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;
022
023/**
024 * Programmatic MCP resource-read handler.
025 *
026 * <p>Routing proves neither authorization nor safe dereference. An application
027 * that maps a resource URI to a filesystem must canonicalize its configured
028 * root and requested target, reject targets outside that root after symlink
029 * resolution, authorize the canonical target under the current admitted
030 * identity, and address deployment-specific races between validation and
031 * opening. Soklet provides no filesystem mapper or containment guarantee.
032 *
033 * <p>The application must also define URI policy by delivery intent. A URI
034 * permitted for direct client loading may need a different scheme, authority,
035 * credential, query, and fragment policy from an application-handler-only
036 * URI. Soklet's URI syntax validation and routing do not establish that a URI
037 * is safe or consumable for either purpose.
038 *
039 * <p>Handlers may complete with
040 * {@link McpCompleteResult#fromResourceOutput(McpResourceOutput)} or return a
041 * declared multi-round-trip result. Implementations must be safe for
042 * concurrent invocation.
043 *
044 * @author <a href="https://www.revetkn.com">Mark Allen</a>
045 */
046@ThreadSafe
047@FunctionalInterface
048public interface McpResourceReadHandler {
049        /**
050         * Reads one routed resource under application authorization and policy.
051         *
052         * @param requestContext request metadata
053         * @param resourceReadContext resolved resource URI and template variables
054         * @param invocationFeatures invocation-scoped optional features
055         * @return recognized non-null operation result
056         * @throws Exception if application handling fails
057         */
058        @NonNull
059        McpOperationResult handle(@NonNull McpRequestContext requestContext,
060                        @NonNull McpResourceReadContext resourceReadContext,
061                        @NonNull McpInvocationFeatures invocationFeatures) throws Exception;
062}