feat(chat): add fetchLid endpoint for PN to LID resolution (EvolutionAPI#2483)

Adds POST /fetchLid endpoint that resolves a phone number (PN) to its
Linked Identity Device (LID) using Baileys signalRepository.

Upstream PR: EvolutionAPI#2483

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: possebon

src/api/controllers/chat.controller.ts

@@ -50,6 +50,10 @@ export class ChatController {
     return await this.waMonitor.waInstances[instanceName].fetchProfile(instanceName, data.number);
   }
 
+  public async fetchLid({ instanceName }: InstanceDto, data: NumberDto) {
+    return await this.waMonitor.waInstances[instanceName].getLid(data.number);
+  }
+
   public async fetchContacts({ instanceName }: InstanceDto, query: Query<Contact>) {
     return await this.waMonitor.waInstances[instanceName].fetchContacts(query);
   }

src/api/integrations/channel/whatsapp/whatsapp.baileys.service.ts

@@ -2054,6 +2054,22 @@ export class BaileysStartupService extends ChannelStartupService {
     }
   }
 
+  public async getLid(number: string) {
+    const jid = createJid(number);
+
+    if (!this.client?.signalRepository) {
+      return { wuid: jid, lid: null };
+    }
+
+    try {
+      const lid = await this.client.signalRepository.lidMapping.getLIDForPN(jid);
+      return { wuid: jid, lid: lid || null };
+    } catch (error) {
+      console.error(`Failed to fetch LID for ${jid}:`, error);
+      return { wuid: jid, lid: null };
+    }
+  }
+
   public async getStatus(number: string) {
     const jid = createJid(number);
 

src/api/routes/chat.router.ts

@@ -24,6 +24,7 @@ import {
   blockUserSchema,
   contactValidateSchema,
   deleteMessageSchema,
+  fetchLidSchema,
   markChatUnreadSchema,
   messageUpSchema,
   messageValidateSchema,
@@ -222,6 +223,16 @@ export class ChatRouter extends RouterBroker {
 
         return res.status(HttpStatus.OK).json(response);
       })
+      .post(this.routerPath('fetchLid'), ...guards, async (req, res) => {
+        const response = await this.dataValidate<NumberDto>({
+          request: req,
+          schema: fetchLidSchema,
+          ClassRef: NumberDto,
+          execute: (instance, data) => chatController.fetchLid(instance, data),
+        });
+
+        return res.status(HttpStatus.OK).json(response);
+      })
       .post(this.routerPath('updateProfileName'), ...guards, async (req, res) => {
         const response = await this.dataValidate<ProfileNameDto>({
           request: req,

src/validate/chat.schema.ts

@@ -316,3 +316,12 @@ export const profileSchema: JSONSchema7 = {
     isBusiness: { type: 'boolean' },
   },
 };
+
+export const fetchLidSchema: JSONSchema7 = {
+  $id: v4(),
+  type: 'object',
+  properties: {
+    number: { type: 'string' },
+  },
+  required: ['number'],
+};