/**
* Session management for HTTP transport
*/
import type { Transport } from "@modelcontextprotocol/sdk/shared/transport.js";
/**
* Session entry stored in the session store
*/
export interface SessionEntry {
/** The transport instance for this session */
transport: Transport;
/** Timestamp when the session was created */
createdAt: number;
/** Timestamp of last activity on this session */
lastActivity: number;
}
/**
* Session store for managing HTTP transport sessions
* Provides storage, retrieval, and cleanup of session data
*/
export class SessionStore {
private sessions: Map<string, SessionEntry>;
constructor() {
this.sessions = new Map();
}
/**
* Get a session by ID
* @param sessionId - The session identifier
* @returns The session entry or undefined if not found
*/
get(sessionId: string): SessionEntry | undefined {
return this.sessions.get(sessionId);
}
/**
* Get a transport by session ID
* @param sessionId - The session identifier
* @returns The transport or undefined if not found
*/
getTransport(sessionId: string): Transport | undefined {
return this.sessions.get(sessionId)?.transport;
}
/**
* Store a session
* @param sessionId - The session identifier
* @param entry - The session entry to store
*/
set(sessionId: string, entry: SessionEntry): void {
this.sessions.set(sessionId, entry);
}
/**
* Delete a session by ID
* @param sessionId - The session identifier
* @returns true if the session was deleted, false if not found
*/
delete(sessionId: string): boolean {
return this.sessions.delete(sessionId);
}
/**
* Check if a session exists
* @param sessionId - The session identifier
* @returns true if the session exists
*/
has(sessionId: string): boolean {
return this.sessions.has(sessionId);
}
/**
* Get the number of active sessions
* @returns The session count
*/
get size(): number {
return this.sessions.size;
}
/**
* Update the last activity timestamp for a session
* @param sessionId - The session identifier
*/
touch(sessionId: string): void {
const entry = this.sessions.get(sessionId);
if (entry) {
entry.lastActivity = Date.now();
}
}
/**
* Helper to close a transport and collect its promise
* @param transport - The transport to close
* @param closePromises - Array to collect close promises
*/
private closeTransport(
transport: Transport,
closePromises: Promise<void>[],
): void {
try {
const closeResult = transport.close?.();
if (closeResult instanceof Promise) {
closePromises.push(closeResult);
}
} catch {
// Ignore errors during close
}
}
/**
* Clean up expired sessions based on max age
* @param maxAge - Maximum age in milliseconds before session expires
* @returns Array of session IDs that were cleaned up
*/
async cleanup(maxAge: number): Promise<string[]> {
const now = Date.now();
const expiredIds: string[] = [];
for (const [sessionId, entry] of this.sessions) {
if (now - entry.lastActivity > maxAge) {
expiredIds.push(sessionId);
}
}
const closePromises: Promise<void>[] = [];
for (const sessionId of expiredIds) {
const entry = this.sessions.get(sessionId);
if (entry) {
this.closeTransport(entry.transport, closePromises);
this.sessions.delete(sessionId);
}
}
// Wait for all transports to close
await Promise.allSettled(closePromises);
return expiredIds;
}
/**
* Close all sessions and clear the store
*/
async closeAll(): Promise<void> {
const closePromises: Promise<void>[] = [];
for (const [_sessionId, entry] of this.sessions) {
this.closeTransport(entry.transport, closePromises);
}
// Wait for all transports to close
await Promise.allSettled(closePromises);
this.sessions.clear();
}
/**
* Get all session IDs
* @returns Array of session IDs
*/
getAllSessionIds(): string[] {
return Array.from(this.sessions.keys());
}
}
