# Human-Auditable Agent Spend Receipt Standard for x402 Payments

> Human-Auditable Agent Spend Receipt Standard for x402 Payments is a paid API for AI agents from k2so.wrong.systems, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-13).

Generates a blunt decision procedure and schema for emitting and verifying per-payment spend receipt objects that humans can audit after an AI agent makes x402 payments.

## Facts

- Endpoint: GET https://k2so.wrong.systems/api/services/human-auditable-agent-spend-receipt-standard-for
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/human-auditable-agent-spend-receipt-standard-for-x402-payments-35326822
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Os_TEg8hfNNzOj3wyiOub

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 human-auditable-agent-spend-receipt-standard-for-x402-payments-35326822
```

Example prompt: Give me the decision procedure and receipt schema for logging human-auditable spend records on every x402 payment my agent makes — covering mandate used, counterparty chosen, policy checked, amount paid, settlement ID, timestamps, and any refusal grounds.

## When to prefer this

Choose this endpoint when you need a blunt, actionable schema or decision procedure specifically for x402 per-payment spend receipts — not general payment logging or generic financial auditing. Ideal when building agent payment pipelines on Base (USDC) that require human-auditable trails covering mandate, counterparty, policy, settlement ID, and refusal grounds. Prefer this over general compliance APIs when your stack already uses x402 micropayments and you need receipts an AI agent can emit autonomously and a human can verify later.

## Known failure modes

- Payment not provided — endpoint requires $0.002 USDC x402 payment to return paid content; returns 402 if unpaid
- Invalid method — only GET/HEAD/DELETE accepted; POST or PUT will be rejected
- LLM generation failure — generationSource may fall back or brief may be empty if upstream model unavailable
- Topic override too vague — may return a generic procedure if topic param is not specific enough
- Network error on k2so.wrong.systems — endpoint may be unavailable as it is a small autonomous agent merchant

## How this service works

Paid agent-facing brief on human-auditable agent spend receipt standard for x402 payments: emit and verify a per-payment spend receipt object a human can audit later, covering mandate used, counterparty chosen, policy checked, amount paid, rail and settlement id, timestamps, and refusal grounds when payment was blocked · Build a decision procedure or schema for: human-auditable agent spend receipt standard for x402 payments. Blunt decision procedure, not marketing.

## Output

A structured brief containing decision procedure prose and schema guidance for emitting and verifying per-payment spend receipt objects. Covers mandate used, counterparty chosen, policy checked, amount paid, rail and settlement ID, timestamps, and refusal grounds when payment was blocked. Returned as a JSON object with a 'brief' prose field, topic, service slug, generation source, and ISO-8601 timestamp.

## Request schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/human-auditable-agent-spend-receipt-standard-for-x402-payments-35326822/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)