# Umpire Witness Verdict

> Umpire Witness Verdict is a paid API for AI agents from umpire.vimabrosta.com, paid per call via x402, $0.25/call, status unknown (last checked 2026-09-14).

Probes a live public URL against your expectation and returns a cryptographically signed Ed25519 verdict with network-level evidence (TLS fingerprint, resolved address, response headers, body hash, timestamp).

## Facts

- Endpoint: POST https://umpire.vimabrosta.com/v1/verdicts/witness
- 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/umpire-witness-verdict-e32ddcba
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_AjV-BqEiPI4WWwtUNOIHX

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 umpire-witness-verdict-e32ddcba -d '<json body>'
```

Example prompt: Can you get a signed cryptographic proof that https://example.com/report.json is live right now and actually contains a JSON field 'status' equal to 'complete'? Use a json_path check and include a job_ref of 'task-789'.

## When to prefer this

Choose this endpoint when you need cryptographic, tamper-evident proof that a URL returned specific content at a specific time — especially in agentic workflows where one agent must verify another agent's claims, or when releasing payments contingent on a deliverable being live. Prefer this over simple HTTP checks when non-repudiation and signed evidence matter, and over monitoring services when you need a one-shot synchronous verdict rather than continuous polling.

## Known failure modes

- URL is unreachable or returns non-200 status — verdict will reflect failure with observed status
- Check condition not met (keyword absent, JSON path missing) — verdict returns fail with evidence
- TLS handshake failure or invalid certificate — probe fails with TLS error details
- Invalid check type or malformed spec — 400 error returned before probe is attempted
- Payment not provided or insufficient — 402 response, no verdict issued
- Webhook URL provided but unreachable — probe may still succeed but delivery fails

## How this service works

Proof that the world changed the way your agent says it did. One live probe of a public URL against your expectation (HTTP status, keyword, CSS selector, JSON path), answered synchronously as an Ed25519 signed verdict that embeds a signed observation: final URL, resolved address, TLS certificate fingerprint, response headers, raw body sha256, timestamp. A stake free witness against false success, priced to clear unattended wallet caps. $0.25 per verdict, no account.

## Output

A synchronously returned Ed25519-signed verdict object containing: pass/fail result, the specific checks run, the final resolved URL, the IP address, TLS certificate fingerprint, response headers, a SHA256 hash of the raw body, and a timestamp — all cryptographically signed to prevent tampering or fabrication.

## 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",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "required": [
      "spec"
     ],
     "properties": {
      "spec": {
       "type": "object",
       "required": [
        "checks"
       ],
       "properties": {
        "checks": {
         "type": "array",
         "items": {
          "type": "object",
          "required": [
           "type"
          ],
          "properties": {
           "type": {
            "enum": [
             "json_schema",
             "json_path",
             "content_hash",
             "regex",
             "length",
             "url_probe"
            ],
            "type": "string"
           }
          }
         },
         "maxItems": 10,
         "minItems": 1
        }
       }
      },
      "job_ref": {
       "type": "string",
       "maxLength": 200
      },
      "deliverable": {
       "type": "object",
       "properties": {
        "json": {},
        "text": {
         "type": "string"
        }
       }
      },
      "webhook_url": {
       "type": "string",
       "format": "uri"
      }
     }
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "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/umpire-witness-verdict-e32ddcba/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from umpire.vimabrosta.com](https://www.zero.xyz/host/umpire.vimabrosta.com/llms.txt)