rpg-mcp

import { z } from 'zod'; import { PubSub } from '../engine/pubsub.js'; import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js'; import { withSession } from './types.js'; export const EventTools = { SUBSCRIBE: { name: 'subscribe_to_events', description: 'Subscribe to real-time events on world or combat topics. Events sent as JSON-RPC notifications.', inputSchema: z.object({ topics: z.array(z.enum(['world', 'combat'])).min(1) }) } } as const; // Track subscriptions per session const activeSubscriptions: Map<string, Array<() => void>> = new Map(); export function registerEventTools(server: McpServer, pubsub: PubSub) { server.tool( EventTools.SUBSCRIBE.name, EventTools.SUBSCRIBE.description, EventTools.SUBSCRIBE.inputSchema.extend({ sessionId: z.string().optional() }).shape, withSession(EventTools.SUBSCRIBE.inputSchema, async (args, ctx) => { const { sessionId } = ctx; // Clean up previous subscriptions for this session const existing = activeSubscriptions.get(sessionId) || []; existing.forEach(unsub => unsub()); const newSubs: Array<() => void> = []; for (const topic of args.topics) { const unsub = pubsub.subscribe(topic, (payload) => { server.server.notification({ method: 'notifications/rpg/event', params: { topic, payload, sessionId // Optional: include sessionId in notification so client knows which session it's for } }); }); newSubs.push(unsub); } activeSubscriptions.set(sessionId, newSubs); return { content: [{ type: 'text', text: `Subscribed to topics: ${args.topics.join(', ')}` }] }; }) ); // Add unsubscribe tool const unsubscribeSchema = z.object({}); server.tool( 'unsubscribe_from_events', 'Unsubscribe from all event topics', unsubscribeSchema.extend({ sessionId: z.string().optional() }).shape, withSession(unsubscribeSchema, async (_args, ctx) => { const { sessionId } = ctx; const subs = activeSubscriptions.get(sessionId) || []; subs.forEach(unsub => unsub()); activeSubscriptions.delete(sessionId); return { content: [{ type: 'text', text: 'Unsubscribed from all topics' }] }; }) ); }