Validate JSON Against Schema

Validate JSON data files against a JSON Schema definition.

Usage

npx tsx scripts/validate.ts <json-file> --schema=<schema-file> [options]

Arguments

Options

Output

Valid JSON:

Valid
  Schema: user-schema.json
  File: user.json

Invalid JSON:

Invalid (3 errors)
  1. /email: must match format "email"
  2. /age: must be >= 0
  3. /name: must be string

Script Execution

npx tsx scripts/validate.ts data.json --schema=schema.json
npx tsx scripts/validate.ts data.json --schema=schema.json --all-errors
npx tsx scripts/validate.ts data.json --schema=schema.json --format=json

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

Batch Validation

Validate multiple files against the same schema using glob patterns:

# Validate all JSON files in a directory
for f in data/*.json; do npx tsx scripts/validate.ts "$f" --schema=schema.json; done

JSON Output Format

When using --format=json:

{
  "valid": false,
  "file": "user.json",
  "schema": "user-schema.json",
  "errors": [
    {
      "path": "/email",
      "message": "must match format \"email\"",
      "keyword": "format"
    }
  ]
}

Error Messages

Common validation errors:

• must be string - Type mismatch
• must match format "..." - Format validation failed
• must be >= N / must be <= N - Number range violation
• must NOT have additional properties - Unknown property
• must have required property '...' - Missing required field
• must match pattern "..." - String pattern mismatch

Related Skills

• Use schema-meta to validate that a schema is well-formed
• Use schema-check to validate a JSON file against its embedded $schema