# Event Attendance Two-Measure Correlation

> Event Attendance Two-Measure Correlation is a paid API for AI agents from market.datapackvibe.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-19).

Computes a two-measure correlation (e.g. registrations vs. attendees) from up to 200 event attendance records, returning a bounded statistical correlation deliverable.

## Facts

- Endpoint: POST https://market.datapackvibe.com/x402/assistant-sector-analytics-event-attendance-correlation?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-19
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/event-attendance-two-measure-correlation-285b3ba1
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Yf0xV2pT_h9inBlMlz6o9

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 event-attendance-two-measure-correlation-285b3ba1 -d '<json body>'
```

Example prompt: Can you run a two-measure correlation on my event attendance data? I have 4 events — group-a on 2026-10-01 with 10 registrations and 1 attendee, group-b on 2026-10-02 with 20 registrations and 2 attendees, group-a on 2026-10-03 with 15 registrations and 3 attendees, and group-b on 2026-10-04 with 30 registrations and 4 attendees.

## When to prefer this

Choose this endpoint when you need a quick, local statistical correlation between exactly two numeric event-attendance measures (registrations and attendees) on up to 200 records, without requiring external data enrichment, forecasting, or multi-variable analysis. Prefer it over general analytics APIs when you want a bounded, reproducible, pay-per-call computation at minimal cost ($0.01 USDC).

## Known failure modes

- Fewer than 1 row supplied — returns validation error
- Row missing required fields (row_id, event_type, date, registrations, attendees) — returns schema validation error
- More than 200 rows submitted — rejected due to maxItems constraint
- Numeric values outside allowed range (±1,000,000,000,000) — rejected
- Malformed date string not matching YYYY-MM-DD pattern — rejected
- All values constant (zero variance) — correlation undefined, may return null or error
- Insufficient numeric variance to compute meaningful correlation

## How this service works

Event attendance - Two-measure correlation: Two-measure correlation for Event attendance. Up to 200 supplied typed records. Local numeric and data-quality processing; no external enrichment or forecasting. One of 25 profiles or calculations across 20 shared operations in this sector. 0.01 USDC includes one bounded two-measure correlation deliverable.

## Output

Returns a bounded two-measure correlation deliverable — specifically the computed correlation coefficient between the two numeric measures (registrations and attendees) across the supplied rows, along with any supporting data-quality indicators, computed locally without external enrichment.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "rows": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "row_id",
     "event_type",
     "date",
     "registrations",
     "attendees"
    ],
    "properties": {
     "date": {
      "type": "string",
      "default": "",
      "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
      "maxLength": 10
     },
     "row_id": {
      "type": "string",
      "default": "",
      "maxLength": 80,
      "minLength": 1
     },
     "attendees": {
      "type": [
       "number",
       "null"
      ],
      "maximum": 1000000000000,
      "minimum": -1000000000000
     },
     "event_type": {
      "type": "string",
      "default": "",
      "maxLength": 80
     },
     "registrations": {
      "type": [
       "number",
       "null"
      ],
      "maximum": 1000000000000,
      "minimum": -1000000000000
     }
    },
    "additionalProperties": false
   },
   "default": [
    {
     "date": "2026-10-01",
     "row_id": "row-1",
     "attendees": 1,
     "event_type": "group-a",
     "registrations": 10
    },
    {
     "date": "2026-10-02",
     "row_id": "row-2",
     "attendees": 2,
     "event_type": "group-b",
     "registrations": 20
    },
    {
     "date": "2026-10-03",
     "row_id": "row-3",
     "attendees": 3,
     "event_type": "group-a",
     "registrations": 15
    },
    {
     "date": "2026-10-04",
     "row_id": "row-4",
     "attendees": 4,
     "event_type": "group-b",
     "registrations": 30
    }
   ],
   "maxItems": 200,
   "minItems": 1
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/event-attendance-two-measure-correlation-285b3ba1/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from market.datapackvibe.com](https://www.zero.xyz/host/market.datapackvibe.com/llms.txt)