| 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: | /** |
| 17: | * Represents the contents of a `_meta` field, which clients and servers use to attach additional metadata to their |
| 18: | * interactions. |
| 19: | * |
| 20: | * Certain key names are reserved by MCP for protocol-level metadata; implementations MUST NOT make assumptions about |
| 21: | * values at these keys. Additionally, specific schema definitions may reserve particular names for purpose-specific |
| 22: | * metadata, as declared in those definitions. |
| 23: | * |
| 24: | * Valid keys have two segments: |
| 25: | * |
| 26: | * **Prefix:** |
| 27: | * - Optional — if specified, MUST be a series of _labels_ separated by dots (`.`), followed by a slash (`/`). |
| 28: | * - Labels MUST start with a letter and end with a letter or digit. Interior characters may be letters, digits, or |
| 29: | * hyphens (`-`). |
| 30: | * - Implementations SHOULD use reverse DNS notation (e.g., `com.example/` rather than `example.com/`). |
| 31: | * - Any prefix where the second label is `modelcontextprotocol` or `mcp` is **reserved** for MCP use. For example: |
| 32: | * `io.modelcontextprotocol/`, `dev.mcp/`, `org.modelcontextprotocol.api/`, and `com.mcp.tools/` are all reserved. |
| 33: | * However, `com.example.mcp/` is NOT reserved, as the second label is `example`. |
| 34: | * |
| 35: | * **Name:** |
| 36: | * - Unless empty, MUST start and end with an alphanumeric character (`[a-z0-9A-Z]`). |
| 37: | * - Interior characters may be alphanumeric, hyphens (`-`), underscores (`_`), or dots (`.`). |
| 38: | * |
| 39: | * @implements Arrayable<array<string, mixed>> |
| 40: | * |
| 41: | * @see https://modelcontextprotocol.io/specification/draft/schema#metaobject |
| 42: | */ |
| 43: | final readonly class MetaObject implements Arrayable |
| 44: | { |
| 45: | /** |
| 46: | * @param array<string, mixed> $extras |
| 47: | */ |
| 48: | public function __construct(public array $extras = []) |
| 49: | { |
| 50: | } |
| 51: | |
| 52: | #[\Override] |
| 53: | public static function fromArray(array $data): static |
| 54: | { |
| 55: | return new self(extras: $data); |
| 56: | } |
| 57: | |
| 58: | #[\Override] |
| 59: | public function toArray(): array |
| 60: | { |
| 61: | return $this->extras; |
| 62: | } |
| 63: | |
| 64: | #[\Override] |
| 65: | public function jsonSerialize(): array|\stdClass |
| 66: | { |
| 67: | return [] === $this->extras ? new \stdClass() : $this->extras; |
| 68: | } |
| 69: | } |
| 70: |