Class Protocol<ContextT>`Abstract`

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

Type Parameters

ContextT extends BaseContext

Hierarchy (View Summary)

Protocol
- Server

Constructors

constructor

new Protocol<ContextT extends BaseContext>(
_options?: ProtocolOptions,
): Protocol<ContextT>
Type Parameters
- ContextT extends BaseContext
Parameters
- Optional_options: ProtocolOptions
Returns Protocol<ContextT>
- Defined in packages/core/src/shared/protocol.ts:437

Properties

`Protected`_supportedProtocolVersions

_supportedProtocolVersions: string[]

`Optional`fallbackNotificationHandler

fallbackNotificationHandler?: (
    notification: {
        method: string;
        params?: {
            _meta?: {
                "io.modelcontextprotocol/related-task"?: { taskId: string };
                progressToken?: string | number;
                [key: string]: unknown;
            };
            [key: string]: unknown;
        };
    },
) => Promise<void>

A handler to invoke for any notification types that do not have their own handler installed.

`Optional`fallbackRequestHandler

fallbackRequestHandler?: (
    request: {
        id: string | number;
        jsonrpc: "2.0";
        method: string;
        params?: {
            _meta?: {
                "io.modelcontextprotocol/related-task"?: { taskId: string };
                progressToken?: string | number;
                [key: string]: unknown;
            };
            [key: string]: unknown;
        };
    },
    ctx: ContextT,
) => Promise<
    {
        _meta?: {
            "io.modelcontextprotocol/related-task"?: { taskId: string };
            progressToken?: string | number;
            [key: string]: unknown;
        };
        [key: string]: unknown;
    },
>

A handler to invoke for any request types that do not have their own handler installed.

`Optional`onclose

onclose?: () => void

Callback for when the connection is closed for any reason.

This is invoked when close() is called as well.

`Optional`onerror

onerror?: (error: Error) => void

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.

Accessors

transport

get transport(): Transport | undefined
Returns Transport | undefined
- Defined in packages/core/src/shared/protocol.ts:986

Methods

assertCanSetRequestHandler

assertCanSetRequestHandler(method: RequestMethod): void
Asserts that a request handler has not already been set for the given method, in preparation for a new one being automatically installed.
Parameters
- method: RequestMethod
Returns void
- Defined in packages/core/src/shared/protocol.ts:1477

`Protected` `Abstract`assertCapabilityForMethod

assertCapabilityForMethod(method: RequestMethod): void
A method to check if a capability is supported by the remote side, for the given method to be called.

This should be implemented by subclasses.
Parameters
- method: RequestMethod
Returns void
- Defined in packages/core/src/shared/protocol.ts:1002

`Protected` `Abstract`assertNotificationCapability

assertNotificationCapability(method: NotificationMethod): void
A method to check if a notification is supported by the local side, for the given method to be sent.

This should be implemented by subclasses.
Parameters
- method: NotificationMethod
Returns void
- Defined in packages/core/src/shared/protocol.ts:1009

`Protected` `Abstract`assertRequestHandlerCapability

assertRequestHandlerCapability(method: string): void
A method to check if a request handler is supported by the local side, for the given method to be handled.

This should be implemented by subclasses.
Parameters
- method: string
Returns void
- Defined in packages/core/src/shared/protocol.ts:1016

`Protected` `Abstract`assertTaskCapability

assertTaskCapability(method: string): void
A method to check if task creation is supported for the given request method.

This should be implemented by subclasses.
Parameters
- method: string
Returns void
- Defined in packages/core/src/shared/protocol.ts:1023

`Protected` `Abstract`assertTaskHandlerCapability

assertTaskHandlerCapability(method: string): void
A method to check if a task handler is supported by the local side, for the given method to be handled.

This should be implemented by subclasses.
Parameters
- method: string
Returns void
- Defined in packages/core/src/shared/protocol.ts:1030

`Protected` `Abstract`buildContext

buildContext(ctx: BaseContext, transportInfo?: MessageExtraInfo): ContextT
Builds the context object for request handlers. Subclasses must override to return the appropriate context type (e.g., ServerContext adds requestInfo).
Parameters
- ctx: BaseContext
- OptionaltransportInfo: MessageExtraInfo
Returns ContextT
- Defined in packages/core/src/shared/protocol.ts:628

`Protected`cancelTask

cancelTask(
    params: { taskId: string },
    options?: RequestOptions,
): Promise<
    {
        _meta?: {
            "io.modelcontextprotocol/related-task"?: { taskId: string };
            progressToken?: string | number;
            [key: string]: unknown;
        };
        createdAt: string;
        lastUpdatedAt: string;
        pollInterval?: number;
        status: | "working"
        | "input_required"
        | "completed"
        | "failed"
        | "cancelled";
        statusMessage?: string;
        taskId: string;
        ttl: number
        | null;
    },
>
Experimental
Cancels a specific task.

Use client.experimental.tasks.cancelTask() to access this method.
Parameters
- params: { taskId: string }
- Optionaloptions: RequestOptions
Returns Promise<
    {
        _meta?: {
            "io.modelcontextprotocol/related-task"?: { taskId: string };
            progressToken?: string | number;
            [key: string]: unknown;
        };
        createdAt: string;
        lastUpdatedAt: string;
        pollInterval?: number;
        status: | "working"
        | "input_required"
        | "completed"
        | "failed"
        | "cancelled";
        statusMessage?: string;
        taskId: string;
        ttl: number
        | null;
    },
>
- Defined in packages/core/src/shared/protocol.ts:1332

close

close(): Promise<void>
Closes the connection.

Returns Promise<void>
- Defined in packages/core/src/shared/protocol.ts:993

connect

connect(transport: Transport): Promise<void>
Attaches to the given transport, starts it, and starts listening for messages.

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.
Parameters
- transport: Transport
Returns Promise<void>
- Defined in packages/core/src/shared/protocol.ts:687

`Protected`getTask

getTask(
    params: {
        _meta?: {
            "io.modelcontextprotocol/related-task"?: { taskId: string };
            progressToken?: string | number;
            [key: string]: unknown;
        };
        taskId: string;
    },
    options?: RequestOptions,
): Promise<
    {
        _meta?: {
            "io.modelcontextprotocol/related-task"?: { taskId: string };
            progressToken?: string | number;
            [key: string]: unknown;
        };
        createdAt: string;
        lastUpdatedAt: string;
        pollInterval?: number;
        status: | "working"
        | "input_required"
        | "completed"
        | "failed"
        | "cancelled";
        statusMessage?: string;
        taskId: string;
        ttl: number
        | null;
    },
>
Experimental
Gets the current status of a task.

Use client.experimental.tasks.getTask() to access this method.
Parameters
- params: {
      _meta?: {
          "io.modelcontextprotocol/related-task"?: { taskId: string };
          progressToken?: string | number;
          [key: string]: unknown;
      };
      taskId: string;
  }
  - Optional_meta?: {
        "io.modelcontextprotocol/related-task"?: { taskId: string };
        progressToken?: string | number;
        [key: string]: unknown;
    }
    See General fields: _meta for notes on _meta usage.
    
    Optionalio.modelcontextprotocol/related-task?: { taskId: string }
    If specified, this request is related to the provided task.
    
    OptionalprogressToken?: string | number
    If specified, the caller is requesting out-of-band progress notifications for this request (as represented by notifications/progress). The value of this parameter is an opaque token that will be attached to any subsequent notifications. The receiver is not obligated to provide these notifications.
  - taskId: string
- Optionaloptions: RequestOptions
Returns Promise<
    {
        _meta?: {
            "io.modelcontextprotocol/related-task"?: { taskId: string };
            progressToken?: string | number;
            [key: string]: unknown;
        };
        createdAt: string;
        lastUpdatedAt: string;
        pollInterval?: number;
        status: | "working"
        | "input_required"
        | "completed"
        | "failed"
        | "cancelled";
        statusMessage?: string;
        taskId: string;
        ttl: number
        | null;
    },
>
- Defined in packages/core/src/shared/protocol.ts:1301

`Protected`getTaskResult

getTaskResult<T extends AnySchema>(
    params: {
        _meta?: {
            "io.modelcontextprotocol/related-task"?: { taskId: string };
            progressToken?: string | number;
            [key: string]: unknown;
        };
        taskId: string;
    },
    resultSchema: T,
    options?: RequestOptions,
): Promise<SchemaOutput<T>>
Experimental
Retrieves the result of a completed task.

Use client.experimental.tasks.getTaskResult() to access this method.
Type Parameters
- T extends AnySchema
Parameters
- params: {
      _meta?: {
          "io.modelcontextprotocol/related-task"?: { taskId: string };
          progressToken?: string | number;
          [key: string]: unknown;
      };
      taskId: string;
  }
  - Optional_meta?: {
        "io.modelcontextprotocol/related-task"?: { taskId: string };
        progressToken?: string | number;
        [key: string]: unknown;
    }
    See General fields: _meta for notes on _meta usage.
    
    Optionalio.modelcontextprotocol/related-task?: { taskId: string }
    If specified, this request is related to the provided task.
    
    OptionalprogressToken?: string | number
    If specified, the caller is requesting out-of-band progress notifications for this request (as represented by notifications/progress). The value of this parameter is an opaque token that will be attached to any subsequent notifications. The receiver is not obligated to provide these notifications.
  - taskId: string
- resultSchema: T
- Optionaloptions: RequestOptions
Returns Promise<SchemaOutput<T>>
- Defined in packages/core/src/shared/protocol.ts:1310

`Protected`listTasks

listTasks(
    params?: { cursor?: string },
    options?: RequestOptions,
): Promise<
    {
        _meta?: {
            "io.modelcontextprotocol/related-task"?: { taskId: string };
            progressToken?: string | number;
            [key: string]: unknown;
        };
        nextCursor?: string;
        tasks: {
            createdAt: string;
            lastUpdatedAt: string;
            pollInterval?: number;
            status: | "working"
            | "input_required"
            | "completed"
            | "failed"
            | "cancelled";
            statusMessage?: string;
            taskId: string;
            ttl: number
            | null;
        }[];
        [key: string]: unknown;
    },
>
Experimental
Lists tasks, optionally starting from a pagination cursor.

Use client.experimental.tasks.listTasks() to access this method.
Parameters
- Optionalparams: { cursor?: string }
- Optionaloptions: RequestOptions
Returns Promise<
    {
        _meta?: {
            "io.modelcontextprotocol/related-task"?: { taskId: string };
            progressToken?: string | number;
            [key: string]: unknown;
        };
        nextCursor?: string;
        tasks: {
            createdAt: string;
            lastUpdatedAt: string;
            pollInterval?: number;
            status: | "working"
            | "input_required"
            | "completed"
            | "failed"
            | "cancelled";
            statusMessage?: string;
            taskId: string;
            ttl: number
            | null;
        }[];
        [key: string]: unknown;
    },
>
- Defined in packages/core/src/shared/protocol.ts:1323

notification

notification(
    notification: {
        method: string;
        params?: {
            _meta?: {
                "io.modelcontextprotocol/related-task"?: { taskId: string };
                progressToken?: string | number;
                [key: string]: unknown;
            };
            [key: string]: unknown;
        };
    },
    options?: NotificationOptions,
): Promise<void>
Emits a notification, which is a one-way message that does not expect a response.
Parameters
- notification: {
      method: string;
      params?: {
          _meta?: {
              "io.modelcontextprotocol/related-task"?: { taskId: string };
              progressToken?: string | number;
              [key: string]: unknown;
          };
          [key: string]: unknown;
      };
  }
- Optionaloptions: NotificationOptions
Returns Promise<void>
- Defined in packages/core/src/shared/protocol.ts:1339

removeNotificationHandler

removeNotificationHandler(method: NotificationMethod): void
Removes the notification handler for the given method.
Parameters
- method: NotificationMethod
Returns void
- Defined in packages/core/src/shared/protocol.ts:1503

removeRequestHandler

removeRequestHandler(method: RequestMethod): void
Removes the request handler for the given method.
Parameters
- method: RequestMethod
Returns void
- Defined in packages/core/src/shared/protocol.ts:1470

request

request<T extends AnySchema>(
    request: {
        method: string;
        params?: {
            _meta?: {
                "io.modelcontextprotocol/related-task"?: { taskId: string };
                progressToken?: string | number;
                [key: string]: unknown;
            };
            [key: string]: unknown;
        };
    },
    resultSchema: T,
    options?: RequestOptions,
): Promise<SchemaOutput<T>>
Sends a request and waits for a response.

Do not use this method to emit notifications! Use notification() instead.
Type Parameters
- T extends AnySchema
Parameters
- request: {
      method: string;
      params?: {
          _meta?: {
              "io.modelcontextprotocol/related-task"?: { taskId: string };
              progressToken?: string | number;
              [key: string]: unknown;
          };
          [key: string]: unknown;
      };
  }
- resultSchema: T
- Optionaloptions: RequestOptions
Returns Promise<SchemaOutput<T>>
- Defined in packages/core/src/shared/protocol.ts:1139

`Protected`requestStream

requestStream<T extends AnyObjectSchema>(
    request: {
        method: string;
        params?: {
            _meta?: {
                "io.modelcontextprotocol/related-task"?: { taskId: string };
                progressToken?: string | number;
                [key: string]: unknown;
            };
            [key: string]: unknown;
        };
    },
    resultSchema: T,
    options?: RequestOptions,
): AsyncGenerator<ResponseMessage<SchemaOutput<T>>, void, void>
Experimental
Sends a request and returns an AsyncGenerator that yields response messages. The generator is guaranteed to end with either a 'result' or 'error' message.

Use client.experimental.tasks.requestStream() to access this method.
Type Parameters
- T extends AnyObjectSchema
Parameters
- request: {
      method: string;
      params?: {
          _meta?: {
              "io.modelcontextprotocol/related-task"?: { taskId: string };
              progressToken?: string | number;
              [key: string]: unknown;
          };
          [key: string]: unknown;
      };
  }
- resultSchema: T
- Optionaloptions: RequestOptions
Returns AsyncGenerator<ResponseMessage<SchemaOutput<T>>, void, void>
- Defined in packages/core/src/shared/protocol.ts:1038

setNotificationHandler

setNotificationHandler<M extends NotificationMethod>(
method: M,
handler: (notification: NotificationTypeMap[M]) => void | Promise<void>,
): void
Registers a handler to invoke when this protocol object receives a notification with the given method.

Note that this will replace any previous notification handler for the same method.
Type Parameters
- M extends NotificationMethod
Parameters
- method: M
- handler: (notification: NotificationTypeMap[M]) => void | Promise<void>
Returns void
- Defined in packages/core/src/shared/protocol.ts:1488

setRequestHandler

setRequestHandler<M extends RequestMethod>(
    method: M,
    handler: (
        request: RequestTypeMap[M],
        ctx: ContextT,
    ) =>
        | {
            _meta?: {
                "io.modelcontextprotocol/related-task"?: { taskId: string };
                progressToken?: string | number;
                [key: string]: unknown;
            };
            [key: string]: unknown;
        }
        | Promise<
            {
                _meta?: {
                    "io.modelcontextprotocol/related-task"?: { taskId: string };
                    progressToken?: string | number;
                    [key: string]: unknown;
                };
                [key: string]: unknown;
            },
        >,
): void
Registers a handler to invoke when this protocol object receives a request with the given method.

Note that this will replace any previous request handler for the same method.
Type Parameters
- M extends RequestMethod
Parameters
- method: M
- handler: (
      request: RequestTypeMap[M],
      ctx: ContextT,
  ) =>
      | {
          _meta?: {
              "io.modelcontextprotocol/related-task"?: { taskId: string };
              progressToken?: string | number;
              [key: string]: unknown;
          };
          [key: string]: unknown;
      }
      | Promise<
          {
              _meta?: {
                  "io.modelcontextprotocol/related-task"?: { taskId: string };
                  progressToken?: string | number;
                  [key: string]: unknown;
              };
              [key: string]: unknown;
          },
      >
Returns void
- Defined in packages/core/src/shared/protocol.ts:1454

Class Protocol<ContextT>Abstract

Type Parameters

Hierarchy (View Summary)

Index

Constructors

Properties

Accessors

Methods

Constructors

constructor

Type Parameters

Parameters

Returns Protocol<ContextT>

Properties

Protected_supportedProtocolVersions

OptionalfallbackNotificationHandler

OptionalfallbackRequestHandler

Optionalonclose

Optionalonerror

Accessors

transport

Returns Transport | undefined

Methods

assertCanSetRequestHandler

Parameters

Returns void

Protected AbstractassertCapabilityForMethod

Parameters

Returns void

Protected AbstractassertNotificationCapability

Parameters

Returns void

Protected AbstractassertRequestHandlerCapability

Parameters

Returns void

Protected AbstractassertTaskCapability

Parameters

Returns void

Protected AbstractassertTaskHandlerCapability

Parameters

Returns void

Protected AbstractbuildContext

Parameters

Returns ContextT

ProtectedcancelTask

Parameters

close

Returns Promise<void>

connect

Parameters

Returns Promise<void>

ProtectedgetTask

Parameters

Optional_meta?: { "io.modelcontextprotocol/related-task"?: { taskId: string }; progressToken?: string | number; [key: string]: unknown;}

Optionalio.modelcontextprotocol/related-task?: { taskId: string }

OptionalprogressToken?: string | number

taskId: string

ProtectedgetTaskResult

Type Parameters

Parameters

Optional_meta?: { "io.modelcontextprotocol/related-task"?: { taskId: string }; progressToken?: string | number; [key: string]: unknown;}

Optionalio.modelcontextprotocol/related-task?: { taskId: string }

OptionalprogressToken?: string | number

taskId: string

Returns Promise<SchemaOutput<T>>

ProtectedlistTasks

Parameters

notification

Parameters

Returns Promise<void>

removeNotificationHandler

Parameters

Returns void

removeRequestHandler

Parameters

Returns void

request

Type Parameters

Parameters

Returns Promise<SchemaOutput<T>>

Class Protocol<ContextT>`Abstract`

`Protected`_supportedProtocolVersions

`Optional`fallbackNotificationHandler

`Optional`fallbackRequestHandler

`Optional`onclose

`Optional`onerror

`Protected` `Abstract`assertCapabilityForMethod

`Protected` `Abstract`assertNotificationCapability

`Protected` `Abstract`assertRequestHandlerCapability

`Protected` `Abstract`assertTaskCapability

`Protected` `Abstract`assertTaskHandlerCapability

`Protected` `Abstract`buildContext

`Protected`cancelTask

`Protected`getTask

`Optional`_meta?: {
"io.modelcontextprotocol/related-task"?: { taskId: string };
progressToken?: string | number;
[key: string]: unknown;
}

`Optional`io.modelcontextprotocol/related-task?: { taskId: string }

`Optional`progressToken?: string | number

`Protected`getTaskResult

`Optional`_meta?: {
"io.modelcontextprotocol/related-task"?: { taskId: string };
progressToken?: string | number;
[key: string]: unknown;
}

`Optional`io.modelcontextprotocol/related-task?: { taskId: string }

`Optional`progressToken?: string | number

`Protected`listTasks

`Protected`requestStream