File Core/Schema/Error/UnsupportedProtocolVersionError.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\Error;
15:
16:	use Nexus\Assert\Assert;
17:	use Nexus\Mcp\Core\Schema\Enum\ProtocolErrorCode;
18:	use Nexus\Mcp\Core\Schema\Error;
19:
20:	/**
21:	* Returned when the request's protocol version is unknown to the server or unsupported (e.g., a known
22:	* experimental or draft version the server has chosen not to implement). For HTTP, the response status
23:	* code MUST be `400 Bad Request`.
24:	*
25:	* @extends Error<array{
26:	* code: -32022,
27:	* message: non-empty-string,
28:	* data: array{supported: list<string>, requested: string},
29:	* }>
30:	*
31:	* @see https://modelcontextprotocol.io/specification/draft/schema#unsupportedprotocolversionerror
32:	*/
33:	final readonly class UnsupportedProtocolVersionError extends Error
34:	{
35:	public const string DEFAULT_MESSAGE = 'Unsupported protocol version';
36:
37:	/**
38:	* @var list<string>
39:	*/
40:	public array $supported;
41:
42:	/**
43:	* @param list<string> $supported
44:	*/
45:	public function __construct(
46:	public string $requested,
47:	array $supported,
48:	string $message = self::DEFAULT_MESSAGE,
49:	) {
50:	$this->supported = $supported;
51:
52:	parent::__construct(
53:	code: ProtocolErrorCode::UnsupportedProtocolVersion,
54:	message: $message,
55:	data: ['supported' => $supported, 'requested' => $requested],
56:	);
57:	}
58:
59:	#[\Override]
60:	public static function fromArray(array $data): static
61:	{
62:	$message = $data['message'] ?? self::DEFAULT_MESSAGE;
63:	Assert::that($message)->isString('error "message" must be a string, {type} given.');
64:
65:	$payload = $data['data'] ?? null;
66:	Assert::that($payload)
67:	->isArray('error "data" must be an object, {type} given.')
68:	->isMap('error "data" must be a string-keyed object.')
69:	;
70:
71:	Assert::that($payload)->hasOffset('requested', 'error "data" is missing the required "requested" key.');
72:	Assert::that($payload['requested'])->isString('error "data.requested" must be a string, {type} given.');
73:	$requested = $payload['requested'];
74:
75:	Assert::that($payload)->hasOffset('supported', 'error "data" is missing the required "supported" key.');
76:	Assert::that($payload['supported'])
77:	->isList('error "data.supported" must be a list of strings, {type} given.')
78:	->values()->isString('each error "data.supported" must be a string, {type} given.')
79:	;
80:	$supported = $payload['supported'];
81:
82:	return new self(requested: $requested, supported: $supported, message: $message);
83:	}
84:
85:	#[\Override]
86:	public function toArray(): array
87:	{
88:	return [
89:	'code' => ProtocolErrorCode::UnsupportedProtocolVersion->value,
90:	'message' => $this->message,
91:	'data' => ['supported' => $this->supported, 'requested' => $this->requested],
92:	];
93:	}
94:	}
95:

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