diff --git a/Makefile b/Makefile
index ba8168617..99a633c0b 100644
--- a/Makefile
+++ b/Makefile
@@ -87,6 +87,14 @@ build: generate
 	@echo "Build complete: $(BINARY_PATH)"
 	@ln -sf $(BINARY_NAME)-$(PLATFORM)-$(ARCH) $(BUILD_DIR)/$(BINARY_NAME)
 
+## build-whatsapp-native: Build with WhatsApp native (whatsmeow) support; larger binary
+build-whatsapp-native: generate
+	@echo "Building $(BINARY_NAME) with WhatsApp native for $(PLATFORM)/$(ARCH)..."
+	@mkdir -p $(BUILD_DIR)
+	@$(GO) build $(GOFLAGS) -tags whatsapp_native $(LDFLAGS) -o $(BINARY_PATH) ./$(CMD_DIR)
+	@echo "Build complete: $(BINARY_PATH)"
+	@ln -sf $(BINARY_NAME)-$(PLATFORM)-$(ARCH) $(BUILD_DIR)/$(BINARY_NAME)
+
 ## build-linux-arm: Build for Linux ARMv7 (e.g. Raspberry Pi Zero 2 W 32-bit)
 build-linux-arm: generate
 	@echo "Building for linux/arm (GOARM=7)..."
diff --git a/README.md b/README.md
index 35c62434f..31495176a 100644
--- a/README.md
+++ b/README.md
@@ -391,7 +391,7 @@ picoclaw gateway
 
 PicoClaw can connect to WhatsApp in two ways:
 
-- **Native (recommended):** In-process using [whatsmeow](https://github.com/tulir/whatsmeow). No separate bridge. Set `"use_native": true` and leave `bridge_url` empty. On first run, scan the QR code with WhatsApp (Linked Devices). Session is stored under your workspace (e.g. `workspace/whatsapp/`).
+- **Native (recommended):** In-process using [whatsmeow](https://github.com/tulir/whatsmeow). No separate bridge. Set `"use_native": true` and leave `bridge_url` empty. On first run, scan the QR code with WhatsApp (Linked Devices). Session is stored under your workspace (e.g. `workspace/whatsapp/`). The native channel is **optional** to keep the default binary small; build with `-tags whatsapp_native` (e.g. `make build-whatsapp-native` or `go build -tags whatsapp_native ./cmd/...`).
 - **Bridge:** Connect to an external WebSocket bridge. Set `bridge_url` (e.g. `ws://localhost:3001`) and keep `use_native` false.
 
 **Configure (native)**
diff --git a/pkg/channels/whatsapp_native.go b/pkg/channels/whatsapp_native.go
index cbd02561f..3099afdcc 100644
--- a/pkg/channels/whatsapp_native.go
+++ b/pkg/channels/whatsapp_native.go
@@ -1,3 +1,5 @@
+//go:build whatsapp_native
+
 // PicoClaw - Ultra-lightweight personal AI agent
 // License: MIT
 //
@@ -58,16 +60,17 @@ type WhatsAppNativeChannel struct {
 
 // NewWhatsAppNativeChannel creates a WhatsApp channel that uses whatsmeow for connection.
 // storePath is the directory for the SQLite session store (e.g. workspace/whatsapp).
-func NewWhatsAppNativeChannel(cfg config.WhatsAppConfig, bus *bus.MessageBus, storePath string) (*WhatsAppNativeChannel, error) {
+func NewWhatsAppNativeChannel(cfg config.WhatsAppConfig, bus *bus.MessageBus, storePath string) (Channel, error) {
 	base := NewBaseChannel("whatsapp", cfg, bus, cfg.AllowFrom)
 	if storePath == "" {
 		storePath = "whatsapp"
 	}
-	return &WhatsAppNativeChannel{
+	c := &WhatsAppNativeChannel{
 		BaseChannel: base,
 		config:      cfg,
 		storePath:   storePath,
-	}, nil
+	}
+	return c, nil
 }
 
 func (c *WhatsAppNativeChannel) Start(ctx context.Context) error {
diff --git a/pkg/channels/whatsapp_native_stub.go b/pkg/channels/whatsapp_native_stub.go
new file mode 100644
index 000000000..b4a826fa4
--- /dev/null
+++ b/pkg/channels/whatsapp_native_stub.go
@@ -0,0 +1,16 @@
+//go:build !whatsapp_native
+
+package channels
+
+import (
+	"fmt"
+
+	"github.com/sipeed/picoclaw/pkg/bus"
+	"github.com/sipeed/picoclaw/pkg/config"
+)
+
+// NewWhatsAppNativeChannel returns an error when the binary was not built with -tags whatsapp_native.
+// Build with: go build -tags whatsapp_native ./cmd/...
+func NewWhatsAppNativeChannel(cfg config.WhatsAppConfig, bus *bus.MessageBus, storePath string) (Channel, error) {
+	return nil, fmt.Errorf("whatsapp native not compiled in; build with -tags whatsapp_native")
+}