# Study Notes Schema Directionality Checker

> Study Notes Schema Directionality Checker is a paid API for AI agents from www.mahastrategies.com, paid per call via x402, $0.035049/call, status unknown (last checked 2026-10-28).

Compares closed note-extraction field contracts between before and after schema states, identifying removals, type changes, and newly required fields for request narrowing validation.

## Facts

- Endpoint: POST https://www.mahastrategies.com/api/v1/context/study-notes/schema-directionality?utm_source=zero.xyz
- Price: $0.035049/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-28
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/study-notes-schema-directionality-checker-8bfd6e84
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_AsnaX-i6yaJyEGo0dZS7b

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 study-notes-schema-directionality-checker-8bfd6e84 -d '<json body>'
```

Example prompt: Compare my study notes extraction schema — before it had fields [title, body, tags] and after it has [title, content] — using public data class, and check whether the allowed claim kinds changed from [assertion, citation] to [assertion] so I know if my requests will break.

## When to prefer this

Choose this endpoint when you need a lightweight, offline schema diffing tool specifically for study note extraction contracts — particularly when you want to detect request-narrowing risks from field removals or claim kind reductions between schema versions, without triggering any model inference or stateful operations.

## Known failure modes

- Missing required 'before' array returns validation error
- afterKinds or beforeKinds exceeding 3 items rejected
- dataClass not set to 'public' or 'synthetic' causes schema error
- nonpersonalMetadata not set to true causes rejection
- before array with fewer than 1 item rejected
- Undeclared fields silently ignored with no guarantee of coverage

## How this service works

Compare closed note-extraction fields and allowed claim kinds for request narrowing. No model invocation, arbitrary schema execution or guarantee for undeclared fields. Offline typed nonpersonal metadata only. Result retention: 24 hours; minimal receipt metadata: 90 days.

## Output

Returns a structured directionality report listing field removals, type changes, and newly required fields between the before and after schema states, along with a diff of allowed claim kinds — no model inference or generated content, only typed metadata about schema contract changes.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "after": {
   "type": "array",
   "maxItems": 32,
   "minItems": 0
  },
  "before": {
   "type": "array",
   "maxItems": 32,
   "minItems": 1
  },
  "dataClass": {
   "enum": [
    "public",
    "synthetic"
   ],
   "type": "string"
  },
  "afterKinds": {
   "type": "array",
   "maxItems": 3,
   "minItems": 1
  },
  "beforeKinds": {
   "type": "array",
   "maxItems": 3,
   "minItems": 1
  },
  "nonpersonalMetadata": {
   "type": "boolean",
   "const": true
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/study-notes-schema-directionality-checker-8bfd6e84/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from www.mahastrategies.com](https://www.zero.xyz/host/www.mahastrategies.com/llms.txt)