feat(#709): add configured Discord interaction binding

apps/gateway/src/chat/chat.gateway.ts

@@ -13,6 +13,8 @@ import { Server, Socket } from 'socket.io';
 import type { AgentSessionEvent } from '@mariozechner/pi-coding-agent';
 import {
   verifyDiscordIngressEnvelope,
+  parseDiscordInteractionBindings,
+  resolveDiscordInteractionBinding,
   type DiscordIngressEnvelope,
   type DiscordIngressPayload,
 } from '@mosaicstack/discord-plugin';
@@ -654,6 +656,24 @@ export class ChatGateway implements OnGatewayInit, OnGatewayConnection, OnGatewa
       this.logger.warn(`Rejected invalid Discord ingress envelope from ${client.id}`);
       return null;
     }
+    try {
+      const binding = resolveDiscordInteractionBinding(
+        parseDiscordInteractionBindings(process.env['DISCORD_INTERACTION_BINDINGS']),
+        payload.guildId,
+        payload.channelId,
+        payload.userId,
+        'send',
+      );
+      if (!binding) {
+        this.logger.warn(`Rejected unpaired Discord ingress from ${client.id}`);
+        return null;
+      }
+    } catch {
+      this.logger.warn(
+        `Rejected Discord ingress without valid binding configuration from ${client.id}`,
+      );
+      return null;
+    }
     if (!this.discordReplayProtector.claim(payload.messageId)) {
       this.logger.warn(
         `Rejected replayed Discord message=${payload.messageId} correlation=${payload.correlationId}`,

apps/gateway/src/plugin/discord-ingress.security.spec.ts

@@ -3,6 +3,7 @@ import {
   createDiscordIngressEnvelope,
   verifyDiscordIngressEnvelope,
   type DiscordIngressPayload,
+  resolveDiscordInteractionBinding,
 } from '@mosaicstack/discord-plugin';
 import { validateDiscordServiceToken } from '../chat/chat.gateway-auth.js';
 import { DiscordReplayProtector } from './discord-replay-protector.js';
@@ -23,6 +24,25 @@ function createPayload(overrides: Partial<DiscordIngressPayload> = {}): DiscordI
 }
 
 describe('Discord ingress security', () => {
+  it('binds a differently named configured interaction instance without code changes', () => {
+    const binding = resolveDiscordInteractionBinding(
+      [
+        {
+          instanceId: 'Nova',
+          guildId: 'guild-001',
+          channelId: 'channel-001',
+          pairedUsers: { 'user-001': 'operator' },
+        },
+      ],
+      'guild-001',
+      'channel-001',
+      'user-001',
+      'send',
+    );
+
+    expect(binding?.instanceId).toBe('Nova');
+  });
+
   it('accepts only the configured Discord service identity', () => {
     expect(validateDiscordServiceToken(SERVICE_TOKEN, SERVICE_TOKEN)).toBe(true);
     expect(validateDiscordServiceToken('wrong-service-token', SERVICE_TOKEN)).toBe(false);

apps/gateway/src/plugin/plugin.module.ts

@@ -6,7 +6,7 @@ import {
   type OnModuleDestroy,
   type OnModuleInit,
 } from '@nestjs/common';
-import { DiscordPlugin } from '@mosaicstack/discord-plugin';
+import { DiscordPlugin, parseDiscordInteractionBindings } from '@mosaicstack/discord-plugin';
 import { TelegramPlugin } from '@mosaicstack/telegram-plugin';
 import { PluginService } from './plugin.service.js';
 import type { IChannelPlugin } from './plugin.interface.js';
@@ -85,6 +85,9 @@ function createPluginRegistry(): IChannelPlugin[] {
           allowedGuildIds: requiredDiscordAllowlist('DISCORD_ALLOWED_GUILD_IDS'),
           allowedChannelIds: requiredDiscordAllowlist('DISCORD_ALLOWED_CHANNEL_IDS'),
           allowedUserIds: requiredDiscordAllowlist('DISCORD_ALLOWED_USER_IDS'),
+          interactionBindings: parseDiscordInteractionBindings(
+            process.env['DISCORD_INTERACTION_BINDINGS'],
+          ),
         }),
       ),
     );