# Privacy-Preserving x402 Payment Verification Decision Procedure

> Privacy-Preserving x402 Payment Verification Decision Procedure is a paid API for AI agents from k2so.wrong.systems, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-30).

Returns a blunt, LLM-generated decision procedure for when to use confidential payment rails (zk-proofs, stealth addresses, private ledgers) in x402 agent payments and how to verify paid claims on opaque ledgers

## Facts

- Endpoint: GET https://k2so.wrong.systems/api/services/privacy-preserving-x402-payment-verification-dec?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/privacy-preserving-x402-payment-verification-decision-procedure-8e0bc9aa
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_YM31etVyFw5JNLa4S1mA0

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 privacy-preserving-x402-payment-verification-decision-procedure-8e0bc9aa
```

Example prompt: Give me a blunt decision procedure for when my autonomous agent should use a confidential payment rail like zk-proof settlement or stealth addresses for x402 payments, and explain how to verify a paid claim when the ledger isn't transparent.

## When to prefer this

Use this endpoint when an agent or developer needs a structured, no-fluff decision procedure specifically for x402 payment privacy: choosing between transparent and confidential settlement rails, understanding zk-proof and stealth address tradeoffs, or verifying payments on opaque ledgers. Prefer this over general blockchain documentation or payment API docs when you need agent-actionable guidance rather than marketing prose.

## Known failure modes

- Payment not provided — returns 402 requiring USDC payment before content is delivered
- Invalid method — only GET/HEAD/DELETE are accepted
- LLM generation failure — generationSource may indicate fallback to deterministic or cached response
- Topic override produces off-topic or low-quality brief if the topic is too vague or unrelated to x402 payment privacy

## How this service works

Paid agent-facing brief on privacy-preserving x402 payment verification: deciding when a confidential rail (zk-proof settlement, stealth addresses, private ledgers) is appropriate for agent payments, and how to verify a paid claim when the ledger is not transparent · Build a decision procedure or schema for: privacy-preserving x402 payment verification: deciding when a confidential rail (zk-proof settlement, stealth address-0. Blunt decision procedure, not marketing.

## Output

A structured JSON response containing a prose decision procedure brief (the 'brief' field) written for agents, covering when confidential payment rails are appropriate and how to verify paid claims on non-transparent ledgers. Also includes metadata: the topic, model used, generation source (llm/reasoning/deterministic), ISO-8601 timestamp, service slug, and payment confirmation fields (payer, transaction, selfPay).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "meta": {
       "enum": [
        "0",
        "1"
       ],
       "type": "string",
       "description": "Set to 1 for free metadata JSON (no payment required)"
      },
      "topic": {
       "type": "string",
       "description": "Optional topic override for the decision procedure"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "title": "privacy-preserving x402 payment verification: deciding when a confiden paid response",
     "$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": {
         
… (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": "privacy-preserving-x402-payment-verification-dec",
   "procedure": "same as brief",
   "generatedAt": "2026-01-01T00:00:00.000Z",
   "generationSource": "deterministic"
  },
  "service": "privacy-preserving-x402-payment-verification-dec",
  "provider": "K-2SO"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/privacy-preserving-x402-payment-verification-decision-procedure-8e0bc9aa/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)