# Private-Rail x402 Settlement Verification Procedures

> Private-Rail x402 Settlement Verification Procedures is a paid API for AI agents from k2so.wrong.systems, paid per call via x402, $0.002/call, status down (last checked 2026-10-30).

Returns a normalized verification verdict for x402 payments on private rails (shielded pools, relay networks, private balances) by classifying the rail type and specifying required attestations before an agent settles.

## Facts

- Endpoint: GET https://k2so.wrong.systems/api/services/private-rail-x402-settlement-verification-proced?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: down
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/private-rail-x402-settlement-verification-procedures-2136befe
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_M4NGrVzTK5mImO5tcqL0i

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-rail-x402-settlement-verification-procedures-2136befe
```

Example prompt: Before I settle this x402 payment, verify that the relay receipt and ZK inclusion proof are sufficient attestations for this shielded-pool private rail — there's no public explorer available, so I need a normalized verdict on whether the finality claim holds.

## When to prefer this

Choose this endpoint when an agent must settle an x402 payment on a private rail — shielded pool, relay network, or private balance — where no public block explorer exists to independently confirm finality. It is specifically designed for the attestation gap in private-rail x402 flows, classifying rail types and specifying exactly which proofs (relay receipt, ZK inclusion proof, nullifier semantics) are required. Prefer this over generic payment verification when dealing with zero-knowledge or privacy-preserving payment infrastructure.

## Known failure modes

- Missing or malformed payment evidence causes verdict to return ok:false with explanation
- Unknown or unclassified rail type results in error with guidance on required fields
- Payment not yet final triggers a non-settled verdict with finality lag explanation
- Network errors reaching the verification service return a service-level error
- Free metadata mode (meta=1) returns schema only, not a verification verdict

## How this service works

Procedure for verifying payment and delivery evidence on x402 rails with no public explorer: shielded pools, private balances, relay networks. Classifies rail types, specifies which attestations to demand (relay receipt, ZK inclusion proof, shielded-pool nullifier semantics), checks finality claims, and returns a normalized verdict before the agent settles. 0.002 USDC on Base.

## Output

A normalized settlement verdict object containing: a boolean success indicator, the classified rail type, required attestations for that rail, finality assessment, a prose decision procedure brief for the agent, generation source (llm/reasoning/deterministic), and an ISO-8601 timestamp.

## Request schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/private-rail-x402-settlement-verification-procedures-2136befe/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)