001/*
002 * Copyright 2022-2026 Revetware LLC.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package com.soklet;
018
019import org.jspecify.annotations.NonNull;
020
021import javax.annotation.concurrent.ThreadSafe;
022import java.util.Optional;
023
024/**
025 * Admission seam for MCP transport requests.
026 *
027 * @author <a href="https://www.revetkn.com">Mark Allen</a>
028 */
029@ThreadSafe
030public interface McpRequestAdmissionPolicy {
031        /**
032         * Decides whether an MCP transport request should proceed.
033         *
034         * @param context the admission context
035         * @return an optional rejection response, or {@link Optional#empty()} to allow the request
036         * @throws Exception if admission logic fails
037         */
038        @NonNull
039        default Optional<Response> checkRequest(@NonNull McpAdmissionContext context) throws Exception {
040                return Optional.empty();
041        }
042
043        /**
044         * Acquires the default no-op admission policy.
045         *
046         * @return the default admission policy instance
047         */
048        @NonNull
049        static McpRequestAdmissionPolicy defaultInstance() {
050                return DefaultMcpRequestAdmissionPolicy.INSTANCE;
051        }
052}
053
054enum DefaultMcpRequestAdmissionPolicy implements McpRequestAdmissionPolicy {
055        INSTANCE
056}