fix: enforce requireMention setting for Feishu group chats

The `bridge_feishu_require_mention` setting existed in the config UI
and was loaded from the database, but was never actually checked in
the message handling pipeline. Group chat messages were always
processed regardless of whether the bot was @mentioned.

Changes:
- Fetch bot identity (open_id) on plugin startup via getBotInfo()
- Check `message.mentions` against botOpenId when requireMention is
  enabled and the message comes from a group chat (chatId starts
  with 'oc_')
- Strip the @bot mention placeholder from message text so the LLM
  receives clean input
- Return null (skip message) when requireMention is true and the
  bot is not mentioned

Author: yan-labs

src/lib/channels/feishu/inbound.ts

@@ -9,10 +9,22 @@ import type { FeishuConfig } from './types';
 
 const LOG_TAG = '[feishu/inbound]';
 
+/**
+ * Check whether the bot is mentioned in the message's mentions array.
+ *
+ * Feishu events include `message.mentions` — an array of objects with
+ * `{ id: { open_id }, key, name }` for each @-mention in the message.
+ */
+function isBotMentioned(mentions: any[] | undefined, botOpenId: string): boolean {
+  if (!mentions || !Array.isArray(mentions) || !botOpenId) return false;
+  return mentions.some((m) => m?.id?.open_id === botOpenId);
+}
+
 /** Parse a raw Feishu im.message.receive_v1 event into an InboundMessage. */
 export function parseInboundMessage(
   eventData: any,
-  _config: FeishuConfig,
+  config: FeishuConfig,
+  botOpenId?: string,
 ): InboundMessage | null {
   try {
     const event = eventData?.event ?? eventData;
@@ -24,6 +36,15 @@ export function parseInboundMessage(
     const sender = event.sender?.sender_id?.open_id || '';
     const msgType = message.message_type;
 
+    // In group chats, skip messages that don't @mention the bot
+    // when requireMention is enabled.
+    const isGroupChat = chatId.startsWith('oc_');
+    if (isGroupChat && config.requireMention) {
+      if (!isBotMentioned(message.mentions, botOpenId || '')) {
+        return null;
+      }
+    }
+
     // Only handle text messages for now
     let text = '';
     if (msgType === 'text') {
@@ -40,6 +61,17 @@ export function parseInboundMessage(
 
     if (!text.trim()) return null;
 
+    // Strip the @bot mention placeholder from text so the LLM sees clean input.
+    // Feishu encodes mentions as placeholders like "@_user_1" in the text body.
+    if (isGroupChat && botOpenId && message.mentions) {
+      const botMention = (message.mentions as any[]).find(
+        (m) => m?.id?.open_id === botOpenId,
+      );
+      if (botMention?.key) {
+        text = text.replace(botMention.key, '').trim();
+      }
+    }
+
     // Build thread-session address if applicable
     const rootId = message.root_id || '';
     const effectiveChatId = rootId ? `${chatId}:thread:${rootId}` : chatId;

src/lib/channels/feishu/index.ts

@@ -11,6 +11,7 @@ import type { FeishuConfig } from './types';
 import { loadFeishuConfig, validateFeishuConfig } from './config';
 import { FeishuGateway } from './gateway';
 import { parseInboundMessage } from './inbound';
+import { getBotInfo } from './identity';
 import { sendMessage, addReaction, removeReaction } from './outbound';
 import { isUserAuthorized } from './policy';
 import { createCardStreamController } from './card-controller';
@@ -23,6 +24,7 @@ export class FeishuChannelPlugin implements ChannelPlugin<FeishuConfig> {
 
   private config: FeishuConfig | null = null;
   private gateway: FeishuGateway | null = null;
+  private botOpenId: string = '';
   private messageQueue: InboundMessage[] = [];
   private waitResolve: ((msg: InboundMessage | null) => void) | null = null;
   /** Track last received messageId per chatId for reaction acknowledgment. */
@@ -66,7 +68,7 @@ export class FeishuChannelPlugin implements ChannelPlugin<FeishuConfig> {
 
     // Register message handler — pushes to internal queue
     this.gateway.registerMessageHandler((data: unknown) => {
-      const msg = parseInboundMessage(data, this.config!);
+      const msg = parseInboundMessage(data, this.config!, this.botOpenId);
       if (!msg) return;
       this.enqueueMessage(msg);
     });
@@ -148,6 +150,16 @@ export class FeishuChannelPlugin implements ChannelPlugin<FeishuConfig> {
     });
 
     await this.gateway.start();
+
+    // Fetch bot identity so we can check @mentions in group chats.
+    const client = this.gateway.getRestClient();
+    if (client) {
+      const info = await getBotInfo(client);
+      if (info?.openId) {
+        this.botOpenId = info.openId;
+        console.log('[feishu/plugin]', 'Bot identity resolved:', info.botName, info.openId);
+      }
+    }
   }
 
   async stop(): Promise<void> {