Class BaseConnector`Abstract`

Implements protocol operations shared by MCP transport connectors.

Subclasses provide transport-specific connection setup and a public identifier. Call BaseConnector.connect, then BaseConnector.initialize, before invoking protocol operations.

Hierarchy (View Summary)

BaseConnector

Constructors

constructor

new BaseConnector(opts?: ConnectorInitOptions): BaseConnector
Creates a connector with shared SDK and callback options.
Parameters
- opts: ConnectorInitOptions = {}
  Connector initialization options.
Returns BaseConnector
- Defined in transport/base.ts:152

Accessors

instructions

get instructions(): string | undefined
Instructions supplied by the connected server, if any.

Returns string | undefined
- Defined in transport/base.ts:586

isClientConnected

get isClientConnected(): boolean
Whether an SDK client currently exists for this connector.

Returns boolean
- Defined in transport/base.ts:495

negotiatedProtocolVersion

get negotiatedProtocolVersion(): string | undefined
The protocol version string negotiated for the active connection.

Returns string | undefined
- Defined in transport/base.ts:601

protocolEra

get protocolEra(): ProtocolEra | undefined
The negotiated protocol era for the active connection.
- "legacy" — 2025-era server, sessionful initialize handshake.
- "modern" — 2026-era server, stateless per-request. undefined before the connection has negotiated.
Returns ProtocolEra | undefined
- Defined in transport/base.ts:596

`Abstract`publicIdentifier

get publicIdentifier(): Record<string, string>
Returns transport-specific fields suitable for logs and telemetry.

Returns Record<string, string>
A record identifying the connector without exposing credentials.
- Defined in transport/base.ts:475

serverCapabilities

get serverCapabilities(): Record<string, unknown>
Capabilities cached during initialization, or an empty object.

Returns Record<string, unknown>
- Defined in transport/base.ts:576

serverInfo

get serverInfo(): MCPServerInfo | null
Server identity cached during initialization, or null.

Returns MCPServerInfo | null
- Defined in transport/base.ts:581

tools

get tools(): {}[]
Returns the tool list cached during initialization.

Returns {}[]

Throws
When BaseConnector.initialize has not completed.
- Defined in transport/base.ts:568

Methods

callTool

callTool(
    name: string,
    args: Record<string, any>,
    options?: RequestOptions,
): Promise<{ [key: string]: unknown }>
Calls a tool on the connected server.
Parameters
- name: string
  Tool name.
- args: Record<string, any>
  Tool arguments.
- Optionaloptions: RequestOptions
  Per-request timeout, cancellation, and progress options.
Returns Promise<{ [key: string]: unknown }>
The tool result returned by the server.

Throws
When the connector is not connected or the tool call fails.
- Defined in transport/base.ts:614

complete

complete(
params: {},
options?: RequestOptions,
): Promise<{ [key: string]: unknown }>
Request completion suggestions for a prompt or resource template argument
Parameters
- params: {}
  Completion request parameters
- Optionaloptions: RequestOptions
  Request options
Returns Promise<{ [key: string]: unknown }>
Completion suggestions from the server
- Defined in transport/base.ts:760

`Abstract`connect

connect(): Promise<void>
Establishes the transport connection and creates the SDK client.

Returns Promise<void>
A promise that resolves when the connector is connected.
- Defined in transport/base.ts:468

disconnect

disconnect(): Promise<void>
Disconnects the SDK client and releases transport resources.

Returns Promise<void>
A promise that resolves after cleanup completes.
- Defined in transport/base.ts:482

getPrompt

getPrompt(
name: string,
args: Record<string, any>,
): Promise<{ [key: string]: unknown }>
Gets a prompt with the supplied arguments.
Parameters
- name: string
  Prompt name.
- args: Record<string, any>
  Prompt arguments.
Returns Promise<{ [key: string]: unknown }>
The rendered prompt returned by the server.
- Defined in transport/base.ts:859

getRoots

getRoots(): {}[]
Returns the roots currently advertised to the server.

Returns {}[]
A copy of the configured roots.
- Defined in transport/base.ts:386

initialize

initialize(defaultRequestOptions?: RequestOptions): Promise<{} | undefined>
Initialise the MCP session after connect() has succeeded.

In the SDK, Client.connect(transport) automatically performs the protocol‑level initialize handshake, so we only need to cache the list of tools and expose some server info.
Parameters
- defaultRequestOptions: RequestOptions = ...
  Options used while fetching the initial tool list.
Returns Promise<{} | undefined>
The capabilities advertised by the server.

Throws
When BaseConnector.connect has not completed.
- Defined in transport/base.ts:510

listAllResources

listAllResources(options?: RequestOptions): Promise<{ resources: any[] }>
List all resources from the server, automatically handling pagination
Parameters
- Optionaloptions: RequestOptions
  Request options
Returns Promise<{ resources: any[] }>
Complete list of all resources
- Defined in transport/base.ts:700

listPrompts

listPrompts(): Promise<{ [key: string]: unknown }>
Lists prompts exposed by the server.

Returns Promise<{ [key: string]: unknown }>
The prompt list, or an empty list when prompts are unsupported.
- Defined in transport/base.ts:827

listResources

listResources(
cursor?: string,
options?: RequestOptions,
): Promise<{ [key: string]: unknown }>
List resources from the server with optional pagination
Parameters
- Optionalcursor: string
  Optional cursor for pagination
- Optionaloptions: RequestOptions
  Request options
Returns Promise<{ [key: string]: unknown }>
Resource list with optional nextCursor for pagination
- Defined in transport/base.ts:685

listResourceTemplates

listResourceTemplates(
options?: RequestOptions,
): Promise<{ [key: string]: unknown }>
List resource templates from the server
Parameters
- Optionaloptions: RequestOptions
  Request options
Returns Promise<{ [key: string]: unknown }>
List of available resource templates
- Defined in transport/base.ts:744

listTools

listTools(options?: RequestOptions): Promise<{}[]>
List all available tools from the MCP server. This method fetches fresh tools from the server, unlike the tools getter which returns cached tools.
Parameters
- Optionaloptions: RequestOptions
  Optional request options
Returns Promise<{}[]>
Array of available tools
- Defined in transport/base.ts:663

onNotification

onNotification(handler: NotificationHandler): void
Register a handler for server notifications
Parameters
- handler: NotificationHandler
  Function to call when a notification is received
Returns void
Example
```
connector.onNotification((notification) => {
  console.log(`Received: ${notification.method}`, notification.params);
});
```
- Defined in transport/base.ts:187

readResource

readResource(
uri: string,
options?: RequestOptions,
): Promise<{ [key: string]: unknown }>
Reads a resource by URI.
Parameters
- uri: string
  Resource URI to read.
- Optionaloptions: RequestOptions
  Per-request options.
Returns Promise<{ [key: string]: unknown }>
The resource contents returned by the server.
- Defined in transport/base.ts:782

request

request(
    method: string,
    params?: Record<string, any> | null,
    options?: RequestOptions,
): Promise<unknown>
Sends a raw, potentially non-standard request through the SDK client.
Parameters
- method: string
  JSON-RPC method name.
- params: Record<string, any> | null = null
  Request parameters. Defaults to an empty object.
- Optionaloptions: RequestOptions
  Per-request options.
Returns Promise<unknown>
The unvalidated result returned by the server.
- Defined in transport/base.ts:876

setRoots

setRoots(roots: {}[]): Promise<void>
Set roots and notify the server. Roots represent directories or files that the client has access to.
Parameters
- roots: {}[]
  Array of Root objects with uri (must start with "file://") and optional name
Returns Promise<void>
Deprecated
Roots are retained only for v1 compatibility.
Example
```
await connector.setRoots([
  { uri: "file:///home/user/project", name: "My Project" },
  { uri: "file:///home/user/data" }
]);
```
- Defined in transport/base.ts:371

subscribeToResource

subscribeToResource(uri: string, options?: RequestOptions): Promise<{}>
Subscribe to resource updates
Parameters
- uri: string
  URI of the resource to subscribe to
- Optionaloptions: RequestOptions
  Request options
Returns Promise<{}>
- Defined in transport/base.ts:798

unsubscribeFromResource

unsubscribeFromResource(uri: string, options?: RequestOptions): Promise<{}>
Unsubscribe from resource updates
Parameters
- uri: string
  URI of the resource to unsubscribe from
- Optionaloptions: RequestOptions
  Request options
Returns Promise<{}>
- Defined in transport/base.ts:813

Class BaseConnectorAbstract

Hierarchy (View Summary)

Index

Constructors

Accessors

Methods

Constructors

constructor

Parameters

Returns BaseConnector

Accessors

instructions

Returns string | undefined

isClientConnected

Returns boolean

negotiatedProtocolVersion

Returns string | undefined

protocolEra

Returns ProtocolEra | undefined

AbstractpublicIdentifier

Returns Record<string, string>

serverCapabilities

Returns Record<string, unknown>

serverInfo

Returns MCPServerInfo | null

tools

Returns {}[]

Throws

Methods

callTool

Parameters

Returns Promise<{ [key: string]: unknown }>

Throws

complete

Parameters

Returns Promise<{ [key: string]: unknown }>

Abstractconnect

Returns Promise<void>

disconnect

Returns Promise<void>

getPrompt

Parameters

Returns Promise<{ [key: string]: unknown }>

getRoots

Returns {}[]

initialize

Parameters

Returns Promise<{} | undefined>

Throws

listAllResources

Parameters

Returns Promise<{ resources: any[] }>

listPrompts

Returns Promise<{ [key: string]: unknown }>

listResources

Parameters

Returns Promise<{ [key: string]: unknown }>

listResourceTemplates

Parameters

Returns Promise<{ [key: string]: unknown }>

listTools

Parameters

Returns Promise<{}[]>

onNotification

Parameters

Returns void

Example

readResource

Parameters

Returns Promise<{ [key: string]: unknown }>

request

Parameters

Returns Promise<unknown>

setRoots

Parameters

Returns Promise<void>

Deprecated

Example

subscribeToResource

Parameters

Class BaseConnector`Abstract`

`Abstract`publicIdentifier

`Abstract`connect