Add: LID support with lid-map and migrations of sessions (#1694)

* fix: add lid-map logic

* fix: lint and simplified version

* fix: single device migration

* fix: lid map discovery

* fix: lint

* fix: lid migration in socket connection

* fix: lint

* fix: decode-wa-message consistency

* fix: yarn lock

* fix: lint

* fix: retry logic

* fix: logger level

package.json

@@ -69,6 +69,7 @@
     "jiti": "^2.4.2",
     "json": "^11.0.0",
     "link-preview-js": "^3.0.0",
+    "lru-cache": "^10.4.3",
     "open": "^8.4.2",
     "prettier": "^3.5.3",
     "protobufjs-cli": "^1.1.3",

src/Signal/libsignal.ts

@@ -1,6 +1,8 @@
 /* @ts-ignore */
 import * as libsignal from 'libsignal'
-import type { SignalAuthState } from '../Types'
+/* @ts-ignore */
+import { LRUCache } from 'lru-cache'
+import type { SignalAuthState, SignalKeyStoreWithTransaction } from '../Types'
 import type { SignalRepository } from '../Types/Signal'
 import { generateSignalPubKey } from '../Utils'
 import { jidDecode } from '../WABinary'
@@ -8,10 +10,18 @@ import type { SenderKeyStore } from './Group/group_cipher'
 import { SenderKeyName } from './Group/sender-key-name'
 import { SenderKeyRecord } from './Group/sender-key-record'
 import { GroupCipher, GroupSessionBuilder, SenderKeyDistributionMessage } from './Group'
+import { LIDMappingStore } from './lid-mapping'
 
 export function makeLibSignalRepository(auth: SignalAuthState): SignalRepository {
-	const storage: SenderKeyStore = signalStorage(auth)
-	return {
+	const lidMapping = new LIDMappingStore(auth.keys as SignalKeyStoreWithTransaction)
+	const storage = signalStorage(auth, lidMapping)
+	// Simple operation-level deduplication (5 minutes)
+	const recentMigrations = new LRUCache<string, boolean>({
+		max: 500,
+		ttl: 5 * 60 * 1000
+	})
+
+	const repository: SignalRepository = {
 		decryptGroupMessage({ group, authorJid, msg }) {
 			const senderName = jidToSignalSenderKeyName(group, authorJid)
 			const cipher = new GroupCipher(storage, senderName)
@@ -58,8 +68,36 @@ export function makeLibSignalRepository(auth: SignalAuthState): SignalRepository
 
 			return result
 		},
+
 		async encryptMessage({ jid, data }) {
-			const addr = jidToSignalProtocolAddress(jid)
+			// LID SINGLE SOURCE OF TRUTH: Always prefer LID when available
+			let encryptionJid = jid
+
+			// Check for LID mapping and use it if session exists
+			if (jid.includes('@s.whatsapp.net')) {
+				const lidForPN = await lidMapping.getLIDForPN(jid)
+				if (lidForPN?.includes('@lid')) {
+					const lidAddr = jidToSignalProtocolAddress(lidForPN)
+					const { [lidAddr.toString()]: lidSession } = await auth.keys.get('session', [lidAddr.toString()])
+
+					if (lidSession) {
+						// LID session exists, use it
+						encryptionJid = lidForPN
+					} else {
+						// Try to migrate if PN session exists
+						const pnAddr = jidToSignalProtocolAddress(jid)
+						const { [pnAddr.toString()]: pnSession } = await auth.keys.get('session', [pnAddr.toString()])
+
+						if (pnSession) {
+							// Migrate PN to LID
+							await repository.migrateSession(jid, lidForPN)
+							encryptionJid = lidForPN
+						}
+					}
+				}
+			}
+
+			const addr = jidToSignalProtocolAddress(encryptionJid)
 			const cipher = new libsignal.SessionCipher(storage, addr)
 
 			const { type: sigType, body } = await cipher.encrypt(data)
@@ -91,26 +129,160 @@ export function makeLibSignalRepository(auth: SignalAuthState): SignalRepository
 		},
 		jidToSignalProtocolAddress(jid) {
 			return jidToSignalProtocolAddress(jid).toString()
+		},
+
+		async storeLIDPNMapping(lid: string, pn: string) {
+			await lidMapping.storeLIDPNMapping(lid, pn)
+		},
+
+		getLIDMappingStore() {
+			return lidMapping
+		},
+
+		async validateSession(jid: string) {
+			try {
+				const addr = jidToSignalProtocolAddress(jid)
+				const session = await storage.loadSession(addr.toString())
+
+				if (!session) {
+					return { exists: false, reason: 'no session' }
+				}
+
+				if (!session.haveOpenSession()) {
+					return { exists: false, reason: 'no open session' }
+				}
+
+				return { exists: true }
+			} catch (error) {
+				return { exists: false, reason: 'validation error' }
+			}
+		},
+
+		async deleteSession(jid: string) {
+			const addr = jidToSignalProtocolAddress(jid)
+
+			return (auth.keys as SignalKeyStoreWithTransaction).transaction(async () => {
+				await auth.keys.set({ session: { [addr.toString()]: null } })
+			})
+		},
+
+		async migrateSession(fromJid: string, toJid: string) {
+			// Only migrate PN → LID
+			if (!fromJid.includes('@s.whatsapp.net') || !toJid.includes('@lid')) {
+				return
+			}
+
+			const fromDecoded = jidDecode(fromJid)
+			const toDecoded = jidDecode(toJid)
+			if (!fromDecoded || !toDecoded) return
+
+			const deviceId = fromDecoded.device || 0
+			const migrationKey = `${fromDecoded.user}.${deviceId}→${toDecoded.user}.${deviceId}`
+
+			// Check if recently migrated (5 min window)
+			if (recentMigrations.has(migrationKey)) {
+				return
+			}
+
+			// Check if LID session already exists
+			const lidAddr = jidToSignalProtocolAddress(toJid)
+			const { [lidAddr.toString()]: lidExists } = await auth.keys.get('session', [lidAddr.toString()])
+			if (lidExists) {
+				recentMigrations.set(migrationKey, true)
+				return
+			}
+
+			return (auth.keys as SignalKeyStoreWithTransaction).transaction(async () => {
+				// Store mapping
+				await lidMapping.storeLIDPNMapping(toJid, fromJid)
+
+				// Load and copy session
+				const fromAddr = jidToSignalProtocolAddress(fromJid)
+				const fromSession = await storage.loadSession(fromAddr.toString())
+
+				if (fromSession?.haveOpenSession()) {
+					// Deep copy session to prevent reference issues
+					const sessionBytes = fromSession.serialize()
+					const copiedSession = libsignal.SessionRecord.deserialize(sessionBytes)
+
+					// Store at LID address
+					await storage.storeSession(lidAddr.toString(), copiedSession)
+
+					// Delete PN session - maintain single encryption layer
+					await auth.keys.set({ session: { [fromAddr.toString()]: null } })
+				}
+
+				recentMigrations.set(migrationKey, true)
+			})
+		},
+
+		async encryptMessageWithWire({ encryptionJid, wireJid, data }) {
+			const result = await repository.encryptMessage({ jid: encryptionJid, data })
+			return { ...result, wireJid }
+		},
+
+		destroy() {
+			recentMigrations.clear()
 		}
 	}
+
+	return repository
 }
 
 const jidToSignalProtocolAddress = (jid: string) => {
-	const { user, device } = jidDecode(jid)!
-	return new libsignal.ProtocolAddress(user, device || 0)
+	const decoded = jidDecode(jid)!
+	const { user, device, server } = decoded
+
+	// LID addresses get _1 suffix for Signal protocol
+	const signalUser = server === 'lid' ? `${user}_1` : user
+	const finalDevice = device || 0
+
+	return new libsignal.ProtocolAddress(signalUser, finalDevice)
 }
 
 const jidToSignalSenderKeyName = (group: string, user: string): SenderKeyName => {
 	return new SenderKeyName(group, jidToSignalProtocolAddress(user))
 }
 
-function signalStorage({ creds, keys }: SignalAuthState): SenderKeyStore & Record<string, any> {
+function signalStorage(
+	{ creds, keys }: SignalAuthState,
+	lidMapping: LIDMappingStore
+): SenderKeyStore & Record<string, any> {
 	return {
 		loadSession: async (id: string) => {
-			const { [id]: sess } = await keys.get('session', [id])
-			if (sess) {
-				return libsignal.SessionRecord.deserialize(sess)
+			try {
+				// LID SINGLE SOURCE OF TRUTH: Auto-redirect PN to LID if mapping exists
+				let actualId = id
+				if (id.includes('.') && !id.includes('_1')) {
+					// This is a PN signal address format (e.g., "1234567890.0")
+					// Convert back to JID to check for LID mapping
+					const parts = id.split('.')
+					const device = parts[1] || '0'
+					const pnJid = device === '0' ? `${parts[0]}@s.whatsapp.net` : `${parts[0]}:${device}@s.whatsapp.net`
+
+					const lidForPN = await lidMapping.getLIDForPN(pnJid)
+					if (lidForPN?.includes('@lid')) {
+						const lidAddr = jidToSignalProtocolAddress(lidForPN)
+						const lidId = lidAddr.toString()
+
+						// Check if LID session exists
+						const { [lidId]: lidSession } = await keys.get('session', [lidId])
+						if (lidSession) {
+							actualId = lidId
+						}
+					}
+				}
+
+				const { [actualId]: sess } = await keys.get('session', [actualId])
+
+				if (sess) {
+					return libsignal.SessionRecord.deserialize(sess)
+				}
+			} catch (e) {
+				return null
 			}
+
+			return null
 		},
 		// TODO: Replace with libsignal.SessionRecord when type exports are added to libsignal
 		storeSession: async (id: string, session: any) => {

src/Signal/lid-mapping.ts

@@ -0,0 +1,101 @@
+import type { SignalKeyStoreWithTransaction } from '../Types'
+import logger from '../Utils/logger'
+import { isJidUser, isLidUser, jidDecode } from '../WABinary'
+
+export class LIDMappingStore {
+	private readonly keys: SignalKeyStoreWithTransaction
+
+	constructor(keys: SignalKeyStoreWithTransaction) {
+		this.keys = keys
+	}
+
+	/**
+	 * Store LID-PN mapping - USER LEVEL
+	 */
+	async storeLIDPNMapping(lid: string, pn: string): Promise<void> {
+		// Validate inputs
+		if (!((isLidUser(lid) && isJidUser(pn)) || (isJidUser(lid) && isLidUser(pn)))) {
+			logger.warn(`Invalid LID-PN mapping: ${lid}, ${pn}`)
+			return
+		}
+
+		const [lidJid, pnJid] = isLidUser(lid) ? [lid, pn] : [pn, lid]
+
+		const lidDecoded = jidDecode(lidJid)
+		const pnDecoded = jidDecode(pnJid)
+
+		if (!lidDecoded || !pnDecoded) return
+
+		const pnUser = pnDecoded.user
+		const lidUser = lidDecoded.user
+
+		logger.trace(`Storing USER LID mapping: PN ${pnUser} → LID ${lidUser}`)
+
+		await this.keys.transaction(async () => {
+			await this.keys.set({
+				'lid-mapping': {
+					[pnUser]: lidUser, // "554396160286" -> "102765716062358"
+					[`${lidUser}_reverse`]: pnUser // "102765716062358_reverse" -> "554396160286"
+				}
+			})
+		})
+
+		logger.trace(`USER LID mapping stored: PN ${pnUser} → LID ${lidUser}`)
+	}
+
+	/**
+	 * Get LID for PN - Returns device-specific LID based on user mapping
+	 */
+	async getLIDForPN(pn: string): Promise<string | null> {
+		if (!isJidUser(pn)) return null
+
+		const decoded = jidDecode(pn)
+		if (!decoded) return null
+
+		// Look up user-level mapping (whatsmeow approach)
+		const pnUser = decoded.user
+		const stored = await this.keys.get('lid-mapping', [pnUser])
+		const lidUser = stored[pnUser]
+
+		if (!lidUser) {
+			logger.trace(`No LID mapping found for PN user ${pnUser}`)
+			return null
+		}
+
+		if (typeof lidUser !== 'string') return null
+
+		// Push the PN device ID to the LID to maintain device separation
+		const pnDevice = decoded.device !== undefined ? decoded.device : 0
+		const deviceSpecificLid = `${lidUser}:${pnDevice}@lid`
+
+		logger.trace(`getLIDForPN: ${pn} → ${deviceSpecificLid} (user mapping with device ${pnDevice})`)
+		return deviceSpecificLid
+	}
+
+	/**
+	 * Get PN for LID - USER LEVEL with device construction
+	 */
+	async getPNForLID(lid: string): Promise<string | null> {
+		if (!isLidUser(lid)) return null
+
+		const decoded = jidDecode(lid)
+		if (!decoded) return null
+
+		// Look up reverse user mapping
+		const lidUser = decoded.user
+		const stored = await this.keys.get('lid-mapping', [`${lidUser}_reverse`])
+		const pnUser = stored[`${lidUser}_reverse`]
+
+		if (!pnUser || typeof pnUser !== 'string') {
+			logger.trace(`No reverse mapping found for LID user: ${lidUser}`)
+			return null
+		}
+
+		// Construct device-specific PN JID
+		const lidDevice = decoded.device !== undefined ? decoded.device : 0
+		const pnJid = `${pnUser}:${lidDevice}@s.whatsapp.net`
+
+		logger.trace(`Found reverse mapping: ${lid} → ${pnJid}`)
+		return pnJid
+	}
+}

src/Socket/messages-recv.ts

@@ -816,6 +816,45 @@ export const makeMessagesRecvSocket = (config: SocketConfig) => {
 			ev.emit('chats.phoneNumberShare', { lid: node.attrs.from!, jid: node.attrs.sender_pn })
 		}
 
+		if (msg.message?.protocolMessage?.lidMigrationMappingSyncMessage?.encodedMappingPayload) {
+			try {
+				const payload = msg.message.protocolMessage.lidMigrationMappingSyncMessage.encodedMappingPayload
+				const decoded = proto.LIDMigrationMappingSyncPayload.decode(payload)
+
+				logger.debug(
+					{
+						mappingCount: decoded.pnToLidMappings?.length || 0,
+						timestamp: decoded.chatDbMigrationTimestamp
+					},
+					'Received LID migration sync message from server'
+				)
+
+				const lidMapping = signalRepository.getLIDMappingStore()
+				if (decoded.pnToLidMappings && decoded.pnToLidMappings.length > 0) {
+					for (const mapping of decoded.pnToLidMappings) {
+						const pn = `${mapping.pn}@s.whatsapp.net`
+						// Use latestLid if available, otherwise assignedLid (proper LID refresh)
+						const lidValue = mapping.latestLid || mapping.assignedLid
+						const lid = `${lidValue}@lid`
+
+						await lidMapping.storeLIDPNMapping(lid, pn)
+						logger.debug(
+							{
+								pn,
+								lid,
+								assignedLid: mapping.assignedLid,
+								latestLid: mapping.latestLid,
+								usedLatest: !!mapping.latestLid
+							},
+							'Stored server-provided PN-LID mapping'
+						)
+					}
+				}
+			} catch (error) {
+				logger.error({ error }, 'Failed to process LID migration sync message')
+			}
+		}
+
 		try {
 			await Promise.all([
 				processingMutex.mutex(async () => {

src/Socket/messages-send.ts

@@ -31,6 +31,7 @@ import {
 	unixTimestampSeconds
 } from '../Utils'
 import { getUrlInfo } from '../Utils/link-preview'
+import { makeKeyedMutex } from '../Utils/make-mutex'
 import {
 	areJidsSameUser,
 	type BinaryNode,
@@ -80,6 +81,9 @@ export const makeMessagesSocket = (config: SocketConfig) => {
 			useClones: false
 		})
 
+	// Prevent race conditions in Signal session encryption by user
+	const encryptionMutex = makeKeyedMutex()
+
 	let mediaConn: Promise<MediaConnInfo>
 	const refreshMediaConn = async (forceGet = false) => {
 		const media = await mediaConn
@@ -185,24 +189,87 @@ export const makeMessagesSocket = (config: SocketConfig) => {
 		await sendReceipts(keys, readType)
 	}
 
+	/** Device info with wire JID format for envelope addressing */
+	type DeviceWithWireJid = JidWithDevice & {
+		wireJid: string // The exact JID format that should be used in wire protocol (envelope addressing)
+	}
+
+	/**
+	 * Deduplicate JIDs when both LID and PN versions exist for same user
+	 * Prefers LID over PN to maintain single encryption layer
+	 */
+	const deduplicateLidPnJids = (jids: string[]): string[] => {
+		const lidUsers = new Set<string>()
+		const filteredJids: string[] = []
+
+		// Collect all LID users
+		for (const jid of jids) {
+			if (jid.includes('@lid')) {
+				const user = jidDecode(jid)?.user
+				if (user) lidUsers.add(user)
+			}
+		}
+
+		// Filter out PN versions when LID exists
+		for (const jid of jids) {
+			if (jid.includes('@s.whatsapp.net')) {
+				const user = jidDecode(jid)?.user
+				if (user && lidUsers.has(user)) {
+					logger.debug({ jid }, 'Skipping PN - LID version exists')
+					continue
+				}
+			}
+
+			filteredJids.push(jid)
+		}
+
+		return filteredJids
+	}
+
 	/** Fetch all the devices we've to send a message to */
-	const getUSyncDevices = async (jids: string[], useCache: boolean, ignoreZeroDevices: boolean) => {
-		const deviceResults: JidWithDevice[] = []
+	const getUSyncDevices = async (
+		jids: string[],
+		useCache: boolean,
+		ignoreZeroDevices: boolean
+	): Promise<DeviceWithWireJid[]> => {
+		const deviceResults: DeviceWithWireJid[] = []
 
 		if (!useCache) {
 			logger.debug('not using cache for devices')
 		}
 
 		const toFetch: string[] = []
-		jids = Array.from(new Set(jids))
+		// Deduplicate and normalize JIDs
+		jids = deduplicateLidPnJids(Array.from(new Set(jids)))
 
 		for (let jid of jids) {
-			const user = jidDecode(jid)?.user
+			const decoded = jidDecode(jid)
+			const user = decoded?.user
+			const device = decoded?.device
+			const isExplicitDevice = typeof device === 'number' && device >= 0
+
+			// Handle explicit device JIDs directly
+			if (isExplicitDevice && user) {
+				deviceResults.push({
+					user,
+					device,
+					wireJid: jid // Preserve exact JID format for wire protocol
+				})
+				continue
+			}
+
+			// For user JIDs, normalize and prepare for device enumeration
 			jid = jidNormalizedUser(jid)
+
 			if (useCache) {
-				const devices = userDevicesCache.get<JidWithDevice[]>(user!)
+				const devices = userDevicesCache.get(user!) as JidWithDevice[]
 				if (devices) {
-					deviceResults.push(...devices)
+					const isLidJid = jid.includes('@lid')
+					const devicesWithWire = devices.map(d => ({
+						...d,
+						wireJid: isLidJid ? jidEncode(d.user, 'lid', d.device) : jidEncode(d.user, 's.whatsapp.net', d.device)
+					}))
+					deviceResults.push(...devicesWithWire)
 
 					logger.trace({ user }, 'using cache for devices')
 				} else {
@@ -217,6 +284,14 @@ export const makeMessagesSocket = (config: SocketConfig) => {
 			return deviceResults
 		}
 
+		const requestedLidUsers = new Set<string>()
+		for (const jid of toFetch) {
+			if (jid.includes('@lid')) {
+				const user = jidDecode(jid)?.user
+				if (user) requestedLidUsers.add(user)
+			}
+		}
+
 		const query = new USyncQuery().withContext('message').withDeviceProtocol()
 
 		for (const jid of toFetch) {
@@ -232,8 +307,33 @@ export const makeMessagesSocket = (config: SocketConfig) => {
 			for (const item of extracted) {
 				deviceMap[item.user] = deviceMap[item.user] || []
 				deviceMap[item.user]?.push(item)
+			}
 
-				deviceResults.push(item)
+			// Process each user's devices as a group for bulk LID migration
+			for (const [user, userDevices] of Object.entries(deviceMap)) {
+				const isLidUser = requestedLidUsers.has(user)
+
+				// Process all devices for this user
+				for (const item of userDevices) {
+					const finalWireJid = isLidUser
+						? jidEncode(user, 'lid', item.device)
+						: jidEncode(item.user, 's.whatsapp.net', item.device)
+
+					deviceResults.push({
+						...item,
+						wireJid: finalWireJid
+					})
+
+					logger.debug(
+						{
+							user: item.user,
+							device: item.device,
+							finalWireJid,
+							usedLid: isLidUser
+						},
+						'Processed device with LID priority'
+					)
+				}
 			}
 
 			for (const key in deviceMap) {
@@ -244,24 +344,216 @@ export const makeMessagesSocket = (config: SocketConfig) => {
 		return deviceResults
 	}
 
+	// Helper to check if JID has migrated LID session
+	const checkForMigratedLidSession = async (jid: string): Promise<boolean> => {
+		if (!jid.includes('@s.whatsapp.net')) return false
+
+		const lidMapping = signalRepository.getLIDMappingStore()
+		const lidForPN = await lidMapping.getLIDForPN(jid)
+		if (!lidForPN?.includes('@lid')) return false
+
+		const lidSignalId = signalRepository.jidToSignalProtocolAddress(lidForPN)
+		const lidSessions = await authState.keys.get('session', [lidSignalId])
+		return !!lidSessions[lidSignalId]
+	}
+
 	const assertSessions = async (jids: string[], force: boolean) => {
 		let didFetchNewSession = false
-		let jidsRequiringFetch: string[] = []
+		const jidsRequiringFetch: string[] = []
+
+		// Apply same deduplication as in getUSyncDevices
+		jids = deduplicateLidPnJids(jids)
+
 		if (force) {
-			jidsRequiringFetch = jids
-		} else {
+			// Check which sessions are missing (with LID migration check)
 			const addrs = jids.map(jid => signalRepository.jidToSignalProtocolAddress(jid))
 			const sessions = await authState.keys.get('session', addrs)
-			for (const jid of jids) {
+
+			// Helper to check session for a JID
+			const checkJidSession = async (jid: string) => {
 				const signalId = signalRepository.jidToSignalProtocolAddress(jid)
-				if (!sessions[signalId]) {
+				let hasSession = !!sessions[signalId]
+
+				// Check for migrated LID session if PN session missing
+				if (!hasSession) {
+					hasSession = await checkForMigratedLidSession(jid)
+					if (hasSession) {
+						logger.debug({ jid }, 'Found migrated LID session during force assert, skipping PN fetch')
+					}
+				}
+
+				// Add to fetch list if no session exists
+				if (!hasSession) {
+					if (jid.includes('@lid')) {
+						logger.debug({ jid }, 'No LID session found, will create new LID session')
+					}
+
 					jidsRequiringFetch.push(jid)
 				}
 			}
+
+			// Process all JIDs
+			for (const jid of jids) {
+				await checkJidSession(jid)
+			}
+		} else {
+			const lidMapping = signalRepository.getLIDMappingStore()
+			const addrs = jids.map(jid => signalRepository.jidToSignalProtocolAddress(jid))
+			const sessions = await authState.keys.get('session', addrs)
+
+			// Group JIDs by user for bulk migration
+			const userGroups = new Map<string, string[]>()
+			for (const jid of jids) {
+				const user = jidNormalizedUser(jid)
+				if (!userGroups.has(user)) {
+					userGroups.set(user, [])
+				}
+
+				userGroups.get(user)!.push(jid)
+			}
+
+			// Helper to check LID mapping for a user
+			const checkUserLidMapping = async (user: string, userJids: string[]) => {
+				if (!userJids.some(jid => jid.includes('@s.whatsapp.net'))) {
+					return { shouldMigrate: false, lidForPN: undefined }
+				}
+
+				try {
+					const mapping = await lidMapping.getLIDForPN(user)
+					if (mapping?.includes('@lid')) {
+						logger.debug(
+							{ user, lidForPN: mapping, deviceCount: userJids.length },
+							'User has LID mapping - preparing bulk migration'
+						)
+						return { shouldMigrate: true, lidForPN: mapping }
+					}
+				} catch (error) {
+					logger.debug({ user, error }, 'Failed to check LID mapping for user')
+				}
+
+				return { shouldMigrate: false, lidForPN: undefined }
+			}
+
+			// Helper to migrate a single device
+			const migrateDeviceToLid = async (jid: string, lidForPN: string) => {
+				if (!jid.includes('@s.whatsapp.net')) return
+
+				try {
+					const jidDecoded = jidDecode(jid)
+					const deviceId = jidDecoded?.device || 0
+					const lidDecoded = jidDecode(lidForPN)
+					const lidWithDevice = jidEncode(lidDecoded?.user!, 'lid', deviceId)
+
+					await signalRepository.migrateSession(jid, lidWithDevice)
+					logger.debug({ fromJid: jid, toJid: lidWithDevice }, 'Migrated device session to LID')
+
+					// Delete PN session after successful migration
+					try {
+						await signalRepository.deleteSession(jid)
+						logger.debug({ deletedPNSession: jid }, 'Deleted PN session after migration')
+					} catch (deleteError) {
+						logger.warn({ jid, error: deleteError }, 'Failed to delete PN session')
+					}
+				} catch (migrationError) {
+					logger.warn({ jid, error: migrationError }, 'Failed to migrate device session')
+				}
+			}
+
+			// Process each user group for potential bulk LID migration
+			for (const [user, userJids] of userGroups) {
+				const mappingResult = await checkUserLidMapping(user, userJids)
+				const shouldMigrateUser = mappingResult.shouldMigrate
+				const lidForPN = mappingResult.lidForPN
+
+				// Migrate all devices for this user if LID mapping exists
+				if (shouldMigrateUser && lidForPN) {
+					// Migrate each device individually
+					for (const jid of userJids) {
+						await migrateDeviceToLid(jid, lidForPN)
+					}
+
+					logger.info(
+						{
+							user,
+							lidMapping: lidForPN,
+							deviceCount: userJids.length
+						},
+						'Completed migration attempt for user devices'
+					)
+				}
+
+				// Helper to check session for migrated user
+				const checkMigratedSession = async (jid: string) => {
+					const signalId = signalRepository.jidToSignalProtocolAddress(jid)
+					let hasSession = !!sessions[signalId]
+					let jidToFetch = jid
+
+					// Check if we should use migrated LID session instead
+					if (shouldMigrateUser && lidForPN && jid.includes('@s.whatsapp.net')) {
+						const originalDecoded = jidDecode(jid)
+						const deviceId = originalDecoded?.device || 0
+						const lidDecoded = jidDecode(lidForPN)
+						const lidWithDevice = jidEncode(lidDecoded?.user!, 'lid', deviceId)
+
+						// Check if LID session exists
+						const lidSignalId = signalRepository.jidToSignalProtocolAddress(lidWithDevice)
+						const lidSessions = await authState.keys.get('session', [lidSignalId])
+						hasSession = !!lidSessions[lidSignalId]
+						jidToFetch = lidWithDevice
+
+						if (hasSession) {
+							logger.debug({ originalJid: jid, lidJid: lidWithDevice }, '✅ Found bulk-migrated LID session')
+						}
+					}
+
+					// Add to fetch list if no session exists
+					if (!hasSession) {
+						jidsRequiringFetch.push(jidToFetch)
+						logger.debug(
+							{ jid: jidToFetch, originalJid: jid !== jidToFetch ? jid : undefined },
+							'Adding to session fetch list'
+						)
+					}
+				}
+
+				// Now check which sessions need to be fetched for this user
+				for (const jid of userJids) {
+					await checkMigratedSession(jid)
+				}
+			}
 		}
 
 		if (jidsRequiringFetch.length) {
 			logger.debug({ jidsRequiringFetch }, 'fetching sessions')
+
+			// DEBUG: Check if there are PN versions of LID users being fetched
+			const lidUsersBeingFetched = new Set<string>()
+			const pnUsersBeingFetched = new Set<string>()
+
+			for (const jid of jidsRequiringFetch) {
+				const user = jidDecode(jid)?.user
+				if (user) {
+					if (jid.includes('@lid')) {
+						lidUsersBeingFetched.add(user)
+					} else if (jid.includes('@s.whatsapp.net')) {
+						pnUsersBeingFetched.add(user)
+					}
+				}
+			}
+
+			// Find overlaps
+			const overlapping = Array.from(pnUsersBeingFetched).filter(user => lidUsersBeingFetched.has(user))
+			if (overlapping.length > 0) {
+				logger.warn(
+					{
+						overlapping,
+						lidUsersBeingFetched: Array.from(lidUsersBeingFetched),
+						pnUsersBeingFetched: Array.from(pnUsersBeingFetched)
+					},
+					'Fetching both LID and PN sessions for same users'
+				)
+			}
+
 			const result = await query({
 				tag: 'iq',
 				attrs: {
@@ -316,7 +608,12 @@ export const makeMessagesSocket = (config: SocketConfig) => {
 		return msgId
 	}
 
-	const createParticipantNodes = async (jids: string[], message: proto.IMessage, extraAttrs?: BinaryNode['attrs']) => {
+	const createParticipantNodes = async (
+		jids: string[],
+		message: proto.IMessage,
+		extraAttrs?: BinaryNode['attrs'],
+		dsmMessage?: proto.IMessage
+	) => {
 		let patched = await patchMessageBeforeSending(message, jids)
 		if (!Array.isArray(patched)) {
 			patched = jids ? jids.map(jid => ({ recipientJid: jid, ...patched })) : [patched]
@@ -324,37 +621,142 @@ export const makeMessagesSocket = (config: SocketConfig) => {
 
 		let shouldIncludeDeviceIdentity = false
 
-		const nodes = await Promise.all(
-			patched.map(async patchedMessageWithJid => {
-				const { recipientJid: jid, ...patchedMessage } = patchedMessageWithJid
-				if (!jid) {
-					return {} as BinaryNode
-				}
+		const meId = authState.creds.me!.id
+		const meLid = authState.creds.me?.lid
+		const meLidUser = meLid ? jidDecode(meLid)?.user : null
 
-				const bytes = encodeWAMessage(patchedMessage)
-				const { type, ciphertext } = await signalRepository.encryptMessage({ jid, data: bytes })
-				if (type === 'pkmsg') {
-					shouldIncludeDeviceIdentity = true
-				}
+		const devicesByUser = new Map<string, Array<{ recipientJid: string; patchedMessage: proto.IMessage }>>()
 
-				const node: BinaryNode = {
-					tag: 'to',
-					attrs: { jid },
-					content: [
-						{
-							tag: 'enc',
-							attrs: {
-								v: '2',
-								type,
-								...(extraAttrs || {})
-							},
-							content: ciphertext
+		for (const patchedMessageWithJid of patched) {
+			const { recipientJid: wireJid, ...patchedMessage } = patchedMessageWithJid
+			if (!wireJid) continue
+
+			// Extract user from JID for grouping
+			const decoded = jidDecode(wireJid)
+			const user = decoded?.user
+
+			if (!user) continue
+
+			if (!devicesByUser.has(user)) {
+				devicesByUser.set(user, [])
+			}
+
+			devicesByUser.get(user)!.push({ recipientJid: wireJid, patchedMessage })
+		}
+
+		// Process each user's devices sequentially, but different users in parallel
+		const userEncryptionPromises = Array.from(devicesByUser.entries()).map(([user, userDevices]) =>
+			encryptionMutex.mutex(user, async () => {
+				logger.debug({ user, deviceCount: userDevices.length }, 'Acquiring encryption lock for user devices')
+
+				const userNodes: BinaryNode[] = []
+
+				// Helper to get encryption JID with LID migration
+				const getEncryptionJid = async (wireJid: string) => {
+					if (!wireJid.includes('@s.whatsapp.net')) return wireJid
+
+					try {
+						const lidMapping = signalRepository.getLIDMappingStore()
+						const lidForPN = await lidMapping.getLIDForPN(wireJid)
+
+						if (!lidForPN?.includes('@lid')) return wireJid
+
+						// Preserve device ID from original wire JID
+						const wireDecoded = jidDecode(wireJid)
+						const deviceId = wireDecoded?.device || 0
+						const lidDecoded = jidDecode(lidForPN)
+						const lidWithDevice = jidEncode(lidDecoded?.user!, 'lid', deviceId)
+
+						// Migrate session to LID for unified encryption layer
+						try {
+							await signalRepository.migrateSession(wireJid, lidWithDevice)
+							const recipientUser = jidNormalizedUser(wireJid)
+							const ownPnUser = jidNormalizedUser(meId)
+							const isOwnDevice = recipientUser === ownPnUser
+							logger.info({ wireJid, lidWithDevice, isOwnDevice }, 'Migrated to LID encryption')
+
+							// Delete PN session after successful migration
+							try {
+								await signalRepository.deleteSession(wireJid)
+								logger.debug({ deletedPNSession: wireJid }, 'Deleted PN session')
+							} catch (deleteError) {
+								logger.warn({ wireJid, error: deleteError }, 'Failed to delete PN session')
+							}
+
+							return lidWithDevice
+						} catch (migrationError) {
+							logger.warn({ wireJid, error: migrationError }, 'Failed to migrate session')
+							return wireJid
 						}
-					]
+					} catch (error) {
+						logger.debug({ wireJid, error }, 'Failed to check LID mapping')
+						return wireJid
+					}
 				}
-				return node
+
+				// Encrypt to this user's devices sequentially to prevent session corruption
+				for (const { recipientJid: wireJid, patchedMessage } of userDevices) {
+					// DSM logic: Use DSM for own other devices (following whatsmeow implementation)
+					let messageToEncrypt = patchedMessage
+					if (dsmMessage) {
+						const { user: targetUser } = jidDecode(wireJid)!
+						const { user: ownPnUser } = jidDecode(meId)!
+						const ownLidUser = meLidUser
+
+						// Check if this is our device (same user, different device)
+						const isOwnUser = targetUser === ownPnUser || (ownLidUser && targetUser === ownLidUser)
+
+						// Exclude exact sender device (whatsmeow: if jid == ownJID || jid == ownLID { continue })
+						const isExactSenderDevice =
+							wireJid === meId || (authState.creds.me?.lid && wireJid === authState.creds.me.lid)
+
+						if (isOwnUser && !isExactSenderDevice) {
+							messageToEncrypt = dsmMessage
+							logger.debug({ wireJid, targetUser }, 'Using DSM for own device')
+						}
+					}
+
+					const bytes = encodeWAMessage(messageToEncrypt)
+
+					// Get encryption JID with LID migration
+					const encryptionJid = await getEncryptionJid(wireJid)
+
+					// ENCRYPT: Use the determined encryption identity (prefers migrated LID)
+					const { type, ciphertext } = await signalRepository.encryptMessage({
+						jid: encryptionJid, // Unified encryption layer (LID when available)
+						data: bytes
+					})
+
+					if (type === 'pkmsg') {
+						shouldIncludeDeviceIdentity = true
+					}
+
+					const node: BinaryNode = {
+						tag: 'to',
+						attrs: { jid: wireJid }, // Always use original wire identity in envelope
+						content: [
+							{
+								tag: 'enc',
+								attrs: {
+									v: '2',
+									type,
+									...(extraAttrs || {})
+								},
+								content: ciphertext
+							}
+						]
+					}
+					userNodes.push(node)
+				}
+
+				logger.debug({ user, nodesCreated: userNodes.length }, 'Releasing encryption lock for user devices')
+				return userNodes
 			})
 		)
+
+		// Wait for all users to complete (users are processed in parallel)
+		const userNodesArrays = await Promise.all(userEncryptionPromises)
+		const nodes = userNodesArrays.flat()
 		return { nodes, shouldIncludeDeviceIdentity }
 	}
 
@@ -372,6 +774,9 @@ export const makeMessagesSocket = (config: SocketConfig) => {
 		}: MessageRelayOptions
 	) => {
 		const meId = authState.creds.me!.id
+		const meLid = authState.creds.me?.lid
+
+		// ADDRESSING CONSISTENCY: Keep envelope addressing as user provided, handle LID migration in encryption
 
 		let shouldIncludeDeviceIdentity = false
 
@@ -382,14 +787,27 @@ export const makeMessagesSocket = (config: SocketConfig) => {
 		const isLid = server === 'lid'
 		const isNewsletter = server === 'newsletter'
 
+		// Keep user's original JID choice for envelope addressing
+		const finalJid = jid
+
+		// ADDRESSING CONSISTENCY: Match own identity to conversation context
+		let ownId = meId
+		if (isLid && meLid) {
+			ownId = meLid
+			logger.debug({ to: jid, ownId }, 'Using LID identity for @lid conversation')
+		} else {
+			logger.debug({ to: jid, ownId }, 'Using PN identity for @s.whatsapp.net conversation')
+		}
+
 		msgId = msgId || generateMessageIDV2(sock.user?.id)
 		useUserDevicesCache = useUserDevicesCache !== false
 		useCachedGroupMetadata = useCachedGroupMetadata !== false && !isStatus
 
 		const participants: BinaryNode[] = []
-		const destinationJid = !isStatus ? jidEncode(user, isLid ? 'lid' : isGroup ? 'g.us' : 's.whatsapp.net') : statusJid
+		const destinationJid = !isStatus ? finalJid : statusJid
+
 		const binaryNodeContent: BinaryNode[] = []
-		const devices: JidWithDevice[] = []
+		const devices: DeviceWithWireJid[] = []
 
 		const meMsg: proto.IMessage = {
 			deviceSentMessage: {
@@ -410,7 +828,11 @@ export const makeMessagesSocket = (config: SocketConfig) => {
 			}
 
 			const { user, device } = jidDecode(participant.jid)!
-			devices.push({ user, device })
+			devices.push({
+				user,
+				device,
+				wireJid: participant.jid // Use the participant JID as wire JID
+			})
 		}
 
 		await authState.keys.transaction(async () => {
@@ -476,9 +898,10 @@ export const makeMessagesSocket = (config: SocketConfig) => {
 					}
 
 					if (!isStatus) {
+						const groupAddressingMode = groupData?.addressingMode || (isLid ? 'lid' : 'pn')
 						additionalAttributes = {
 							...additionalAttributes,
-							addressing_mode: groupData?.addressingMode || 'pn'
+							addressing_mode: groupAddressingMode
 						}
 					}
 
@@ -494,20 +917,26 @@ export const makeMessagesSocket = (config: SocketConfig) => {
 
 				const bytes = encodeWAMessage(patched)
 
+				// This should match the group's addressing mode and conversation context
+				const groupAddressingMode = groupData?.addressingMode || (isLid ? 'lid' : 'pn')
+				const groupSenderIdentity = groupAddressingMode === 'lid' && meLid ? meLid : meId
+
 				const { ciphertext, senderKeyDistributionMessage } = await signalRepository.encryptGroupMessage({
 					group: destinationJid,
 					data: bytes,
-					meId
+					meId: groupSenderIdentity
 				})
 
 				const senderKeyJids: string[] = []
 				// ensure a connection is established with every device
-				for (const { user, device } of devices) {
-					const jid = jidEncode(user, groupData?.addressingMode === 'lid' ? 'lid' : 's.whatsapp.net', device)
-					if (!senderKeyMap[jid] || !!participant) {
-						senderKeyJids.push(jid)
+				for (const device of devices) {
+					// This preserves the LID migration results from getUSyncDevices
+					const deviceJid = device.wireJid
+					const hasKey = !!senderKeyMap[deviceJid]
+					if (!hasKey || !!participant) {
+						senderKeyJids.push(deviceJid)
 						// store that this person has had the sender keys sent to them
-						senderKeyMap[jid] = true
+						senderKeyMap[deviceJid] = true
 					}
 				}
 
@@ -539,30 +968,70 @@ export const makeMessagesSocket = (config: SocketConfig) => {
 
 				await authState.keys.set({ 'sender-key-memory': { [jid]: senderKeyMap } })
 			} else {
-				const { user: meUser } = jidDecode(meId)!
+				const { user: ownUser } = jidDecode(ownId)!
 
 				if (!participant) {
-					devices.push({ user })
-					if (user !== meUser) {
-						devices.push({ user: meUser })
+					const targetUserServer = isLid ? 'lid' : 's.whatsapp.net'
+					devices.push({
+						user,
+						device: 0,
+						wireJid: jidEncode(user, targetUserServer, 0)
+					})
+
+					// Own user matches conversation addressing mode
+					if (user !== ownUser) {
+						const ownUserServer = isLid ? 'lid' : 's.whatsapp.net'
+						const ownUserForAddressing = isLid && meLid ? jidDecode(meLid)!.user : jidDecode(meId)!.user
+
+						devices.push({
+							user: ownUserForAddressing,
+							device: 0,
+							wireJid: jidEncode(ownUserForAddressing, ownUserServer, 0)
+						})
 					}
 
 					if (additionalAttributes?.['category'] !== 'peer') {
-						const additionalDevices = await getUSyncDevices([meId, jid], !!useUserDevicesCache, true)
-						devices.push(...additionalDevices)
+						// Clear placeholders and enumerate actual devices
+						devices.length = 0
+
+						// Use conversation-appropriate sender identity
+						const senderIdentity =
+							isLid && meLid
+								? jidEncode(jidDecode(meLid)?.user!, 'lid', undefined)
+								: jidEncode(jidDecode(meId)?.user!, 's.whatsapp.net', undefined)
+
+						// Enumerate devices for sender and target with consistent addressing
+						const sessionDevices = await getUSyncDevices([senderIdentity, jid], false, false)
+						devices.push(...sessionDevices)
+
+						logger.debug(
+							{
+								deviceCount: devices.length,
+								devices: devices.map(d => `${d.user}:${d.device}@${jidDecode(d.wireJid)?.server}`)
+							},
+							'Device enumeration complete with unified addressing'
+						)
 					}
 				}
 
 				const allJids: string[] = []
 				const meJids: string[] = []
 				const otherJids: string[] = []
-				for (const { user, device } of devices) {
-					const isMe = user === meUser
-					const jid = jidEncode(
-						isMe && isLid ? authState.creds?.me?.lid!.split(':')[0] || user : user,
-						isLid ? 'lid' : 's.whatsapp.net',
-						device
-					)
+				const { user: mePnUser } = jidDecode(meId)!
+				const { user: meLidUser } = meLid ? jidDecode(meLid)! : { user: null }
+
+				for (const { user, wireJid } of devices) {
+					const isExactSenderDevice = wireJid === meId || (meLid && wireJid === meLid)
+					if (isExactSenderDevice) {
+						logger.debug({ wireJid, meId, meLid }, 'Skipping exact sender device (whatsmeow pattern)')
+						continue
+					}
+
+					// Check if this is our device (could match either PN or LID user)
+					const isMe = user === mePnUser || (meLidUser && user === meLidUser)
+
+					const jid = wireJid
+
 					if (isMe) {
 						meJids.push(jid)
 					} else {
@@ -572,14 +1041,15 @@ export const makeMessagesSocket = (config: SocketConfig) => {
 					allJids.push(jid)
 				}
 
-				await assertSessions(allJids, false)
+				await assertSessions([...otherJids, ...meJids], false)
 
 				const [
 					{ nodes: meNodes, shouldIncludeDeviceIdentity: s1 },
 					{ nodes: otherNodes, shouldIncludeDeviceIdentity: s2 }
 				] = await Promise.all([
-					createParticipantNodes(meJids, meMsg, extraAttrs),
-					createParticipantNodes(otherJids, message, extraAttrs)
+					// For own devices: use DSM if available (1:1 chats only)
+					createParticipantNodes(meJids, meMsg || message, extraAttrs),
+					createParticipantNodes(otherJids, message, extraAttrs, meMsg)
 				])
 				participants.push(...meNodes)
 				participants.push(...otherNodes)
@@ -597,6 +1067,7 @@ export const makeMessagesSocket = (config: SocketConfig) => {
 					binaryNodeContent.push({
 						tag: 'participants',
 						attrs: {},
+
 						content: participants
 					})
 				}
@@ -606,11 +1077,13 @@ export const makeMessagesSocket = (config: SocketConfig) => {
 				tag: 'message',
 				attrs: {
 					id: msgId,
+					to: destinationJid,
 					type: getMessageType(message),
 					...(additionalAttributes || {})
 				},
 				content: binaryNodeContent
 			}
+
 			// if the participant to send to is explicitly specified (generally retry recp)
 			// ensure the message is only sent to that person
 			// if a retry receipt is sent to everyone -- it'll fail decryption for everyone else who received the msg

src/Socket/socket.ts

@@ -759,6 +759,25 @@ export const makeSocket = (config: SocketConfig) => {
 		ev.emit('creds.update', { me: { ...authState.creds.me!, lid: node.attrs.lid } })
 
 		ev.emit('connection.update', { connection: 'open' })
+
+		if (node.attrs.lid && authState.creds.me?.id) {
+			const myLID = node.attrs.lid
+			process.nextTick(async () => {
+				try {
+					const myPN = authState.creds.me!.id
+
+					// Store our own LID-PN mapping
+					await signalRepository.storeLIDPNMapping(myLID, myPN)
+
+					// Create LID session for ourselves (whatsmeow pattern)
+					await signalRepository.migrateSession(myPN, myLID)
+
+					logger.info({ myPN, myLID }, 'Own LID session created successfully')
+				} catch (error) {
+					logger.error({ error, lid: myLID }, 'Failed to create own LID session')
+				}
+			})
+		}
 	})
 
 	ws.on('CB:stream:error', (node: BinaryNode) => {

src/Types/Auth.ts

@@ -72,6 +72,7 @@ export type SignalDataTypeMap = {
 	'sender-key-memory': { [jid: string]: boolean }
 	'app-state-sync-key': proto.Message.IAppStateSyncKeyData
 	'app-state-sync-version': LTHashState
+	'lid-mapping': string
 }
 
 export type SignalDataSet = { [T in keyof SignalDataTypeMap]?: { [id: string]: SignalDataTypeMap[T] | null } }

src/Types/Signal.ts

@@ -1,4 +1,5 @@
 import { proto } from '../../WAProto/index.js'
+import type { LIDMappingStore } from '../Signal/lid-mapping'
 
 type DecryptGroupSignalOpts = {
 	group: string
@@ -22,6 +23,12 @@ type EncryptMessageOpts = {
 	data: Uint8Array
 }
 
+type EncryptMessageWithWireOpts = {
+	encryptionJid: string // JID used for session lookup (LID)
+	wireJid: string // JID used for envelope (PN)
+	data: Uint8Array
+}
+
 type EncryptGroupMessageOpts = {
 	group: string
 	data: Uint8Array
@@ -57,10 +64,21 @@ export type SignalRepository = {
 		type: 'pkmsg' | 'msg'
 		ciphertext: Uint8Array
 	}>
+	encryptMessageWithWire(opts: EncryptMessageWithWireOpts): Promise<{
+		type: 'pkmsg' | 'msg'
+		ciphertext: Uint8Array
+		wireJid: string // Return the wire JID for envelope
+	}>
 	encryptGroupMessage(opts: EncryptGroupMessageOpts): Promise<{
 		senderKeyDistributionMessage: Uint8Array
 		ciphertext: Uint8Array
 	}>
 	injectE2ESession(opts: E2ESessionOpts): Promise<void>
 	jidToSignalProtocolAddress(jid: string): string
+	storeLIDPNMapping(lid: string, pn: string): Promise<void>
+	getLIDMappingStore(): LIDMappingStore
+	migrateSession(fromJid: string, toJid: string): Promise<void>
+	validateSession(jid: string): Promise<{ exists: boolean; reason?: string }>
+	deleteSession(jid: string): Promise<void>
+	destroy(): void
 }

src/Utils/decode-wa-message.ts

@@ -10,11 +10,51 @@ import {
 	isJidNewsletter,
 	isJidStatusBroadcast,
 	isJidUser,
-	isLidUser
+	isLidUser,
+	jidDecode,
+	jidEncode,
+	jidNormalizedUser
 } from '../WABinary'
 import { unpadRandomMax16 } from './generics'
 import type { ILogger } from './logger'
 
+const getDecryptionJid = async (sender: string, repository: SignalRepository): Promise<string> => {
+	if (!sender.includes('@s.whatsapp.net')) {
+		return sender
+	}
+
+	const lidMapping = repository.getLIDMappingStore()
+	const normalizedSender = jidNormalizedUser(sender)
+	const lidForPN = await lidMapping.getLIDForPN(normalizedSender)
+
+	if (lidForPN?.includes('@lid')) {
+		const senderDecoded = jidDecode(sender)
+		const deviceId = senderDecoded?.device || 0
+		return jidEncode(jidDecode(lidForPN)!.user, 'lid', deviceId)
+	}
+
+	return sender
+}
+
+const storeMappingFromEnvelope = async (
+	stanza: BinaryNode,
+	sender: string,
+	decryptionJid: string,
+	repository: SignalRepository,
+	logger: ILogger
+): Promise<void> => {
+	const { senderAlt } = extractAddressingContext(stanza)
+
+	if (senderAlt && isLidUser(senderAlt) && isJidUser(sender) && decryptionJid === sender) {
+		try {
+			await repository.storeLIDPNMapping(senderAlt, sender)
+			logger.debug({ sender, senderAlt }, 'Stored LID mapping from envelope')
+		} catch (error) {
+			logger.warn({ sender, senderAlt, error }, 'Failed to store LID mapping')
+		}
+	}
+}
+
 export const NO_MESSAGE_FOUND_ERROR_TEXT = 'Message absent from node'
 export const MISSING_KEYS_ERROR_TEXT = 'Key used already or never filled'
 
@@ -43,6 +83,28 @@ type MessageType =
 	| 'other_status'
 	| 'newsletter'
 
+export const extractAddressingContext = (stanza: BinaryNode) => {
+	const addressingMode = stanza.attrs.addressing_mode || 'pn'
+	let senderAlt: string | undefined
+	let recipientAlt: string | undefined
+
+	if (addressingMode === 'lid') {
+		// Message is LID-addressed: sender is LID, extract corresponding PN
+		senderAlt = stanza.attrs.participant_pn || stanza.attrs.sender_pn
+		recipientAlt = stanza.attrs.recipient_pn
+	} else {
+		// Message is PN-addressed: sender is PN, extract corresponding LID
+		senderAlt = stanza.attrs.participant_lid || stanza.attrs.sender_lid
+		recipientAlt = stanza.attrs.recipient_lid
+	}
+
+	return {
+		addressingMode,
+		senderAlt,
+		recipientAlt
+	}
+}
+
 /**
  * Decode the received node as a message.
  * @note this will only parse the message, not decrypt it
@@ -187,11 +249,15 @@ export const decryptMessageNode = (
 							case 'pkmsg':
 							case 'msg':
 								const user = isJidUser(sender) ? sender : author
+								const decryptionJid = await getDecryptionJid(user, repository)
+
 								msgBuffer = await repository.decryptMessage({
-									jid: user,
+									jid: decryptionJid,
 									type: e2eType,
 									ciphertext: content
 								})
+
+								await storeMappingFromEnvelope(stanza, user, decryptionJid, repository, logger)
 								break
 							case 'plaintext':
 								msgBuffer = content

yarn.lock

@@ -2863,6 +2863,7 @@ __metadata:
     json: "npm:^11.0.0"
     libsignal: "git+https://github.com/whiskeysockets/libsignal-node"
     link-preview-js: "npm:^3.0.0"
+    lru-cache: "npm:^10.4.3"
     music-metadata: "npm:^11.7.0"
     open: "npm:^8.4.2"
     pino: "npm:^9.6"
@@ -7307,7 +7308,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"lru-cache@npm:^10.0.1, lru-cache@npm:^10.2.0":
+"lru-cache@npm:^10.0.1, lru-cache@npm:^10.2.0, lru-cache@npm:^10.4.3":
   version: 10.4.3
   resolution: "lru-cache@npm:10.4.3"
   checksum: 10c0/ebd04fbca961e6c1d6c0af3799adcc966a1babe798f685bb84e6599266599cd95d94630b10262f5424539bc4640107e8a33aa28585374abf561d30d16f4b39fb