# Air Quality Observations – Category Frequencies

> Air Quality Observations – Category Frequencies 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 category frequency distributions from a batch of air quality observation records (PM2.5, humidity) grouped by station and date.

## Facts

- Endpoint: POST https://market.datapackvibe.com/x402/assistant-ar-analytics-air-quality-observations-category-counts?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/air-quality-observations-category-frequencies-2d748dbe
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_X3CYok1QruM75fajJXY2W

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 air-quality-observations-category-frequencies-2d748dbe -d '<json body>'
```

Example prompt: Analyze these air quality readings from my monitoring stations and give me a category frequency breakdown — I have up to 200 records with station names, dates, PM2.5 values, and humidity percentages, and I want to see how many observations fall into each category.

## When to prefer this

Choose this endpoint when you have a bounded batch of up to 200 raw air quality observation records and need a quick, low-cost ($0.01 USDC) descriptive frequency breakdown by category — no external data, forecasting, or enrichment needed. Ideal for local analytics pipelines, environmental reporting dashboards, or lightweight station audits where you supply the data and need category counts back immediately.

## Known failure modes

- Empty or missing rows array returns an error
- More than 200 rows submitted exceeds the maxItems limit and is rejected
- Missing required fields (row_id, station, date, pm25, humidity_percent) cause record-level validation failure
- Invalid date format (not YYYY-MM-DD) triggers pattern validation error
- Non-numeric values for pm25 or humidity_percent cause type validation failure

## How this service works

Air quality observations - Category frequencies: Category frequencies for Air quality observations. Up to 200 supplied typed records. Local descriptive analytics; no enrichment or forecast. One of 25 new profiles across 20 shared operations in this industry. 0.01 USDC includes one bounded category frequencies report.

## Output

A bounded category frequencies report listing how many observations (out of up to 200 supplied records) fall into each air quality category, derived from PM2.5 and humidity values grouped by station and date. No forecasting or external enrichment is included — purely local descriptive analytics on the supplied data.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "rows": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "row_id",
     "station",
     "date",
     "pm25",
     "humidity_percent"
    ],
    "properties": {
     "date": {
      "type": "string",
      "default": "",
      "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
      "maxLength": 10
     },
     "pm25": {
      "type": [
       "number",
       "null"
      ],
      "maximum": 1000000000000,
      "minimum": -1000000000000
     },
     "row_id": {
      "type": "string",
      "default": "",
      "maxLength": 80,
      "minLength": 1
     },
     "station": {
      "type": "string",
      "default": "",
      "maxLength": 80
     },
     "humidity_percent": {
      "type": [
       "number",
       "null"
      ],
      "maximum": 1000000000000,
      "minimum": -1000000000000
     }
    },
    "additionalProperties": false
   },
   "default": [
    {
     "date": "2026-10-01",
     "pm25": 10,
     "row_id": "row-1",
     "station": "group-a",
     "humidity_percent": 1
    },
    {
     "date": "2026-10-02",
     "pm25": 20,
     "row_id": "row-2",
     "station": "group-b",
     "humidity_percent": 2
    },
    {
     "date": "2026-10-03",
     "pm25": 15,
     "row_id": "row-3",
     "station": "group-a",
     "humidity_percent": 3
    },
    {
     "date": "2026-10-04",
     "pm25": 30,
     "row_id": "row-4",
     "station": "group-b",
     "humidity_percent": 4
    }
   ],
   "maxItems": 200,
   "minItems": 1
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/air-quality-observations-category-frequencies-2d748dbe/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)