# Anonymous URL Witness & Presence Verifier

> Anonymous URL Witness & Presence Verifier is a paid API for AI agents from pyfile-agent.taile3ff35.ts.net:10000, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-15).

Fetches a target URL anonymously (no cookies/auth/referer) and reports whether expected content is present or absent, along with a negative control from the same run

## Facts

- Endpoint: GET https://pyfile-agent.taile3ff35.ts.net:10000/data/witness
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/anonymous-url-witness-presence-verifier-6a4989a6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_n0KR-NGBtzpvw_mITGigS

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 anonymous-url-witness-presence-verifier-6a4989a6
```

Example prompt: Fetch https://example.com/status anonymously — no cookies, no login — and tell me whether the text 'Service is operational' is present and that 'Maintenance mode' is absent from the page.

## When to prefer this

Choose this endpoint when you need an independent, anonymous, third-party witness of what a public URL actually returns — especially when you want to confirm content presence and absence together in a single run with a negative control. Prefer it over a plain HTTP fetch when reader identity transparency (no cookies, no auth, no referer) and declared vantage limitations matter, such as verifying public accessibility of deployed pages, confirming content removal, or auditing what anonymous visitors see.

## Known failure modes

- Target URL is unreachable or returns non-200 status — report will indicate fetch failure
- Expected substring not found — mismatch reported with actual page excerpt
- Expect_absent substring unexpectedly found — presence flagged as a validation failure
- URL requires authentication to view content — anonymous fetch will see login page instead of target content
- Network timeout or DNS resolution failure for the target host
- URL parameter missing or malformed — request returns an error

## How this service works

Independent anonymous fetch-and-report witness: target + negative control from the same run, declared blind_spot, reader identity (anonymous, no cookies/auth/referer) and vantage (single host; not a second region). ?url=https://...&expect=<substring>&expect_absent=<substring>

## Output

Returns a witness report including: whether the expected substring was found in the page body, whether the expect_absent substring was confirmed missing, the negative control result from the same run, a declared blind_spot (e.g. single-host vantage), and reader identity metadata confirming anonymous fetch (no cookies, no auth, no referer).

## 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": {}
    }
   }
  },
  "output": {
   "type": "object"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/anonymous-url-witness-presence-verifier-6a4989a6/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from pyfile-agent.taile3ff35.ts.net:10000](https://www.zero.xyz/host/pyfile-agent.taile3ff35.ts.net%3A10000/llms.txt)