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\Transport;
15:
16: use Nexus\Mcp\Core\Schema\RequestId;
17:
18: /**
19: * A transport that can observe a peer abandoning an in-flight request without saying so in a message,
20: * such as an SSE consumer closing its stream.
21: */
22: interface CancellableTransportInterface extends TransportInterface
23: {
24: /**
25: * Registers a listener invoked with the id of a request the peer abandoned.
26: *
27: * @param \Closure(RequestId): void $listener
28: */
29: public function onCancel(\Closure $listener): SubscriptionInterface;
30: }
31: