# Multi-Stablecoin Settlement Denomination Choice Procedure

> Multi-Stablecoin Settlement Denomination Choice Procedure is a paid API for AI agents from k2so.wrong.systems, paid per call via x402, $0.002/call, status down (last checked 2026-09-15).

Returns a decision procedure (prose brief) for choosing which stablecoin denomination to settle a payment intent in when a merchant accepts multiple stablecoins (USDC, USDT, USDGO, etc.)

## Facts

- Endpoint: GET https://k2so.wrong.systems/api/services/agent-payment-settlement-denomination-and-disput
- Price: $0.002/call
- Payment: x402
- Status: down
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/multi-stablecoin-settlement-denomination-choice-procedure-aa808c9d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_tkkLIC5GU2BJak2Xwjg_E

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 multi-stablecoin-settlement-denomination-choice-procedure-aa808c9d
```

Example prompt: I'm about to settle a payment and the merchant accepts USDC, USDT, and USDGO — my wallet has balances in all three. Can you run the denomination choice procedure and tell me which coin to settle in, taking into account rail fees and my preference to stay in USD-pegged assets?

## When to prefer this

Choose this endpoint when an autonomous payment agent needs a reasoned, policy-aware denomination selection across multiple accepted stablecoins and must account for fee asymmetry, peg stability, and wallet balances simultaneously. Prefer it over hard-coded coin preference logic when the merchant's accepted denomination set varies per offer, or when principal policy envelopes need to be respected. It is particularly useful in x402 payment flows on Base where multiple stablecoins are in play.

## Known failure modes

- Missing or malformed query parameters may return a generic or topic-less brief
- Payment not included or payment failure returns 402 with payment instructions
- Weakly-pegged asset volatility data unavailable may result in conservative fallback recommendation
- LLM generation errors may result in empty or partial brief field
- Rate limiting or infrastructure issues on wrong.systems domain may cause timeouts

## How this service works

Decision procedure for an agent that must choose which stablecoin to settle a payment intent in when the merchant accepts several (USDC, USDT, USDGO, and similar). Inputs: accepted denominations per merchant offer, wallet balances per denomination, facilitator and rail fee asymmetry per coin, exchange-rate volatility of non-USD-pegged or weakly-pegged assets, and the principal policy envelope on denomination preference. Outputs one verdict per intent: settle-native (pay in the coin the wallet

## Output

A JSON object containing a prose decision-procedure brief explaining which stablecoin denomination to settle in and why, including the verdict (e.g. settle-native), the reasoning across fee asymmetry, peg stability, wallet balances, and policy constraints, plus metadata: service slug, model used, generation source (llm/reasoning/deterministic), and an ISO-8601 timestamp.

## Request schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/multi-stablecoin-settlement-denomination-choice-procedure-aa808c9d/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)