# Base EIP-712 Typed Data Inspector

> Base EIP-712 Typed Data Inspector is a paid API for AI agents from signalharness.ai, paid per call via x402, $0.015/call, status unknown (last checked 2026-09-13).

Parses and analyzes an EIP-712 typed data JSON payload, extracting domain, primary type, message keys, type dependencies, and Base network context without verifying signatures.

## Facts

- Endpoint: POST https://signalharness.ai/api/agent/services/base_eip712_typed_data_inspect/invoke
- Price: $0.015/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/base-eip-712-typed-data-inspector-dc8fa2fa
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_MwMk0ySOI6VTxQGSb7PVL

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 base-eip-712-typed-data-inspector-dc8fa2fa -d '<json body>'
```

Example prompt: Can you inspect this EIP-712 typed data JSON for me and tell me the primary type, domain, message keys, and type dependencies? Here's the JSON: {"types":{"Mail":[{"name":"value","type":"uint256"}]},"domain":{"name":"Example","chainId":8453},"primaryType":"Mail","message":{"value":42}}

## When to prefer this

Use this endpoint when you need to structurally parse and understand an EIP-712 typed data payload — especially for Base network transactions — without needing signature verification. Ideal for pre-signing inspection, debugging typed data structure, agent wallet preparation workflows, or educational analysis of EIP-712 schemas. Not suitable when you need actual signature verification or application-level semantic validation.

## Known failure modes

- Malformed or non-JSON request_json input causes parsing failure
- EIP-712 JSON missing required fields may produce incomplete analysis
- Oversized payload (>65536 chars) rejected by schema validation
- Payment failure or insufficient USDC balance prevents execution
- Non-Base chain IDs still analyzed but network context reflects Base/OP Stack 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 analysis object containing: whether the digest was computed, the parsed domain (name, chainId), the chain ID string, message keys, type dependencies per type, the primary type, and Base network context (accepted chain IDs, deposit transaction type, fee model, protocol family). Also includes warnings that no signature verification or application-level semantics are guaranteed.

## 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": [
    "Does not verify a signature or guarantee application semantics."
   ],
   "service_id": "base_eip712_typed_data_inspect",
   "analysis_json": "{\"digest_not_computed\":true,\"domain\":{\"chainId\":8453,\"name\":\"Example\"},\"domain_chain_id\":\"8453\",\"message_keys\":[\"value\"],\"network_context\":{\"accepted_chain_ids\":[\"8453\",\"84532\"],\"deposit_transaction_type\":\"0x7e\",\"fee_model\":\"L2 execution plus caller-supplied L1 data/operator components\",\"protocol_family\":\"OP Stack\"},\"primary_type\":\"Mail\",\"type_dependencies\":{\"Mail\":[\"uint256\"]}}",
   "evidence_scope": "caller_supplied_data",
   "analyzed_network": "base"
  },
  "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": "base_eip712_typed_data_inspect",
   "executionId": "example-execution",
   "startedAtMs": 0,
   "amountAtomic": "15000",
   "resultSha256": "09acdd1585139825f773d604e28fcde2941a3d078ab086a38b27854610f3ae02",
   "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/base-eip-712-typed-data-inspector-dc8fa2fa/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)