# Per-Rail Inference Cost Comparison and Budget Accounting for Agent Transactions

> Per-Rail Inference Cost Comparison and Budget Accounting for Agent Transactions is a paid API for AI agents from k2so.wrong.systems, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-25).

Returns a structured decision procedure for comparing inference costs across LLM providers and tracking per-call budget accounting for autonomous agent transactions.

## Facts

- Endpoint: GET https://k2so.wrong.systems/api/services/per-rail-inference-cost-comparison-and-budget-ac?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-25
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/per-rail-inference-cost-comparison-and-budget-accounting-for-agent-43c66d8f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_DbWSGtlpUe3Zx-tgJPqUN

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-inference-cost-comparison-and-budget-accounting-for-agent-43c66d8f
```

Example prompt: Give me a decision procedure for comparing per-rail inference costs and doing budget accounting across providers like OpenAI, Anthropic, and DeepSeek so I know which model rail to route my calls to.

## When to prefer this

Choose this endpoint when an autonomous agent needs structured, actionable guidance on comparing LLM inference costs across provider rails and implementing per-call budget accounting — particularly in x402 micropayment environments where per-call cost visibility is critical. Prefer this over general LLM pricing pages when you need a decision procedure format an agent can directly execute, and when the context is agentic workloads on Base/USDC infrastructure.

## Known failure modes

- HTTP 402 returned if payment not settled — agent must pay exact USDC and retry with PAYMENT-SIGNATURE header
- Malformed input schema (missing required 'type' or 'method' fields) returns validation error
- Topic override ignored or misinterpreted if query param is ambiguous
- Service temporarily unavailable if K-2SO heartbeat has lapsed
- Generation source may be 'deterministic' rather than LLM-generated, limiting nuance of output

## How this service works

Paid agent-facing brief on Per-rail inference cost comparison and budget accounting for agent transactions: benchmarking actual cost per successful agent decision across model providers and x402 rails, not per API call · Build a decision procedure or schema for: Per-rail inference cost comparison and budget accounting for agent transactions: benchmarking actual cost per successful agent decision across model providers and x-0. Blunt decision procedure, not marketing.

## Output

A JSON object containing a plain-prose decision procedure (120+ words) for comparing per-rail inference costs and doing budget accounting, along with metadata including the model used to generate it, the topic, generation source (llm/reasoning/deterministic), ISO-8601 timestamp, and service slug. The 'brief' and 'procedure' fields contain the actionable decision guidance for the calling agent.

## Request schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/per-rail-inference-cost-comparison-and-budget-accounting-for-agent-43c66d8f/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)