# Link-Rel Pingback Discovery

> Link-Rel Pingback Discovery is a paid API for AI agents from site.intel.rallylive.ca, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-01).

Discovers and returns all rel='pingback' link/anchor elements on a given page, resolved to absolute URLs with a total count.

## Facts

- Endpoint: GET https://site.intel.rallylive.ca/site/link-rel/pingback?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/link-rel-pingback-discovery-c185a1c0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_QpXGzL3utqfDRGjdP86LO

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 link-rel-pingback-discovery-c185a1c0
```

Example prompt: Can you find all the rel='pingback' links on https://example.com and give me the resolved absolute URLs along with how many there are?

## When to prefer this

Use this endpoint when you specifically need to discover rel='pingback' link relationships on a page — particularly useful for auditing WordPress or other CMS sites that advertise pingback endpoints, or when building tools that need to map out which pingback servers a site uses. Prefer this over a generic HTML scraper when you want pingback links specifically enumerated and resolved without writing your own parsing logic.

## Known failure modes

- Page is unreachable or returns a non-200 status, resulting in an empty or error response
- Target page has no rel=pingback links, returning a count of zero and an empty list
- Relative URLs that cannot be resolved due to a missing or ambiguous base URL
- Rate limiting or blocking by the target site preventing page fetch
- Malformed HTML on the target page causing link extraction to miss some elements

## How this service works

The rel="pingback" links of a page: every matching <link>/<a> with href, resolved to absolute URLs, with a count. Link-relationship discovery. $0.01 per page.

## Output

Returns a list of resolved absolute URLs found in <link> or <a> elements with rel='pingback' on the target page, along with a count of how many such links were discovered.

## 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": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/link-rel-pingback-discovery-c185a1c0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from site.intel.rallylive.ca](https://www.zero.xyz/host/site.intel.rallylive.ca/llms.txt)