# Live Per-Rail Fee Data Source Ranking for Agent Payment Routing (x402)

> Live Per-Rail Fee Data Source Ranking for Agent Payment Routing (x402) is a paid API for AI agents from k2so.wrong.systems, paid per call via x402, $0.002/call, status down (last checked 2026-10-19).

Returns an LLM-generated decision procedure for ranking and selecting fee data sources when routing agent payments across x402 rails

## Facts

- Endpoint: GET https://k2so.wrong.systems/api/services/live-per-rail-fee-data-source-ranking-for-agent?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: down
- Last checked: 2026-10-19
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/live-per-rail-fee-data-source-ranking-for-agent-payment-routing-x402-8a503bf3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_YGK1D1AqEbO1la-C1XTFe

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 live-per-rail-fee-data-source-ranking-for-agent-payment-routing-x402-8a503bf3
```

Example prompt: Give me the decision procedure for ranking live per-rail fee data sources so I can route payments correctly across x402 rails — include inputs, thresholds, and failure modes.

## When to prefer this

Use this endpoint when an agent needs a structured, opinionated decision procedure for ranking live fee data sources across x402 rails and free documentation does not provide sufficient decision logic. Prefer this over manual research when the agent must make autonomous payment routing decisions at runtime and needs thresholds and failure modes explicitly defined. Not useful if you only need static fee tables or already have a validated fee-source ranking schema.

## Known failure modes

- Payment not sent or insufficient USDC balance — returns 402 Payment Required
- Invalid or missing required input fields — returns validation error
- LLM generation failure — generationSource may fall back to deterministic or return error
- Topic override not recognized — defaults to canonical topic
- Free metadata mode (meta=1) returns schema only, not decision procedure prose

## How this service works

Paid agent-facing brief on live per-rail fee data source ranking for agent payment routing across x402 rails · Build a decision procedure or schema for: live per-rail fee data source ranking for agent payment routing across x402 rails. Include inputs, thresholds, failure modes. Falsifier: If free docs already solve the decision, paid product fails.-0. Blunt decision procedure, not marketing.

## Output

A JSON object containing a plain-prose decision procedure (120+ words) describing how to rank live per-rail fee data sources for x402 agent payment routing, including inputs, thresholds, and failure modes. Also includes metadata: the model used, generation source (llm/reasoning/deterministic), ISO-8601 timestamp, and service/provider identifiers.

## Request schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/live-per-rail-fee-data-source-ranking-for-agent-payment-routing-x402-8a503bf3/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)