MCPServer

@codebolt/mcp

---

Class: MCPServer<T>

Defined in: packages/mcp/src/mcpServer.ts:1221

Class representing a toolbox for FastMCP. Manages tools, resources, and prompts for a Model Context Protocol server.

Extends

• FastMCPEventEmitter

Type Parameters

Type Parameter	Default type
T extends Record<string, unknown> | undefined	undefined

Constructors

Constructor

new MCPServer<T>(options: ServerOptions<T>): MCPServer<T>;

Defined in: packages/mcp/src/mcpServer.ts:1236

Creates a new ToolBox instance.

Parameters

Parameter	Type	Description
options	ServerOptions<T>	Configuration options for the toolbox

Returns

MCPServer<T>

Overrides

FastMCPEventEmitter.constructor

Properties

Property	Modifier	Type	Description	Inherited from	Defined in
_emitterType?	public	EventEmitter<DefaultEventMap>	-	FastMCPEventEmitter. _emitterType	node_modules/.pnpm/strict-event-emitter-types@2.0.0/node_modules/strict-event-emitter-types/types/src/index.d.ts:5
_emitType?	public	FastMCPEvents<FastMCPSessionAuth>	-	FastMCPEventEmitter. _emitType	node_modules/.pnpm/strict-event-emitter-types@2.0.0/node_modules/strict-event-emitter-types/types/src/index.d.ts:7
_eventsType?	public	FastMCPEvents<FastMCPSessionAuth>	-	FastMCPEventEmitter. _eventsType	node_modules/.pnpm/strict-event-emitter-types@2.0.0/node_modules/strict-event-emitter-types/types/src/index.d.ts:6
[captureRejectionSymbol]?	public	<K>(error: Error, event: string | symbol, ...args: AnyRest) => void	-	FastMCPEventEmitter.[captureRejectionSymbol]	node_modules/.pnpm/@types+node@20.19.19/node_modules/@types/node/events.d.ts:103
options	public	ServerOptions<T>	Configuration options for the toolbox	-	packages/mcp/src/mcpServer.ts:1236

Accessors

sessions

Get Signature

get sessions(): FastMCPSession<T>[];

Defined in: packages/mcp/src/mcpServer.ts:1246

Gets all active sessions.

Returns

FastMCPSession<T>[]

Methods

activate()

activate(options: 
  | {
  transportType: "stdio";
}
  | {
  sse: {
     endpoint: `/${string}`;
     port: number;
  };
  transportType: "sse";
}): Promise<void>;

Defined in: packages/mcp/src/mcpServer.ts:1346

Activates the server.

Parameters

Parameter	Type	Description
options	| { transportType: "stdio"; } | { sse: { endpoint: `/$\{string\}`; port: number; }; transportType: "sse"; }	Options for the server transport

Returns

Promise<void>

---

addListener()

Call Signature

addListener<P, T>(
   this: T, 
   event: P, 
   listener: (...args: ListenerType<FastMCPEvents<FastMCPSessionAuth>[P]>) => void): T;

Defined in: node_modules/.pnpm/strict-event-emitter-types@2.0.0/node_modules/strict-event-emitter-types/types/src/index.d.ts:17

Type Parameters

Type Parameter
P extends keyof FastMCPEvents<FastMCPSessionAuth>
T

Parameters

Parameter	Type
this	T
event	P
listener	(...args: ListenerType<FastMCPEvents<FastMCPSessionAuth>[P]>) => void

Returns

T

Inherited from

FastMCPEventEmitter.addListener

Call Signature

addListener(event: typeof assignmentCompatibilityHack, listener: (...args: any[]) => any): void;

Defined in: node_modules/.pnpm/strict-event-emitter-types@2.0.0/node_modules/strict-event-emitter-types/types/src/index.d.ts:18

Parameters

Parameter	Type
event	typeof assignmentCompatibilityHack
listener	(...args: any[]) => any

Returns

void

Inherited from

FastMCPEventEmitter.addListener

---

addPrompt()

addPrompt<Args>(prompt: InputPrompt<Args>): void;

Defined in: packages/mcp/src/mcpServer.ts:1284

Adds a prompt to the server.

Type Parameters

Type Parameter
Args extends Readonly<{ complete?: ArgumentValueCompleter; description?: string; enum?: string[]; name: string; required?: boolean; }>[]

Parameters

Parameter	Type	Description
prompt	InputPrompt<Args>	The prompt to add

Returns

void

---

addResource()

addResource(resource: Resource): void;

Defined in: packages/mcp/src/mcpServer.ts:1264

Adds a resource to the server.

Parameters

Parameter	Type	Description
resource	Resource	The resource to add

Returns

void

---

addResourceTemplate()

addResourceTemplate<Args>(resource: InputResourceTemplate<Args>): void;

Defined in: packages/mcp/src/mcpServer.ts:1273

Adds a resource template to the server.

Type Parameters

Type Parameter
Args extends Readonly<{ complete?: ArgumentValueCompleter; description?: string; name: string; }>[]

Parameters

Parameter	Type	Description
resource	InputResourceTemplate<Args>	The resource template to add

Returns

void

---

addTool()

addTool<Params>(tool: Tool<T, Params>): void;

Defined in: packages/mcp/src/mcpServer.ts:1255

Adds a tool to the server.

Type Parameters

Type Parameter
Params extends ZodTypeAny

Parameters

Parameter	Type	Description
tool	Tool<T, Params>	The tool to add

Returns

void

---

emit()

Call Signature

emit<P, T>(
   this: T, 
   event: P, ...
   args: ListenerType<FastMCPEvents<FastMCPSessionAuth>[P]>): T;

Defined in: node_modules/.pnpm/strict-event-emitter-types@2.0.0/node_modules/strict-event-emitter-types/types/src/index.d.ts:27

Type Parameters

Type Parameter
P extends keyof FastMCPEvents<FastMCPSessionAuth>
T

Parameters

Parameter	Type
this	T
event	P
...args	ListenerType<FastMCPEvents<FastMCPSessionAuth>[P]>

Returns

T

Inherited from

FastMCPEventEmitter.emit

Call Signature

emit(event: typeof assignmentCompatibilityHack, ...args: any[]): void;

Defined in: node_modules/.pnpm/strict-event-emitter-types@2.0.0/node_modules/strict-event-emitter-types/types/src/index.d.ts:28

Parameters

Parameter	Type
event	typeof assignmentCompatibilityHack
...args	any[]

Returns

void

Inherited from

FastMCPEventEmitter.emit

---

eventNames()

eventNames(): (string | symbol)[];

Defined in: node_modules/.pnpm/@types+node@20.19.19/node_modules/@types/node/events.d.ts:968

Returns an array listing the events for which the emitter has registered listeners. The values in the array are strings or Symbols.

import { EventEmitter } from 'node:events';

const myEE = new EventEmitter();
myEE.on('foo', () => {});
myEE.on('bar', () => {});

const sym = Symbol('symbol');
myEE.on(sym, () => {});

console.log(myEE.eventNames());
// Prints: [ 'foo', 'bar', Symbol(symbol) ]

Returns

(string | symbol)[]

Since

v6.0.0

Inherited from

FastMCPEventEmitter.eventNames

---

getMaxListeners()

getMaxListeners(): number;

Defined in: node_modules/.pnpm/@types+node@20.19.19/node_modules/@types/node/events.d.ts:820

Returns the current max listener value for the EventEmitter which is either set by emitter.setMaxListeners(n) or defaults to EventEmitter.defaultMaxListeners.

Returns

number

Since

v1.0.0

Inherited from

FastMCPEventEmitter.getMaxListeners

---

listenerCount()

listenerCount<K>(eventName: string | symbol, listener?: Function): number;

Defined in: node_modules/.pnpm/@types+node@20.19.19/node_modules/@types/node/events.d.ts:914

Returns the number of listeners listening for the event named eventName. If listener is provided, it will return how many times the listener is found in the list of the listeners of the event.

Type Parameters

Type Parameter
K

Parameters

Parameter	Type	Description
eventName	string | symbol	The name of the event being listened for
listener?	Function	The event handler function

Returns

number

Since

v3.2.0

Inherited from

FastMCPEventEmitter.listenerCount

---

listeners()

listeners<K>(eventName: string | symbol): Function[];

Defined in: node_modules/.pnpm/@types+node@20.19.19/node_modules/@types/node/events.d.ts:833

Returns a copy of the array of listeners for the event named eventName.

server.on('connection', (stream) => {
  console.log('someone connected!');
});
console.log(util.inspect(server.listeners('connection')));
// Prints: [ [Function] ]

Type Parameters

Type Parameter
K

Parameters

Parameter	Type
eventName	string | symbol

Returns

Function[]

Since

v0.1.26

Inherited from

FastMCPEventEmitter.listeners

---

off()

off<K>(eventName: string | symbol, listener: (...args: any[]) => void): this;

Defined in: node_modules/.pnpm/@types+node@20.19.19/node_modules/@types/node/events.d.ts:793

Alias for emitter.removeListener().

Type Parameters

Type Parameter
K

Parameters

Parameter	Type
eventName	string | symbol
listener	(...args: any[]) => void

Returns

this

Since

v10.0.0

Inherited from

FastMCPEventEmitter.off

---

on()

Call Signature

on<P, T>(
   this: T, 
   event: P, 
   listener: (...args: ListenerType<FastMCPEvents<FastMCPSessionAuth>[P]>) => void): T;

Defined in: node_modules/.pnpm/strict-event-emitter-types@2.0.0/node_modules/strict-event-emitter-types/types/src/index.d.ts:15

Type Parameters

Type Parameter
P extends keyof FastMCPEvents<FastMCPSessionAuth>
T

Parameters

Parameter	Type
this	T
event	P
listener	(...args: ListenerType<FastMCPEvents<FastMCPSessionAuth>[P]>) => void

Returns

T

Inherited from

FastMCPEventEmitter.on

Call Signature

on(event: typeof assignmentCompatibilityHack, listener: (...args: any[]) => any): void;

Defined in: node_modules/.pnpm/strict-event-emitter-types@2.0.0/node_modules/strict-event-emitter-types/types/src/index.d.ts:16

Parameters

Parameter	Type
event	typeof assignmentCompatibilityHack
listener	(...args: any[]) => any

Returns

void

Inherited from

FastMCPEventEmitter.on

---

once()

Call Signature

once<P, T>(
   this: T, 
   event: P, 
   listener: (...args: ListenerType<FastMCPEvents<FastMCPSessionAuth>[P]>) => void): T;

Defined in: node_modules/.pnpm/strict-event-emitter-types@2.0.0/node_modules/strict-event-emitter-types/types/src/index.d.ts:25

Type Parameters

Type Parameter
P extends keyof FastMCPEvents<FastMCPSessionAuth>
T

Parameters

Parameter	Type
this	T
event	P
listener	(...args: ListenerType<FastMCPEvents<FastMCPSessionAuth>[P]>) => void

Returns

T

Inherited from

FastMCPEventEmitter.once

Call Signature

once(event: typeof assignmentCompatibilityHack, listener: (...args: any[]) => any): void;

Defined in: node_modules/.pnpm/strict-event-emitter-types@2.0.0/node_modules/strict-event-emitter-types/types/src/index.d.ts:26

Parameters

Parameter	Type
event	typeof assignmentCompatibilityHack
listener	(...args: any[]) => any

Returns

void

Inherited from

FastMCPEventEmitter.once

---

prependListener()

prependListener<K>(eventName: string | symbol, listener: (...args: any[]) => void): this;

Defined in: node_modules/.pnpm/@types+node@20.19.19/node_modules/@types/node/events.d.ts:932

Adds the listener function to the beginning of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventName and listener will result in the listener being added, and called, multiple times.

server.prependListener('connection', (stream) => {
  console.log('someone connected!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

Type Parameters

Type Parameter
K

Parameters

Parameter	Type	Description
eventName	string | symbol	The name of the event.
listener	(...args: any[]) => void	The callback function

Returns

this

Since

v6.0.0

Inherited from

FastMCPEventEmitter.prependListener

---

prependOnceListener()

prependOnceListener<K>(eventName: string | symbol, listener: (...args: any[]) => void): this;

Defined in: node_modules/.pnpm/@types+node@20.19.19/node_modules/@types/node/events.d.ts:948

Adds a one-timelistener function for the event named eventName to the beginning of the listeners array. The next time eventName is triggered, this listener is removed, and then invoked.

server.prependOnceListener('connection', (stream) => {
  console.log('Ah, we have our first user!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

Type Parameters

Type Parameter
K

Parameters

Parameter	Type	Description
eventName	string | symbol	The name of the event.
listener	(...args: any[]) => void	The callback function

Returns

this

Since

v6.0.0

Inherited from

FastMCPEventEmitter.prependOnceListener

---

rawListeners()

rawListeners<K>(eventName: string | symbol): Function[];

Defined in: node_modules/.pnpm/@types+node@20.19.19/node_modules/@types/node/events.d.ts:864

Returns a copy of the array of listeners for the event named eventName, including any wrappers (such as those created by .once()).

import { EventEmitter } from 'node:events';
const emitter = new EventEmitter();
emitter.once('log', () => console.log('log once'));

// Returns a new Array with a function `onceWrapper` which has a property
// `listener` which contains the original listener bound above
const listeners = emitter.rawListeners('log');
const logFnWrapper = listeners[0];

// Logs "log once" to the console and does not unbind the `once` event
logFnWrapper.listener();

// Logs "log once" to the console and removes the listener
logFnWrapper();

emitter.on('log', () => console.log('log persistently'));
// Will return a new Array with a single function bound by `.on()` above
const newListeners = emitter.rawListeners('log');

// Logs "log persistently" twice
newListeners[0]();
emitter.emit('log');

Type Parameters

Type Parameter
K

Parameters

Parameter	Type
eventName	string | symbol

Returns

Function[]

Since

v9.4.0

Inherited from

FastMCPEventEmitter.rawListeners

---

removeAllListeners()

removeAllListeners(eventName?: string | symbol): this;

Defined in: node_modules/.pnpm/@types+node@20.19.19/node_modules/@types/node/events.d.ts:804

Removes all listeners, or those of the specified eventName.

It is bad practice to remove listeners added elsewhere in the code, particularly when the EventEmitter instance was created by some other component or module (e.g. sockets or file streams).

Returns a reference to the EventEmitter, so that calls can be chained.

Parameters

Parameter	Type
eventName?	string | symbol

Returns

this

Since

v0.1.26

Inherited from

FastMCPEventEmitter.removeAllListeners

---

removeListener()

Call Signature

removeListener<P, T>(
   this: T, 
   event: P, 
   listener: (...args: any[]) => any): T;

Defined in: node_modules/.pnpm/strict-event-emitter-types@2.0.0/node_modules/strict-event-emitter-types/types/src/index.d.ts:21

Type Parameters

Type Parameter
P extends keyof FastMCPEvents<FastMCPSessionAuth>
T

Parameters

Parameter	Type
this	T
event	P
listener	(...args: any[]) => any

Returns

T

Inherited from

FastMCPEventEmitter.removeListener

Call Signature

removeListener(event: typeof assignmentCompatibilityHack, listener: (...args: any[]) => any): void;

Defined in: node_modules/.pnpm/strict-event-emitter-types@2.0.0/node_modules/strict-event-emitter-types/types/src/index.d.ts:22

Parameters

Parameter	Type
event	typeof assignmentCompatibilityHack
listener	(...args: any[]) => any

Returns

void

Inherited from

FastMCPEventEmitter.removeListener

---

setMaxListeners()

setMaxListeners(n: number): this;

Defined in: node_modules/.pnpm/@types+node@20.19.19/node_modules/@types/node/events.d.ts:814

By default EventEmitters will print a warning if more than 10 listeners are added for a particular event. This is a useful default that helps finding memory leaks. The emitter.setMaxListeners() method allows the limit to be modified for this specific EventEmitter instance. The value can be set to Infinity (or 0) to indicate an unlimited number of listeners.

Returns a reference to the EventEmitter, so that calls can be chained.

Parameters

Parameter	Type
n	number

Returns

this

Since

v0.3.5

Inherited from

FastMCPEventEmitter.setMaxListeners

---

start()

start(options: 
  | {
  transportType: "stdio";
}
  | {
  sse: {
     endpoint: `/${string}`;
     port: number;
  };
  transportType: "sse";
}): Promise<void>;

Defined in: packages/mcp/src/mcpServer.ts:1295

Starts the server.

Parameters

Parameter	Type	Description
options	| { transportType: "stdio"; } | { sse: { endpoint: `/$\{string\}`; port: number; }; transportType: "sse"; }	Options for the server transport

Returns

Promise<void>

---

stop()

stop(): Promise<void>;

Defined in: packages/mcp/src/mcpServer.ts:1335

Stops the server.

Returns

Promise<void>