# x402 Payment Scam Surface Triage for Autonomous Agents

> x402 Payment Scam Surface Triage for Autonomous Agents is a paid API for AI agents from k2so.wrong.systems, paid per call via x402, $0.002/call, status down (last checked 2026-11-01).

Returns a structured decision procedure helping autonomous agents detect and avoid payment scams when processing x402 micropayments, covering fake merchants, swarm micro-transaction fraud, and TOCTOU attacks.

## Facts

- Endpoint: GET https://k2so.wrong.systems/api/services/x402-payment-scam-surface-triage-for-autonomous?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: down
- Last checked: 2026-11-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-payment-scam-surface-triage-for-autonomous-agents-48a08cc1
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_fwbYl05ADoegdOM-5Y2yp

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 x402-payment-scam-surface-triage-for-autonomous-agents-48a08cc1
```

Example prompt: Before I approve this x402 payment quote, run a scam surface triage on it — check for fake merchant signals, micro-transaction fraud patterns, and whether the quote URL matches the challenge URL so I know it's safe to sign.

## When to prefer this

Choose this endpoint when an autonomous agent needs structured, actionable fraud-detection guidance specific to x402 payment flows before approving a payment. It is purpose-built for the three most common x402 attack surfaces (fake merchants, swarm micro-charges, TOCTOU), making it more targeted than generic fraud detection APIs. Prefer it over manual rule checks when the agent lacks built-in x402 security heuristics or needs an auditable, LLM-generated decision procedure it can log alongside a transaction.

## Known failure modes

- Missing required 'type' or 'method' fields returns a validation error
- Invalid method values outside GET/HEAD/DELETE are rejected
- Service unavailability or upstream LLM failure may return non-200 responses
- Topic override may produce off-target procedure if unrelated to x402 payment security
- Free metadata mode (meta=1) returns schema only, not a full triage result

## How this service works

Decision procedure for an agent deciding whether a proposed x402 payment is safe to approve. Covers three attack classes in order: fake merchant endpoints (fresh domain, no receipt schema, mismatched payTo address, challenge URL differs from quoted URL), swarm micro-transaction fraud (many tiny charges from one merchant identity, spend velocity above policy threshold, one merchant splitting a single intent into repeated quotes), and TOCTOU between quote and settlement (re-quote before signing,

## Output

A JSON object containing a decision procedure brief (prose guidance for the agent), a boolean success flag, payment metadata, a service slug, provider identifier, generation source (llm, reasoning, or deterministic), and an ISO-8601 timestamp of generation. The 'brief' field is the core actionable text describing the triage outcome and recommended action.

## Request schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-payment-scam-surface-triage-for-autonomous-agents-48a08cc1/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)