fix(mom): private channel messages not being logged

- Add message.groups to required bot events in README
- Add groups:history and groups:read to required scopes in README
- app_mention handler now logs messages directly instead of relying on message event
- Add deduplication in ChannelStore.logMessage() to prevent double-logging
- Remove redundant current message append in agent.ts (already in log)

packages/mom/src/agent.ts

@@ -364,15 +364,7 @@ export function createAgentRunner(sandboxConfig: SandboxConfig): AgentRunner {
 
 			const channelId = ctx.message.channel;
 			const workspacePath = executor.getWorkspacePath(channelDir.replace(`/${channelId}`, ""));
-			const recentMessagesFromLog = getRecentMessages(channelDir, 50);
-
-			// Append the current message (may not be in log yet due to race condition
-			// between app_mention and message events)
-			const currentMsgDate = new Date(parseFloat(ctx.message.ts) * 1000).toISOString().substring(0, 19);
-			const currentMsgUser = ctx.message.userName || ctx.message.user;
-			const currentMsgAttachments = ctx.message.attachments.map((a) => a.local).join(",");
-			const currentMsgLine = `${currentMsgDate}\t${currentMsgUser}\t${ctx.message.rawText}\t${currentMsgAttachments}`;
-			const recentMessages = recentMessagesFromLog + "\n" + currentMsgLine;
+			const recentMessages = getRecentMessages(channelDir, 50);
 
 			const memory = getMemory(channelDir);
 			const systemPrompt = buildSystemPrompt(

packages/mom/src/slack.ts

@@ -208,7 +208,6 @@ export class MomBot {
 
 	private setupEventHandlers(): void {
 		// Handle @mentions in channels
-		// Note: We don't log here - the message event handler logs all messages
 		this.socketClient.on("app_mention", async ({ event, ack }) => {
 			await ack();
 
@@ -220,6 +219,15 @@ export class MomBot {
 				files?: Array<{ name: string; url_private_download?: string; url_private?: string }>;
 			};
 
+			// Log the mention message (message event may not fire for all channel types)
+			await this.logMessage({
+				text: slackEvent.text,
+				channel: slackEvent.channel,
+				user: slackEvent.user,
+				ts: slackEvent.ts,
+				files: slackEvent.files,
+			});
+
 			const ctx = await this.createContext(slackEvent);
 			await this.handler.onChannelMention(ctx);
 		});

packages/mom/src/store.ts

@@ -35,6 +35,9 @@ export class ChannelStore {
 	private botToken: string;
 	private pendingDownloads: PendingDownload[] = [];
 	private isDownloading = false;
+	// Track recently logged message timestamps to prevent duplicates
+	// Key: "channelId:ts", automatically cleaned up after 60 seconds
+	private recentlyLogged = new Map<string, number>();
 
 	constructor(config: ChannelStoreConfig) {
 		this.workingDir = config.workingDir;
@@ -107,8 +110,19 @@ export class ChannelStore {
 
 	/**
 	 * Log a message to the channel's log.jsonl
+	 * Returns false if message was already logged (duplicate)
 	 */
-	async logMessage(channelId: string, message: LoggedMessage): Promise<void> {
+	async logMessage(channelId: string, message: LoggedMessage): Promise<boolean> {
+		// Check for duplicate (same channel + timestamp)
+		const dedupeKey = `${channelId}:${message.ts}`;
+		if (this.recentlyLogged.has(dedupeKey)) {
+			return false; // Already logged
+		}
+
+		// Mark as logged and schedule cleanup after 60 seconds
+		this.recentlyLogged.set(dedupeKey, Date.now());
+		setTimeout(() => this.recentlyLogged.delete(dedupeKey), 60000);
+
 		const logPath = join(this.getChannelDir(channelId), "log.jsonl");
 
 		// Ensure message has a date field
@@ -127,6 +141,7 @@ export class ChannelStore {
 
 		const line = JSON.stringify(message) + "\n";
 		await appendFile(logPath, line, "utf-8");
+		return true;
 	}
 
 	/**