# SignalHarness Model Output Cost Comparator (Caller-Supplied Usage)

> SignalHarness Model Output Cost Comparator (Caller-Supplied Usage) is a paid API for AI agents from signalharness.ai, paid per call via x402, $0.015/call, status unknown (last checked 2026-09-15).

Compares LLM model output costs based on caller-supplied usage data, returning a structured cost analysis across models.

## Facts

- Endpoint: POST https://signalharness.ai/api/agent/services/model_output_cost_compare_from_supplied_usage/invoke
- Price: $0.015/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/signalharness-model-output-cost-comparator-caller-supplied-usage-97231bf8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_CRZsYJUxbaxjylxwE256a

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 signalharness-model-output-cost-comparator-caller-supplied-usage-97231bf8 -d '<json body>'
```

Example prompt: Compare the output costs across major LLM models using this usage data I have — input tokens: 12000, output tokens: 4500, for GPT-4o, Claude 3.5 Sonnet, and Gemini 1.5 Pro — and tell me which is cheapest for my workload.

## When to prefer this

Choose this endpoint when you have your own token usage data and want a structured, automated cost comparison across LLM providers without manually consulting each provider's pricing page. Ideal for agents optimizing model selection, auditing AI spend, or making build-vs-buy decisions based on real usage patterns. Prefer over manual lookups when you need machine-readable output with receipt provenance.

## Known failure modes

- Invalid or malformed request_json input results in validation error
- Missing or empty request_json field returns schema error
- Caller-supplied usage data is inaccurate leading to misleading cost comparison (warned in response)
- Payment failure via x402 protocol prevents execution
- Model identifiers not recognized may result in incomplete comparison

## How this service works

Explore 330 pay-per-call x402 API services and 27 agent-native digital products, with Base USDC pricing, secure Polar checkout, and free discovery.

## Output

Returns a JSON analysis object containing a cost comparison derived from the caller-supplied usage data, along with warnings noting that results depend on the accuracy of the submitted data. Includes service metadata, a receipt with payment details, and an analysis_json field containing the structured comparison results.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "request_json": {
   "type": "string",
   "maxLength": 65536,
   "minLength": 2
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "replay": false,
  "result": {
   "warnings": [
    "Verify the caller-supplied data before relying on this result."
   ],
   "service_id": "model_output_cost_compare_from_supplied_usage",
   "analysis_json": "{\"example\":\"schema-valid caller-supplied data\"}",
   "evidence_scope": "caller_supplied_data"
  },
  "status": "succeeded",
  "receipt": {
   "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
   "usage": [],
   "status": "succeeded",
   "network": "eip155:8453",
   "artifacts": [],
   "endedAtMs": 0,
   "latencyMs": 0,
   "paymentId": "example-payment",
   "receiptId": "example-receipt",
   "requestId": "example-request",
   "serviceId": "model_output_cost_compare_from_supplied_usage",
   "executionId": "example-execution",
   "startedAtMs": 0,
   "amountAtomic": "15000",
   "resultSha256": "6919303e542fe79c8f493a960e0ee11db4c49a6932d026aa74e6b109bb2d6a32",
   "serviceVersion": "1.0.0",
   "settlementReference": "0x0000000000000000000000000000000000000000000000000000000000000000"
  },
  "artifacts": [],
  "requestId": "example-request",
  "executionId": "example-execution"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/signalharness-model-output-cost-comparator-caller-supplied-usage-97231bf8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from signalharness.ai](https://www.zero.xyz/host/signalharness.ai/llms.txt)