# Penny Army Column Completeness Probe

> Penny Army Column Completeness Probe is a paid API for AI agents from penny-army-reference-mainnet.spruceboundgranitestudio.workers.dev, paid per call via x402, $0.05/call, status unknown (last checked 2026-10-11).

Analyzes JSON records to classify each specified field as absent (missing key), explicitly null, blank string, or populated, across a batch of rows.

## Facts

- Endpoint: POST https://penny-army-reference-mainnet.spruceboundgranitestudio.workers.dev/v1/probes/column-completeness?utm_source=zero.xyz
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/penny-army-column-completeness-probe-c5424eb8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_38SQl9nHOCV6UOO2y-w0e

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 penny-army-column-completeness-probe-c5424eb8 -d '<json body>'
```

Example prompt: For these 50 JSON records, tell me which of the fields 'email', 'phone', 'address', and 'date_of_birth' are absent entirely, explicitly null, blank strings, or actually filled in — I need to understand the completeness pattern per field.

## When to prefer this

Choose this endpoint when you need to rigorously distinguish between three distinct forms of 'missing' data — absent keys, explicit nulls, and blank strings — in a batch of JSON records. It is particularly valuable before ETL pipelines, data ingestion, or data quality reporting where the semantic difference between a field that was never sent, one that was sent as null, and one that was sent as an empty string matters for downstream logic. Prefer it over generic schema validators that only check types or presence without differentiating nulls from blanks.

## Known failure modes

- rows array exceeds 128 items — request rejected with validation error
- fields array exceeds 64 items or contains empty strings — validation failure
- malformed JSON body — parse error returned
- field name exceeds 128 characters — schema violation
- payment not included or insufficient — 402 payment required response

## How this service works

For supplied field names, distinguish absent keys, explicit nulls, blank strings and populated values across JSON records.

## Output

A per-field breakdown across all submitted rows indicating how many records fall into each completeness category: absent key (field not present in the object), explicit null (key present but value is null), blank string (key present with empty string value), and populated (key present with a non-null, non-empty value).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "rows": {
   "type": "array",
   "items": {
    "type": "object",
    "propertyNames": {
     "type": "string",
     "maxLength": 128
    },
    "additionalProperties": {
     "$ref": "#/properties/input/properties/body/$defs/__schema0"
    }
   },
   "maxItems": 128
  },
  "fields": {
   "type": "array",
   "items": {
    "type": "string",
    "maxLength": 128,
    "minLength": 1
   },
   "maxItems": 64
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/penny-army-column-completeness-probe-c5424eb8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from penny-army-reference-mainnet.spruceboundgranitestudio.workers.dev](https://www.zero.xyz/host/penny-army-reference-mainnet.spruceboundgranitestudio.workers.dev/llms.txt)