diff --git a/CHANGELOG.md b/CHANGELOG.md
index 10935941f..5dad1c15c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@
 - Telegram: add `/whoami` + `/id` commands to reveal sender id for allowlists.
 - Telegram/Onboarding: allow `@username` and prefixed ids in `allowFrom` prompts (with stability warning).
 - Control UI: stop auto-writing `telegram.groups["*"]` and warn/confirm before enabling wildcard groups.
+- WhatsApp: send ack reactions only for handled messages and ignore legacy `messages.ackReaction` (doctor copies to `whatsapp.ackReaction`). (#629) — thanks @pasogott.
 
 ## 2026.1.11-6
 
diff --git a/docs/providers/whatsapp.md b/docs/providers/whatsapp.md
index e425adb17..5adce09b8 100644
--- a/docs/providers/whatsapp.md
+++ b/docs/providers/whatsapp.md
@@ -159,6 +159,55 @@ Behavior:
 - WhatsApp Web sends standard messages (no quoted reply threading in the current gateway).
 - Reply tags are ignored on this provider.
 
+## Acknowledgment reactions (auto-react on receipt)
+
+WhatsApp can automatically send emoji reactions to incoming messages immediately upon receipt, before the bot generates a reply. This provides instant feedback to users that their message was received.
+
+**Configuration:**
+```json
+{
+  "whatsapp": {
+    "ackReaction": {
+      "emoji": "👀",
+      "direct": true,
+      "group": "mentions"
+    }
+  }
+}
+```
+
+**Options:**
+- `emoji` (string): Emoji to use for acknowledgment (e.g., "👀", "✅", "📨"). Empty or omitted = feature disabled.
+- `direct` (boolean, default: `true`): Send reactions in direct/DM chats.
+- `group` (string, default: `"mentions"`): Group chat behavior:
+  - `"always"`: React to all group messages (even without @mention)
+  - `"mentions"`: React only when bot is @mentioned
+  - `"never"`: Never react in groups
+
+**Per-account override:**
+```json
+{
+  "whatsapp": {
+    "accounts": {
+      "work": {
+        "ackReaction": {
+          "emoji": "✅",
+          "direct": false,
+          "group": "always"
+        }
+      }
+    }
+  }
+}
+```
+
+**Behavior notes:**
+- Reactions are sent **immediately** upon message receipt, before typing indicators or bot replies.
+- In groups with `requireMention: false` (activation: always), `group: "mentions"` will react to all messages (not just @mentions).
+- Fire-and-forget: reaction failures are logged but don't prevent the bot from replying.
+- Participant JID is automatically included for group reactions.
+- WhatsApp ignores `messages.ackReaction`; use `whatsapp.ackReaction` instead.
+
 ## Agent tool (reactions)
 - Tool: `whatsapp` with `react` action (`chatJid`, `messageId`, `emoji`, optional `remove`).
 - Optional: `participant` (group sender), `fromMe` (reacting to your own message), `accountId` (multi-account).
@@ -205,8 +254,10 @@ Behavior:
 - `whatsapp.selfChatMode` (same-phone setup; bot uses your personal WhatsApp number).
 - `whatsapp.allowFrom` (DM allowlist).
 - `whatsapp.mediaMaxMb` (inbound media save cap).
+- `whatsapp.ackReaction` (auto-reaction on message receipt: `{emoji, direct, group}`).
 - `whatsapp.accounts.<accountId>.*` (per-account settings + optional `authDir`).
 - `whatsapp.accounts.<accountId>.mediaMaxMb` (per-account inbound media cap).
+- `whatsapp.accounts.<accountId>.ackReaction` (per-account ack reaction override).
 - `whatsapp.groupAllowFrom` (group sender allowlist).
 - `whatsapp.groupPolicy` (group policy).
 - `whatsapp.historyLimit` / `whatsapp.accounts.<accountId>.historyLimit` (group history context; `0` disables).
diff --git a/docs/tools/slash-commands.md b/docs/tools/slash-commands.md
index 39206d9e3..c8fe4bdf3 100644
--- a/docs/tools/slash-commands.md
+++ b/docs/tools/slash-commands.md
@@ -40,8 +40,10 @@ Directives (`/think`, `/verbose`, `/reasoning`, `/elevated`) are parsed even whe
 Text + native (when enabled):
 - `/help`
 - `/commands`
-- `/status` (show current status; includes a short usage line when available; alias: `/usage`)
-- `/whoami` (show your sender id; alias: `/id`)
+- `/status`
+- `/status` (show current status; includes a short usage line when available)
+- `/usage` (alias: `/status`)
+- `/whoami` (alias: `/id`)
 - `/config show|get|set|unset` (persist config to disk, owner-only; requires `commands.config: true`)
 - `/debug show|set|unset|reset` (runtime overrides, owner-only; requires `commands.debug: true`)
 - `/cost on|off` (toggle per-response usage line)
diff --git a/src/commands/doctor-legacy-config.ts b/src/commands/doctor-legacy-config.ts
index 4e359b675..4e0312b51 100644
--- a/src/commands/doctor-legacy-config.ts
+++ b/src/commands/doctor-legacy-config.ts
@@ -251,6 +251,39 @@ export function normalizeLegacyConfigValues(cfg: ClawdbotConfig): {
     }
   }
 
+  const legacyAckReaction = cfg.messages?.ackReaction?.trim();
+  if (legacyAckReaction) {
+    const hasWhatsAppAck = cfg.whatsapp?.ackReaction !== undefined;
+    if (!hasWhatsAppAck) {
+      const legacyScope = cfg.messages?.ackReactionScope ?? "group-mentions";
+      let direct = true;
+      let group: "always" | "mentions" | "never" = "mentions";
+      if (legacyScope === "all") {
+        direct = true;
+        group = "always";
+      } else if (legacyScope === "direct") {
+        direct = true;
+        group = "never";
+      } else if (legacyScope === "group-all") {
+        direct = false;
+        group = "always";
+      } else if (legacyScope === "group-mentions") {
+        direct = false;
+        group = "mentions";
+      }
+      next = {
+        ...next,
+        whatsapp: {
+          ...next.whatsapp,
+          ackReaction: { emoji: legacyAckReaction, direct, group },
+        },
+      };
+      changes.push(
+        `Copied messages.ackReaction → whatsapp.ackReaction (scope: ${legacyScope}).`,
+      );
+    }
+  }
+
   return { config: next, changes };
 }
 
diff --git a/src/config/types.ts b/src/config/types.ts
index 545566495..235177962 100644
--- a/src/config/types.ts
+++ b/src/config/types.ts
@@ -169,6 +169,21 @@ export type WhatsAppConfig = {
       requireMention?: boolean;
     }
   >;
+  /** Acknowledgment reaction sent immediately upon message receipt. */
+  ackReaction?: {
+    /** Emoji to use for acknowledgment (e.g., "👀"). Empty = disabled. */
+    emoji?: string;
+    /** Send reactions in direct chats. Default: true. */
+    direct?: boolean;
+    /**
+     * Send reactions in group chats:
+     * - "always": react to all group messages
+     * - "mentions": react only when bot is mentioned
+     * - "never": never react in groups
+     * Default: "mentions"
+     */
+    group?: "always" | "mentions" | "never";
+  };
 };
 
 export type WhatsAppAccountConfig = {
@@ -202,6 +217,21 @@ export type WhatsAppAccountConfig = {
       requireMention?: boolean;
     }
   >;
+  /** Acknowledgment reaction sent immediately upon message receipt. */
+  ackReaction?: {
+    /** Emoji to use for acknowledgment (e.g., "👀"). Empty = disabled. */
+    emoji?: string;
+    /** Send reactions in direct chats. Default: true. */
+    direct?: boolean;
+    /**
+     * Send reactions in group chats:
+     * - "always": react to all group messages
+     * - "mentions": react only when bot is mentioned
+     * - "never": never react in groups
+     * Default: "mentions"
+     */
+    group?: "always" | "mentions" | "never";
+  };
 };
 
 export type BrowserProfileConfig = {
diff --git a/src/config/zod-schema.ts b/src/config/zod-schema.ts
index 0d38a8c64..d7fd6d04b 100644
--- a/src/config/zod-schema.ts
+++ b/src/config/zod-schema.ts
@@ -1375,6 +1375,16 @@ export const ClawdbotSchema = z
                       .optional(),
                   )
                   .optional(),
+                ackReaction: z
+                  .object({
+                    emoji: z.string().optional(),
+                    direct: z.boolean().optional().default(true),
+                    group: z
+                      .enum(["always", "mentions", "never"])
+                      .optional()
+                      .default("mentions"),
+                  })
+                  .optional(),
               })
               .superRefine((value, ctx) => {
                 if (value.dmPolicy !== "open") return;
@@ -1421,6 +1431,16 @@ export const ClawdbotSchema = z
               .optional(),
           )
           .optional(),
+        ackReaction: z
+          .object({
+            emoji: z.string().optional(),
+            direct: z.boolean().optional().default(true),
+            group: z
+              .enum(["always", "mentions", "never"])
+              .optional()
+              .default("mentions"),
+          })
+          .optional(),
       })
       .superRefine((value, ctx) => {
         if (value.dmPolicy !== "open") return;
diff --git a/src/web/accounts.ts b/src/web/accounts.ts
index 4d71c2a0f..6536ae4ed 100644
--- a/src/web/accounts.ts
+++ b/src/web/accounts.ts
@@ -26,6 +26,7 @@ export type ResolvedWhatsAppAccount = {
   textChunkLimit?: number;
   mediaMaxMb?: number;
   blockStreaming?: boolean;
+  ackReaction?: WhatsAppAccountConfig["ackReaction"];
   groups?: WhatsAppAccountConfig["groups"];
 };
 
@@ -129,6 +130,7 @@ export function resolveWhatsAppAccount(params: {
     mediaMaxMb: accountCfg?.mediaMaxMb ?? params.cfg.whatsapp?.mediaMaxMb,
     blockStreaming:
       accountCfg?.blockStreaming ?? params.cfg.whatsapp?.blockStreaming,
+    ackReaction: accountCfg?.ackReaction ?? params.cfg.whatsapp?.ackReaction,
     groups: accountCfg?.groups ?? params.cfg.whatsapp?.groups,
   };
 }
diff --git a/src/web/auto-reply.ack-reaction.test.ts b/src/web/auto-reply.ack-reaction.test.ts
new file mode 100644
index 000000000..83dffe491
--- /dev/null
+++ b/src/web/auto-reply.ack-reaction.test.ts
@@ -0,0 +1,285 @@
+import { describe, expect, it } from "vitest";
+import type { ClawdbotConfig } from "../config/types.js";
+
+describe("WhatsApp ack reaction logic", () => {
+  // Helper to simulate the logic from auto-reply.ts
+  function shouldSendReaction(
+    cfg: ClawdbotConfig,
+    msg: {
+      id?: string;
+      chatType: "direct" | "group";
+      wasMentioned?: boolean;
+    },
+    groupActivation?: "always" | "mention",
+  ): boolean {
+    const ackConfig = cfg.whatsapp?.ackReaction;
+    const emoji = (ackConfig?.emoji ?? "").trim();
+    const directEnabled = ackConfig?.direct ?? true;
+    const groupMode = ackConfig?.group ?? "mentions";
+
+    if (!emoji) return false;
+    if (!msg.id) return false;
+
+    // Direct chat logic
+    if (msg.chatType === "direct") {
+      return directEnabled;
+    }
+
+    // Group chat logic
+    if (msg.chatType === "group") {
+      if (groupMode === "never") return false;
+      if (groupMode === "always") return true;
+      if (groupMode === "mentions") {
+        // If group activation is "always", always react
+        if (groupActivation === "always") return true;
+        // Otherwise, only react if bot was mentioned
+        return msg.wasMentioned === true;
+      }
+    }
+
+    return false;
+  }
+
+  describe("direct chat", () => {
+    it("should react when direct=true", () => {
+      const cfg: ClawdbotConfig = {
+        whatsapp: { ackReaction: { emoji: "👀", direct: true } },
+      };
+      expect(
+        shouldSendReaction(cfg, {
+          id: "msg1",
+          chatType: "direct",
+        }),
+      ).toBe(true);
+    });
+
+    it("should not react when direct=false", () => {
+      const cfg: ClawdbotConfig = {
+        whatsapp: { ackReaction: { emoji: "👀", direct: false } },
+      };
+      expect(
+        shouldSendReaction(cfg, {
+          id: "msg1",
+          chatType: "direct",
+        }),
+      ).toBe(false);
+    });
+
+    it("should not react when emoji is empty", () => {
+      const cfg: ClawdbotConfig = {
+        whatsapp: { ackReaction: { emoji: "", direct: true } },
+      };
+      expect(
+        shouldSendReaction(cfg, {
+          id: "msg1",
+          chatType: "direct",
+        }),
+      ).toBe(false);
+    });
+
+    it("should not react when message id is missing", () => {
+      const cfg: ClawdbotConfig = {
+        whatsapp: { ackReaction: { emoji: "👀", direct: true } },
+      };
+      expect(
+        shouldSendReaction(cfg, {
+          chatType: "direct",
+        }),
+      ).toBe(false);
+    });
+  });
+
+  describe("group chat - always mode", () => {
+    it("should react to all messages when group=always", () => {
+      const cfg: ClawdbotConfig = {
+        whatsapp: { ackReaction: { emoji: "👀", group: "always" } },
+      };
+      expect(
+        shouldSendReaction(cfg, {
+          id: "msg1",
+          chatType: "group",
+          wasMentioned: false,
+        }),
+      ).toBe(true);
+    });
+
+    it("should react even with mention when group=always", () => {
+      const cfg: ClawdbotConfig = {
+        whatsapp: { ackReaction: { emoji: "👀", group: "always" } },
+      };
+      expect(
+        shouldSendReaction(cfg, {
+          id: "msg1",
+          chatType: "group",
+          wasMentioned: true,
+        }),
+      ).toBe(true);
+    });
+  });
+
+  describe("group chat - mentions mode", () => {
+    it("should react when mentioned", () => {
+      const cfg: ClawdbotConfig = {
+        whatsapp: { ackReaction: { emoji: "👀", group: "mentions" } },
+      };
+      expect(
+        shouldSendReaction(cfg, {
+          id: "msg1",
+          chatType: "group",
+          wasMentioned: true,
+        }),
+      ).toBe(true);
+    });
+
+    it("should not react when not mentioned", () => {
+      const cfg: ClawdbotConfig = {
+        whatsapp: { ackReaction: { emoji: "👀", group: "mentions" } },
+      };
+      expect(
+        shouldSendReaction(
+          cfg,
+          {
+            id: "msg1",
+            chatType: "group",
+            wasMentioned: false,
+          },
+          "mention", // group activation
+        ),
+      ).toBe(false);
+    });
+
+    it("should react to all messages when group activation is always", () => {
+      const cfg: ClawdbotConfig = {
+        whatsapp: { ackReaction: { emoji: "👀", group: "mentions" } },
+      };
+      expect(
+        shouldSendReaction(
+          cfg,
+          {
+            id: "msg1",
+            chatType: "group",
+            wasMentioned: false,
+          },
+          "always", // group has requireMention=false
+        ),
+      ).toBe(true);
+    });
+  });
+
+  describe("group chat - never mode", () => {
+    it("should not react even with mention", () => {
+      const cfg: ClawdbotConfig = {
+        whatsapp: { ackReaction: { emoji: "👀", group: "never" } },
+      };
+      expect(
+        shouldSendReaction(cfg, {
+          id: "msg1",
+          chatType: "group",
+          wasMentioned: true,
+        }),
+      ).toBe(false);
+    });
+
+    it("should not react without mention", () => {
+      const cfg: ClawdbotConfig = {
+        whatsapp: { ackReaction: { emoji: "👀", group: "never" } },
+      };
+      expect(
+        shouldSendReaction(cfg, {
+          id: "msg1",
+          chatType: "group",
+          wasMentioned: false,
+        }),
+      ).toBe(false);
+    });
+  });
+
+  describe("combinations", () => {
+    it("direct=false, group=always: only groups", () => {
+      const cfg: ClawdbotConfig = {
+        whatsapp: {
+          ackReaction: { emoji: "✅", direct: false, group: "always" },
+        },
+      };
+
+      expect(shouldSendReaction(cfg, { id: "m1", chatType: "direct" })).toBe(
+        false,
+      );
+
+      expect(
+        shouldSendReaction(cfg, {
+          id: "m2",
+          chatType: "group",
+          wasMentioned: false,
+        }),
+      ).toBe(true);
+    });
+
+    it("direct=true, group=never: only direct", () => {
+      const cfg: ClawdbotConfig = {
+        whatsapp: {
+          ackReaction: { emoji: "🤖", direct: true, group: "never" },
+        },
+      };
+
+      expect(shouldSendReaction(cfg, { id: "m1", chatType: "direct" })).toBe(
+        true,
+      );
+
+      expect(
+        shouldSendReaction(cfg, {
+          id: "m2",
+          chatType: "group",
+          wasMentioned: true,
+        }),
+      ).toBe(false);
+    });
+  });
+
+  describe("defaults", () => {
+    it("should default direct=true", () => {
+      const cfg: ClawdbotConfig = {
+        whatsapp: { ackReaction: { emoji: "👀" } },
+      };
+      expect(shouldSendReaction(cfg, { id: "m1", chatType: "direct" })).toBe(
+        true,
+      );
+    });
+
+    it("should default group=mentions", () => {
+      const cfg: ClawdbotConfig = {
+        whatsapp: { ackReaction: { emoji: "👀" } },
+      };
+
+      expect(
+        shouldSendReaction(cfg, {
+          id: "m1",
+          chatType: "group",
+          wasMentioned: false,
+        }),
+      ).toBe(false);
+
+      expect(
+        shouldSendReaction(cfg, {
+          id: "m2",
+          chatType: "group",
+          wasMentioned: true,
+        }),
+      ).toBe(true);
+    });
+  });
+
+  describe("legacy config is ignored", () => {
+    it("does not use messages.ackReaction for WhatsApp", () => {
+      const cfg: ClawdbotConfig = {
+        messages: { ackReaction: "👀", ackReactionScope: "all" },
+      };
+      expect(
+        shouldSendReaction(cfg, {
+          id: "m1",
+          chatType: "direct",
+        }),
+      ).toBe(false);
+    });
+  });
+});
diff --git a/src/web/auto-reply.ts b/src/web/auto-reply.ts
index c41f6de11..6b3c4adc0 100644
--- a/src/web/auto-reply.ts
+++ b/src/web/auto-reply.ts
@@ -68,7 +68,7 @@ import { resolveWhatsAppAccount } from "./accounts.js";
 import { setActiveWebListener } from "./active-listener.js";
 import { monitorWebInbox } from "./inbound.js";
 import { loadWebMedia } from "./media.js";
-import { sendMessageWhatsApp } from "./outbound.js";
+import { sendMessageWhatsApp, sendReactionWhatsApp } from "./outbound.js";
 import {
   computeBackoff,
   newConnectionId,
@@ -826,6 +826,7 @@ export async function monitorWebProvider(
     ...baseCfg,
     whatsapp: {
       ...baseCfg.whatsapp,
+      ackReaction: account.ackReaction,
       messagePrefix: account.messagePrefix,
       allowFrom: account.allowFrom,
       groupAllowFrom: account.groupAllowFrom,
@@ -1199,6 +1200,64 @@ export async function monitorWebProvider(
         return false;
       }
 
+      // Send ack reaction immediately upon message receipt (post-gating)
+      if (msg.id) {
+        const ackConfig = cfg.whatsapp?.ackReaction;
+        const emoji = (ackConfig?.emoji ?? "").trim();
+        const directEnabled = ackConfig?.direct ?? true;
+        const groupMode = ackConfig?.group ?? "mentions";
+        const conversationIdForCheck = msg.conversationId ?? msg.from;
+
+        const shouldSendReaction = () => {
+          if (!emoji) return false;
+
+          if (msg.chatType === "direct") {
+            return directEnabled;
+          }
+
+          if (msg.chatType === "group") {
+            if (groupMode === "never") return false;
+            if (groupMode === "always") return true;
+            if (groupMode === "mentions") {
+              const activation = resolveGroupActivationFor({
+                agentId: route.agentId,
+                sessionKey: route.sessionKey,
+                conversationId: conversationIdForCheck,
+              });
+              if (activation === "always") return true;
+              return msg.wasMentioned === true;
+            }
+          }
+
+          return false;
+        };
+
+        if (shouldSendReaction()) {
+          replyLogger.info(
+            { chatId: msg.chatId, messageId: msg.id, emoji },
+            "sending ack reaction",
+          );
+          sendReactionWhatsApp(msg.chatId, msg.id, emoji, {
+            verbose,
+            fromMe: false,
+            participant: msg.senderJid,
+            accountId: route.accountId,
+          }).catch((err) => {
+            replyLogger.warn(
+              {
+                error: formatError(err),
+                chatId: msg.chatId,
+                messageId: msg.id,
+              },
+              "failed to send ack reaction",
+            );
+            logVerbose(
+              `WhatsApp ack reaction failed for chat ${msg.chatId}: ${formatError(err)}`,
+            );
+          });
+        }
+      }
+
       const correlationId = msg.id ?? newConnectionId();
       replyLogger.info(
         {