feat(gateway): Discord channel auto-creation on project bootstrap (#200)

Co-authored-by: Jason Woltje <jason@diversecanvas.com>
Co-committed-by: Jason Woltje <jason@diversecanvas.com>

apps/gateway/src/plugin/plugin.interface.ts

@@ -2,4 +2,10 @@ export interface IChannelPlugin {
   readonly name: string;
   start(): Promise<void>;
   stop(): Promise<void>;
+  /** Called when a new project is bootstrapped. Return channelId if a channel was created. */
+  onProjectCreated?(project: {
+    id: string;
+    name: string;
+    description?: string;
+  }): Promise<{ channelId: string } | null>;
 }

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

@@ -24,6 +24,14 @@ class DiscordChannelPluginAdapter implements IChannelPlugin {
   async stop(): Promise<void> {
     await this.plugin.stop();
   }
+
+  async onProjectCreated(project: {
+    id: string;
+    name: string;
+    description?: string;
+  }): Promise<{ channelId: string } | null> {
+    return this.plugin.createProjectChannel(project);
+  }
 }
 
 class TelegramChannelPluginAdapter implements IChannelPlugin {

apps/gateway/src/workspace/project-bootstrap.service.ts

@@ -1,6 +1,7 @@
 import { Inject, Injectable, Logger } from '@nestjs/common';
 import type { Brain } from '@mosaic/brain';
 import { BRAIN } from '../brain/brain.tokens.js';
+import { PluginService } from '../plugin/plugin.service.js';
 import { WorkspaceService } from './workspace.service.js';
 
 export interface BootstrapProjectParams {
@@ -23,6 +24,7 @@ export class ProjectBootstrapService {
   constructor(
     @Inject(BRAIN) private readonly brain: Brain,
     private readonly workspace: WorkspaceService,
+    private readonly pluginService: PluginService,
   ) {}
 
   /**
@@ -67,6 +69,28 @@ export class ProjectBootstrapService {
       status: 'active',
     });
 
+    // 4. Notify plugins so they can set up project-specific resources (e.g. Discord channel)
+    try {
+      for (const plugin of this.pluginService.getPlugins()) {
+        if (plugin.onProjectCreated) {
+          const result = await plugin.onProjectCreated({
+            id: project.id,
+            name: params.name,
+            description: params.description,
+          });
+          if (result?.channelId) {
+            await this.brain.projects.update(project.id, {
+              metadata: { discordChannelId: result.channelId },
+            });
+          }
+        }
+      }
+    } catch (err) {
+      this.logger.warn(
+        `Plugin project notification failed: ${err instanceof Error ? err.message : String(err)}`,
+      );
+    }
+
     this.logger.log(`Project ${project.id} bootstrapped at ${workspacePath}`);
 
     return { projectId: project.id, workspacePath };

plugins/discord/src/index.ts

@@ -1,4 +1,4 @@
-import { Client, GatewayIntentBits, type Message as DiscordMessage } from 'discord.js';
+import { ChannelType, Client, GatewayIntentBits, type Message as DiscordMessage } from 'discord.js';
 import { io, type Socket } from 'socket.io-client';
 
 export interface DiscordPluginConfig {
@@ -86,6 +86,34 @@ export class DiscordPlugin {
     await this.client.destroy();
   }
 
+  async createProjectChannel(project: {
+    id: string;
+    name: string;
+    description?: string;
+  }): Promise<{ channelId: string } | null> {
+    if (!this.config.guildId) return null;
+
+    const guild = this.client.guilds.cache.get(this.config.guildId);
+    if (!guild) return null;
+
+    // Slugify project name for channel: lowercase, replace spaces/special chars with hyphens
+    const channelName = `mosaic-${project.name
+      .toLowerCase()
+      .replace(/[^a-z0-9]+/g, '-')
+      .replace(/^-|-$/g, '')}`;
+
+    const channel = await guild.channels.create({
+      name: channelName,
+      type: ChannelType.GuildText,
+      topic: project.description ?? `Mosaic project: ${project.name}`,
+    });
+
+    // Register the channel mapping so messages route correctly
+    this.channelConversations.set(channel.id, `discord-${channel.id}`);
+
+    return { channelId: channel.id };
+  }
+
   private handleDiscordMessage(message: DiscordMessage): void {
     // Ignore bot messages
     if (message.author.bot) return;