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

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

Arguments

| Argument | Required | Description | |----------|----------|-------------| | json-file | Yes | Path to the JSON file with $schema property |

Options

| Option | Description | |--------|-------------| | --all-errors | Report all errors, not just the first | | --no-cache | Bypass cache when fetching remote schemas | | --strict | Enable strict mode validation | | --verbose | Show detailed validation output | | --format | Output format: text (default), json |

Output

Valid JSON:

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

Invalid JSON:

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

No schema reference:

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

Script Execution

npx 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:

Remote URLs - Fetched and cached (24h TTL)

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

Local file paths - Resolved relative to the JSON file
```
{ "$schema": "./schemas/config.schema.json" }
```

Absolute paths

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

Common $schema Values

| Schema URI | Description | |------------|-------------| | https://json-schema.org/draft/2020-12/schema | JSON Schema Draft 2020-12 | | https://json-schema.org/draft/2019-09/schema | JSON Schema Draft 2019-09 | | http://json-schema.org/draft-07/schema# | JSON Schema Draft 7 | | http://json-schema.org/draft-06/schema# | JSON Schema Draft 6 | | http://json-schema.org/draft-04/schema# | JSON Schema Draft 4 |

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