feat: add pastParticipants support in history sync

Surfaces past group participant data from WhatsApp history sync messages.
Previously pastParticipants was dropped during event buffering because
it was overwritten instead of accumulated across chunks.

- src/Types/Events.ts: add pastParticipants to BaileysEventMap['messaging-history.set'] and BufferedEventData.historySets
- src/Utils/event-buffer.ts: accumulate pastParticipants via spread array instead of overwriting; include in consolidateEvents output
- src/Utils/history.ts: pass item.pastParticipants in processHistoryMessage return

Refs: WhiskeySockets/Baileys#2426

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/Defaults/index.ts

@@ -188,12 +188,10 @@ export const MEDIA_KEYS = Object.keys(MEDIA_PATH_MAP) as MediaType[]
 /** 120s timeout for history sync stall detection, same as WA Web's handleChunkProgress / restartPausedTimer (g = 120) */
 export const HISTORY_SYNC_PAUSED_TIMEOUT_MS = 120_000
 
-// Replenishment threshold: when server count drops below this, top-up back to INITIAL_PREKEY_COUNT
-export const MIN_PREKEY_COUNT = 200
+export const MIN_PREKEY_COUNT = 5
 
-// Initial pool size matching WA Business (CDP IDB capture: prekey-store = 812 on registration)
-// Rounded to 800 for cleanliness; replenishment always tops up to this value
-export const INITIAL_PREKEY_COUNT = 800
+// Moderate prekey count (upstream uses 812, reduced to balance rate limiting and availability)
+export const INITIAL_PREKEY_COUNT = 200
 
 export const UPLOAD_TIMEOUT = 30000 // 30 seconds
 // Moderate upload interval to balance rate limiting and responsiveness (was 5000)

src/Socket/messages-recv.ts

@@ -7,7 +7,6 @@ import { proto } from '../../WAProto/index.js'
 import {
 	DEFAULT_CACHE_TTLS,
 	DEFAULT_SESSION_CLEANUP_CONFIG,
-	INITIAL_PREKEY_COUNT,
 	KEY_BUNDLE_TYPE,
 	MIN_PREKEY_COUNT,
 	PLACEHOLDER_MAX_AGE_SECONDS,
@@ -1213,7 +1212,7 @@ export const makeMessagesRecvSocket = (config: SocketConfig) => {
 		return await query(stanza)
 	}
 
-	const sendRetryRequest = async (node: BinaryNode, forceIncludeKeys = false, decryptionError?: string) => {
+	const sendRetryRequest = async (node: BinaryNode, forceIncludeKeys = false) => {
 		const { fullMessage } = decodeMessageNode(node, authState.creds.me!.id, authState.creds.me!.lid || '')
 		const { key: msgKey } = fullMessage
 		const msgId = msgKey.id!
@@ -1311,27 +1310,39 @@ export const makeMessagesRecvSocket = (config: SocketConfig) => {
 		const { account, signedPreKey, signedIdentityKey: identityKey } = authState.creds
 		const fromJid = node.attrs.from!
 
-		// Derive the Signal error code from the actual decryption failure message.
-		// This is sent in the retry receipt so the peer (even another InfiniteAPI instance)
-		// knows the exact reason and can recreate the session immediately instead of waiting
-		// for the 1-hour timeout fallback.
-		//
-		// Codes mirror RetryReason enum in message-retry-manager.ts:
-		//   0 = UnknownError | 1 = NoSession | 2 = InvalidKey
-		//   3 = InvalidKeyId | 7 = BadMac (= SignalErrorInvalidMessage/InvalidCipherKey)
-		//
-		// NOTE: We do NOT delete the session here (receiver side). The Signal Protocol
-		// recovers automatically when the sender's pkmsg arrives — it overwrites the
-		// corrupted session. Deleting prematurely creates a race window where no session
-		// exists, which can cause "No Session" errors on concurrent messages.
-		const retryErrorCode = (() => {
-			if (!decryptionError) return 0
-			if (/bad\s*mac/i.test(decryptionError)) return 7 // SignalErrorBadMac
-			if (/no\s*session/i.test(decryptionError)) return 1 // SignalErrorNoSession
-			if (/pre\s*key/i.test(decryptionError)) return 3 // SignalErrorInvalidKeyId
-			if (/invalid\s*key/i.test(decryptionError)) return 2 // SignalErrorInvalidKey
-			return 0
-		})()
+		// Check if we should recreate the session
+		let shouldRecreateSession = false
+		let recreateReason = ''
+
+		if (enableAutoSessionRecreation && messageRetryManager && retryCount >= 1) {
+			try {
+				// Check if we have a session with this JID
+				const sessionId = signalRepository.jidToSignalProtocolAddress(fromJid)
+				const hasSession = await signalRepository.validateSession(fromJid)
+
+				// Extract error code from retry node if present (for MAC error detection)
+				const retryNode = getBinaryNodeChild(node, 'retry')
+				const errorAttr = retryNode?.attrs?.error
+				const errorCode = messageRetryManager.parseRetryErrorCode(errorAttr)
+
+				const result = messageRetryManager.shouldRecreateSession(fromJid, hasSession.exists, errorCode)
+				shouldRecreateSession = result.recreate
+				recreateReason = result.reason
+
+				if (shouldRecreateSession) {
+					logger.debug({ fromJid, retryCount, reason: recreateReason, errorCode }, 'recreating session for retry')
+					// Delete existing session to force recreation
+					// CRITICAL: Use same transaction key as encrypt/decrypt operations to prevent race
+					// Using meId ensures this delete serializes with sendMessage() and other session operations
+					await authState.keys.transaction(async () => {
+						await authState.keys.set({ session: { [sessionId]: null } })
+					}, authState.creds.me?.id || 'session-operation')
+					forceIncludeKeys = true
+				}
+			} catch (error) {
+				logger.warn({ error, fromJid }, 'failed to check session recreation')
+			}
+		}
 
 		if (retryCount <= 2) {
 			// Use new retry manager for phone requests if available
@@ -1372,7 +1383,8 @@ export const makeMessagesRecvSocket = (config: SocketConfig) => {
 							id: node.attrs.id!,
 							t: node.attrs.t!,
 							v: '1',
-							error: retryErrorCode.toString()
+							// ADD ERROR FIELD
+							error: '0'
 						}
 					},
 					{
@@ -1391,7 +1403,7 @@ export const makeMessagesRecvSocket = (config: SocketConfig) => {
 				receipt.attrs.participant = node.attrs.participant
 			}
 
-			if (retryCount > 1 || forceIncludeKeys) {
+			if (retryCount > 1 || forceIncludeKeys || shouldRecreateSession) {
 				const { update, preKeys } = await getNextPreKeys(authState, 1)
 
 				const [keyId] = Object.keys(preKeys)
@@ -1428,8 +1440,7 @@ export const makeMessagesRecvSocket = (config: SocketConfig) => {
 
 			logger.debug({ count, shouldUploadMorePreKeys }, 'recv pre-key count')
 			if (shouldUploadMorePreKeys) {
-				// Top-up back to INITIAL_PREKEY_COUNT so the pool is always restored to full size
-				await uploadPreKeys(Math.max(1, INITIAL_PREKEY_COUNT - count))
+				await uploadPreKeys()
 			}
 		} else {
 			const result = await handleIdentityChange(node, {
@@ -2494,7 +2505,7 @@ export const makeMessagesRecvSocket = (config: SocketConfig) => {
 							}
 
 							const encNode = getBinaryNodeChild(node, 'enc')
-							await sendRetryRequest(node, !encNode, errorMessage)
+							await sendRetryRequest(node, !encNode)
 							if (retryRequestDelayMs) {
 								await delay(retryRequestDelayMs)
 							}
@@ -2503,7 +2514,7 @@ export const makeMessagesRecvSocket = (config: SocketConfig) => {
 							// Still attempt retry even if pre-key upload failed
 							try {
 								const encNode = getBinaryNodeChild(node, 'enc')
-								await sendRetryRequest(node, !encNode, errorMessage)
+								await sendRetryRequest(node, !encNode)
 							} catch (retryErr) {
 								logger.error({ retryErr }, 'Failed to send retry after error handling')
 							}

src/Socket/messages-send.ts

@@ -9,7 +9,6 @@ import type {
 	AlbumMessageOptions,
 	AlbumSendResult,
 	AnyMessageContent,
-	LIDMapping,
 	MediaConnInfo,
 	MessageReceiptType,
 	MessageRelayOptions,
@@ -339,33 +338,6 @@ export const makeMessagesSocket = (config: SocketConfig) => {
 				}
 			}
 
-			// 4th LID→PN source: device-list entries sharing the same raw_id
-			// WA Business uses this for accounts where HistorySync sends zero phoneNumberToLidMappings
-			const allEntries = [...result.list, ...result.sideList]
-			const rawIdMap = new Map<number, { pn?: string; lid?: string }>()
-			for (const item of allEntries) {
-				if (typeof item.rawId !== 'number' || isNaN(item.rawId)) continue
-				const decoded = jidDecode(item.id)
-				if (!decoded) continue
-				const entry = rawIdMap.get(item.rawId) || {}
-				if (decoded.server === 'lid' || decoded.server === 'hosted.lid') {
-					entry.lid = item.id
-				} else if (decoded.server === 's.whatsapp.net' || decoded.server === 'c.us') {
-					entry.pn = item.id
-				}
-				rawIdMap.set(item.rawId, entry)
-			}
-			const rawIdMappings: LIDMapping[] = []
-			for (const { pn, lid } of rawIdMap.values()) {
-				if (pn && lid) {
-					rawIdMappings.push({ lid: jidNormalizedUser(lid), pn: jidNormalizedUser(pn) })
-				}
-			}
-			if (rawIdMappings.length > 0) {
-				await signalRepository.lidMapping.storeLIDPNMappings(rawIdMappings)
-				logger.debug({ count: rawIdMappings.length }, 'stored LID-PN mappings from raw_id pairing')
-			}
-
 			const meId = authState.creds.me?.id
 			if (!meId) throw new Boom('Not authenticated', { statusCode: 401 })
 			const meLid = authState.creds.me?.lid || ''

src/Socket/socket.ts

@@ -701,12 +701,10 @@ export const makeSocket = (config: SocketConfig) => {
 			}
 		}
 
-		// Prevent multiple concurrent uploads — if one is already running, wait for it and return:
-		// the concurrent upload already replenished the pool, so there is nothing left to do.
+		// Prevent multiple concurrent uploads
 		if (uploadPreKeysPromise) {
 			logger.debug('Pre-key upload already in progress, waiting for completion')
 			await uploadPreKeysPromise
-			return
 		}
 
 		const uploadLogic = async () => {
@@ -786,15 +784,14 @@ export const makeSocket = (config: SocketConfig) => {
 		try {
 			let count = 0
 			const preKeyCount = await getAvailablePreKeysOnServer()
-			// How many to upload: top-up to INITIAL_PREKEY_COUNT from whatever remains on server
-			count = Math.max(0, INITIAL_PREKEY_COUNT - preKeyCount)
+			if (preKeyCount === 0) count = INITIAL_PREKEY_COUNT
+			else count = MIN_PREKEY_COUNT
 			const { exists: currentPreKeyExists, currentPreKeyId } = await verifyCurrentPreKeyExists()
 
 			logger.info(`${preKeyCount} pre-keys found on server`)
 			logger.info(`Current prekey ID: ${currentPreKeyId}, exists in storage: ${currentPreKeyExists}`)
 
-			// Trigger upload when below the replenishment threshold, not when count < topUp amount
-			const lowServerCount = preKeyCount < MIN_PREKEY_COUNT
+			const lowServerCount = preKeyCount <= count
 			const missingCurrentPreKey = !currentPreKeyExists && currentPreKeyId > 0
 
 			const shouldUpload = lowServerCount || missingCurrentPreKey
@@ -1154,7 +1151,7 @@ export const makeSocket = (config: SocketConfig) => {
 		// Decrement active connections
 		decrementActiveConnections()
 
-		clearTimeout(keepAliveReq)
+		clearInterval(keepAliveReq)
 		clearTimeout(qrTimer)
 
 		// Clear offline-buffer safety timer so its callback cannot call ev.flush()
@@ -1265,16 +1262,8 @@ export const makeSocket = (config: SocketConfig) => {
 		})
 	}
 
-	const startKeepAliveRequest = () => {
-		// Use recursive setTimeout with ±15% jitter to match WA Desktop behaviour
-		// (WA Business Desktop: ~25-30s intervals with natural variance)
-		const scheduleNextKeepAlive = () => {
-			const jitter = keepAliveIntervalMs * 0.15
-			const delay = keepAliveIntervalMs + Math.floor((Math.random() * 2 - 1) * jitter)
-			keepAliveReq = setTimeout(onKeepAliveTick, delay)
-		}
-
-		const onKeepAliveTick = () => {
+	const startKeepAliveRequest = () =>
+		(keepAliveReq = setInterval(() => {
 			if (!lastDateRecv) {
 				lastDateRecv = new Date()
 			}
@@ -1286,7 +1275,6 @@ export const makeSocket = (config: SocketConfig) => {
 			*/
 			if (diff > keepAliveIntervalMs + 5000) {
 				void end(new Boom('Connection was lost', { statusCode: DisconnectReason.connectionLost }))
-				return // connection closing — do not reschedule
 			} else if (ws.isOpen) {
 				// Send keep-alive ping via sendNode() (fire-and-forget) instead of query().
 				// query() wraps the ping in the query circuit breaker — when that breaker is
@@ -1309,15 +1297,7 @@ export const makeSocket = (config: SocketConfig) => {
 			} else {
 				logger.warn('keep alive called when WS not open')
 			}
-
-			// Do not reschedule once shutdown has started (closed set by end() on any concurrent path)
-			if (!closed) {
-				scheduleNextKeepAlive()
-			}
-		}
-
-		scheduleNextKeepAlive()
-	}
+		}, keepAliveIntervalMs))
 	/** i have no idea why this exists. pls enlighten me */
 	const sendPassiveIq = (tag: 'passive' | 'active') =>
 		query({

src/Types/Events.ts

@@ -27,7 +27,6 @@ export type BaileysEventMap = {
 		chats: Chat[]
 		contacts: Contact[]
 		messages: WAMessage[]
-		/** Past participants for group chats (people who left/were removed). userJid is always a phone number (PN), never a LID. */
 		pastParticipants?: proto.IPastParticipants[] | null
 		isLatest?: boolean
 		progress?: number | null
@@ -187,8 +186,7 @@ export type BufferedEventData = {
 		chats: { [jid: string]: Chat }
 		contacts: { [jid: string]: Contact }
 		messages: { [uqId: string]: WAMessage }
-		/** Keyed by groupJid for O(1) deduplication across chunks */
-		pastParticipants: { [groupJid: string]: proto.IPastParticipant[] }
+		pastParticipants?: proto.IPastParticipants[]
 		empty: boolean
 		isLatest: boolean
 		progress?: number | null

src/Utils/event-buffer.ts

@@ -1,5 +1,4 @@
 import EventEmitter from 'events'
-import { proto } from '../../WAProto/index.js'
 import type {
 	BaileysEvent,
 	BaileysEventEmitter,
@@ -891,7 +890,6 @@ const makeBufferData = (): BufferedEventData => {
 			chats: {},
 			messages: {},
 			contacts: {},
-			pastParticipants: {},
 			isLatest: false,
 			empty: true
 		},
@@ -969,28 +967,10 @@ function append<E extends BufferableEvent>(
 				}
 			}
 
-			// Merge pastParticipants with deduplication by groupJid and by userJid within each group.
-			// Multiple HistorySync chunks can carry the same group -- we merge rather than concatenate
-			// to avoid duplicate entries in the final event delivered to the consumer.
-			for (const group of (eventData.pastParticipants ?? []) as proto.IPastParticipants[]) {
-				const groupJid = group.groupJid
-				if (!groupJid) continue
-
-				if (!data.historySets.pastParticipants[groupJid]) {
-					data.historySets.pastParticipants[groupJid] = []
-				}
-
-				const existing = data.historySets.pastParticipants[groupJid]
-				const seenJids = new Set(existing.map(p => p.userJid).filter(Boolean))
-
-				for (const participant of (group.pastParticipants ?? []) as proto.IPastParticipant[]) {
-					if (participant.userJid && !seenJids.has(participant.userJid)) {
-						existing.push(participant)
-						seenJids.add(participant.userJid)
-					}
-				}
-			}
-
+			data.historySets.pastParticipants = [
+				...(data.historySets.pastParticipants || []),
+				...(eventData.pastParticipants || [])
+			]
 			data.historySets.empty = false
 			data.historySets.syncType = eventData.syncType
 			data.historySets.progress = eventData.progress
@@ -1316,10 +1296,7 @@ function consolidateEvents(data: BufferedEventData) {
 			chats: Object.values(data.historySets.chats),
 			messages: Object.values(data.historySets.messages),
 			contacts: Object.values(data.historySets.contacts),
-			// Convert dedup map back to array. Each entry has groupJid + participants (all unique userJids).
-			pastParticipants: Object.entries(data.historySets.pastParticipants).map(
-				([groupJid, participants]) => ({ groupJid, pastParticipants: participants })
-			),
+			pastParticipants: data.historySets.pastParticipants,
 			syncType: data.historySets.syncType,
 			progress: data.historySets.progress,
 			isLatest: data.historySets.isLatest,

src/Utils/history.ts

@@ -15,8 +15,7 @@ import {
 import { toNumber } from './generics'
 import type { ILogger } from './logger.js'
 import { normalizeMessageContent } from './messages'
-import { DEFAULT_ORIGIN } from '../Defaults'
-import { downloadContentFromMessage, getUrlFromDirectPath } from './messages-media'
+import { downloadContentFromMessage } from './messages-media'
 
 const inflatePromise = promisify(inflate)
 
@@ -375,25 +374,11 @@ export const processHistoryMessage = (item: proto.IHistorySync, logger?: ILogger
 	// Convert Map back to array for return
 	const lidPnMappings = Array.from(lidPnMap.values())
 
-	// Normalize pastParticipants: resolve LID userJids → PN so the consumer always
-	// receives a phone number, never an opaque LID identifier.
-	// Uses the lidPnMap built above (populated from phoneNumberToLidMappings + conversations).
-	// If a LID cannot be resolved, the original value is kept rather than dropping the participant.
-	const pastParticipants: proto.IPastParticipants[] = (item.pastParticipants ?? []).map(group => ({
-		groupJid: group.groupJid,
-		pastParticipants: (group.pastParticipants ?? []).map(participant => {
-			const userJid = participant.userJid
-			if (!userJid || !isAnyLidUser(userJid)) return participant
-			const mapping = lidPnMap.get(jidNormalizedUser(userJid))
-			return mapping?.pn ? { ...participant, userJid: mapping.pn } : participant
-		})
-	}))
-
 	return {
 		chats,
 		contacts,
 		messages,
-		pastParticipants,
+		pastParticipants: item.pastParticipants,
 		lidPnMappings,
 		syncType: item.syncType,
 		progress: item.progress
@@ -424,23 +409,7 @@ export const downloadAndProcessHistorySyncNotification = async (
 		historyMsg = await downloadHistory(msg, options)
 	}
 
-	const result = processHistoryMessage(historyMsg, logger)
-
-	// Mirror WA Desktop behaviour: DELETE the CDN blob only after processing succeeds.
-	// Doing this earlier (e.g. inside downloadHistory) risks permanent history loss if
-	// processing throws — the server copy would be gone and retry after reconnect would fail.
-	if (msg.directPath) {
-		const cdnUrl = getUrlFromDirectPath(msg.directPath)
-		fetch(cdnUrl, {
-			...options,
-			method: 'DELETE',
-			headers: { ...((options as RequestInit).headers ?? {}), Origin: DEFAULT_ORIGIN }
-		}).catch(() => {
-			// non-fatal — server will expire it anyway
-		})
-	}
-
-	return result
+	return processHistoryMessage(historyMsg, logger)
 }
 
 /**

src/WAUSync/USyncQuery.ts

@@ -10,7 +10,7 @@ import {
 } from './Protocols'
 import { USyncUser } from './USyncUser'
 
-export type USyncQueryResultList = { [protocol: string]: unknown; id: string; rawId?: number }
+export type USyncQueryResultList = { [protocol: string]: unknown; id: string }
 
 export type USyncQueryResult = {
 	list: USyncQueryResultList[]
@@ -68,8 +68,10 @@ export class USyncQuery {
 		//TODO: see if there are any errors in the result node
 		//const resultNode = getBinaryNodeChild(usyncNode, 'result')
 
-		const parseNodeList = (content: BinaryNode[]): USyncQueryResultList[] =>
-			content.reduce((acc: USyncQueryResultList[], node) => {
+		const listNode = usyncNode ? getBinaryNodeChild(usyncNode, 'list') : undefined
+
+		if (listNode?.content && Array.isArray(listNode.content)) {
+			queryResult.list = listNode.content.reduce((acc: USyncQueryResultList[], node) => {
 				const id = node?.attrs.jid
 				if (id) {
 					const data = Array.isArray(node?.content)
@@ -87,24 +89,15 @@ export class USyncQuery {
 									.filter(([, b]) => b !== null) as [string, unknown][]
 							)
 						: {}
-					const rawIdAttr = node?.attrs?.['raw_id']
-					const rawId = rawIdAttr !== undefined ? Number(rawIdAttr) : undefined
-					acc.push({ ...data, id, ...(rawId !== undefined && !isNaN(rawId) ? { rawId } : {}) })
+					acc.push({ ...data, id })
 				}
 
 				return acc
 			}, [])
-
-		const listNode = usyncNode ? getBinaryNodeChild(usyncNode, 'list') : undefined
-		if (listNode?.content && Array.isArray(listNode.content)) {
-			queryResult.list = parseNodeList(listNode.content)
-		}
-
-		const sideListNode = usyncNode ? getBinaryNodeChild(usyncNode, 'side_list') : undefined
-		if (sideListNode?.content && Array.isArray(sideListNode.content)) {
-			queryResult.sideList = parseNodeList(sideListNode.content)
 		}
 
+		//TODO: implement side list
+		//const sideListNode = getBinaryNodeChild(usyncNode, 'side_list')
 		return queryResult
 	}