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
023import static java.util.Objects.requireNonNull;
024
025/**
026 * Common contract implemented by MCP endpoint classes.
027 *
028 * @author <a href="https://www.revetkn.com">Mark Allen</a>
029 */
030@ThreadSafe
031public interface McpEndpoint {
032        /**
033         * Initializes a newly-created MCP session.
034         *
035         * @param context the initialization request context
036         * @param session the blank or previously-composed session context
037         * @return the session context that should be persisted for the new session
038         * @throws Exception if initialization fails
039         */
040        @NonNull
041        default McpSessionContext initialize(@NonNull McpInitializationContext context,
042                                                                                                                                                         @NonNull McpSessionContext session) throws Exception {
043                requireNonNull(context);
044                requireNonNull(session);
045                return session;
046        }
047
048        /**
049         * Maps a thrown tool exception to an MCP tool result.
050         *
051         * @param throwable the thrown exception
052         * @param context the tool-call context
053         * @return the tool result to return to the client
054         */
055        @NonNull
056        default McpToolResult handleToolError(@NonNull Throwable throwable,
057                                                                                                                                                                @NonNull McpToolCallContext context) {
058                requireNonNull(throwable);
059                requireNonNull(context);
060                return McpToolResult.fromErrorMessage(throwable.getMessage() == null ? throwable.getClass().getSimpleName() : throwable.getMessage());
061        }
062
063        /**
064         * Maps a non-tool MCP exception to a JSON-RPC error.
065         *
066         * @param throwable the thrown exception
067         * @param context the request context
068         * @return the JSON-RPC error to return to the client
069         */
070        @NonNull
071        default McpJsonRpcError handleError(@NonNull Throwable throwable,
072                                                                                                                                                        @NonNull McpRequestContext context) {
073                requireNonNull(throwable);
074                requireNonNull(context);
075                return McpJsonRpcError.fromCodeAndMessage(-32603, "Internal error");
076        }
077}