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'],
+          ),
         }),
       ),
     );

plugins/discord/src/index.ts

@@ -12,6 +12,75 @@ export interface DiscordPluginConfig {
   allowedGuildIds: readonly string[];
   allowedChannelIds: readonly string[];
   allowedUserIds: readonly string[];
+  /** Provisioned interaction bindings; instance identity is configuration, never code. */
+  interactionBindings?: readonly DiscordInteractionBinding[];
+}
+
+export type DiscordInteractionOperation = 'bind' | 'attach' | 'send' | 'approve';
+export type DiscordInteractionRole = 'viewer' | 'operator' | 'admin';
+
+export interface DiscordInteractionBinding {
+  instanceId: string;
+  guildId: string;
+  channelId: string;
+  /** Pairing roster keyed by Discord user ID. */
+  pairedUsers: Readonly<Record<string, DiscordInteractionRole>>;
+}
+
+const operationRoles: Readonly<
+  Record<DiscordInteractionOperation, readonly DiscordInteractionRole[]>
+> = {
+  bind: ['admin'],
+  attach: ['operator', 'admin'],
+  send: ['operator', 'admin'],
+  approve: ['admin'],
+};
+
+/** Resolves a configuration-owned binding and applies pairing/RBAC before ingress. */
+export function resolveDiscordInteractionBinding(
+  bindings: readonly DiscordInteractionBinding[],
+  guildId: string,
+  channelId: string,
+  userId: string,
+  operation: DiscordInteractionOperation,
+): DiscordInteractionBinding | null {
+  const binding = bindings.find(
+    (candidate) => candidate.guildId === guildId && candidate.channelId === channelId,
+  );
+  if (!binding) return null;
+  const role = binding.pairedUsers[userId];
+  return role && operationRoles[operation].includes(role) ? binding : null;
+}
+
+/** Parses provisioned binding roster JSON and rejects malformed or empty data. */
+export function parseDiscordInteractionBindings(
+  value: string | undefined,
+): DiscordInteractionBinding[] {
+  if (!value) throw new Error('DISCORD_INTERACTION_BINDINGS is required when Discord is enabled');
+  const parsed: unknown = JSON.parse(value);
+  if (!Array.isArray(parsed) || parsed.length === 0) {
+    throw new Error('DISCORD_INTERACTION_BINDINGS must be a non-empty JSON array');
+  }
+  return parsed.map((binding: unknown): DiscordInteractionBinding => {
+    if (typeof binding !== 'object' || binding === null)
+      throw new Error('Invalid Discord interaction binding');
+    const candidate = binding as Partial<DiscordInteractionBinding>;
+    if (
+      !candidate.instanceId ||
+      !candidate.guildId ||
+      !candidate.channelId ||
+      !candidate.pairedUsers ||
+      typeof candidate.pairedUsers !== 'object'
+    ) {
+      throw new Error('Invalid Discord interaction binding');
+    }
+    return {
+      instanceId: candidate.instanceId,
+      guildId: candidate.guildId,
+      channelId: candidate.channelId,
+      pairedUsers: candidate.pairedUsers,
+    };
+  });
 }
 
 export interface DiscordIngressPayload {
@@ -22,6 +91,15 @@ export interface DiscordIngressPayload {
   userId: string;
   conversationId: string;
   content: string;
+  threadId?: string;
+  attachments?: readonly DiscordAttachment[];
+}
+
+export interface DiscordAttachment {
+  id: string;
+  name: string;
+  url: string;
+  contentType: string | null;
 }
 
 export interface DiscordIngressEnvelope {
@@ -44,6 +122,8 @@ function signedPayload(payload: DiscordIngressPayload): string {
     payload.userId,
     payload.conversationId,
     payload.content,
+    payload.threadId ?? '',
+    JSON.stringify(payload.attachments ?? []),
   ].join('\n');
 }
 
@@ -214,7 +294,18 @@ export class DiscordPlugin {
     }
 
     const channelId = message.channelId;
-    const conversationId = this.channelConversations.get(channelId) ?? `discord-${channelId}`;
+    const parentChannelId = 'parentId' in message.channel ? message.channel.parentId : null;
+    const bindingChannelId = parentChannelId ?? channelId;
+    const binding = resolveDiscordInteractionBinding(
+      this.config.interactionBindings ?? [],
+      message.guildId,
+      bindingChannelId,
+      message.author.id,
+      'send',
+    );
+    if (!binding) return;
+    const conversationId =
+      this.channelConversations.get(channelId) ?? `${binding.instanceId}:discord:${channelId}`;
     this.channelConversations.set(channelId, conversationId);
 
     const envelope = createDiscordIngressEnvelope(
@@ -222,10 +313,17 @@ export class DiscordPlugin {
         correlationId: randomUUID(),
         messageId: message.id,
         guildId: message.guildId,
-        channelId,
+        channelId: bindingChannelId,
         userId: message.author.id,
         conversationId,
         content,
+        threadId: parentChannelId ? channelId : undefined,
+        attachments: Array.from(message.attachments.values()).map((attachment) => ({
+          id: attachment.id,
+          name: attachment.name,
+          url: attachment.url,
+          contentType: attachment.contentType,
+        })),
       },
       this.config.serviceToken,
     );