# Per-Rail Settlement Timeout Decision Standard

> Per-Rail Settlement Timeout Decision Standard is a paid API for AI agents from k2so-8080.on.ascii.dev, paid per call via x402, $0.015/call, status unknown (last checked 2026-10-16).

Returns a decision procedure brief for x402 payment agents on how to assign rail-specific confirmation windows, apply retry/backoff policies, escalate to facilitator, and declare a payment lost.

## Facts

- Endpoint: GET https://k2so-8080.on.ascii.dev/api/services/per-rail-settlement-timeout-decision-standard?utm_source=zero.xyz
- Price: $0.015/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/per-rail-settlement-timeout-decision-standard-1c6db66f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_DFGRrRYFjfAPR0H9GciPH

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 per-rail-settlement-timeout-decision-standard-1c6db66f
```

Example prompt: What timeout windows and retry/backoff policies should I apply per payment rail for x402 settlements, and when should I escalate to a facilitator or declare a payment lost?

## When to prefer this

Use this endpoint when building or debugging an x402 payment agent that needs authoritative, agent-readable policy guidance on settlement timeouts, retry logic, and escalation paths across multiple payment rails. Prefer it over general blockchain documentation when you need a concise, actionable decision procedure specifically formatted for autonomous agent consumption in the x402 protocol context.

## Known failure modes

- Payment required but no valid x402 payment header provided — returns 402 with payment details
- Invalid query parameter values for 'meta' or 'topic' — may return validation error
- Service temporarily unavailable — upstream LLM or reasoning engine timeout
- Empty or malformed response if topic override is unrecognizable

## How this service works

Decision procedure for x402 payment agents to assign rail-specific confirmation windows, apply retry and backoff policies, decide when to escalate to facilitator or manual review, and declare a payment lost across multi-rail settlement.

## Output

A prose decision procedure brief (plus structured metadata including topic, model, generationSource, and timestamp) guiding the agent on rail-specific confirmation windows, retry and backoff schedules, escalation triggers to facilitator or manual review, and criteria for declaring a payment lost in multi-rail x402 settlement scenarios.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "meta": {
       "enum": [
        "0",
        "1"
       ],
       "type": "string",
       "description": "Set to 1 for free metadata JSON (no payment required)"
      },
      "topic": {
       "type": "string",
       "description": "Optional topic override for the decision procedure"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "title": "Per-rail settlement timeout decision standard paid response",
     "$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/per-rail-settlement-timeout-decision-standard-1c6db66f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from k2so-8080.on.ascii.dev](https://www.zero.xyz/host/k2so-8080.on.ascii.dev/llms.txt)