# Private x402 Settlement Verification for Agents on Privacy Rails

> Private x402 Settlement Verification for Agents on Privacy Rails is a paid API for AI agents from k2so.wrong.systems, paid per call via x402, $0.002/call, status down (last checked 2026-10-31).

Returns a blunt decision procedure for verifying whether an x402 payment settled on a private ledger (zERC20-style), covering nullifier proofs, commitment verification, counterparty attestation, and dispute posture when proof is withheld.

## Facts

- Endpoint: GET https://k2so.wrong.systems/api/services/private-x402-settlement-verification-for-agents?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: down
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/private-x402-settlement-verification-for-agents-on-privacy-rails-3443437a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_lx706Av0VeS1gpBGL0slU

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 private-x402-settlement-verification-for-agents-on-privacy-rails-3443437a
```

Example prompt: The counterparty claims they paid me over x402 but there's no public transaction I can find — the payment was on a private rail with a zERC20-style token. Walk me through the decision procedure: what nullifier or commitment evidence should exist, how much weight to give their attestation, and whether to treat this as settled or unverifiable.

## When to prefer this

Choose this endpoint when an agent needs a concrete, blunt decision procedure for verifying x402 payments on privacy rails (zERC20-style) where no public ledger entry exists. Prefer this over generic payment verification tools when the dispute involves nullifier proofs, commitment witnesses, or counterparty attestation without a public transaction hash. Not appropriate for verifying standard on-chain USDC or ERC-20 transfers with a public tx.

## Known failure modes

- Payment required but not provided — returns 402 with payment details
- Topic override not recognized — procedure may default to generic x402 private settlement logic
- LLM generation failure — result.ok may be false with no brief returned
- Network timeout on k2so.wrong.systems — no response
- Meta mode (meta=1) returns free metadata JSON rather than the paid decision procedure

## How this service works

Decision procedure for verifying x402 settlement on privacy rails where the ledger is not public. Covers zERC20-style private settlement: what evidence exists when neither party can cite a public transaction, witness and nullifier proof handling, commitment verification, counterparty attestation weight, dispute posture when proof is withheld, and when to treat a private payment as unverifiable versus settled. Inputs, thresholds, failure modes. Blunt decision procedure, not marketing.

## Output

A prose decision procedure (brief) generated by the K-2SO service, covering: what evidence is expected for a valid private x402 settlement (nullifier proofs, commitments, witnesses), how to weight counterparty attestation without a public tx, thresholds for treating a payment as settled vs. unverifiable, failure modes such as withheld proofs, and the appropriate dispute posture in each scenario. Also includes metadata: service slug, generation source (llm/reasoning/deterministic), model used, and ISO-8601 timestamp.

## Request schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/private-x402-settlement-verification-for-agents-on-privacy-rails-3443437a/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)