# Polygon Calldata Inspector

> Polygon Calldata 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).

Decodes and analyzes raw Ethereum/Polygon calldata, extracting the function selector, name, arguments, and network context for a given transaction payload.

## Facts

- Endpoint: POST https://signalharness.ai/api/agent/services/polygon_calldata_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/polygon-calldata-inspector-9fbec0f6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_zXYIf8E85_lLHIXz5Ccan

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-calldata-inspector-9fbec0f6 -d '<json body>'
```

Example prompt: Can you decode this Polygon calldata for me — `0xa9059cbb0000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000006400` — and tell me what function it's calling, what the arguments are, and which network it's for?

## When to prefer this

Choose this endpoint when you need a fast, cheap ($0.01 USDC) programmatic way to decode raw Polygon calldata without running a full Ethereum node or relying on a block explorer UI. Ideal for agents building transaction monitoring pipelines, security auditors inspecting suspicious calldata, or developers debugging smart contract interactions on Polygon PoS or Amoy testnet. Not suited for on-chain ABI verification or live transaction simulation.

## Known failure modes

- Malformed or non-hex calldata string causes parsing failure
- Calldata shorter than 4 bytes (no selector) may not be decodable
- Unknown or non-standard function selectors return unrecognized function names
- ABI is not authenticated or simulated — decoded output is caller-supplied data only
- Invalid JSON in request_json field causes schema validation error

## 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 containing the decoded function name, 4-byte selector, list of decoded arguments, total calldata byte length, and Polygon network context (accepted chain IDs, bridge model, completion policy, protocol family). Also includes any warnings about limitations such as no on-chain ABI simulation, plus execution metadata (service ID, status, receipt, requestId).

## 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 simulate or authenticate the ABI."
   ],
   "service_id": "polygon_calldata_inspect",
   "analysis_json": "{\"args\":[\"0x0000000000000000000000000000000000000002\",\"100\"],\"calldata_bytes\":68,\"function_name\":\"transfer\",\"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\"},\"selector\":\"0xa9059cbb\"}",
   "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_calldata_inspect",
   "executionId": "example-execution",
   "startedAtMs": 0,
   "amountAtomic": "10000",
   "resultSha256": "57bf5fb5a790314f97c10c7ceb5db09e5c9abd77a24210c51344d667c5544932",
   "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-calldata-inspector-9fbec0f6/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)