# Live Listing Proof

> Live Listing Proof is a paid API for AI agents from live-listing-proof.mattskowronis.workers.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-15).

Verifies a public marketplace, classified, or auction listing URL against a natural-language claim about its current availability, price, or location — returning source-supported facts or an explicit evidence state.

## Facts

- Endpoint: POST https://live-listing-proof.mattskowronis.workers.dev/v1/verify
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/live-listing-proof-74d078bb
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_MKnEDYgzBKvRBaFe59eY2

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 live-listing-proof-74d078bb -d '<json body>'
```

Example prompt: Before you recommend it, can you verify that this eBay listing is still active and actually priced at $149? Here's the URL: https://www.ebay.com/itm/123456789

## When to prefer this

Use this endpoint when an AI agent is about to recommend or act on a marketplace, classified, auction, or rental listing and needs ground-truth confirmation that the listing still exists and matches a specific claim — especially before sending a recommendation to a user or triggering a downstream action. Prefer this over general web scraping tools when you need an explicit verification verdict (removed, blocked, unreachable, etc.) rather than raw page content, and when you need the response framed as evidence-backed confirmation or denial of a specific claim.

## Known failure modes

- Listing URL is paywalled or requires login — returns 'blocked' state
- Listing has been removed or taken down — returns 'removed' state
- Domain or URL is not a supported marketplace — returns 'unsupported' state
- Network timeout or site is unreachable — returns 'unreachable' state
- Page content is insufficient to verify the claim — returns 'insufficient-evidence' state
- Malformed or non-HTTP URL provided — request rejected at input validation
- Claim text is too short (under 3 characters) or too long (over 2000 characters)

## How this service works

Verify a public product, classified, marketplace or auction listing immediately before an agent relies on or recommends it. Returns source-supported listing facts when retrievable, and explicit removed, blocked, unreachable, unsupported or insufficient-evidence states instead of inventing facts.

## Output

Returns source-supported facts about the listing when retrievable — such as current availability, price, and location — or explicit states like 'removed', 'blocked', 'unreachable', 'unsupported', or 'insufficient evidence' when the listing cannot be confirmed, rather than hallucinating or guessing.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "maxLength": 2048,
   "description": "Public HTTP or HTTPS listing page URL to inspect."
  },
  "claim": {
   "type": "string",
   "maxLength": 2000,
   "minLength": 3,
   "description": "Natural-language claim about current availability, price, and/or location."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/live-listing-proof-74d078bb/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from live-listing-proof.mattskowronis.workers.dev](https://www.zero.xyz/host/live-listing-proof.mattskowronis.workers.dev/llms.txt)