# QuantOracle Z-Score Calculator

> QuantOracle Z-Score Calculator is a paid API for AI agents from api.quantoracle.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-14).

Computes z-scores, rolling z-scores, and detects statistical outliers/extremes in a numeric time series with a configurable window and threshold

## Facts

- Endpoint: POST https://api.quantoracle.dev/v1/stats/zscore
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-quantoracle-dev-01837e93
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Zquk48DUIe2-Q5lImKl8A

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 api-quantoracle-dev-01837e93 -d '<json body>'
```

Example prompt: Run a z-score analysis on this price series [100.5, 102.3, 98.7, 115.2, 101.1, 99.8, 103.4] using a rolling window of 5 and flag anything beyond 2 standard deviations as extreme — I want to know which data points are statistical outliers.

## When to prefer this

Use this endpoint when you need fast, statistical z-score analysis on a numeric series — especially for financial price data, detecting unusual moves, or computing rolling normalization. Prefer this over generic stats libraries when you need a hosted, pay-per-call API with both full-series and rolling z-scores plus built-in extreme-value flagging in a single call.

## Known failure modes

- Series too short for the specified window — returns error if series length is less than window size
- Invalid threshold value — non-positive threshold may return validation error
- Empty series input — returns error for missing or empty series array
- Non-numeric values in series — parsing error for strings or nulls in the data array

## How this service works

QuantOracle: stats/zscore

## Output

Returns the mean, standard deviation, per-point z-scores for the entire series, rolling z-scores computed over the specified window, the current (most recent) z-score, a count of extreme observations, and the indices of those extreme values — all delivered in ~18ms.

## Example request

```json
{
 "input": {
  "body": {
   "series": [
    100.5,
    102.3,
    98.7,
    115.2,
    101.1,
    99.8,
    103.4
   ],
   "window": 5,
   "threshold": 2
  },
  "type": "http",
  "method": "POST",
  "bodyType": "json"
 }
}
```

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "series": {
   "type": "array",
   "items": {
    "type": "number"
   },
   "title": "Series",
   "maxItems": 5000,
   "minItems": 3,
   "description": "Numeric data series (max 5000)"
  },
  "window": {
   "anyOf": [
    {
     "type": "integer",
     "maximum": 5000,
     "minimum": 2
    },
    {
     "type": "null"
    }
   ],
   "title": "Window",
   "description": "Rolling window size (null for static z-scores)"
  },
  "threshold": {
   "type": "number",
   "title": "Threshold",
   "default": 2,
   "description": "Z-score threshold for extreme value detection"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-quantoracle-dev-01837e93/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.quantoracle.dev](https://www.zero.xyz/host/api.quantoracle.dev/llms.txt)