README

High-performance JSON Schema validator for PHP as a PECL extension.

Features

• JSON Schema Draft-04/06/07 support
• 2178 tests passed from JSON Schema Test Suite
• jsonrainbow/json-schema compatible API
• Native C implementation for performance

Requirements

• PHP 8.1+

Installation

PECL Extension

git clone https://github.com/koriym/ext-json-schema.git
cd ext-json-schema
phpize
./configure
make
make install

Add to your php.ini:

extension=json_schema.so

PHP Adapter (Optional)

For ValidatorAdapter that provides jsonrainbow/json-schema compatible API:

composer require koriym/ext-json-schema:dev-1.x

Usage

Procedural API

$data = ['name' => 'John', 'age' => 30];
$schema = [
    'type' => 'object',
    'properties' => [
        'name' => ['type' => 'string'],
        'age' => ['type' => 'integer', 'minimum' => 0]
    ],
    'required' => ['name']
];

if (json_schema_validate($data, $schema)) {
    echo "Valid!";
}

OOP API

$validator = new JsonSchema\Validator();
$validator->validate($data, $schema);

if ($validator->isValid()) {
    echo "Valid!";
} else {
    print_r($validator->getErrors());
}

jsonrainbow/json-schema Compatible Adapter

For projects using jsonrainbow/json-schema, use ValidatorAdapter for a drop-in replacement:

use JsonSchema\ValidatorAdapter;

$validator = new ValidatorAdapter();
$validator->validate($data, $schema);

// Same API as jsonrainbow/json-schema
$validator->isValid();
$validator->getErrors();    // Compatible error format
$validator->numErrors();
$validator->reset();

Error Format

Errors match jsonrainbow/json-schema format:

[
    'property'   => 'user.email',     // Dot notation path
    'pointer'    => '/user/email',    // JSON Pointer
    'message'    => 'Type mismatch',
    'constraint' => 'type',           // Constraint name
    'context'    => 1                 // ERROR_DOCUMENT_VALIDATION
]

Supported Keywords

Quality Assurance

This extension was implemented with Claude Code (Opus 4.5) and undergoes rigorous testing:

Memory Safety

# Run with Valgrind memory check
USE_ZEND_ALLOC=0 ZEND_DONT_UNLOAD_MODULES=1 \
make test TESTS=tests/*.phpt TEST_PHP_ARGS="-m"

# Result: Tests leaked: 0 (0.0%)

Continuous Integration

All tests run automatically on every push via GitHub Actions, including:

• Compilation on multiple PHP versions
• Full test suite execution
• Memory leak detection with Valgrind

License

MIT