# Delx Commerce — Pairs Z-Score Calculator

> Delx Commerce — Pairs Z-Score Calculator is a paid API for AI agents from commerce.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-01).

Computes the z-score, mean, and standard deviation of a spread series for statistical pairs trading analysis

## Facts

- Endpoint: POST https://commerce.delx.ai/api/v1/x402/pairs-zscore?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-commerce-pairs-z-score-calculator-73d7308c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_vezUUxo0Gdv9DedZ9JqJW

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 delx-commerce-pairs-z-score-calculator-73d7308c -d '<json body>'
```

Example prompt: Calculate the z-score for this spread series I got from subtracting ETH prices from BTC prices over the last 30 days: [0.5, 0.7, 0.3, -0.1, 0.8, 1.2, 0.9, 0.4, -0.2, 0.6] — I need the mean, standard deviation, and z-score to decide if the spread is extreme enough to trade.

## When to prefer this

Choose this endpoint when you need a lightweight, pay-per-call statistical computation of z-scores for pairs trading or spread analysis without managing your own math infrastructure. It is ideal for AI agents running quantitative strategies that need on-demand, verifiable statistical results billed in USDC with no signup or subscription required.

## Known failure modes

- Empty or missing 'spread' array results in a validation error
- Non-numeric values in the spread array cause computation failure
- A spread array with fewer than 2 elements cannot produce a meaningful standard deviation
- Payment failure via x402 (insufficient USDC balance) blocks the request
- Malformed JSON body returns a 400-level error

## How this service works

Pay-per-result APIs for agents. No signup. Exact price. Verifiable delivery. USDC on Base + Solana via x402.

## Output

Returns a JSON object containing the mean of the spread series, the standard deviation (stdev), the current z-score of the spread, and a schema identifier string ('delx/util-pairs-zscore/v1') for versioned result validation.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "spread": {
   "type": "array",
   "description": "Spread series for pairs z-score"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "mean": 1,
  "stdev": 0.1290994448735805,
  "schema": "delx/util-pairs-zscore/v1",
  "zscore": 0
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-commerce-pairs-z-score-calculator-73d7308c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from commerce.delx.ai](https://www.zero.xyz/host/commerce.delx.ai/llms.txt)