[**@jupyterlite**](../../../README.md)

***

[@jupyterlite](../../../README.md) / [@jupyterlite/services](../README.md) / BaseKernel

# Class: `abstract` BaseKernel

Defined in: [packages/services/src/kernel/base.ts:11](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L11)

A base kernel class handling basic kernel messaging.

## Implements

- [`IKernel`](../interfaces/IKernel.md)

## Constructors

### Constructor

> **new BaseKernel**(`options`): `BaseKernel`

Defined in: [packages/services/src/kernel/base.ts:17](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L17)

Construct a new BaseKernel.

#### Parameters

##### options

[`IOptions`](../namespaces/IKernel/interfaces/IOptions.md)

The instantiation options for a BaseKernel.

#### Returns

`BaseKernel`

## Accessors

### disposed

#### Get Signature

> **get** **disposed**(): `ISignal`\<`this`, `void`\>

Defined in: [packages/services/src/kernel/base.ts:42](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L42)

A signal emitted when the kernel is disposed.

##### Returns

`ISignal`\<`this`, `void`\>

A signal emitted when the object is disposed.

#### Implementation of

[`IKernel`](../interfaces/IKernel.md).[`disposed`](../interfaces/IKernel.md#disposed)

***

### executionCount

#### Get Signature

> **get** **executionCount**(): `number`

Defined in: [packages/services/src/kernel/base.ts:70](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L70)

The current execution count

##### Returns

`number`

***

### id

#### Get Signature

> **get** **id**(): `string`

Defined in: [packages/services/src/kernel/base.ts:49](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L49)

Get the kernel id

##### Returns

`string`

The id of the server-side kernel.

#### Implementation of

[`IKernel`](../interfaces/IKernel.md).[`id`](../interfaces/IKernel.md#id)

***

### isDisposed

#### Get Signature

> **get** **isDisposed**(): `boolean`

Defined in: [packages/services/src/kernel/base.ts:35](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L35)

Return whether the kernel is disposed.

##### Returns

`boolean`

Test whether the object has been disposed.

#### Notes
This property is always safe to access.

#### Implementation of

[`IKernel`](../interfaces/IKernel.md).[`isDisposed`](../interfaces/IKernel.md#isdisposed)

***

### location

#### Get Signature

> **get** **location**(): `string`

Defined in: [packages/services/src/kernel/base.ts:63](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L63)

The location in the virtual filesystem from which the kernel was started.

##### Returns

`string`

The location in the virtual filesystem from which the kernel was started.

#### Implementation of

[`IKernel`](../interfaces/IKernel.md).[`location`](../interfaces/IKernel.md#location)

***

### name

#### Get Signature

> **get** **name**(): `string`

Defined in: [packages/services/src/kernel/base.ts:56](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L56)

Get the name of the kernel

##### Returns

`string`

The name of the server-side kernel.

#### Implementation of

[`IKernel`](../interfaces/IKernel.md).[`name`](../interfaces/IKernel.md#name)

***

### parent

#### Get Signature

> **get** **parent**(): `undefined` \| `IMessage`\<`MessageType`\>

Defined in: [packages/services/src/kernel/base.ts:84](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L84)

Get the last parent message (mimic ipykernel's get_parent)

##### Returns

`undefined` \| `IMessage`\<`MessageType`\>

***

### parentHeader

#### Get Signature

> **get** **parentHeader**(): `undefined` \| `IHeader`\<`MessageType`\>

Defined in: [packages/services/src/kernel/base.ts:77](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L77)

Get the last parent header

##### Returns

`undefined` \| `IHeader`\<`MessageType`\>

***

### ready

#### Get Signature

> **get** **ready**(): `Promise`\<`void`\>

Defined in: [packages/services/src/kernel/base.ts:28](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L28)

A promise that is fulfilled when the kernel is ready.

##### Returns

`Promise`\<`void`\>

A promise that is fulfilled when the kernel is ready.

#### Implementation of

[`IKernel`](../interfaces/IKernel.md).[`ready`](../interfaces/IKernel.md#ready)

## Methods

### clearOutput()

> `protected` **clearOutput**(`content`, `parentHeader`): `void`

Defined in: [packages/services/src/kernel/base.ts:393](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L393)

Send a `clear_output` message to the client.

#### Parameters

##### content

The clear_output content.

###### wait

`boolean`

##### parentHeader

The parent header.

`undefined` | `IHeader`\<`MessageType`\>

#### Returns

`void`

***

### commClose()

> `abstract` **commClose**(`msg`): `Promise`\<`void`\>

Defined in: [packages/services/src/kernel/base.ts:232](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L232)

Send an `comm_close` message.

#### Parameters

##### msg

`ICommCloseMsg`

#### Returns

`Promise`\<`void`\>

***

### commInfoRequest()

> `abstract` **commInfoRequest**(`content`): `Promise`\<`ReplyContent`\<`ICommInfoReply`\>\>

Defined in: [packages/services/src/kernel/base.ts:202](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L202)

Handle a `comm_info_request` message.

#### Parameters

##### content

The content of the request.

###### target_name?

`string`

The comm target name to filter returned comms

#### Returns

`Promise`\<`ReplyContent`\<`ICommInfoReply`\>\>

A promise that resolves with the response message.

***

### commMsg()

> `abstract` **commMsg**(`msg`): `Promise`\<`void`\>

Defined in: [packages/services/src/kernel/base.ts:225](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L225)

Send an `comm_msg` message.

#### Parameters

##### msg

`ICommMsgMsg`

The comm_msg message.

#### Returns

`Promise`\<`void`\>

***

### commOpen()

> `abstract` **commOpen**(`msg`): `Promise`\<`void`\>

Defined in: [packages/services/src/kernel/base.ts:218](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L218)

Send an `comm_open` message.

#### Parameters

##### msg

`ICommOpenMsg`

The comm_open message.

#### Returns

`Promise`\<`void`\>

***

### completeRequest()

> `abstract` **completeRequest**(`content`): `Promise`\<`ReplyContent`\<`ICompleteReply`\>\>

Defined in: [packages/services/src/kernel/base.ts:169](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L169)

Handle a `complete_request` message.

#### Parameters

##### content

The content of the request.

###### code

`string`

###### cursor_pos

`number`

#### Returns

`Promise`\<`ReplyContent`\<`ICompleteReply`\>\>

***

### displayData()

> `protected` **displayData**(`content`, `parentHeader`): `void`

Defined in: [packages/services/src/kernel/base.ts:265](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L265)

Send a `display_data` message to the client.

#### Parameters

##### content

The display_data content.

###### data

`IMimeBundle`

###### metadata

`PartialJSONObject`

###### transient?

\{ `display_id`: `string`; \}

###### transient.display_id?

`string`

##### parentHeader

The parent header.

`undefined` | `IHeader`\<`MessageType`\>

#### Returns

`void`

***

### dispose()

> **dispose**(): `void`

Defined in: [packages/services/src/kernel/base.ts:91](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L91)

Dispose the kernel.

#### Returns

`void`

#### Implementation of

[`IKernel`](../interfaces/IKernel.md).[`dispose`](../interfaces/IKernel.md#dispose)

***

### executeRequest()

> `abstract` **executeRequest**(`content`): `Promise`\<`ReplyContent`\<`IExecuteReply`\> & `IExecuteCount`\>

Defined in: [packages/services/src/kernel/base.ts:160](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L160)

Handle an `execute_request` message.

#### Parameters

##### content

The content of the execute_request kernel message

###### allow_stdin?

`boolean`

Whether to allow stdin requests.
The default is `true`.

###### code

`string`

The code to execute.

###### silent?

`boolean`

Whether to execute the code as quietly as possible.
The default is `false`.

###### stop_on_error?

`boolean`

Whether to the abort execution queue on an error.
The default is `false`.

###### store_history?

`boolean`

Whether to store history of the execution.
The default `true` if silent is False.
It is forced to  `false ` if silent is `true`.

###### user_expressions?

`JSONObject`

A mapping of names to expressions to be evaluated in the
kernel's interactive namespace.

#### Returns

`Promise`\<`ReplyContent`\<`IExecuteReply`\> & `IExecuteCount`\>

***

### handleComm()

> `protected` **handleComm**(`type`, `content`, `metadata`, `buffers`, `parentHeader`): `void`

Defined in: [packages/services/src/kernel/base.ts:417](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L417)

Send a `comm` message to the client.

#### Parameters

##### type

`"comm_close"` | `"comm_msg"` | `"comm_open"`

##### content

###### comm_id

`string`

###### data

`JSONObject`

##### metadata

`JSONObject`

##### buffers

`undefined` | (`ArrayBufferView` \| `ArrayBuffer`)[]

##### parentHeader

`undefined` | `IHeader`\<`MessageType`\>

#### Returns

`void`

***

### handleMessage()

> **handleMessage**(`msg`): `Promise`\<`void`\>

Defined in: [packages/services/src/kernel/base.ts:104](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L104)

Handle an incoming message from the client.

#### Parameters

##### msg

`IMessage`

The message to handle

#### Returns

`Promise`\<`void`\>

#### Implementation of

[`IKernel`](../interfaces/IKernel.md).[`handleMessage`](../interfaces/IKernel.md#handlemessage)

***

### inputReply()

> `abstract` **inputReply**(`content`): `void`

Defined in: [packages/services/src/kernel/base.ts:211](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L211)

Send an `input_reply` message.

#### Parameters

##### content

`ReplyContent`\<`IInputReply`\>

The content of the reply.

#### Returns

`void`

***

### inputRequest()

> `protected` **inputRequest**(`content`, `parentHeader`): `void`

Defined in: [packages/services/src/kernel/base.ts:293](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L293)

Send a `input_request` message to the client.

#### Parameters

##### content

The input_request content.

###### password

`boolean`

Whether the request is for a password.
If so, the frontend shouldn't echo input.

###### prompt

`string`

The text to show at the prompt.

##### parentHeader

The parent header.

`undefined` | `IHeader`\<`MessageType`\>

#### Returns

`void`

***

### inspectRequest()

> `abstract` **inspectRequest**(`content`): `Promise`\<`ReplyContent`\<`IInspectReply`\>\>

Defined in: [packages/services/src/kernel/base.ts:180](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L180)

Handle an `inspect_request` message.

#### Parameters

##### content

The content of the request.

###### code

`string`

###### cursor_pos

`number`

###### detail_level

`0` \| `1`

#### Returns

`Promise`\<`ReplyContent`\<`IInspectReply`\>\>

A promise that resolves with the response message.

***

### isCompleteRequest()

> `abstract` **isCompleteRequest**(`content`): `Promise`\<`ReplyContent`\<`IIsCompleteReplyIncomplete` \| `IIsCompleteReplyOther`\>\>

Defined in: [packages/services/src/kernel/base.ts:191](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L191)

Handle an `is_complete_request` message.

#### Parameters

##### content

The content of the request.

###### code

`string`

#### Returns

`Promise`\<`ReplyContent`\<`IIsCompleteReplyIncomplete` \| `IIsCompleteReplyOther`\>\>

A promise that resolves with the response message.

***

### kernelInfoRequest()

> `abstract` **kernelInfoRequest**(): `Promise`\<`ReplyContent`\<`IInfoReply`\>\>

Defined in: [packages/services/src/kernel/base.ts:153](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L153)

Handle a `kernel_info_request` message.

#### Returns

`Promise`\<`ReplyContent`\<`IInfoReply`\>\>

A promise that resolves with the kernel info.

***

### publishExecuteError()

> `protected` **publishExecuteError**(`content`, `parentHeader`): `void`

Defined in: [packages/services/src/kernel/base.ts:343](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L343)

Send an `error` message to the client.

#### Parameters

##### content

The error content.

###### ename

`string`

###### evalue

`string`

###### traceback

`string`[]

##### parentHeader

The parent header.

`undefined` | `IHeader`\<`MessageType`\>

#### Returns

`void`

***

### publishExecuteResult()

> `protected` **publishExecuteResult**(`content`, `parentHeader`): `void`

Defined in: [packages/services/src/kernel/base.ts:318](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L318)

Send an `execute_result` message.

#### Parameters

##### content

The execute result content.

###### data

`IMimeBundle`

###### execution_count

`ExecutionCount`

###### metadata

`PartialJSONObject`

###### transient?

\{ `display_id`: `string`; \}

###### transient.display_id?

`string`

##### parentHeader

The parent header.

`undefined` | `IHeader`\<`MessageType`\>

#### Returns

`void`

***

### stream()

> `protected` **stream**(`content`, `parentHeader`): `void`

Defined in: [packages/services/src/kernel/base.ts:240](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L240)

Stream an event from the kernel

#### Parameters

##### content

The stream content.

###### name

`"stdout"` \| `"stderr"`

###### text

`string`

##### parentHeader

The parent header.

`undefined` | `IHeader`\<`MessageType`\>

#### Returns

`void`

***

### updateDisplayData()

> `protected` **updateDisplayData**(`content`, `parentHeader`): `void`

Defined in: [packages/services/src/kernel/base.ts:368](https://github.com/jupyterlite/jupyterlite/blob/14439ec34e3cade5baa221a050277e15da9d0c06/packages/services/src/kernel/base.ts#L368)

Send a `update_display_data` message to the client.

#### Parameters

##### content

`object` & `object`

The update_display_data content.

##### parentHeader

The parent header.

`undefined` | `IHeader`\<`MessageType`\>

#### Returns

`void`