---

name: schema-check description: Validate a JSON file against the schema referenced in its $schema property. Use when the user asks to check JSON against its own schema, validate self-describing JSON, auto-validate JSON files, or verify JSON with embedded schema reference.

Validate JSON Against Embedded $schema

Validate a JSON file against the schema referenced in its $schema property. This is useful for self-describing JSON documents that declare their own schema.

Usage

Copynpx tsx scripts/check.ts <json-file> [options]

Arguments

Options

Output

Valid JSON:

CopyValid
  Schema: https://json-schema.org/draft/2020-12/schema
  File: my-schema.json

Invalid JSON:

CopyInvalid (2 errors)
  Schema: ./schemas/config.schema.json
  1. /settings/timeout: must be number
  2. /settings/retries: must be >= 0

No schema reference:

CopyError: No $schema property found in config.json
  Hint: Use schema-validate to validate against a specific schema

Script Execution

Copynpx tsx scripts/check.ts config.json
npx tsx scripts/check.ts config.json --all-errors
npx tsx scripts/check.ts config.json --no-cache --verbose

Run from the json-schema plugin directory: ~/.claude/plugins/cache/json-schema/

Schema Resolution

The $schema property can reference:

1. Remote URLs - Fetched and cached (24h TTL)

   Copy{ "$schema": "https://json-schema.org/draft/2020-12/schema" }
   

2. Local file paths - Resolved relative to the JSON file

   Copy{ "$schema": "./schemas/config.schema.json" }
   

3. Absolute paths

   Copy{ "$schema": "/Users/joe/schemas/config.schema.json" }
   

Common $schema Values

Caching

Remote schemas are cached for 24 hours using the OS temporary directory. Use --no-cache to bypass caching and fetch fresh schemas.

Related Skills

• Use schema-meta to validate that a schema is well-formed
• Use schema-validate to validate JSON against an arbitrary schema file