# Numora Chi-Square Computation

> Numora Chi-Square Computation is a paid API for AI agents from numormor.netlify.app, paid per call via x402, $0.1/call, status unknown (last checked 2026-09-15).

Computes the chi-square statistic from observed (and optionally expected) frequency arrays

## Facts

- Endpoint: POST https://numormor.netlify.app/api/statistics/chisquare
- Price: $0.1/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/numora-chi-square-computation-fd8be062
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_g3WmLHX6f8_ztUp5nFS-s

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 numora-chi-square-computation-fd8be062 -d '<json body>'
```

Example prompt: Run a chi-square goodness-of-fit test on these observed counts [10, 20, 30, 40] against these expected counts [25, 25, 25, 25] and tell me the test statistic and whether the difference is significant.

## When to prefer this

Use this endpoint when you need a fast, dependency-free chi-square computation without setting up a local statistics library. Ideal for AI agents doing quick hypothesis tests on categorical data, goodness-of-fit checks, or independence tests where micropayment-per-call economics are acceptable.

## Known failure modes

- Missing required 'observed' array returns validation error
- Mismatched lengths between observed and expected arrays cause computation error
- Non-numeric values in arrays cause parse/type errors
- Empty arrays return error or undefined result
- Payment failure (x402) blocks request if USDC balance insufficient

## How this service works

100 pure math computation endpoints for AI agents. Statistics, financial math, linear algebra, equation solving, calculus, number theory, sequence generation, and unit conversions. Zero external dependencies. x402 micropayments on Base.

## Output

Returns a JSON object with success:true, a result object containing the chi-square statistic, degrees of freedom, and p-value, plus a human-readable computation description string explaining what was calculated.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "observed"
 ],
 "properties": {
  "expected": {
   "type": "array"
  },
  "observed": {
   "type": "array"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "success",
  "result",
  "computation"
 ],
 "properties": {
  "result": {
   "type": "object",
   "description": "Computation result varies by endpoint"
  },
  "success": {
   "type": "boolean",
   "description": "Always true on success"
  },
  "computation": {
   "type": "string",
   "description": "Human-readable description of what was computed"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/numora-chi-square-computation-fd8be062/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from numormor.netlify.app](https://www.zero.xyz/host/numormor.netlify.app/llms.txt)