# Polygon State Sync Event Inspector

> Polygon State Sync Event 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).

Analyzes and inspects Polygon PoS state sync events from caller-supplied data, returning structured analysis of state ID, sender, receiver, data hash, and relay completion status.

## Facts

- Endpoint: POST https://signalharness.ai/api/agent/services/polygon_state_sync_event_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/polygon-state-sync-event-inspector-688e70ca
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_-7osKJW_VJgyWnLsan3Md

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 polygon-state-sync-event-inspector-688e70ca -d '<json body>'
```

Example prompt: Can you inspect this Polygon state sync event for me — here's the raw JSON — and tell me the state ID, sender, receiver, data hash, and whether the relay was completed?

## When to prefer this

Use this endpoint when you need to programmatically parse and analyze Polygon PoS state sync event data — particularly for bridge monitoring, DeFi protocol auditing, or debugging cross-chain message relay — and you have the raw event JSON available. It is specifically designed for Polygon root-child state sync events using the checkpoint evidence model, not for Ethereum mainnet events or other L2 bridge protocols.

## Known failure modes

- Invalid or malformed request_json input results in a parse error
- Missing required state sync fields in the JSON may produce incomplete analysis
- Registration and relay completion cannot be verified from caller-supplied data alone — a warning is always returned for this
- Unsupported chain IDs outside Polygon mainnet (137) or Amoy testnet (80002) may not be analyzed correctly
- Payment failure (insufficient USDC balance) prevents the call from executing

## 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 JSON analysis including the state ID, sender and receiver addresses, data bytes count, data hash, relay completion claim status, registration verification flag, network context (accepted chain IDs, bridge model, completion policy, protocol family), and any warnings about what cannot be proven from the supplied data alone.

## 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 prove registered pairing or relay completion."
   ],
   "service_id": "polygon_state_sync_event_inspect",
   "analysis_json": "{\"data_bytes\":1,\"data_hash\":\"0x2e3ad575f5877fefc27082d4e7b82e91839c5107c6b82619026d71e2119763dd\",\"network_context\":{\"accepted_chain_ids\":[\"137\",\"80002\"],\"bridge_model\":\"root-child state sync plus checkpoint evidence\",\"completion_policy\":\"never inferred without supplied evidence\",\"protocol_family\":\"Polygon PoS\"},\"receiver\":\"0x0000000000000000000000000000000000000002\",\"registration_verified\":false,\"relay_completion_claimed\":false,\"sender\":\"0x0000000000000000000000000000000000000001\",\"state_id\":\"1\"}",
   "evidence_scope": "caller_supplied_data",
   "analyzed_network": "polygon"
  },
  "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": "polygon_state_sync_event_inspect",
   "executionId": "example-execution",
   "startedAtMs": 0,
   "amountAtomic": "15000",
   "resultSha256": "36b17d791bde1c3fd05f184317e57094e230dbec65e8bd9d45aeb4a541e4e8ff",
   "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/polygon-state-sync-event-inspector-688e70ca/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)