feat(whatsapp): add debounceMs for batching rapid messages

Add a `debounceMs` configuration option to WhatsApp channel settings
that batches rapid consecutive messages from the same sender into a
single response. This prevents triggering separate agent runs for
each message when a user sends multiple short messages in quick
succession (e.g., "Hey!", "how are you?", "I was wondering...").

Changes:
- Add `debounceMs` config to WhatsAppConfig and WhatsAppAccountConfig
- Implement message buffering in `monitorWebInbox` with:
  - Map-based buffer keyed by sender (DM) or chat ID (groups)
  - Debounce timer that resets on each new message
  - Message combination with newline separator
  - Single message optimization (no modification if only one message)
- Wire `debounceMs` through account resolution and monitor tuning
- Add UI hints and schema documentation

Usage example:
{
  "channels": {
    "whatsapp": {
      "debounceMs": 5000  // 5 second window
    }
  }
}

Default behavior: `debounceMs: 0` (disabled by default)

Verified: All existing tests pass (3204 tests), TypeScript compilation
succeeds with no errors.

Implemented with assistance from AI coding tools.

Closes #967

src/config/schema.ts

@@ -189,6 +189,7 @@ const FIELD_LABELS: Record<string, string> = {
   "channels.telegram.timeoutSeconds": "Telegram API Timeout (seconds)",
   "channels.whatsapp.dmPolicy": "WhatsApp DM Policy",
   "channels.whatsapp.selfChatMode": "WhatsApp Self-Phone Mode",
+  "channels.whatsapp.debounceMs": "WhatsApp Message Debounce (ms)",
   "channels.signal.dmPolicy": "Signal DM Policy",
   "channels.imessage.dmPolicy": "iMessage DM Policy",
   "channels.discord.dm.policy": "Discord DM Policy",
@@ -348,6 +349,8 @@ const FIELD_HELP: Record<string, string> = {
   "channels.whatsapp.dmPolicy":
     'Direct message access control ("pairing" recommended). "open" requires channels.whatsapp.allowFrom=["*"].',
   "channels.whatsapp.selfChatMode": "Same-phone setup (bot uses your personal WhatsApp number).",
+  "channels.whatsapp.debounceMs":
+    "Debounce window (ms) for batching rapid consecutive messages from the same sender (0 to disable).",
   "channels.signal.dmPolicy":
     'Direct message access control ("pairing" recommended). "open" requires channels.signal.allowFrom=["*"].',
   "channels.imessage.dmPolicy":

src/config/types.whatsapp.ts

@@ -75,6 +75,8 @@ export type WhatsAppConfig = {
      */
     group?: "always" | "mentions" | "never";
   };
+  /** Debounce window (ms) for batching rapid consecutive messages from the same sender (0 to disable). */
+  debounceMs?: number;
 };
 
 export type WhatsAppAccountConfig = {
@@ -131,4 +133,6 @@ export type WhatsAppAccountConfig = {
      */
     group?: "always" | "mentions" | "never";
   };
+  /** Debounce window (ms) for batching rapid consecutive messages from the same sender (0 to disable). */
+  debounceMs?: number;
 };

src/config/zod-schema.providers-whatsapp.ts

@@ -46,6 +46,7 @@ export const WhatsAppAccountSchema = z
         group: z.enum(["always", "mentions", "never"]).optional().default("mentions"),
       })
       .optional(),
+    debounceMs: z.number().int().nonnegative().optional().default(0),
   })
   .superRefine((value, ctx) => {
     if (value.dmPolicy !== "open") return;
@@ -101,6 +102,7 @@ export const WhatsAppConfigSchema = z
         group: z.enum(["always", "mentions", "never"]).optional().default("mentions"),
       })
       .optional(),
+    debounceMs: z.number().int().nonnegative().optional().default(0),
   })
   .superRefine((value, ctx) => {
     if (value.dmPolicy !== "open") return;

src/web/accounts.ts

@@ -26,6 +26,7 @@ export type ResolvedWhatsAppAccount = {
   blockStreaming?: boolean;
   ackReaction?: WhatsAppAccountConfig["ackReaction"];
   groups?: WhatsAppAccountConfig["groups"];
+  debounceMs?: number;
 };
 
 function listConfiguredAccountIds(cfg: ClawdbotConfig): string[] {
@@ -153,6 +154,7 @@ export function resolveWhatsAppAccount(params: {
     blockStreaming: accountCfg?.blockStreaming ?? rootCfg?.blockStreaming,
     ackReaction: accountCfg?.ackReaction ?? rootCfg?.ackReaction,
     groups: accountCfg?.groups ?? rootCfg?.groups,
+    debounceMs: accountCfg?.debounceMs ?? rootCfg?.debounceMs,
   };
 }
 

src/web/auto-reply/monitor.ts

@@ -175,6 +175,7 @@ export async function monitorWebChannel(
       authDir: account.authDir,
       mediaMaxMb: account.mediaMaxMb,
       sendReadReceipts: account.sendReadReceipts,
+      debounceMs: tuning.debounceMs ?? account.debounceMs,
       onMessage: async (msg: WebInboundMsg) => {
         handledMessages += 1;
         lastMessageAt = Date.now();

src/web/auto-reply/types.ts

@@ -30,4 +30,6 @@ export type WebMonitorTuning = {
   statusSink?: (status: WebChannelStatus) => void;
   /** WhatsApp account id. Default: "default". */
   accountId?: string;
+  /** Debounce window (ms) for batching rapid consecutive messages from the same sender. */
+  debounceMs?: number;
 };

src/web/inbound/monitor.ts

@@ -28,6 +28,8 @@ export async function monitorWebInbox(options: {
   mediaMaxMb?: number;
   /** Send read receipts for incoming messages (default true). */
   sendReadReceipts?: boolean;
+  /** Debounce window (ms) for batching rapid consecutive messages from the same sender (0 to disable). */
+  debounceMs?: number;
 }) {
   const inboundLogger = getChildLogger({ module: "web-inbound" });
   const inboundConsoleLog = createSubsystemLogger("gateway/channels/whatsapp").child("inbound");
@@ -56,6 +58,27 @@ export async function monitorWebInbox(options: {
 
   const selfJid = sock.user?.id;
   const selfE164 = selfJid ? jidToE164(selfJid) : null;
+  // Message batching for debounce
+  const debounceWindowMs = options.debounceMs ?? 0;
+  const messageBuffer = new Map<
+    string,
+    { messages: WebInboundMessage[]; timeout: ReturnType<typeof setTimeout> | null }
+  >();
+
+  const processBufferedMessages = async (key: string) => {
+    const buffered = messageBuffer.get(key);
+    if (!buffered) return;
+    const { messages } = buffered;
+    messageBuffer.delete(key);
+    if (messages.length === 0) return;
+    if (messages.length === 1) {
+      await options.onMessage(messages[0]);
+      return;
+    }
+    const combinedBody = messages.map((m) => m.body).join("\n");
+    const combinedMessage: WebInboundMessage = { ...messages[0], body: combinedBody };
+    await options.onMessage(combinedMessage);
+  };
   const groupMetaCache = new Map<
     string,
     { subject?: string; participants?: string[]; expires: number }
@@ -217,9 +240,7 @@ export async function monitorWebInbox(options: {
         { from, to: selfE164 ?? "me", body, mediaPath, mediaType, timestamp },
         "inbound message",
       );
-      try {
+      const inboundMessage: WebInboundMessage = {
-        const task = Promise.resolve(
-          options.onMessage({
         id,
         from,
         conversationId: from,
@@ -247,7 +268,29 @@ export async function monitorWebInbox(options: {
         sendMedia,
         mediaPath,
         mediaType,
-          }),
+      };
+      try {
+        const task = Promise.resolve(
+          (async () => {
+            // Apply debounce batching if configured
+            if (debounceWindowMs > 0) {
+              const bufferKey = group ? remoteJid : from;
+              const existing = messageBuffer.get(bufferKey);
+              if (existing) {
+                if (existing.timeout) clearTimeout(existing.timeout);
+                existing.messages.push(inboundMessage);
+                existing.timeout = setTimeout(() => processBufferedMessages(bufferKey), debounceWindowMs);
+              } else {
+                messageBuffer.set(bufferKey, {
+                  messages: [inboundMessage],
+                  timeout: setTimeout(() => processBufferedMessages(bufferKey), debounceWindowMs),
+                });
+              }
+            } else {
+              // No debouncing, process immediately
+              await options.onMessage(inboundMessage);
+            }
+          })(),
         );
         void task.catch((err) => {
           inboundLogger.error({ error: String(err) }, "failed handling inbound web message");