Enable Explicit Api (#21)

.idea/vcs.xml

@@ -2,6 +2,5 @@
 <project version="4">
   <component name="VcsDirectoryMappings">
     <mapping directory="$PROJECT_DIR$" vcs="Git" />
-    <mapping directory="$PROJECT_DIR$/samples/kotlin-mcp-server" vcs="Git" />
   </component>
 </project>

build.gradle.kts

@@ -1,4 +1,5 @@
 import org.jetbrains.dokka.gradle.engine.parameters.VisibilityModifier
+import org.jetbrains.kotlin.gradle.dsl.ExplicitApiMode
 
 plugins {
     alias(libs.plugins.kotlin.jvm)
@@ -207,6 +208,8 @@ val generateLibVersionTask =
     tasks.register<GenerateLibVersionTask>("generateLibVersion", version.toString(), sourcesDir)
 
 kotlin {
+    explicitApi = ExplicitApiMode.Strict
+
     jvmToolchain(21)
 
     sourceSets {

src/main/kotlin/org/jetbrains/kotlinx/mcp/client/Client.kt

@@ -17,8 +17,8 @@ import org.jetbrains.kotlinx.mcp.shared.Transport
  * @property capabilities The capabilities this client supports.
  * @property enforceStrictCapabilities Whether to strictly enforce capabilities when interacting with the server.
  */
-class ClientOptions(
-    val capabilities: ClientCapabilities = ClientCapabilities(),
+public class ClientOptions(
+    public val capabilities: ClientCapabilities = ClientCapabilities(),
     enforceStrictCapabilities: Boolean = true,
 ) : ProtocolOptions(enforceStrictCapabilities = enforceStrictCapabilities)
 
@@ -33,7 +33,7 @@ class ClientOptions(
  * @param clientInfo Information about the client implementation (name, version).
  * @param options Configuration options for this client.
  */
-open class Client(
+public open class Client(
     private val clientInfo: Implementation,
     options: ClientOptions = ClientOptions(),
 ) : Protocol<ClientRequest, ClientNotification, ClientResult>(options) {
@@ -95,7 +95,7 @@ open class Client(
      *
      * @return The server's capabilities, or `null` if initialization is not yet complete.
      */
-    fun getServerCapabilities(): ServerCapabilities? {
+    public fun getServerCapabilities(): ServerCapabilities? {
         return serverCapabilities
     }
 
@@ -104,7 +104,7 @@ open class Client(
      *
      * @return Information about the server's implementation, or `null` if initialization is not yet complete.
      */
-    fun getServerVersion(): Implementation? {
+    public fun getServerVersion(): Implementation? {
         return serverVersion
     }
 
@@ -219,7 +219,7 @@ open class Client(
      * @param options Optional request options.
      * @throws IllegalStateException If the server does not support the ping method (unlikely).
      */
-    suspend fun ping(options: RequestOptions? = null): EmptyRequestResult {
+    public suspend fun ping(options: RequestOptions? = null): EmptyRequestResult {
         return request<EmptyRequestResult>(PingRequest(), options)
     }
 
@@ -231,7 +231,7 @@ open class Client(
      * @return The completion result returned by the server, or `null` if none.
      * @throws IllegalStateException If the server does not support prompts or completion.
      */
-    suspend fun complete(params: CompleteRequest, options: RequestOptions? = null): CompleteResult? {
+    public suspend fun complete(params: CompleteRequest, options: RequestOptions? = null): CompleteResult? {
         return request<CompleteResult>(params, options)
     }
 
@@ -242,7 +242,7 @@ open class Client(
      * @param options Optional request options.
      * @throws IllegalStateException If the server does not support logging.
      */
-    suspend fun setLoggingLevel(level: LoggingLevel, options: RequestOptions? = null): EmptyRequestResult {
+    public suspend fun setLoggingLevel(level: LoggingLevel, options: RequestOptions? = null): EmptyRequestResult {
         return request<EmptyRequestResult>(SetLevelRequest(level), options)
     }
 
@@ -254,7 +254,7 @@ open class Client(
      * @return The requested prompt details, or `null` if not found.
      * @throws IllegalStateException If the server does not support prompts.
      */
-    suspend fun getPrompt(request: GetPromptRequest, options: RequestOptions? = null): GetPromptResult? {
+    public suspend fun getPrompt(request: GetPromptRequest, options: RequestOptions? = null): GetPromptResult? {
         return request<GetPromptResult>(request, options)
     }
 
@@ -266,7 +266,7 @@ open class Client(
      * @return The list of available prompts, or `null` if none.
      * @throws IllegalStateException If the server does not support prompts.
      */
-    suspend fun listPrompts(
+    public suspend fun listPrompts(
         request: ListPromptsRequest = ListPromptsRequest(),
         options: RequestOptions? = null,
     ): ListPromptsResult? {
@@ -281,7 +281,7 @@ open class Client(
      * @return The list of resources, or `null` if none.
      * @throws IllegalStateException If the server does not support resources.
      */
-    suspend fun listResources(
+    public suspend fun listResources(
         request: ListResourcesRequest = ListResourcesRequest(),
         options: RequestOptions? = null,
     ): ListResourcesResult? {
@@ -296,7 +296,7 @@ open class Client(
      * @return The list of resource templates, or `null` if none.
      * @throws IllegalStateException If the server does not support resources.
      */
-    suspend fun listResourceTemplates(
+    public suspend fun listResourceTemplates(
         request: ListResourceTemplatesRequest,
         options: RequestOptions? = null,
     ): ListResourceTemplatesResult? {
@@ -311,7 +311,10 @@ open class Client(
      * @return The resource content, or `null` if the resource is not found.
      * @throws IllegalStateException If the server does not support resources.
      */
-    suspend fun readResource(request: ReadResourceRequest, options: RequestOptions? = null): ReadResourceResult? {
+    public suspend fun readResource(
+        request: ReadResourceRequest,
+        options: RequestOptions? = null,
+    ): ReadResourceResult? {
         return request<ReadResourceResult>(request, options)
     }
 
@@ -322,7 +325,10 @@ open class Client(
      * @param options Optional request options.
      * @throws IllegalStateException If the server does not support resource subscriptions.
      */
-    suspend fun subscribeResource(request: SubscribeRequest, options: RequestOptions? = null): EmptyRequestResult {
+    public suspend fun subscribeResource(
+        request: SubscribeRequest,
+        options: RequestOptions? = null,
+    ): EmptyRequestResult {
         return request<EmptyRequestResult>(request, options)
     }
 
@@ -333,7 +339,10 @@ open class Client(
      * @param options Optional request options.
      * @throws IllegalStateException If the server does not support resource subscriptions.
      */
-    suspend fun unsubscribeResource(request: UnsubscribeRequest, options: RequestOptions? = null): EmptyRequestResult {
+    public suspend fun unsubscribeResource(
+        request: UnsubscribeRequest,
+        options: RequestOptions? = null,
+    ): EmptyRequestResult {
         return request<EmptyRequestResult>(request, options)
     }
 
@@ -347,7 +356,7 @@ open class Client(
      * @return The result of the tool call, or `null` if none.
      * @throws IllegalStateException If the server does not support tools.
      */
-    suspend fun callTool(
+    public suspend fun callTool(
         name: String,
         arguments: Map<String, Any?>,
         compatibility: Boolean = false,
@@ -380,7 +389,7 @@ open class Client(
      * @return The result of the tool call, or `null` if none.
      * @throws IllegalStateException If the server does not support tools.
      */
-    suspend fun callTool(
+    public suspend fun callTool(
         request: CallToolRequest,
         compatibility: Boolean = false,
         options: RequestOptions? = null,
@@ -400,7 +409,7 @@ open class Client(
      * @return The list of available tools, or `null` if none.
      * @throws IllegalStateException If the server does not support tools.
      */
-    suspend fun listTools(
+    public suspend fun listTools(
         request: ListToolsRequest = ListToolsRequest(),
         options: RequestOptions? = null,
     ): ListToolsResult? {
@@ -413,7 +422,7 @@ open class Client(
      *
      * @throws IllegalStateException If the client or server does not support roots.
      */
-    suspend fun sendRootsListChanged() {
+    public suspend fun sendRootsListChanged() {
         notification(RootsListChangedNotification())
     }
-}
+}

src/main/kotlin/org/jetbrains/kotlinx/mcp/client/SSEClientTransport.kt

@@ -18,7 +18,7 @@ import kotlin.time.Duration
  * Client transport for SSE: this will connect to a server using Server-Sent Events for receiving
  * messages and make separate POST requests for sending messages.
  */
-class SSEClientTransport(
+public class SSEClientTransport(
     private val client: HttpClient,
     private val urlString: String?,
     private val reconnectionTime: Duration? = null,

src/main/kotlin/org/jetbrains/kotlinx/mcp/client/StdioClientTransport.kt

@@ -23,7 +23,7 @@ import kotlin.text.Charsets.UTF_8
  * @param input The input stream where messages are received.
  * @param output The output stream where messages are sent.
  */
-class StdioClientTransport(
+public class StdioClientTransport(
     private val input: InputStream,
     private val output: OutputStream
 ) : Transport {
@@ -128,4 +128,4 @@ class StdioClientTransport(
             }
         }
     }
-}
+}

src/main/kotlin/org/jetbrains/kotlinx/mcp/client/WebSocketClientTransport.kt

@@ -12,7 +12,7 @@ import kotlin.properties.Delegates
 /**
  * Client transport for WebSocket: this will connect to a server over the WebSocket protocol.
  */
-class WebSocketClientTransport(
+public class WebSocketClientTransport(
     private val client: HttpClient,
     private val urlString: String?,
     private val requestBuilder: HttpRequestBuilder.() -> Unit = {},

src/main/kotlin/org/jetbrains/kotlinx/mcp/client/WebSocketMcpKtorClientExtensions.kt

@@ -13,7 +13,7 @@ import org.jetbrains.kotlinx.mcp.shared.IMPLEMENTATION_NAME
  * @param requestBuilder Optional lambda to configure the HTTP request.
  * @return A [WebSocketClientTransport] configured for MCP communication.
  */
-fun HttpClient.mcpWebSocketTransport(
+public fun HttpClient.mcpWebSocketTransport(
     urlString: String? = null,
     requestBuilder: HttpRequestBuilder.() -> Unit = {},
 ): WebSocketClientTransport = WebSocketClientTransport(this, urlString, requestBuilder)
@@ -25,7 +25,7 @@ fun HttpClient.mcpWebSocketTransport(
  * @param requestBuilder Optional lambda to configure the HTTP request.
  * @return A connected [Client] ready for MCP communication.
  */
-suspend fun HttpClient.mcpWebSocket(
+public suspend fun HttpClient.mcpWebSocket(
     urlString: String? = null,
     requestBuilder: HttpRequestBuilder.() -> Unit = {},
 ): Client {

src/main/kotlin/org/jetbrains/kotlinx/mcp/client/sse.ktor.kt

@@ -15,7 +15,7 @@ import kotlin.time.Duration
  * @param  requestBuilder Optional lambda to configure the HTTP request.
  * @return A [SSEClientTransport] configured for MCP communication.
  */
-fun HttpClient.mcpSseTransport(
+public fun HttpClient.mcpSseTransport(
     urlString: String? = null,
     reconnectionTime: Duration? = null,
     requestBuilder: HttpRequestBuilder.() -> Unit = {},
@@ -29,7 +29,7 @@ fun HttpClient.mcpSseTransport(
  * @param requestBuilder Optional lambda to configure the HTTP request.
  * @return A connected [Client] ready for MCP communication.
  */
-suspend fun HttpClient.mcpSse(
+public suspend fun HttpClient.mcpSse(
     urlString: String? = null,
     reconnectionTime: Duration? = null,
     requestBuilder: HttpRequestBuilder.() -> Unit = {},

src/main/kotlin/org/jetbrains/kotlinx/mcp/server/McpKtorServerPlugin.kt

@@ -13,7 +13,7 @@ private val logger = KotlinLogging.logger {}
 /**
  * Configures the Ktor Application to handle Model Context Protocol (MCP) over Server-Sent Events (SSE).
  */
-fun Application.MCP(block: () -> Server) {
+public fun Application.MCP(block: () -> Server) {
     val servers = ConcurrentMap<String, Server>()
 
     install(SSE)
@@ -51,4 +51,4 @@ fun Application.MCP(block: () -> Server) {
             logger.trace { "Message handled for sessionId: $sessionId" }
         }
     }
-}
+}

src/main/kotlin/org/jetbrains/kotlinx/mcp/server/SSEServerTransport.kt

@@ -21,14 +21,14 @@ internal const val SESSION_ID_PARAM = "sessionId"
  *
  * Creates a new SSE server transport, which will direct the client to POST messages to the relative or absolute URL identified by `_endpoint`.
  */
-class SSEServerTransport(
+public class SSEServerTransport(
     private val endpoint: String,
     private val session: ServerSSESession,
 ) : Transport {
     private val initialized = AtomicBoolean(false)
 
     @OptIn(ExperimentalUuidApi::class)
-    val sessionId: String = Uuid.random().toString()
+    public val sessionId: String = Uuid.random().toString()
 
     override var onClose: (() -> Unit)? = null
     override var onError: ((Throwable) -> Unit)? = null
@@ -62,7 +62,7 @@ class SSEServerTransport(
      *
      * This should be called when a POST request is made to send a message to the server.
      */
-    suspend fun handlePostMessage(call: ApplicationCall) {
+    public suspend fun handlePostMessage(call: ApplicationCall) {
         if (!initialized.get()) {
             val message = "SSE connection not established"
             call.respondText(message, status = HttpStatusCode.InternalServerError)
@@ -96,7 +96,7 @@ class SSEServerTransport(
      * Handle a client message, regardless of how it arrived.
      * This can be used to inform the server of messages that arrive via a means different from HTTP POST.
      */
-    suspend fun handleMessage(message: String) {
+    public suspend fun handleMessage(message: String) {
         try {
             val parsedMessage = McpJson.decodeFromString<JSONRPCMessage>(message)
             onMessage?.invoke(parsedMessage)

src/main/kotlin/org/jetbrains/kotlinx/mcp/server/Server.kt

@@ -16,8 +16,8 @@ private val logger = KotlinLogging.logger {}
  * @property capabilities The capabilities this server supports.
  * @property enforceStrictCapabilities Whether to strictly enforce capabilities when interacting with clients.
  */
-class ServerOptions(
-    val capabilities: ServerCapabilities,
+public class ServerOptions(
+    public val capabilities: ServerCapabilities,
     enforceStrictCapabilities: Boolean = true,
 ) : ProtocolOptions(enforceStrictCapabilities = enforceStrictCapabilities)
 
@@ -568,4 +568,4 @@ data class RegisteredPrompt(
 data class RegisteredResource(
     val resource: Resource,
     val readHandler: suspend (ReadResourceRequest) -> ReadResourceResult
-)
+)

src/main/kotlin/org/jetbrains/kotlinx/mcp/server/StdioServerTransport.kt

@@ -17,9 +17,9 @@ import kotlin.coroutines.CoroutineContext
  *
  * Reads from System.in and writes to System.out.
  */
-class StdioServerTransport(
+public class StdioServerTransport(
     private val inputStream: BufferedInputStream = BufferedInputStream(System.`in`),
-    private val outputStream: PrintStream = System.out
+    outputStream: PrintStream = System.out
 ) : Transport {
     private val logger = KotlinLogging.logger {}
     override var onClose: (() -> Unit)? = null
@@ -115,4 +115,4 @@ class StdioServerTransport(
             outputWriter.flush()
         }
     }
-}
+}

src/main/kotlin/org/jetbrains/kotlinx/mcp/server/WebSocketMcpKtorServerExtensions.kt

@@ -13,7 +13,7 @@ import org.jetbrains.kotlinx.mcp.shared.IMPLEMENTATION_NAME
  * @param options Optional server configuration settings for the MCP server.
  * @param handler A suspend function that defines the server's behavior.
  */
-fun Route.mcpWebSocket(
+public fun Route.mcpWebSocket(
     options: ServerOptions? = null,
     handler: suspend Server.() -> Unit = {},
 ) {
@@ -29,7 +29,7 @@ fun Route.mcpWebSocket(
  * @param options Optional server configuration settings for the MCP server.
  * @param handler A suspend function that defines the server's behavior.
  */
-fun Route.mcpWebSocket(
+public fun Route.mcpWebSocket(
     path: String,
     options: ServerOptions? = null,
     handler: suspend Server.() -> Unit = {},
@@ -44,7 +44,7 @@ fun Route.mcpWebSocket(
  *
  * @param handler A suspend function that defines the behavior of the transport layer.
  */
-fun Route.mcpWebSocketTransport(
+public fun Route.mcpWebSocketTransport(
     handler: suspend WebSocketMcpServerTransport.() -> Unit = {},
 ) {
     webSocket {
@@ -61,7 +61,7 @@ fun Route.mcpWebSocketTransport(
  * @param path The URL path at which to register the WebSocket route.
  * @param handler A suspend function that defines the behavior of the transport layer.
  */
-fun Route.mcpWebSocketTransport(
+public fun Route.mcpWebSocketTransport(
     path: String,
     handler: suspend WebSocketMcpServerTransport.() -> Unit = {},
 ) {

src/main/kotlin/org/jetbrains/kotlinx/mcp/server/WebSocketMcpServerTransport.kt

@@ -10,7 +10,7 @@ import org.jetbrains.kotlinx.mcp.shared.WebSocketMcpTransport
  *
  * @property session The WebSocket server session used for communication.
  */
-class WebSocketMcpServerTransport(
+public class WebSocketMcpServerTransport(
     override val session: WebSocketServerSession,
 ) : WebSocketMcpTransport() {
     override suspend fun initializeSession() {

src/main/kotlin/org/jetbrains/kotlinx/mcp/shared/Protocol.kt

@@ -27,6 +27,7 @@ import kotlinx.serialization.serializer
 import org.jetbrains.kotlinx.mcp.fromJSON
 import org.jetbrains.kotlinx.mcp.toJSON
 import kotlin.collections.get
+import kotlin.reflect.KType
 import kotlin.reflect.typeOf
 import kotlin.time.Duration
 import kotlin.time.Duration.Companion.milliseconds
@@ -38,7 +39,7 @@ internal const val IMPLEMENTATION_NAME = "mcp-ktor"
 /**
  * Callback for progress notifications.
  */
-typealias ProgressCallback = (Progress) -> Unit
+public typealias ProgressCallback = (Progress) -> Unit
 
 @OptIn(ExperimentalSerializationApi::class)
 @PublishedApi
@@ -55,7 +56,7 @@ internal val McpJson: Json by lazy {
 /**
  * Additional initialization options.
  */
-open class ProtocolOptions(
+public open class ProtocolOptions(
     /**
      * Whether to restrict emitted requests to only those that the remote side has indicated
      * that they can handle, through their advertised capabilities.
@@ -66,20 +67,20 @@ open class ProtocolOptions(
      * Currently this defaults to false, for backwards compatibility with SDK versions
      * that did not advertise capabilities correctly. In future, this will default to true.
      */
-    var enforceStrictCapabilities: Boolean = false,
+    public var enforceStrictCapabilities: Boolean = false,
 
-    var timeout: Duration = DEFAULT_REQUEST_TIMEOUT
+    public var timeout: Duration = DEFAULT_REQUEST_TIMEOUT,
 )
 
 /**
  * The default request timeout.
  */
-val DEFAULT_REQUEST_TIMEOUT: Duration = 60000.milliseconds
+public val DEFAULT_REQUEST_TIMEOUT: Duration = 60000.milliseconds
 
 /**
  * Options that can be given per request.
  */
-data class RequestOptions(
+public data class RequestOptions(
     /**
      * If set, requests progress notifications from the remote end (if supported).
      * When progress notifications are received, this callback will be invoked.
@@ -92,13 +93,13 @@ data class RequestOptions(
      *
      * If not specified, `DEFAULT_REQUEST_TIMEOUT` will be used as the timeout.
      */
-    val timeout: Duration = DEFAULT_REQUEST_TIMEOUT
+    val timeout: Duration = DEFAULT_REQUEST_TIMEOUT,
 )
 
 /**
  * Extra data given to request handlers.
  */
-class RequestHandlerExtra()
+public class RequestHandlerExtra()
 
 internal val COMPLETED = CompletableDeferred(Unit).also { it.complete(Unit) }
 
@@ -106,16 +107,16 @@ internal val COMPLETED = CompletableDeferred(Unit).also { it.complete(Unit) }
  * Implements MCP protocol framing on top of a pluggable transport, including
  * features like request/response linking, notifications, and progress.
  */
-abstract class Protocol<SendRequestT : Request, SendNotificationT : Notification, SendResultT : RequestResult>(
-    @PublishedApi internal val _options: ProtocolOptions?
+public abstract class Protocol<SendRequestT : Request, SendNotificationT : Notification, SendResultT : RequestResult>(
+    @PublishedApi internal val options: ProtocolOptions?,
 ) {
-    var transport: Transport? = null
+    public var transport: Transport? = null
         private set
 
     @PublishedApi
     internal val requestHandlers: MutableMap<String, suspend (request: JSONRPCRequest, extra: RequestHandlerExtra) -> SendResultT?> =
         mutableMapOf()
-    val notificationHandlers: MutableMap<String, suspend (notification: JSONRPCNotification) -> Unit> =
+    public val notificationHandlers: MutableMap<String, suspend (notification: JSONRPCNotification) -> Unit> =
         mutableMapOf()
 
     @PublishedApi
@@ -130,24 +131,25 @@ abstract class Protocol<SendRequestT : Request, SendNotificationT : Notification
      *
      * This is invoked when close() is called as well.
      */
-    open fun onclose() {}
+    public open fun onclose() {}
 
     /**
      * Callback for when an error occurs.
      *
      * Note that errors are not necessarily fatal they are used for reporting any kind of exceptional condition out of band.
      */
-    open fun onerror(error: Throwable) {}
+    public open fun onerror(error: Throwable) {}
 
     /**
      * A handler to invoke for any request types that do not have their own handler installed.
      */
-    var fallbackRequestHandler: (suspend (request: JSONRPCRequest, extra: RequestHandlerExtra) -> SendResultT?)? = null
+    public var fallbackRequestHandler: (suspend (request: JSONRPCRequest, extra: RequestHandlerExtra) -> SendResultT?)? =
+        null
 
     /**
      * A handler to invoke for any notification types that do not have their own handler installed.
      */
-    var fallbackNotificationHandler: (suspend (notification: JSONRPCNotification) -> Unit)? = null
+    public var fallbackNotificationHandler: (suspend (notification: JSONRPCNotification) -> Unit)? = null
 
     init {
         setNotificationHandler<ProgressNotification>(Method.Defined.NotificationsProgress) { notification ->
@@ -166,7 +168,7 @@ abstract class Protocol<SendRequestT : Request, SendNotificationT : Notification
      *
      * The Protocol object assumes ownership of the Transport, replacing any callbacks that have already been set, and expects that it is the only user of the Transport instance going forward.
      */
-    open suspend fun connect(transport: Transport) {
+    public open suspend fun connect(transport: Transport) {
         this.transport = transport
         transport.onClose = {
             this.onClose()
@@ -258,13 +260,15 @@ abstract class Protocol<SendRequestT : Request, SendNotificationT : Notification
         } catch (cause: Throwable) {
             LOGGER.error(cause) { "Error handling request: ${request.method} (id: ${request.id})" }
 
-            transport!!.send(JSONRPCResponse(
-                id = request.id,
-                error = JSONRPCError(
-                    ErrorCode.Defined.InternalError,
-                    message = cause.message ?: "Internal error",
+            transport!!.send(
+                JSONRPCResponse(
+                    id = request.id,
+                    error = JSONRPCError(
+                        ErrorCode.Defined.InternalError,
+                        message = cause.message ?: "Internal error",
+                    )
                 )
-            ))
+            )
         }
     }
 
@@ -314,7 +318,7 @@ abstract class Protocol<SendRequestT : Request, SendNotificationT : Notification
     /**
      * Closes the connection.
      */
-    suspend fun close() {
+    public suspend fun close() {
         transport?.close()
     }
 
@@ -323,7 +327,7 @@ abstract class Protocol<SendRequestT : Request, SendNotificationT : Notification
      *
      * This should be implemented by subclasses.
      */
-    abstract fun assertCapabilityForMethod(method: Method)
+    protected abstract fun assertCapabilityForMethod(method: Method)
 
     /**
      * A method to check if a notification is supported by the local side, for the given method to be sent.
@@ -337,14 +341,14 @@ abstract class Protocol<SendRequestT : Request, SendNotificationT : Notification
      *
      * This should be implemented by subclasses.
      */
-    abstract fun assertRequestHandlerCapability(method: Method)
+    public abstract fun assertRequestHandlerCapability(method: Method)
 
     /**
      * Sends a request and wait for a response.
      *
      * Do not use this method to emit notifications! Use notification() instead.
      */
-    suspend fun <T : RequestResult> request(
+    public suspend fun <T : RequestResult> request(
         request: SendRequestT,
         options: RequestOptions? = null,
     ): T {
@@ -352,7 +356,7 @@ abstract class Protocol<SendRequestT : Request, SendNotificationT : Notification
         val result = CompletableDeferred<T>()
         val transport = this@Protocol.transport ?: throw Error("Not connected")
 
-        if (_options?.enforceStrictCapabilities == true) {
+        if (this@Protocol.options?.enforceStrictCapabilities == true) {
             assertCapabilityForMethod(request.method)
         }
 
@@ -364,7 +368,7 @@ abstract class Protocol<SendRequestT : Request, SendNotificationT : Notification
             progressHandlers[messageId] = options.onProgress
         }
 
-        responseHandlers.set(messageId, { response, error ->
+        responseHandlers[messageId] = set@{ response, error ->
             if (error != null) {
                 result.completeExceptionally(error)
                 return@set
@@ -381,7 +385,7 @@ abstract class Protocol<SendRequestT : Request, SendNotificationT : Notification
             } catch (error: Throwable) {
                 result.completeExceptionally(error)
             }
-        })
+        }
 
         val cancel: suspend (Throwable) -> Unit = { reason: Throwable ->
             responseHandlers.remove(messageId)
@@ -423,7 +427,7 @@ abstract class Protocol<SendRequestT : Request, SendNotificationT : Notification
     /**
      * Emits a notification, which is a one-way message that does not expect a response.
      */
-    suspend fun notification(notification: SendNotificationT) {
+    public suspend fun notification(notification: SendNotificationT) {
         LOGGER.trace { "Sending notification: ${notification.method}" }
         val transport = this.transport ?: error("Not connected")
         assertNotificationCapability(notification.method)
@@ -440,18 +444,27 @@ abstract class Protocol<SendRequestT : Request, SendNotificationT : Notification
      *
      * Note that this will replace any previous request handler for the same method.
      */
-    inline fun <reified T : Request> setRequestHandler(
+    public inline fun <reified T : Request> setRequestHandler(
         method: Method,
-        noinline block: suspend (T, RequestHandlerExtra) -> SendResultT?
+        noinline block: suspend (T, RequestHandlerExtra) -> SendResultT?,
+    ) {
+        setRequestHandler(typeOf<T>(), method, block)
+    }
+
+    @PublishedApi
+    internal fun <T : Request> setRequestHandler(
+        requestType: KType,
+        method: Method,
+        block: suspend (T, RequestHandlerExtra) -> SendResultT?,
     ) {
         assertRequestHandlerCapability(method)
 
-        val type = typeOf<T>()
-        val serializer = McpJson.serializersModule.serializer(type)
+        val serializer = McpJson.serializersModule.serializer(requestType)
 
         requestHandlers[method.value] = { request, extraHandler ->
             val result = request.params?.let { McpJson.decodeFromJsonElement(serializer, it) }
             val response = if (result != null) {
+                @Suppress("UNCHECKED_CAST")
                 block(result as T, extraHandler)
             } else {
                 EmptyRequestResult()
@@ -465,7 +478,7 @@ abstract class Protocol<SendRequestT : Request, SendNotificationT : Notification
     /**
      * Removes the request handler for the given method.
      */
-    fun removeRequestHandler(method: Method) {
+    public fun removeRequestHandler(method: Method) {
         requestHandlers.remove(method.value)
     }
 
@@ -474,7 +487,7 @@ abstract class Protocol<SendRequestT : Request, SendNotificationT : Notification
      *
      * Note that this will replace any previous notification handler for the same method.
      */
-    fun <T : Notification> setNotificationHandler(method: Method, handler: (notification: T) -> Deferred<Unit>) {
+    public fun <T : Notification> setNotificationHandler(method: Method, handler: (notification: T) -> Deferred<Unit>) {
         this.notificationHandlers[method.value] = {
             @Suppress("UNCHECKED_CAST")
             handler(it.fromJSON() as T)
@@ -484,7 +497,7 @@ abstract class Protocol<SendRequestT : Request, SendNotificationT : Notification
     /**
      * Removes the notification handler for the given method.
      */
-    fun removeNotificationHandler(method: Method) {
+    public fun removeNotificationHandler(method: Method) {
         this.notificationHandlers.remove(method.value)
     }
 }

src/main/kotlin/org/jetbrains/kotlinx/mcp/shared/ReadBuffer.kt

@@ -10,14 +10,14 @@ import kotlinx.serialization.encodeToString
 /**
  * Buffers a continuous stdio stream into discrete JSON-RPC messages.
  */
-class ReadBuffer {
+public class ReadBuffer {
     private val buffer: Buffer = Buffer()
 
-    fun append(chunk: ByteArray) {
+    public fun append(chunk: ByteArray) {
         buffer.writeFully(chunk)
     }
 
-    fun readMessage(): JSONRPCMessage? {
+    public fun readMessage(): JSONRPCMessage? {
         if (buffer.exhausted()) return null
         var lfIndex = buffer.indexOf('\n'.code.toByte())
         val line = when (lfIndex) {
@@ -41,7 +41,7 @@ class ReadBuffer {
         return deserializeMessage(line)
     }
 
-    fun clear() {
+    public fun clear() {
         buffer.clear()
     }
 }

src/main/kotlin/org/jetbrains/kotlinx/mcp/shared/Transport.kt

@@ -5,7 +5,7 @@ import org.jetbrains.kotlinx.mcp.JSONRPCMessage
 /**
  * Describes the minimal contract for a MCP transport that a client or server can communicate over.
  */
-interface Transport {
+public interface Transport {
     /**
      * Starts processing messages on the transport, including any connection steps that might need to be taken.
      *
@@ -14,24 +14,24 @@ interface Transport {
      * NOTE: This method should not be called explicitly when using Client, Server, or Protocol classes,
      * as they will implicitly call start().
      */
-    suspend fun start()
+    public suspend fun start()
 
     /**
      * Sends a JSON-RPC message (request or response).
      */
-    suspend fun send(message: JSONRPCMessage)
+    public suspend fun send(message: JSONRPCMessage)
 
     /**
      * Closes the connection.
      */
-    suspend fun close()
+    public suspend fun close()
 
     /**
      * Callback for when the connection is closed for any reason.
      *
      * This should be invoked when close() is called as well.
      */
-    var onClose: (() -> Unit)?
+    public var onClose: (() -> Unit)?
 
     /**
      * Callback for when an error occurs.
@@ -39,10 +39,10 @@ interface Transport {
      * Note that errors are not necessarily fatal; they are used for reporting any kind of
      * exceptional condition out of band.
      */
-    var onError: ((Throwable) -> Unit)?
+    public var onError: ((Throwable) -> Unit)?
 
     /**
      * Callback for when a message (request or response) is received over the connection.
      */
-    var onMessage: (suspend ((JSONRPCMessage) -> Unit))?
+    public var onMessage: (suspend ((JSONRPCMessage) -> Unit))?
 }

src/main/kotlin/org/jetbrains/kotlinx/mcp/shared/WebSocketMcpTransport.kt

@@ -21,7 +21,7 @@ internal const val MCP_SUBPROTOCOL = "mcp"
  * Abstract class representing a WebSocket transport for the Model Context Protocol (MCP).
  * Handles communication over a WebSocket session.
  */
-abstract class WebSocketMcpTransport : Transport {
+public abstract class WebSocketMcpTransport : Transport {
     private val scope by lazy {
         CoroutineScope(session.coroutineContext + SupervisorJob())
     }

src/test/kotlin/InMemoryTransport.kt

@@ -1,5 +1,3 @@
-import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.SupervisorJob
 import org.jetbrains.kotlinx.mcp.JSONRPCMessage
 import org.jetbrains.kotlinx.mcp.shared.Transport
 
@@ -7,8 +5,6 @@ import org.jetbrains.kotlinx.mcp.shared.Transport
  * In-memory transport for creating clients and servers that talk to each other within the same process.
  */
 class InMemoryTransport : Transport {
-    private val scope = CoroutineScope(SupervisorJob())
-
     private var otherTransport: InMemoryTransport? = null
     private val messageQueue: MutableList<JSONRPCMessage> = mutableListOf()
 
@@ -55,4 +51,4 @@ class InMemoryTransport : Transport {
             other.messageQueue.add(message)
         }
     }
-}
+}