# Sampling Observations — Category Frequencies + Base-100 Series

> Sampling Observations — Category Frequencies + Base-100 Series is a paid API for AI agents from market.datapackvibe.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-15).

Computes category frequency distributions and a base-100 index series from user-supplied weighted sampling observation records

## Facts

- Endpoint: POST https://market.datapackvibe.com/x402/assistant-ib26-analytics-15-105?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sampling-observations-category-frequencies-base-100-series-ef04a49c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_3OAfuRPe78wejbq8sNTcw

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 sampling-observations-category-frequencies-base-100-series-ef04a49c -d '<json body>'
```

Example prompt: I have up to 200 rows of weighted sampling observations with a sample_value and sample_weight per row, grouped by dataset_group and dated — can you run the category frequency report and base-100 index series on the sample_value field, using row index 0 as the base?

## When to prefer this

Choose this endpoint when you have up to 200 pre-collected weighted observation records and need two complementary statistical summaries — category frequency distributions and a base-100 normalized index series — computed offline without any external data lookups, predictions, or professional assessments. It is ideal for lightweight, reproducible statistical reporting on survey, sampling, or time-series datasets at very low cost ($0.01 per call covering both reports).

## Known failure modes

- Input array exceeds 200 rows — request will be rejected
- Missing required row fields (row_id, dataset_group, date, sample_value, sample_weight) cause validation errors
- base_index out of range (0–199) relative to actual number of rows supplied
- null sample_value or sample_weight values may affect index computation and frequency counts
- Malformed date strings not matching YYYY-MM-DD pattern will fail schema validation
- Payment of 0.01 USDC not fulfilled will result in 402 response

## How this service works

Sampling observations — Category frequencies + Base-100 series: Category frequencies + Base-100 series for supplied sampling observations records (sample_value, sample_weight). Up to 200 rows; 2 independent reports using shared local analytical engines. No live lookup, prediction, professional assessment or external action. 0.01 USDC includes 2 supplied-data reports for up to 200 rows.

## Output

Returns two analytical reports: (1) category frequency distributions showing how often each dataset_group category appears, optionally weighted; and (2) a base-100 index series normalizing the specified field (sample_value or sample_weight) relative to a chosen base row, covering up to 200 input rows processed entirely with local analytical engines.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "rows": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "row_id",
     "dataset_group",
     "date",
     "sample_value",
     "sample_weight"
    ],
    "properties": {
     "date": {
      "type": "string",
      "default": "",
      "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
      "maxLength": 10
     },
     "row_id": {
      "type": "string",
      "default": "",
      "maxLength": 80,
      "minLength": 1
     },
     "sample_value": {
      "type": [
       "number",
       "null"
      ],
      "maximum": 1000000000000,
      "minimum": -1000000000000
     },
     "dataset_group": {
      "type": "string",
      "default": "",
      "maxLength": 80
     },
     "sample_weight": {
      "type": [
       "number",
       "null"
      ],
      "maximum": 1000000000000,
      "minimum": -1000000000000
     }
    },
    "additionalProperties": false
   },
   "default": [
    {
     "date": "2026-10-01",
     "row_id": "row-1",
     "sample_value": 10,
     "dataset_group": "group-a",
     "sample_weight": 1
    },
    {
     "date": "2026-10-02",
     "row_id": "row-2",
     "sample_value": 20,
     "dataset_group": "group-b",
     "sample_weight": 2
    },
    {
     "date": "2026-10-03",
     "row_id": "row-3",
     "sample_value": 15,
     "dataset_group": "group-a",
     "sample_weight": 3
    },
    {
     "date": "2026-10-04",
     "row_id": "row-4",
     "sample_value": 30,
     "dataset_group": "group-b",
     "sample_weight": 4
    }
   ],
   "maxItems": 200,
   "minItems": 1
  },
  "field": {
   "enum": [
    "sample_value",
    "sample_weight"
   ],
   "type": "string",
   "default": "sample_value"
  },
  "base_index": {
   "type": "integer",
   "default": 0,
   "maximum": 199,
   "minimum": 0
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/sampling-observations-category-frequencies-base-100-series-ef04a49c/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)