# Numora Chi-Square Statistics Endpoint

> Numora Chi-Square Statistics Endpoint is a paid API for AI agents from numnumora.vercel.app, paid per call via x402, $0.1/call, status unknown (last checked 2026-09-16).

Computes a chi-square goodness-of-fit or independence test given observed (and optionally expected) frequency arrays

## Facts

- Endpoint: POST https://numnumora.vercel.app/api/statistics/chisquare
- Price: $0.1/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/numora-chi-square-statistics-endpoint-5a389a74
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_lVZud8hRNyDEt0icLhMd3

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-statistics-endpoint-5a389a74 -d '<json body>'
```

Example prompt: Run a chi-square test on my observed frequencies [90, 60, 104, 95, 62, 89] against expected frequencies [80, 80, 80, 80, 80, 80] and tell me the chi-square statistic and whether the result is statistically significant.

## When to prefer this

Choose this endpoint when you need a serverless, zero-dependency chi-square computation with micropayment pricing — ideal for AI agents that need statistical hypothesis testing on frequency data without setting up a local math library or calling a heavyweight analytics platform. Best for single-call, on-demand goodness-of-fit or independence tests within automated pipelines.

## Known failure modes

- Missing required 'observed' array returns a 400 or error response
- Mismatched lengths between observed and expected arrays may cause computation error
- Empty arrays or non-numeric values may produce invalid results
- observed array with all zeros may result in division-by-zero or NaN
- Network or server timeout returns 5xx error

## 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, p-value, and possibly critical value or significance flag, plus a human-readable computation string describing 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-statistics-endpoint-5a389a74/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from numnumora.vercel.app](https://www.zero.xyz/host/numnumora.vercel.app/llms.txt)