# SignalHarness EVM Transaction Inspector

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

Inspects and analyzes an EVM transaction request, returning warnings, risk signals, and a detailed transaction inspection report.

## Facts

- Endpoint: POST https://signalharness.ai/api/agent/services/evm_transaction_inspect/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-evm-transaction-inspector-6ccbd096
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_8S69ZBPg052U5VzsNFkht

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-evm-transaction-inspector-6ccbd096 -d '<json body>'
```

Example prompt: Before I approve this transaction, can you inspect this EVM transaction request and tell me if there are any warnings or red flags I should know about? Here's the raw transaction data: 0x...

## When to prefer this

Choose this endpoint when you need a fast, per-transaction AI-powered inspection of raw EVM transaction data before signing or broadcasting — especially useful in agentic wallets, DApp browsers, or security bots that need to flag risky approvals, drainer calls, or suspicious calldata on EVM-compatible chains like Base or Ethereum. Prefer this over general blockchain explorers when you want structured warnings and a natural-language inspection rather than raw on-chain data.

## Known failure modes

- Invalid or malformed EVM transaction string returns an error
- Transaction data too short (below minLength of 2) or too long (above 65536 chars) fails validation
- Payment not received or insufficient USDC results in 402 rejection
- Ambiguous or non-EVM formatted input may return generic or low-confidence inspection results
- Network or service timeout may cause execution failure with no result

## 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 'transaction_inspection' narrative, a list of 'warnings', an 'evidence_scope' field (e.g. caller_supplied_data), a 'replay' boolean indicating replay risk, and a full receipt with payment and execution metadata including latency, service version, and result hash.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "replay": false,
  "result": {
   "warnings": [
    "Supplied transaction fields are not independently verified on-chain."
   ],
   "service_id": "evm_transaction_inspect",
   "evidence_scope": "caller_supplied_data",
   "transaction_inspection": "{\"from\":\"0x0000000000000000000000000000000000000001\",\"gas_limit\":\"21000\",\"hash\":\"0xaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\",\"input_bytes\":0,\"nonce\":\"1\",\"supplied_fields\":[\"from\",\"gas\",\"hash\",\"input\",\"nonce\",\"to\",\"value\"],\"to\":\"0x0000000000000000000000000000000000000002\",\"type\":null,\"value_atomic\":\"10\"}"
  },
  "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": "evm_transaction_inspect",
   "executionId": "example-execution",
   "startedAtMs": 0,
   "amountAtomic": "10000",
   "resultSha256": "9589bdd9a678a1ba003f45ee3be6d05229d07a03a8a71c10f89825700247c8b1",
   "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-evm-transaction-inspector-6ccbd096/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)