# Confidential Claim Verifier

> Confidential Claim Verifier is a paid API for AI agents from k2so.wrong.systems, paid per call via x402, $0.002/call, status down (last checked 2026-09-13).

Verifies x402 payment claims using zero-knowledge attestation, returning a proof of payment validity without exposing payer identity, wallet balance, or spend history.

## Facts

- Endpoint: GET https://k2so.wrong.systems/api/services/confidential-claim-verifier
- Price: $0.002/call
- Payment: x402
- Status: down
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/confidential-claim-verifier-def6e73d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_8WNX9MW0vnMspJoCUcSAb

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 confidential-claim-verifier-def6e73d
```

Example prompt: Can you verify that this x402 payment claim is valid without revealing who paid or any wallet details — I need a zero-knowledge proof I can show to the counterparty?

## When to prefer this

Choose this endpoint when you need to verify an x402 payment claim while preserving payer privacy — specifically when the counterparty or on-chain verifier must not learn the payer's wallet address, balance, or transaction history. Prefer this over standard payment receipt checks when privacy guarantees are a requirement, or when operating in a multi-agent context where payment metadata must remain confidential across agent boundaries.

## Known failure modes

- Invalid or malformed x402 payment claim returns ok: false with an error detail
- Payment claim that cannot be verified on-chain results in a failed attestation
- Missing required 'type' or 'method' fields returns a schema validation error
- Network or on-chain lookup failures may cause timeouts or incomplete proofs
- Unsupported HTTP method (e.g. POST, PUT) returns a method-not-allowed error

## How this service works

Zero-knowledge attestation service that verifies x402 payment claims without revealing payer identity, wallet balance, or historical spend. Agents receive a proof of payment validity that can be checked on-chain or by a counterparty while keeping the underlying payment metadata private.

## Output

Returns a structured JSON object containing a boolean validity result (ok), payment status (paid), a decision procedure brief in prose for agents, the service slug, provider identifier (K-2SO), generation source (llm, reasoning, or deterministic), and an ISO-8601 timestamp. The proof can be checked on-chain or presented to a counterparty without revealing payer identity, wallet balance, or historical spend.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "meta": {
       "enum": [
        "0",
        "1"
       ],
       "type": "string",
       "description": "Set to 1 for free metadata JSON (no payment required)"
      },
      "topic": {
       "type": "string",
       "description": "Optional topic override for the decision procedure"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "title": "Confidential Claim Verifier paid response",
     "$schema": "https://json-schema.org/draft/2020-12/schema",
     "required": [
      "ok",
      "paid",
      "service",
      "provider",
      "result"
     ],
     "properties": {
      "ok": {
       "type": "boolean"
      },
      "paid": {
       "type": "boolean"
      },
      "result": {
       "type": "object",
       "required": [
        "ok",
        "service"
       ],
       "properties": {
        "ok": {
         "type": "boolean",
         "description": "Handler success"
        },
        "brief": {
         "type": "string",
         "description": "Decision procedure prose for agents"
        },
        "model": {
         "type": "string"
        },
        "topic": {
         "type": "string"
        },
        "service": {
         "type": "string",
         "description": "Service slug"
        },
        "procedure": {
         "type": "string"
        },
        "generatedAt": {
         "type": "string",
         "description": "ISO-8601 timestamp"
        },
        "generationSource": {
         "enum": [
          "llm",
          "reasoning",
          "deterministic"
         ],
         "type": "string"
        }
       }
      },
      "payment": {
       "type": "object",
       "properties": {
        "code": {
         "type": "string"
        },
        "payer": {
         "type": "string"
        },
        "detail": {
         "type": "string"
        },
        "selfPa
… (truncated)
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "paid": true,
  "result": {
   "ok": true,
   "brief": "plain prose decision procedure (120+ words)",
   "model": "deepseek/deepseek-v4-flash-0731",
   "topic": "string topic",
   "service": "confidential-claim-verifier",
   "procedure": "same as brief",
   "generatedAt": "2026-01-01T00:00:00.000Z",
   "generationSource": "deterministic"
  },
  "service": "confidential-claim-verifier",
  "provider": "K-2SO"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/confidential-claim-verifier-def6e73d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from k2so.wrong.systems](https://www.zero.xyz/host/k2so.wrong.systems/llms.txt)