# SignalHarness Wallet Nonce Gap Analyzer

> SignalHarness Wallet Nonce Gap Analyzer is a paid API for AI agents from signalharness.ai, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-13).

Analyzes a wallet's transaction nonce history to identify gaps, inconsistencies, or anomalies that could indicate replay risks or stuck transactions.

## Facts

- Endpoint: POST https://signalharness.ai/api/agent/services/wallet_nonce_gaps/invoke
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/signalharness-wallet-nonce-gap-analyzer-f1d00451
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_2Pa5VXtj8yOsHeh8JVLTY

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-wallet-nonce-gap-analyzer-f1d00451 -d '<json body>'
```

Example prompt: Can you check this wallet's nonce history for any gaps or missing nonces that might be causing transactions to get stuck or indicate a replay risk?

## When to prefer this

Choose this endpoint when you need to programmatically detect nonce gaps or sequence anomalies in a wallet's transaction history — especially when diagnosing stuck transactions, auditing wallet security pre-deployment, or monitoring an automated agent's on-chain activity. It is particularly suited to agent-native workflows that need structured, verifiable output (SHA-256 receipt) and micropayment-gated access via x402.

## Known failure modes

- Invalid or malformed wallet_nonce_request input returns an error
- Empty or too-short input (below 2 characters) rejected by schema validation
- Malformed nonce data that cannot be parsed results in failed status
- Payment failure via x402 protocol prevents execution
- Network issues on Base (eip155:8453) may delay settlement

## 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 'wallet_nonce_gaps' field with identified gap details, a list of warnings, an evidence scope indicator ('caller_supplied_data'), a replay risk boolean flag, and a full execution receipt including payment confirmation, latency, and a SHA-256 hash of the result for verification.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "replay": false,
  "result": {
   "warnings": [
    "Pending and replaced transactions may affect interpretation."
   ],
   "service_id": "wallet_nonce_gaps",
   "evidence_scope": "caller_supplied_data",
   "wallet_nonce_gaps": "{\"duplicates\":[\"3\"],\"maximum_nonce\":\"3\",\"minimum_nonce\":\"1\",\"missing\":[\"2\"],\"truncated\":false}"
  },
  "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": "wallet_nonce_gaps",
   "executionId": "example-execution",
   "startedAtMs": 0,
   "amountAtomic": "5000",
   "resultSha256": "9f0f1ece534a8caa2af856fb92d80a59f8de15c958384a7dff70d6e27a273e9f",
   "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-wallet-nonce-gap-analyzer-f1d00451/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)