/**
* ListChanged notification system for MCP protocol
* Emits notifications when tools, resources, or prompts lists change
*/
import { Server } from "@modelcontextprotocol/sdk/server/index.js";
import { createLogger } from "../utils/logger.js";
const logger = createLogger("usql-mcp:notifications:list-changed");
type ListType = "tools" | "resources" | "prompts";
class ListChangedNotifier {
private server: Server | null = null;
/**
* Initialize the notifier with a server instance
*/
initialize(server: Server): void {
this.server = server;
logger.debug("[list-changed] Initialized with server");
}
/**
* Emit a list changed notification
*/
async notifyListChanged(listType: ListType): Promise<void> {
if (!this.server) {
logger.warn("[list-changed] Cannot notify, server not initialized");
return;
}
const method = `notifications/${listType}/list_changed`;
logger.debug("[list-changed] Emitting notification", { method, listType });
try {
await this.server.notification({
method,
});
} catch (error) {
logger.error("[list-changed] Error sending notification", { method, error });
}
}
/**
* Notify that tools list has changed
*/
async notifyToolsChanged(): Promise<void> {
await this.notifyListChanged("tools");
}
/**
* Notify that resources list has changed
*/
async notifyResourcesChanged(): Promise<void> {
await this.notifyListChanged("resources");
}
/**
* Notify that prompts list has changed
*/
async notifyPromptsChanged(): Promise<void> {
await this.notifyListChanged("prompts");
}
}
// Singleton instance
const notifier = new ListChangedNotifier();
export function initializeListChangedNotifier(server: Server): void {
notifier.initialize(server);
}
export function notifyToolsChanged(): Promise<void> {
return notifier.notifyToolsChanged();
}
export function notifyResourcesChanged(): Promise<void> {
return notifier.notifyResourcesChanged();
}
export function notifyPromptsChanged(): Promise<void> {
return notifier.notifyPromptsChanged();
}
