouts for Merchant Feed Audit, Base USDC receipts, and recent wallet statements.

## Output

A JSON object containing the input URL, the resolved og:url (Open Graph URL), and the canonical URL as declared in the page's HTML link tag (e.g. {"url": "https://example.com", "ogUrl": "", "canonical": "https://example.com/"}).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "url": {
       "type": "string"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "url": "https://example.com",
  "ogUrl": "",
  "canonical": "https://example.com/"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/unprice-canonical-url-extractor-3c116a59/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from volkov.evgeny.m2.fvds.ru](https://www.zero.xyz/host/volkov.evgeny.m2.fvds.ru/llms.txt)