kotlin-sdk-core/io.modelcontextprotocol.kotlin.sdk.shared

Package-level declarations

Types

abstract class AbstractClientTransport : AbstractTransport

Abstract base class representing a client-side transport layer for communication.

abstract class AbstractTransport : Transport

Implements onClose, onError and onMessage functions of Transport providing corresponding _onClose, _onError and _onMessage properties to use for an implementation.

ClientTransportState

enum ClientTransportState : Enum<ClientTransportState>

States of a client transport within the protocol lifecycle

ProgressCallback

typealias ProgressCallback = (Progress) -> Unit

Callback for progress notifications.

Protocol

abstract class Protocol(options: ProtocolOptions?)

Implements MCP protocol framing on top of a pluggable transport, including features like request/response linking, notifications, and progress.

ProtocolOptions

open class ProtocolOptions(var enforceStrictCapabilities: Boolean = false, var timeout: Duration = DEFAULT_REQUEST_TIMEOUT)

Additional initialization options.

ReadBuffer

class ReadBuffer

Buffers a continuous stdio stream into discrete JSON-RPC messages.

RequestHandlerExtra

class RequestHandlerExtra

Extra data given to request handlers.

RequestOptions

class RequestOptions(relatedRequestId: RequestId? = null, resumptionToken: String? = null, onResumptionToken: (String) -> Unit? = null, val onProgress: ProgressCallback? = null, val timeout: Duration = DEFAULT_REQUEST_TIMEOUT) : TransportSendOptions

Options that can be given per request.

Transport

interface Transport

Describes the minimal contract for MCP transport that a client or server can communicate over.

TransportSendOptions

open class TransportSendOptions(val relatedRequestId: RequestId? = null, val resumptionToken: String? = null, val onResumptionToken: (String) -> Unit? = null)

Options for sending a JSON-RPC message through transport.

WebSocketMcpTransport

abstract class WebSocketMcpTransport : AbstractTransport

Abstract class representing a WebSocket transport for the Model Context Protocol (MCP). Handles communication over a WebSocket session.

Properties

DEFAULT_REQUEST_TIMEOUT

val DEFAULT_REQUEST_TIMEOUT: Duration

The default request timeout.

IMPLEMENTATION_NAME

const val IMPLEMENTATION_NAME: String

Default implementation name used in MCP handshake.

MCP_SUBPROTOCOL

const val MCP_SUBPROTOCOL: String

WebSocket subprotocol identifier for MCP connections.

Functions

serializeMessage

fun serializeMessage(message: JSONRPCMessage): String

Serializes a JSONRPCMessage to its JSON string representation with a trailing newline.