# SignalHarness Typed Data Inspector

> SignalHarness Typed Data Inspector is a paid API for AI agents from signalharness.ai, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-13).

Inspects and analyzes EIP-712 typed structured data (or similar typed data formats) to surface warnings, validate structure, and assess replay risk.

## Facts

- Endpoint: POST https://signalharness.ai/api/agent/services/typed_data_inspect/invoke
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/signalharness-typed-data-inspector-270f7ef3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_datgKplNWFu-9oTa4Y56p

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-typed-data-inspector-270f7ef3 -d '<json body>'
```

Example prompt: Can you inspect this EIP-712 typed data payload and tell me if there are any warnings or replay risks before I sign it? Here's the typed data: {"types":{"EIP712Domain":[{"name":"name","type":"string"}]},"domain":{"name":"MyApp"},"primaryType":"Order","message":{"amount":"100"}}

## When to prefer this

Choose this endpoint when you need a quick, cheap ($0.01 USDC) automated inspection of EIP-712 or other typed structured data before signing or processing — especially useful for AI agents acting autonomously on behalf of users in Web3 workflows where replay attack detection and structured data validation are critical safety gates.

## Known failure modes

- Input string too short (below 2 chars) or too long (above 65536 chars) returns validation error
- Malformed or unparseable typed data may yield empty or low-confidence inspection
- Payment failure via x402 protocol results in 402 response before execution
- Network issues on Base (eip155:8453) may delay or fail settlement
- Ambiguous or non-standard typed data formats may produce generic warnings only

## 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 object containing: a boolean replay flag indicating replay risk, a typed_data_inspection string with the analysis narrative, a warnings array listing any detected issues, the evidence_scope confirming the data source, and a full receipt with payment and execution metadata including requestId, executionId, latencyMs, and a SHA-256 hash of the result.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "replay": false,
  "result": {
   "warnings": [
    "Inspection does not prove signer intent or contract acceptance."
   ],
   "service_id": "typed_data_inspect",
   "evidence_scope": "caller_supplied_data",
   "typed_data_inspection": "{\"cycles\":[],\"dependencies\":{\"Note\":[]},\"digest\":\"0x8db8c5ec3114da2288a018bc3f8bae3e5e0ef77c3848832fe9adbea12c047e1b\",\"primary_type\":\"Note\",\"type_count\":1}"
  },
  "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": "typed_data_inspect",
   "executionId": "example-execution",
   "startedAtMs": 0,
   "amountAtomic": "10000",
   "resultSha256": "480517af2e8dd70dc8a034225025d5027cd47c129473117e26371bb150ecbdce",
   "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-typed-data-inspector-270f7ef3/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)