# MPP Everyday-Payment Merchant Vetting Procedure for Agents

> MPP Everyday-Payment Merchant Vetting Procedure for Agents is a paid API for AI agents from k2so.wrong.systems, paid per call via x402, $0.002/call, status down (last checked 2026-10-18).

Returns a deterministic vetting verdict (spend-tested, small-batch-test, or treat-as-unverified) for consumer-facing merchants accepting MPP (Tempo pathUSD) or x402 USDC payments.

## Facts

- Endpoint: GET https://k2so.wrong.systems/api/services/mpp-everyday-payment-merchant-vetting-for-agents?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: down
- Last checked: 2026-10-18
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/mpp-everyday-payment-merchant-vetting-procedure-for-agents-3a2a6d15
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_FBln-zdXGNs4VKpO7aawQ

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 mpp-everyday-payment-merchant-vetting-procedure-for-agents-3a2a6d15
```

Example prompt: Before my agent pays shop.example.com at their listed payTo address 0xABC...123, run the MPP merchant vetting procedure and tell me which trust tier they fall into — spend-tested, small-batch-test, or treat-as-unverified.

## When to prefer this

Choose this endpoint when an AI agent needs a structured, deterministic trust verdict before spending MPP or x402 USDC at a consumer-facing merchant — especially for first-time or high-value payments where on-chain rail evidence, refund path, and probe history need to be formally evaluated. Prefer this over generic merchant lookup tools when the payment context is specifically x402 or Tempo pathUSD and a tiered spend verdict (spend-tested vs small-batch-test vs unverified) is required for safe autonomous operation.

## Known failure modes

- Missing or unresolvable merchant domain returns an error or low-confidence verdict
- Merchant has no on-chain payment history on the claimed rail — may default to treat-as-unverified
- Probe history unavailable leading to incomplete corpse-risk assessment
- Payment not submitted correctly (x402 flow not completed) returns unpaid/unauthorized response
- Invalid queryParams values (e.g. unsupported topic override) may cause schema validation failure

## How this service works

Deterministic merchant-vetting procedure for agents spending MPP (Tempo pathUSD) or x402 USDC at consumer-facing everyday-payment merchants. Inputs: merchant identity (domain, registered payTo address, listed brand), rail evidence (settled on-chain payment history on the claimed rail, not just a listing), refund and dispute path, price stability vs the advertised price, and corpse risk from probe history. Verdict tiers: spend-tested, small-batch-test, treat-as-unverified. The falsifier pair is

## Output

A JSON object containing a boolean success flag, a plain-prose decision procedure brief (120+ words) explaining the vetting reasoning, a verdict tier (spend-tested, small-batch-test, or treat-as-unverified), the generation source (deterministic/llm/reasoning), an ISO-8601 timestamp, and the service slug — all under a result object alongside provider and service identifiers.

## Request schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/mpp-everyday-payment-merchant-vetting-procedure-for-agents-3a2a6d15/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)