# Agent Payment Payee-Address Verification Against Address Poisoning

> Agent Payment Payee-Address Verification Against Address Poisoning is a paid API for AI agents from k2so.wrong.systems, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-14).

Returns a decision procedure (prose brief) for verifying a crypto payee address against address-poisoning attacks before an agent payment settles

## Facts

- Endpoint: GET https://k2so.wrong.systems/api/services/agent-payment-payee-address-verification-against
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent-payment-payee-address-verification-against-address-poisoning-c6d5317e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_XsvmD0F2abAapzb4lB6Xf

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 agent-payment-payee-address-verification-against-address-poisoning-c6d5317e
```

Example prompt: Before you settle this payment, verify the payee address 0x1234...abcd against our known-good registry and check for any address poisoning signals — dust amounts, lookalike characters, or suspiciously similar first/last 4 digits — and give me the decision procedure.

## When to prefer this

Use this endpoint when an AI agent is about to settle a crypto payment and needs a structured, deterministic decision procedure to detect address-poisoning attacks — especially when the payee address is new, appeared after a dust transaction, or closely resembles a known-good address. Prefer this over generic address-format validators when you need lookalike character analysis (0/O, l/1), edit-distance checks, and registry matching in one call within an x402 payment pipeline.

## Known failure modes

- Payment required (402) if no valid x402 payment header is provided
- Address not found in registry — flagged for manual review
- Malformed or non-normalized address input causes validation error
- Registry unavailable — procedure falls back to heuristic-only checks
- Topic override not recognized — defaults to standard procedure
- Rate limiting or upstream LLM failure may delay or prevent generation

## How this service works

Decision procedure for verifying a payee address before any agent payment settles. Inputs: payee address, known-good address registry, prior payment history, dust amount observed in ledger. Steps: 1. Exact match against the registry first, after normalizing checksum casing and removing whitespace. 2. If no exact match, flag the address and run lookalike checks: edit distance under 4, repeated characters (0/O, l/1, o/0), identical first 4 and last 4 characters, and any address that appears in a

## Output

A JSON object containing a plain-prose decision procedure (120+ words) describing the verification steps and outcome, along with metadata including the model used, generation source (llm, reasoning, or deterministic), an ISO-8601 timestamp, and the service slug. The 'brief' and 'procedure' fields contain the actionable text for the agent.

## Request schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent-payment-payee-address-verification-against-address-poisoning-c6d5317e/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)