# SignalHarness Market VWAP Calculator

> SignalHarness Market VWAP 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).

Computes the Volume-Weighted Average Price (VWAP) for a specified market instrument based on caller-supplied data

## Facts

- Endpoint: POST https://signalharness.ai/api/agent/services/market_vwap/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-market-vwap-calculator-01c64c36
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_a8sNi8yTN83ng7yDEklZN

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-market-vwap-calculator-01c64c36 -d '<json body>'
```

Example prompt: Calculate the VWAP for BTC/USD using my supplied trade data: a series of price-volume pairs from today's session — I need the volume-weighted average price and any warnings about data quality.

## When to prefer this

Choose this endpoint when you need a verifiable, on-chain-receipted VWAP computation with cryptographic proof of the result (SHA-256 hash), especially in agent workflows that require auditability. Prefer it over ad-hoc calculations when operating in crypto-native or DeFi contexts where payment via USDC on Base is natural and a tamper-evident receipt is valuable.

## Known failure modes

- Empty or malformed vwap_request string returns a validation error
- Request string below 2 characters or above 65536 characters is rejected
- Insufficient or inconsistent price-volume data may trigger warnings in the response
- Payment failure via x402 protocol results in 402 response before execution
- Malformed JSON in the request body causes a parse 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 object containing the computed VWAP calculation result, any data quality warnings, evidence scope label, service status, and a detailed receipt including payment ID, network, latency, and a SHA-256 hash of the result for verification.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "replay": false,
  "result": {
   "warnings": [
    "VWAP reflects only supplied data and volume."
   ],
   "service_id": "market_vwap",
   "evidence_scope": "caller_supplied_data",
   "vwap_calculation": "{\"observation_count\":2,\"total_volume\":\"3\",\"vwap\":\"10.666666666666666666\"}"
  },
  "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": "market_vwap",
   "executionId": "example-execution",
   "startedAtMs": 0,
   "amountAtomic": "5000",
   "resultSha256": "6c9c86694a7b1b408445297678836ffae355c9a4c5ddb9b0894777409bfa08f4",
   "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-market-vwap-calculator-01c64c36/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)