import type { NodeStreamableHTTPServerTransport } from '@modelcontextprotocol/node';
import type { McpServer } from '@modelcontextprotocol/server';
export interface SessionModel {
id: string;
createdAt: number;
lastActivity: number;
requestCount: number;
notes: string[];
}
export interface SessionRuntime {
session: SessionModel;
server: McpServer;
transport: NodeStreamableHTTPServerTransport;
}
export interface SessionSummary {
id: string;
createdAt: number;
lastActivity: number;
requestCount: number;
noteCount: number;
}
export class SessionRegistry {
private readonly sessions = new Map<string, SessionRuntime>();
constructor(private readonly sessionTtlMs: number) {}
set(runtime: SessionRuntime): void {
this.sessions.set(runtime.session.id, runtime);
}
get(sessionId: string): SessionRuntime | undefined {
return this.sessions.get(sessionId);
}
count(): number {
return this.sessions.size;
}
touch(sessionId: string): void {
const runtime = this.sessions.get(sessionId);
if (!runtime) {
return;
}
runtime.session.lastActivity = Date.now();
runtime.session.requestCount += 1;
}
summaries(): SessionSummary[] {
return [...this.sessions.values()].map((runtime) => ({
id: runtime.session.id,
createdAt: runtime.session.createdAt,
lastActivity: runtime.session.lastActivity,
requestCount: runtime.session.requestCount,
noteCount: runtime.session.notes.length,
}));
}
async remove(sessionId: string): Promise<void> {
const runtime = this.sessions.get(sessionId);
if (!runtime) {
return;
}
this.sessions.delete(sessionId);
await this.closeRuntime(runtime);
}
async closeExpired(now: number = Date.now()): Promise<string[]> {
const expired = [...this.sessions.values()]
.filter((runtime) => now - runtime.session.lastActivity > this.sessionTtlMs)
.map((runtime) => runtime.session.id);
for (const sessionId of expired) {
await this.remove(sessionId);
}
return expired;
}
async closeAll(): Promise<void> {
for (const sessionId of [...this.sessions.keys()]) {
await this.remove(sessionId);
}
}
private async closeRuntime(runtime: SessionRuntime): Promise<void> {
runtime.transport.onclose = undefined;
await Promise.allSettled([runtime.transport.close(), runtime.server.close()]);
}
}
