# SignalHarness Agent Step Result Match

> SignalHarness Agent Step Result Match is a paid API for AI agents from signalharness.ai, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

Validates and matches agent step output JSON against expected schemas or results, returning structured analysis with warnings and evidence scope.

## Facts

- Endpoint: POST https://signalharness.ai/api/agent/services/agent_step_result_match/invoke
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/signalharness-agent-step-result-match-71f138e1
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_63r7vV0OJZFUgAUv4Csdc

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-agent-step-result-match-71f138e1 -d '<json body>'
```

Example prompt: Can you validate this agent step output JSON to make sure it matches the expected result — here's the payload: {"step":"data_fetch","result":{"rows":42,"status":"ok"}}?

## When to prefer this

Choose this endpoint when you need a lightweight, pay-per-call validation step to verify that an agent's intermediate or final step output conforms to expected patterns or schemas — especially within agentic pipelines where auditability (via SHA-256 receipts) and traceability matter. Prefer it over generic JSON validators when you need a cryptographic receipt for accountability, or when integrating with x402 micropayment infrastructure on Base.

## Known failure modes

- Invalid or malformed request_json (not valid JSON string) returns a schema validation error
- Payload exceeds 65536 character limit causing rejection
- Payment failure via x402 protocol results in no execution
- Empty or too-short request_json (under 2 chars) rejected by schema
- Network or service unavailability returns a non-200 response with no receipt

## 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 structured response containing: a status field ('succeeded' or error), an analysis_json string with match details, a list of warnings (e.g. reminders to verify caller-supplied data), an evidence_scope label indicating data provenance, and a cryptographic receipt with payment ID, service version, latency, and a SHA-256 hash of the result for auditability.

## 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": "agent_step_result_match",
   "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": "agent_step_result_match",
   "executionId": "example-execution",
   "startedAtMs": 0,
   "amountAtomic": "10000",
   "resultSha256": "d8ca861b3069061fbd2b01e0004bd9f420ef5814f0b652195f35e8f5b6eadf24",
   "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-agent-step-result-match-71f138e1/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)