diff --git a/extensions/README.md b/extensions/README.md
new file mode 100644
index 0000000..99a5fcc
--- /dev/null
+++ b/extensions/README.md
@@ -0,0 +1,64 @@
+# BearBrowser Bundled Extensions
+
+Two first-party extensions ship bundled with every BearBrowser build.
+They are force-installed at first launch via enterprise policy — no manual
+installation required.
+
+---
+
+## Bear Spaces (`bear-spaces@bearbrowser.local`)
+
+**Tab workspaces for BearBrowser.** Organises open tabs into named, persistent
+workspaces (similar to Arc Spaces). Each workspace maintains its own tab set;
+switching workspaces hides the current set and reveals the selected one without
+closing any tabs.
+
+Permissions: `tabs`, `tabHide`, `storage`, `contextMenus`, `nativeMessaging`.
+
+---
+
+## Bear Containers (`bear-containers@mdheller`)
+
+**Multi-account container isolation.** Each container gets its own cookie jar,
+localStorage, IndexedDB, and network cache, preventing cross-site tracking and
+enabling simultaneous sessions under different identities (work, personal, research,
+etc.) in the same browser window.
+
+Permissions: `cookies`, `tabs`, `storage`, `contextMenus`, `webRequest`,
+`webRequestBlocking`, `contextualIdentities`, `<all_urls>`.
+
+---
+
+## Development: loading via about:debugging
+
+To iterate on an extension without running a full overlay build:
+
+1. Open BearBrowser and navigate to `about:debugging#/runtime/this-firefox`.
+2. Click **Load Temporary Add-on...**.
+3. Select the `manifest.json` inside the extension directory
+   (`extensions/bear-spaces/manifest.json` or `extensions/bear-containers/manifest.json`).
+4. The extension loads for the current session.  It is removed on restart.
+
+For persistent dev loads without a full build, create a developer profile and
+add the extension to it directly.
+
+---
+
+## How bundling works in the overlay build
+
+During `scripts/bearbrowser-overlay-binary.sh` (step 7/10):
+
+1. **`scripts/bearbrowser-pack-extensions.sh`** zips each directory under
+   `extensions/` into a `.xpi` named by its gecko ID and writes the files to
+   `build/extensions/`.
+
+2. **`scripts/bearbrowser-install-extensions.sh`** copies the `.xpi` files into
+   `BearBrowser.app/Contents/Resources/distribution/extensions/` and merges the
+   following into `distribution/policies.json`:
+   - `Extensions.Install` — the `file://` URLs of each `.xpi`
+   - `ExtensionSettings.<gecko-id>.installation_mode = "force_installed"` — so
+     the extensions install silently even though the wildcard policy blocks
+     user-initiated installs
+
+On first browser launch the enterprise policy engine installs both extensions
+automatically.  No user action is required.
diff --git a/scripts/bearbrowser-install-extensions.sh b/scripts/bearbrowser-install-extensions.sh
new file mode 100755
index 0000000..89f60ec
--- /dev/null
+++ b/scripts/bearbrowser-install-extensions.sh
@@ -0,0 +1,148 @@
+#!/usr/bin/env bash
+# MIT License
+# Copyright (c) 2026 @mdheller
+#
+# bearbrowser-install-extensions.sh — Install packed .xpi extensions into a
+# BearBrowser.app bundle and wire them into policies.json as force-installed
+# enterprise extensions.
+#
+# This script runs AFTER bearbrowser-pack-extensions.sh has produced .xpi files
+# in build/extensions/ and AFTER the overlay build's profile injection step has
+# written distribution/policies.json.  It:
+#
+#   1. Creates <app>/Contents/Resources/distribution/extensions/
+#   2. Copies .xpi files from build/extensions/ into that directory
+#   3. Merges Extension and ExtensionSettings policies into the existing
+#      policies.json (or creates one if absent), preserving all other policies.
+#
+# The force_installed installation_mode causes Firefox/LibreWolf to install the
+# extension silently on first run without any user prompt, even when the wildcard
+# ExtensionSettings blocks other installs.
+#
+# Usage:
+#   ./scripts/bearbrowser-install-extensions.sh [/path/to/BearBrowser.app]
+#
+# Arguments:
+#   /path/to/BearBrowser.app    App bundle to install into.
+#                               Default: /Applications/BearBrowser.app
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+REPO="$(cd "$SCRIPT_DIR/.." && pwd)"
+
+APP="${1:-/Applications/BearBrowser.app}"
+XPI_SRC="$REPO/build/extensions"
+
+if [ ! -d "$APP" ]; then
+  echo "ERROR: app bundle not found: $APP" >&2
+  exit 64
+fi
+
+if [ ! -d "$XPI_SRC" ]; then
+  echo "ERROR: packed extensions directory not found: $XPI_SRC" >&2
+  echo "Run bearbrowser-pack-extensions.sh first." >&2
+  exit 1
+fi
+
+DIST_DIR="$APP/Contents/Resources/distribution"
+EXT_DIR="$DIST_DIR/extensions"
+POLICIES_JSON="$DIST_DIR/policies.json"
+
+mkdir -p "$EXT_DIR"
+
+echo "bearbrowser-install-extensions: installing into $APP"
+
+# ── Step 1: Copy .xpi files ─────────────────────────────────────────────────
+installed_ids=()
+for xpi in "$XPI_SRC"/*.xpi; do
+  if [ ! -f "$xpi" ]; then
+    continue
+  fi
+  xpi_name="$(basename "$xpi")"
+  cp "$xpi" "$EXT_DIR/$xpi_name"
+  # Derive gecko ID from filename (strip .xpi)
+  gecko_id="${xpi_name%.xpi}"
+  installed_ids+=("$gecko_id")
+  echo "  copied: $xpi_name → distribution/extensions/"
+done
+
+if [ "${#installed_ids[@]}" -eq 0 ]; then
+  echo "  WARNING: no .xpi files found in $XPI_SRC" >&2
+  exit 0
+fi
+
+# ── Step 2: Merge extension policies into policies.json ──────────────────────
+# Absolute install URL paths used in the policy (the app must live at $APP at
+# runtime for file:// URLs to resolve; for build-time bundling they are
+# relative to the bundle so we compute the canonical path).
+# The bundle's canonical install location is the path the user has the app at.
+# We write paths relative to the bundle root using a placeholder and let the
+# policy mergeread from the distribution/extensions/ dir which is always a
+# sibling of the policies.json file.
+#
+# Firefox policy: install_url in ExtensionSettings must be an https:// or
+# file:// URL.  For bundled local .xpi files the file:// URL must point to
+# where the app is installed.  We write the canonical /Applications path here;
+# if the app lives elsewhere the admin should re-run this script with the
+# correct APP path.
+
+python3 - "$POLICIES_JSON" "$EXT_DIR" "${installed_ids[@]}" <<'PY'
+import json, sys, os, pathlib
+
+policies_path = sys.argv[1]
+ext_dir = sys.argv[2]
+gecko_ids = sys.argv[3:]
+
+# Load existing policies.json if present
+if os.path.exists(policies_path):
+    with open(policies_path, "r", encoding="utf-8") as f:
+        doc = json.load(f)
+else:
+    doc = {}
+
+policies = doc.setdefault("policies", {})
+
+# Build the Install list and ExtensionSettings entries
+install_urls = []
+ext_settings = {}
+for gid in gecko_ids:
+    xpi_name = f"{gid}.xpi"
+    # Compute the file:// URL.  At runtime the .app lives wherever the user
+    # installed it; the ext_dir argument is the absolute path inside the bundle
+    # as it sits on disk right now.  Use that path so the URL is accurate for
+    # the current install location.
+    xpi_path = os.path.realpath(os.path.join(ext_dir, xpi_name))
+    xpi_url = pathlib.Path(xpi_path).as_uri()
+    install_urls.append(xpi_url)
+    ext_settings[gid] = {
+        "installation_mode": "force_installed",
+        "install_url": xpi_url,
+    }
+
+# Merge — preserve any pre-existing Extensions.Install entries
+existing_install = (
+    policies.get("Extensions", {}).get("Install", [])
+)
+# Deduplicate: remove stale entries for the same gecko IDs, then re-add
+existing_install = [
+    u for u in existing_install
+    if not any(gid in u for gid in gecko_ids)
+]
+existing_install.extend(install_urls)
+
+policies.setdefault("Extensions", {})["Install"] = existing_install
+
+# Merge ExtensionSettings: keep existing entries, overlay our force_installed
+existing_ext_settings = policies.setdefault("ExtensionSettings", {})
+existing_ext_settings.update(ext_settings)
+
+with open(policies_path, "w", encoding="utf-8") as f:
+    json.dump(doc, f, indent=2, ensure_ascii=False)
+    f.write("\n")
+
+print(f"  policies.json updated: {policies_path}")
+for gid in gecko_ids:
+    print(f"    force_installed: {gid}")
+PY
+
+echo "bearbrowser-install-extensions: done (${#installed_ids[@]} extension(s) installed)"
diff --git a/scripts/bearbrowser-overlay-binary.sh b/scripts/bearbrowser-overlay-binary.sh
index 7bfa242..6f1c080 100644
--- a/scripts/bearbrowser-overlay-binary.sh
+++ b/scripts/bearbrowser-overlay-binary.sh
@@ -37,9 +37,10 @@ Steps:
   4. Write BearBrowser Info.plist from the canonical template.
   5. Install the BearBrowser icon.
   6. Inject profile settings (user.js, policies.json).
-  7. Strip quarantine extended attributes.
-  8. Apply ad-hoc code signature.
-  9. Run branding and identity verification (unless --skip-verify).
+  7. Pack and install bundled extensions (Bear Spaces, Bear Containers).
+  8. Strip quarantine extended attributes.
+  9. Apply ad-hoc code signature.
+  10. Run branding and identity verification (unless --skip-verify).
 
 Options:
   --input-app     Path to the source LibreWolf.app bundle. Required.
@@ -98,14 +99,14 @@ echo "version=$version"
 echo
 
 # ── Step 1: Copy the base bundle ─────────────────────────────────────────────
-echo "[1/9] Copying base bundle..."
+echo "[1/10] Copying base bundle..."
 rm -rf "$out_app"
 mkdir -p "$(dirname "$out_app")"
 cp -R "$input_app" "$out_app"
 echo "      done → $out_app"
 
 # ── Step 2: Apply text-format branding overlay ───────────────────────────────
-echo "[2/9] Applying BearBrowser text branding overlay..."
+echo "[2/10] Applying BearBrowser text branding overlay..."
 bash "$script_dir/apply-bearbrowser-branding.sh" --workspace "$out_app"
 # The branding script creates .bearbrowser/branding.json at the workspace root.
 # Inside an app bundle this file sits outside Contents/ and breaks codesign's
@@ -122,7 +123,7 @@ find "$out_app" -maxdepth 1 -not -name "Contents" -not -path "$out_app" -delete
 echo "      done"
 
 # ── Step 3: Create the BearBrowser wrapper launcher ──────────────────────────
-echo "[3/9] Creating BearBrowser launcher wrapper..."
+echo "[3/10] Creating BearBrowser launcher wrapper..."
 macos_dir="$out_app/Contents/MacOS"
 
 # Detect the real Firefox/LibreWolf executable name. The main entry point is
@@ -155,7 +156,7 @@ chmod +x "$macos_dir/BearBrowser"
 echo "      created $macos_dir/BearBrowser → exec $real_bin"
 
 # ── Step 4: Write BearBrowser Info.plist ──────────────────────────────────────
-echo "[4/9] Writing BearBrowser Info.plist..."
+echo "[4/10] Writing BearBrowser Info.plist..."
 if [ ! -f "$info_template" ]; then
   echo "ERROR: Info.plist template missing: $info_template" >&2
   exit 1
@@ -189,7 +190,7 @@ PY
 echo "      done"
 
 # ── Step 5: Install BearBrowser icon ─────────────────────────────────────────
-echo "[5/9] Installing BearBrowser icon..."
+echo "[5/10] Installing BearBrowser icon..."
 icon_svg="$repo_root/branding/bearbrowser.svg"
 if [ -f "$icon_svg" ]; then
   cp "$icon_svg" "$out_app/Contents/Resources/BearBrowser.svg"
@@ -204,7 +205,7 @@ else
 fi
 
 # ── Step 6: Inject profile settings ─────────────────────────────────────────
-echo "[6/9] Injecting profile settings (profile=$profile)..."
+echo "[6/10] Injecting profile settings (profile=$profile)..."
 profile_dir="$repo_root/settings/profiles/$profile"
 if [ -d "$profile_dir" ]; then
   # The packaged app applies shipped prefs from a default-pref file
@@ -276,16 +277,22 @@ else
   echo "      WARNING: no bundled fonts in $fonts_src — font allowlist will be a safe no-op"
 fi
 
-# ── Step 7: Strip quarantine extended attributes ─────────────────────────────
-echo "[7/9] Stripping quarantine attributes..."
+# ── Step 7: Pack and install bundled extensions ──────────────────────────────
+echo "[7/10] Packing and installing bundled extensions..."
+"$script_dir/bearbrowser-pack-extensions.sh" "$repo_root/build/extensions" 2>&1 | sed 's/^/       /'
+"$script_dir/bearbrowser-install-extensions.sh" "$out_app" 2>&1 | sed 's/^/       /'
+echo "       done"
+
+# ── Step 8: Strip quarantine extended attributes ─────────────────────────────
+echo "[8/10] Stripping quarantine attributes..."
 xattr -cr "$out_app" 2>/dev/null || true
 echo "      done"
 
-# ── Step 8: Ad-hoc code signature ────────────────────────────────────────────
+# ── Step 9: Ad-hoc code signature ────────────────────────────────────────────
 if [ "$skip_sign" = "true" ]; then
-  echo "[8/9] Skipping signing (--skip-sign)."
+  echo "[9/10] Skipping signing (--skip-sign)."
 else
-  echo "[8/9] Applying ad-hoc code signature..."
+  echo "[9/10] Applying ad-hoc code signature..."
   if command -v codesign >/dev/null 2>&1; then
     # Ad-hoc signing a modified Gecko bundle requires signing inner components
     # first (frameworks, helpers, nested apps) then the outer bundle.
@@ -306,11 +313,11 @@ else
   fi
 fi
 
-# ── Step 9: Verify BearBrowser identity ──────────────────────────────────────
+# ── Step 10: Verify BearBrowser identity ─────────────────────────────────────
 if [ "$skip_verify" = "true" ]; then
-  echo "[9/9] Skipping verification (--skip-verify)."
+  echo "[10/10] Skipping verification (--skip-verify)."
 else
-  echo "[9/9] Verifying BearBrowser identity..."
+  echo "[10/10] Verifying BearBrowser identity..."
   # Pass --skip-signing to the verifier since ad-hoc signatures won't pass
   # spctl --assess (Gatekeeper requires a notarized Developer ID signature).
   bash "$script_dir/verify-macos-app.sh" --app "$out_app" --skip-signing 2>&1 | sed 's/^/      /'
diff --git a/scripts/bearbrowser-pack-extensions.sh b/scripts/bearbrowser-pack-extensions.sh
new file mode 100755
index 0000000..918e576
--- /dev/null
+++ b/scripts/bearbrowser-pack-extensions.sh
@@ -0,0 +1,87 @@
+#!/usr/bin/env bash
+# MIT License
+# Copyright (c) 2026 @mdheller
+#
+# bearbrowser-pack-extensions.sh — Pack BearBrowser extension directories into
+# signed-free .xpi files ready for sideloading into the app bundle.
+#
+# Each extension directory under extensions/ is zipped from the inside (not
+# wrapping the directory itself) and named by its gecko extension ID read from
+# manifest.json's browser_specific_settings.gecko.id field.
+#
+# Usage:
+#   ./scripts/bearbrowser-pack-extensions.sh [output_dir]
+#
+# Arguments:
+#   output_dir    Directory to write .xpi files into. Default: build/extensions/
+#
+# Output:
+#   <output_dir>/<gecko-id>.xpi  for each extension in extensions/
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+REPO="$(cd "$SCRIPT_DIR/.." && pwd)"
+_out_arg="${1:-$REPO/build/extensions}"
+# Absolutize the output path before any cd changes the working directory
+mkdir -p "$_out_arg"
+OUT="$(cd "$_out_arg" && pwd)"
+
+echo "bearbrowser-pack-extensions: packing to $OUT"
+
+packed=0
+for ext_dir in "$REPO/extensions"/*/; do
+  if [ ! -d "$ext_dir" ]; then
+    continue
+  fi
+  ext_name="$(basename "$ext_dir")"
+  manifest="$ext_dir/manifest.json"
+
+  if [ ! -f "$manifest" ]; then
+    echo "  WARNING: no manifest.json in $ext_dir — skipping" >&2
+    continue
+  fi
+
+  # Resolve gecko extension ID from manifest; fall back to <name>@bearbrowser.local
+  gecko_id="$(python3 - "$manifest" "$ext_name" <<'PY'
+import json, sys
+manifest_path, fallback_name = sys.argv[1], sys.argv[2]
+try:
+    m = json.load(open(manifest_path))
+    gecko_id = (
+        m.get("browser_specific_settings", {})
+         .get("gecko", {})
+         .get("id")
+        or m.get("applications", {})
+         .get("gecko", {})
+         .get("id")
+    )
+    if not gecko_id:
+        gecko_id = f"{fallback_name}@bearbrowser.local"
+except Exception as e:
+    sys.exit(f"ERROR reading {manifest_path}: {e}")
+print(gecko_id)
+PY
+)"
+
+  xpi_path="$OUT/${gecko_id}.xpi"
+  # Remove stale xpi so zip doesn't append into an existing archive
+  rm -f "$xpi_path"
+  (
+    cd "$ext_dir"
+    zip -r "$xpi_path" . \
+      -x "*.DS_Store" \
+      -x ".git*" \
+      -x "__pycache__/*" \
+      -x "*.pyc" \
+      -x "*.swp" \
+      >/dev/null
+  )
+  echo "  packed: $ext_name  →  ${gecko_id}.xpi"
+  packed=$((packed + 1))
+done
+
+if [ "$packed" -eq 0 ]; then
+  echo "  WARNING: no extensions found under $REPO/extensions/" >&2
+else
+  echo "bearbrowser-pack-extensions: $packed extension(s) packed → $OUT"
+fi