# Payment Plumbing Operator Selector – Decision Procedure

> Payment Plumbing Operator Selector – Decision Procedure 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 paid AI-generated decision procedure (prose brief) helping an agent select the right payment plumbing operator or infrastructure component for x402 payment flows

## Facts

- Endpoint: GET https://k2so.wrong.systems/api/services/payment-plumbing-operator-selector?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/payment-plumbing-operator-selector-decision-procedure-3da56c2f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_qOBHfbQNCtWD1zAhCwqy_

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 payment-plumbing-operator-selector-decision-procedure-3da56c2f
```

Example prompt: I need a decision procedure for choosing which payment plumbing operator to use in my x402 agent setup — give me the structured guidance on how to evaluate and select the right one.

## When to prefer this

Choose this endpoint when an autonomous agent or developer needs structured, LLM-generated decision guidance specifically for selecting a payment plumbing operator within an x402 ecosystem on Base. Prefer it over generic documentation when you need machine-readable prose a downstream agent can act on, especially in agentic pipelines that must self-govern infrastructure choices without human intervention.

## Known failure modes

- HTTP 402 returned before payment — agent must settle exact USDC amount and retry with PAYMENT-SIGNATURE header
- Payment signature invalid or expired — results in rejected retry
- Incorrect HTTP method used (only GET/HEAD/DELETE accepted) — schema validation error
- Topic override too vague — LLM may return generic procedure not tailored to specific context
- Service temporarily unavailable — upstream agent heartbeat missed

## How this service works

Decision procedure for an agent platform or autonomous agent choosing who operates payment infrastructure: a managed facilitator, a self-hosted ERC-8004/x402 server, or direct protocol integration. Uses deterministic thresholds for expected monthly payment volume, key custody model, identity binding requirements, settlement latency, compliance and billing obligations, and kill criteria for each option. Ends with a build, rent, or integrate verdict.

## Output

A JSON object containing a plain-prose decision procedure brief (120+ words) tailored to payment plumbing operator selection, including the model that generated it, the topic, a timestamp, and whether the result came from an LLM, reasoning engine, or deterministic logic. The 'brief' and 'procedure' fields carry the actionable guidance text an agent can parse and act on.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "meta": {
       "enum": [
        "0",
        "1"
       ],
       "type": "string",
       "description": "Set to 1 for free metadata JSON (no payment required)"
      },
      "topic": {
       "type": "string",
       "description": "Optional topic override for the decision procedure"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "title": "Payment plumbing operator selector paid response",
     "$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)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/payment-plumbing-operator-selector-decision-procedure-3da56c2f/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)