PHP implementation of JSON schema. Fork of the project

JSON Schema for PHP

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A PHP Implementation for validating JSON Structures against a given Schema.

See json-schema for more details.



git clone


Install PHP Composer

composer require justinrainbow/json-schema



$data = json_decode(file_get_contents('data.json'));

// Validate
$validator = new JsonSchema\Validator;
$validator->check($data, (object)['$ref' => 'file://' . realpath('schema.json')]);

if ($validator->isValid()) {
    echo "The supplied JSON validates against the schema.\n";
} else {
    echo "JSON does not validate. Violations:\n";
    foreach ($validator->getErrors() as $error) {
        echo sprintf("[%s] %s\n", $error['property'], $error['message']);

Type coercion

If you're validating data passed to your application via HTTP, you can cast strings and booleans to the expected types defined by your schema:


use JsonSchema\SchemaStorage;
use JsonSchema\Validator;
use JsonSchema\Constraints\Factory;
use JsonSchema\Constraints\Constraint;

$request = (object)[

$validator->coerce($request, (object) [
]); // validates!

is_bool($request->processRefund); // true
is_int($request->refundAmount); // true

With inline references


use JsonSchema\SchemaStorage;
use JsonSchema\Validator;
use JsonSchema\Constraints\Factory;

$jsonSchema = <<<'JSON'
    "type": "object",
    "properties": {
        "data": {
            "oneOf": [
                { "$ref": "#/definitions/integerData" },
                { "$ref": "#/definitions/stringData" }
    "required": ["data"],
    "definitions": {
        "integerData" : {
            "type": "integer",
            "minimum" : 0
        "stringData" : {
            "type": "string"

// Schema must be decoded before it can be used for validation
$jsonSchemaObject = json_decode($jsonSchema);

// The SchemaStorage can resolve references, loading additional schemas from file as needed, etc.
$schemaStorage = new SchemaStorage();

// This does two things:
// 1) Mutates $jsonSchemaObject to normalize the references (to file://mySchema#/definitions/integerData, etc)
// 2) Tells $schemaStorage that references to file://mySchema... should be resolved by looking in $jsonSchemaObject
$schemaStorage->addSchema('file://mySchema', $jsonSchemaObject);

// Provide $schemaStorage to the Validator so that references can be resolved during validation
$jsonValidator = new Validator( new Factory($schemaStorage));

// JSON must be decoded before it can be validated
$jsonToValidateObject = json_decode('{"data":123}');

// Do validation (use isValid() and getErrors() to check the result)
$jsonValidator->check($jsonToValidateObject, $jsonSchemaObject);

Running the tests

composer test
composer testOnly TestClass
composer testOnly TestClass::testMethod