# Change Audit: Elm JSON Schema Validator

> Change Audit: Elm JSON Schema Validator is a paid API for AI agents from market.datapackvibe.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-24).

Audits JSON document changes (before/after) against a pinned Elm SchemaStore definition, reporting added/removed/changed paths and introduced/resolved validation errors.

## Facts

- Endpoint: POST https://market.datapackvibe.com/x402/assistant-schema-elm-8d297983-changes?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-24
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/change-audit-elm-json-schema-validator-4a42e744
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Ngk4loXJ60szX6XDLpqVO

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 change-audit-elm-json-schema-validator-4a42e744 -d '<json body>'
```

Example prompt: Audit my Elm JSON config change — here's the before document and the after document — and tell me which paths were added, removed, or changed, and whether any new schema violations were introduced or old ones resolved.

## When to prefer this

Choose this endpoint when you need a schema-aware diff of two Elm JSON documents — specifically when you want both a structural change report (added/removed/changed paths) and a validation error delta (introduced/resolved violations) in a single call. Prefer this over generic JSON diff tools when Elm schema compliance matters, and over generic schema validators when you need the before/after comparison in one step. Not suitable for YAML/TOML configs or for deployment or security guarantees.

## Known failure modes

- Document exceeds 100 KB limit — request rejected
- Nesting depth exceeds 32 levels — request rejected
- Input is not valid JSON (YAML/TOML not supported) — parse error returned
- Payment not included or insufficient — 402 response
- SchemaStore definition unavailable or pinned version mismatch — validation may be incomplete

## How this service works

Change audit: Elm: Audit JSON changes and validate before/after for Elm. Uses a pinned SchemaStore definition on this PC. Reports JSON pointers and rule violations, added/removed/changed paths and introduced/resolved errors. Up to 100 KB per document; no YAML/TOML parsing or deployment/security guarantee. 0.01 USDC includes one two-document change audit.

## Output

Returns JSON pointers and rule violations for both the before and after documents, with a structured diff of added, removed, and changed paths, and a list of validation errors that were introduced or resolved by the change. Each document is validated against a pinned SchemaStore definition for Elm. Maximum 100 KB per document, up to 32 nesting levels.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "after": {
   "default": {
    "agent_market_example": true
   },
   "description": "JSON value to validate; maximum 100 KB, 32 levels."
  },
  "before": {
   "default": {},
   "description": "JSON value to validate; maximum 100 KB, 32 levels."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/change-audit-elm-json-schema-validator-4a42e744/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)