# SignalDesk AI Standard Deviation Calculator

> SignalDesk AI Standard Deviation Calculator is a paid API for AI agents from x402-agent.kariguetoazul.workers.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-13).

Computes the standard deviation of a provided array of numeric observations

## Facts

- Endpoint: POST https://x402-agent.kariguetoazul.workers.dev/api/stats/standard-deviation?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/signaldesk-ai-standard-deviation-calculator-747cd68d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_kFwV-V5CedkXMDRjh4B0r

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 signaldesk-ai-standard-deviation-calculator-747cd68d -d '<json body>'
```

Example prompt: Can you calculate the standard deviation of these values for me: 2, 4, 4, 4, 5, 5, 7, 9?

## When to prefer this

Choose this endpoint when you need a quick, inexpensive, server-side standard deviation calculation on up to 1000 numeric values without implementing the math yourself. Ideal for AI agents needing statistical dispersion on the fly during analysis pipelines. At $0.001 USDC per call via x402, it is cost-effective for per-request use. Prefer this over rolling your own computation when correctness, auditability, and simplicity matter.

## Known failure modes

- Empty array provided — minItems:1 requires at least one value
- Array exceeds 1000 items — maxItems:1000 limit enforced
- Non-numeric values in array cause validation failure
- Values outside ±1,000,000,000,000,000 range rejected
- Payment not included or insufficient — x402 payment required at $0.001 USDC per call
- Network timeout from Cloudflare Workers execution limits

## How this service works

Evidence-backed autonomous AI jobs and paid data tools. Queue/D1/cron run outside the chat; free quotas and bounded execution apply.

## Output

A JSON object containing a single field 'standard_deviation' with the computed standard deviation as a floating-point number (e.g. {"standard_deviation": 0.816496580927726})

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "values": {
   "type": "array",
   "items": {
    "type": "number",
    "maximum": 1000000000000000,
    "minimum": -1000000000000000
   },
   "maxItems": 1000,
   "minItems": 1,
   "description": "Up to 1000 finite observations."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "standard_deviation": 0.816496580927726
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/signaldesk-ai-standard-deviation-calculator-747cd68d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-agent.kariguetoazul.workers.dev](https://www.zero.xyz/host/x402-agent.kariguetoazul.workers.dev/llms.txt)