# SignalHarness Model Output Format Comparator

> SignalHarness Model Output Format Comparator is a paid API for AI agents from signalharness.ai, paid per call via x402, $0.015/call, status unknown (last checked 2026-09-16).

Compares and analyzes model output formats from caller-supplied JSON data to surface structural and schema differences

## Facts

- Endpoint: POST https://signalharness.ai/api/agent/services/model_output_format_compare/invoke
- Price: $0.015/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/signalharness-model-output-format-comparator-b028f7a0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_YclY6yIOYHAnQiCPlF3Ux

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-format-comparator-b028f7a0 -d '<json body>'
```

Example prompt: Compare these two model output formats for me and tell me how they differ structurally — I'm passing in a JSON object with both the OpenAI and Anthropic response schemas and want to know if they're compatible.

## When to prefer this

Use this endpoint when you need a quick, low-cost ($0.015 USDC) programmatic comparison of two or more AI model output format schemas — especially in pipelines where you need to verify cross-model compatibility, detect output drift after model updates, or standardize response structures. Prefer this over manual inspection or custom diffing logic when you want a structured analysis result with audit-trail receipts on Base USDC.

## Known failure modes

- Malformed or invalid JSON in request_json returns a parse error
- request_json below minimum length (2 chars) or above maximum (65536 chars) is rejected
- Missing required request_json field causes a validation error
- Caller-supplied data that is structurally ambiguous may trigger warnings in the analysis
- Empty or trivially small JSON may produce low-confidence analysis results

## 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 an analysis_json object containing the comparison findings between the supplied model output formats, along with any warnings about data reliability. The response also includes a receipt with payment metadata (paymentId, amountAtomic, network, latency) and an evidence_scope field indicating the data source was caller-supplied.

## 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_format_compare",
   "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_format_compare",
   "executionId": "example-execution",
   "startedAtMs": 0,
   "amountAtomic": "15000",
   "resultSha256": "174530b0091f3e0b45d79c56aaa8ee5164494253f20b0885763703ba534700a8",
   "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-format-comparator-b028f7a0/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)