# SignalHarness NFT Royalty Calculator

> SignalHarness NFT Royalty Calculator is a paid API for AI agents from signalharness.ai, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-13).

Calculates NFT royalty amounts based on caller-supplied NFT transaction or sale data

## Facts

- Endpoint: POST https://signalharness.ai/api/agent/services/nft_royalty_calculate/invoke
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/signalharness-nft-royalty-calculator-15557907
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_P2dm584RFIJ_OgysXoTqv

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-nft-royalty-calculator-15557907 -d '<json body>'
```

Example prompt: Calculate the NFT royalty for a secondary sale of 2.5 ETH with a 10% royalty rate on token #4821 from the CryptoPunks collection — I need to know exactly how much the creator should receive.

## When to prefer this

Choose this endpoint when you need a fast, per-call computation of NFT royalty amounts based on caller-supplied transaction data without requiring on-chain lookups. Ideal for marketplace builders, NFT creators, or agents reconciling royalty payouts who already have the relevant sale and royalty parameters available. At $0.005 USDC per call via x402, it suits high-frequency per-transaction checks.

## Known failure modes

- Invalid or malformed nft_royalty_request string returns an error
- Request string below minimum length (2 chars) rejected with validation error
- Missing required nft_royalty_request field returns 400-level error
- Ambiguous or incomplete royalty data may return warnings in the result
- Payment failure via x402 protocol results in 402 response before execution

## 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 the computed NFT royalty calculation result, any warnings about the input data, an evidence scope indicator (caller_supplied_data), the service ID, and a full receipt with payment details, execution metadata, and a SHA256 result hash for verification.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "replay": false,
  "result": {
   "warnings": [
    "Royalty configuration and enforceability are not independently verified."
   ],
   "service_id": "nft_royalty_calculate",
   "evidence_scope": "caller_supplied_data",
   "nft_royalty_calculation": "{\"basis_points\":500,\"royalty_atomic\":\"500\",\"sale_atomic\":\"10000\",\"seller_proceeds_before_fees_atomic\":\"9500\"}"
  },
  "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": "nft_royalty_calculate",
   "executionId": "example-execution",
   "startedAtMs": 0,
   "amountAtomic": "5000",
   "resultSha256": "dd59eb1aae7d7cf86a56c6302bf1876a304fe43ca30791e9be7203989721fb42",
   "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-nft-royalty-calculator-15557907/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)