# SiteCheck JSON Schema Validator

> SiteCheck JSON Schema Validator is a paid API for AI agents from api.sitecheck-api.workers.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-15).

Validates any JSON value against a provided JSON Schema and returns detailed validation errors with paths and keywords

## Facts

- Endpoint: POST https://api.sitecheck-api.workers.dev/api/json-validate?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sitecheck-json-schema-validator-17811569
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_xuu_S2vAvFM31W8c_E0-b

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 sitecheck-json-schema-validator-17811569 -d '<json body>'
```

Example prompt: Can you validate this JSON object against my schema and tell me exactly which fields are wrong and why? The data is {"id": "abc", "name": "Alice"} and the schema requires id to be an integer.

## When to prefer this

Choose this endpoint when you need programmatic JSON Schema validation with detailed per-field error reporting including JSON paths and schema keywords. Ideal for agents that need to verify API payloads, config files, or data structures against a formal schema before processing or forwarding them. Prefer over manual inspection when the schema is complex or errors need to be surfaced to end users.

## Known failure modes

- Missing 'data' field returns validation error or empty result
- Invalid or malformed JSON Schema object causes schema parsing error
- Deeply nested schemas may produce many error entries
- Draft version mismatch between schema and validator may produce unexpected results
- Non-object schema values may be rejected

## How this service works

Validates JSON data against a JSON Schema (draft 2020-12): valid true or false, and up to 50 errors with the instance path, the keyword and the message. Schema and data are each limited to 200 KB. Remote $ref targets are not fetched. No network call.

## Output

Returns a JSON object indicating the JSON Schema draft used, a boolean 'valid' flag, an array of error objects each containing the JSON path, the failing keyword, and a human-readable message, plus the validator source (@cfworker/json-schema), the timestamp of the check, and a total error count.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "data": {
   "description": "Any JSON value to validate"
  },
  "schema": {
   "type": "object",
   "description": "A JSON Schema (object or boolean)"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "draft": "2020-12",
  "valid": false,
  "errors": [
   {
    "path": "#",
    "keyword": "properties",
    "message": "Property \"id\" does not match schema."
   },
   {
    "path": "#/id",
    "keyword": "type",
    "message": "Instance type \"string\" is invalid. Expected \"integer\"."
   }
  ],
  "source": "@cfworker/json-schema",
  "checkedAt": "2026-10-14T07:00:59.162Z",
  "errorCount": 2
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/sitecheck-json-schema-validator-17811569/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.sitecheck-api.workers.dev](https://www.zero.xyz/host/api.sitecheck-api.workers.dev/llms.txt)