File Core/Schema/ProtocolVersion.php

1:	<?php
2:
3:	declare(strict_types=1);
4:
5:	/**
6:	* This file is part of the Nexus MCP SDK package.
7:	*
8:	* (c) 2026 John Paul E. Balandan, CPA <paulbalandan@gmail.com>
9:	*
10:	* For the full copyright and license information, please view
11:	* the LICENSE file that was distributed with this source code.
12:	*/
13:
14:	namespace Nexus\Mcp\Core\Schema;
15:
16:	use Nexus\Assert\Assert;
17:
18:	/**
19:	* A revision of the Model Context Protocol identified by its release date.
20:	*
21:	* @see https://modelcontextprotocol.io/specification/2025-11-25/basic/lifecycle#version-negotiation
22:	*/
23:	final readonly class ProtocolVersion
24:	{
25:	public const string LATEST_VERSION = '2025-11-25';
26:
27:	/**
28:	* Previously published spec revisions in reverse chronological order.
29:	*/
30:	public const array PREVIOUS_VERSIONS = [
31:	'2025-06-18',
32:	'2025-03-26',
33:	'2024-11-05',
34:	];
35:
36:	/**
37:	* @var non-empty-string
38:	*/
39:	public string $version;
40:
41:	public function __construct(string $version)
42:	{
43:	Assert::that($version)
44:	->isNonEmptyString('"protocolVersion" must be a non-empty string.')
45:	->matchesRegularExpression('/\A\d{4}-\d{2}-\d{2}\z/', '"protocolVersion" must be in the format "YYYY-MM-DD".')
46:	;
47:
48:	$this->version = $version;
49:	}
50:	}
51: