# ERC-721 Transfer Decode

> ERC-721 Transfer Decode is a paid API for AI agents from signalharness.ai, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-13).

Decodes an ERC-721 NFT transfer transaction or calldata into human-readable structured fields

## Facts

- Endpoint: POST https://signalharness.ai/api/agent/services/erc721_transfer_decode/invoke
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/erc-721-transfer-decode-b451ee95
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_o3PgVm3f53PrU9p9-Hpz-

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 erc-721-transfer-decode-b451ee95 -d '<json body>'
```

Example prompt: Can you decode this ERC-721 transfer data for me and tell me the from address, to address, and token ID? Here's the raw transfer request: 0xa9059cbb000000000000000000000000...

## When to prefer this

Choose this endpoint when you need to programmatically decode raw ERC-721 transfer calldata or transaction payloads into structured, readable fields without running your own ABI decoder. It is particularly useful for agents handling NFT transaction pipelines, compliance logging, wallet UX, or smart contract debugging on EVM-compatible chains, and it operates at low cost ($0.01 USDC) with x402 micropayment support for per-call billing.

## Known failure modes

- Malformed or non-ERC-721 calldata returns an error or warning in the decoded result
- Input string too short (below 2 chars) or too long (above 65536 chars) triggers schema validation failure
- Non-hex or unrecognized encoding may produce warnings rather than a clean decode
- Payment failure (insufficient USDC) results in a 402 response before execution
- Network or service errors return a failed status in the receipt

## 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 decoded ERC-721 transfer object containing the parsed transfer details (e.g. from/to addresses, token ID), any warnings about the input data, an evidence scope indicator noting the data is caller-supplied, and a receipt with execution metadata including payment ID, latency, and a SHA-256 result hash for verification.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "erc721_transfer_request": {
   "type": "string",
   "maxLength": 65536,
   "minLength": 2
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "replay": false,
  "result": {
   "warnings": [
    "Decoding does not prove ownership or transfer success."
   ],
   "service_id": "erc721_transfer_decode",
   "evidence_scope": "caller_supplied_data",
   "decoded_erc721_transfer": "{\"args\":[\"0x0000000000000000000000000000000000000001\",\"0x0000000000000000000000000000000000000002\",\"1\"],\"kind\":\"calldata\",\"operation\":\"transferFrom\"}"
  },
  "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": "erc721_transfer_decode",
   "executionId": "example-execution",
   "startedAtMs": 0,
   "amountAtomic": "10000",
   "resultSha256": "5058453d4ce46a944d905ac3520c9bf8ba10faa0739e4b1f4724e2a1a893f4d5",
   "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/erc-721-transfer-decode-b451ee95/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)