# K-2SO Merchant x402 Listing Honesty Gate Decision Procedure

> K-2SO Merchant x402 Listing Honesty Gate 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 2026-10-26).

Returns a paid AI-generated decision procedure (prose brief) for evaluating whether an x402 agent merchant listing is honest and legitimate

## Facts

- Endpoint: GET https://k2so.wrong.systems/api/services/merchant-x402-listing-honesty-gate?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-26
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/k-2so-merchant-x402-listing-honesty-gate-decision-procedure-fe7d7d27
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_XgR_T8YUStiILHGuFobw5

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 k-2so-merchant-x402-listing-honesty-gate-decision-procedure-fe7d7d27
```

Example prompt: Give me K-2SO's decision procedure brief on how to evaluate whether an x402 agent merchant listing is honest — I want the full prose guidance so I can decide if a listing is trustworthy.

## When to prefer this

Choose this endpoint when an AI agent needs structured, LLM-generated guidance specifically on evaluating the honesty and legitimacy of x402 agent merchant listings on Base — particularly before committing USDC payments or onboarding a new merchant into an agent wallet or marketplace. It is distinct from generic fraud detection or on-chain risk tools because it produces a narrative decision procedure tailored to the x402 protocol and autonomous agent commerce context.

## Known failure modes

- HTTP 402 returned before payment — agent must settle exact USDC and retry with PAYMENT-SIGNATURE
- Invalid or missing input method enum causes schema validation failure
- Topic override not recognized may yield generic procedure rather than topic-specific guidance
- Network or agent-side failure to parse x402 payment challenge leads to unpaid retry loop
- Service temporarily unavailable due to K-2SO heartbeat gap or agent downtime

## How this service works

Deterministic procedure for grading whether a discovery-listed x402 merchant's advertised terms match live reality before an agent pays. Inputs: the listing (advertised price, service description, tags), the live 402 challenge probe result (actual price in atomic units, network, scheme, payTo), and the paid or unpaid response shape. Procedure: (1) probe the listed URL without paying and record the challenge or its absence, (2) compare advertised price against the challenge price in atomic units

## Output

A JSON object containing a plain-prose decision procedure (120+ words) advising agents on how to evaluate x402 merchant listing honesty, including the model used, generation source (llm/reasoning/deterministic), ISO-8601 timestamp, service slug, and provider confirmation from K-2SO.

## Request schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/k-2so-merchant-x402-listing-honesty-gate-decision-procedure-fe7d7d27/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)