diff --git a/scripts/build.sh b/scripts/build.sh
index 0168a6e..6660b1a 100755
--- a/scripts/build.sh
+++ b/scripts/build.sh
@@ -1,7 +1,14 @@
 #!/bin/bash
 set -e
 
-# Individual build scripts
+# ============================================================
+# Verstak build script
+# Usage: ./scripts/build.sh [gui|server|extensions|all]
+# ============================================================
+
+BUILD_DIR="build"
+
+# --- GUI binary ---
 
 build_gui() {
   echo "==> Building GUI binary..."
@@ -16,31 +23,105 @@ build_gui() {
 
   # Build Go binary with Wails v2
   # Tags: webkit2_41 required for WebKitGTK 2.41+, desktop/production for Wails
-  go build -tags "webkit2_41 desktop production" -ldflags="-s -w" -o build/verstak-gui-linux-amd64 ./cmd/verstak-gui/
+  go build -tags "webkit2_41 desktop production" -ldflags="-s -w" -o "$BUILD_DIR/verstak-gui-linux-amd64" ./cmd/verstak-gui/
 
-  echo "==> GUI binary: build/verstak-gui-linux-amd64"
+  echo "==> GUI binary: $BUILD_DIR/verstak-gui-linux-amd64"
 }
 
+# --- Server binary ---
+
 build_server() {
   echo "==> Building server binary..."
-  go build -ldflags="-s -w" -o build/verstak-server-linux-amd64 ./cmd/verstak-server/
-  echo "==> Server binary: build/verstak-server-linux-amd64"
+  go build -ldflags="-s -w" -o "$BUILD_DIR/verstak-server-linux-amd64" ./cmd/verstak-server/
+  echo "==> Server binary: $BUILD_DIR/verstak-server-linux-amd64"
 }
 
+# --- Chrome extension ---
+
+build_chrome_extension() {
+  echo "==> Building Chrome extension..."
+
+  local ext_dir="extension"
+  local out_file="$BUILD_DIR/verstak-bridge-chrome.zip"
+
+  if [ ! -d "$ext_dir" ]; then
+    echo "ERROR: $ext_dir/ directory not found"
+    return 1
+  fi
+
+  # Create a clean zip: manifest.json, background.js, popup/*
+  # Exclude any hidden files, icons (not needed for dev install), and OS junk
+  cd "$ext_dir"
+  zip -r "../$out_file" \
+    manifest.json \
+    background.js \
+    popup/ \
+    -x "*/.DS_Store" "*/Thumbs.db" "*/__MACOSX/*" "*/.git/*"
+  cd ..
+
+  echo "==> Chrome extension: $out_file"
+}
+
+# --- Firefox extension ---
+
+build_firefox_extension() {
+  echo "==> Building Firefox extension..."
+
+  local ext_dir="extension-firefox"
+  local out_file="$BUILD_DIR/verstak-bridge-firefox.xpi"
+
+  if [ ! -d "$ext_dir" ]; then
+    echo "ERROR: $ext_dir/ directory not found"
+    return 1
+  fi
+
+  # Firefox xpi is a zip with .xpi extension
+  # Must include manifest.json at root
+  cd "$ext_dir"
+  zip -r "../$out_file" \
+    manifest.json \
+    background.js \
+    popup/ \
+    -x "*/.DS_Store" "*/Thumbs.db" "*/__MACOSX/*" "*/.git/*"
+  cd ..
+
+  echo "==> Firefox extension: $out_file"
+}
+
+# --- All extensions ---
+
+build_extensions() {
+  mkdir -p "$BUILD_DIR"
+  build_chrome_extension
+  build_firefox_extension
+  echo "==> Extensions built."
+  ls -lh "$BUILD_DIR"/verstak-bridge-*
+}
+
+# --- Everything ---
+
 build_all() {
-  mkdir -p build
+  mkdir -p "$BUILD_DIR"
   build_gui
   build_server
-  echo "==> All binaries built."
-  ls -lh build/
+  build_chrome_extension
+  build_firefox_extension
+  echo ""
+  echo "==> All builds complete."
+  ls -lh "$BUILD_DIR/"
 }
 
+# --- Main ---
+
 case "${1:-all}" in
-  gui)    build_gui ;;
-  server) build_server ;;
-  all)    build_all ;;
+  gui)         build_gui ;;
+  server)      build_server ;;
+  extensions)  build_extensions ;;
+  chrome)      mkdir -p "$BUILD_DIR"; build_chrome_extension ;;
+  firefox)     mkdir -p "$BUILD_DIR"; build_firefox_extension ;;
+  all)         build_all ;;
   *)
-    echo "Usage: $0 [gui|server|all]"
+    echo "Usage: $0 [gui|server|extensions|chrome|firefox|all]"
     exit 1
     ;;
 esac