diff --git a/.githooks/pre-commit b/.githooks/pre-commit
new file mode 100755
index 0000000..7f99c80
--- /dev/null
+++ b/.githooks/pre-commit
@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+exec "$(git rev-parse --show-toplevel)/scripts/check-bun-locks.sh"
diff --git a/scripts/check-bun-locks.sh b/scripts/check-bun-locks.sh
new file mode 100755
index 0000000..8617be8
--- /dev/null
+++ b/scripts/check-bun-locks.sh
@@ -0,0 +1,62 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+workspaces=(
+  "cli"
+  "control-plane/dashboard-ui"
+)
+
+repo_root="$(git rev-parse --show-toplevel)"
+staged_files=()
+while IFS= read -r staged_file; do
+  staged_files+=("$staged_file")
+done < <(git diff --cached --name-only --diff-filter=ACMR)
+
+if [[ "${#staged_files[@]}" -eq 0 ]]; then
+  exit 0
+fi
+
+needs_check() {
+  local workspace="$1"
+  local manifest="$workspace/package.json"
+  local file
+
+  for file in "${staged_files[@]}"; do
+    if [[ "$file" == "$manifest" ]]; then
+      return 0
+    fi
+  done
+
+  return 1
+}
+
+check_workspaces=()
+for workspace in "${workspaces[@]}"; do
+  if needs_check "$workspace"; then
+    check_workspaces+=("$workspace")
+  fi
+done
+
+if [[ "${#check_workspaces[@]}" -eq 0 ]]; then
+  exit 0
+fi
+
+if ! command -v bun >/dev/null 2>&1; then
+  echo "bun is required to verify lockfile sync before committing." >&2
+  exit 1
+fi
+
+for workspace in "${check_workspaces[@]}"; do
+  lockfile="$workspace/bun.lock"
+  before="$(git -C "$repo_root" hash-object "$lockfile")"
+
+  echo "Checking $workspace bun.lock"
+  (cd "$repo_root/$workspace" && bun install --frozen-lockfile)
+
+  after="$(git -C "$repo_root" hash-object "$lockfile")"
+  if [[ "$before" != "$after" ]]; then
+    echo "$lockfile changed after bun install --frozen-lockfile." >&2
+    echo "Stage the updated lockfile and commit again." >&2
+    exit 1
+  fi
+done
diff --git a/scripts/install-git-hooks.sh b/scripts/install-git-hooks.sh
new file mode 100755
index 0000000..254e66c
--- /dev/null
+++ b/scripts/install-git-hooks.sh
@@ -0,0 +1,6 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+repo_root="$(git rev-parse --show-toplevel)"
+git -C "$repo_root" config core.hooksPath .githooks
+echo "Configured git hooks path: .githooks"
diff --git a/tests/hooks/check-bun-locks.test.sh b/tests/hooks/check-bun-locks.test.sh
new file mode 100644
index 0000000..8474dfb
--- /dev/null
+++ b/tests/hooks/check-bun-locks.test.sh
@@ -0,0 +1,125 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
+SCRIPT="$ROOT/scripts/check-bun-locks.sh"
+
+assert_file_contains() {
+  local file="$1"
+  local expected="$2"
+
+  if ! grep -Fq "$expected" "$file"; then
+    echo "expected $file to contain: $expected" >&2
+    echo "actual:" >&2
+    cat "$file" >&2
+    exit 1
+  fi
+}
+
+new_repo() {
+  local dir
+  dir="$(mktemp -d)"
+
+  git -C "$dir" init -q
+  git -C "$dir" config user.email test@example.com
+  git -C "$dir" config user.name "Test User"
+
+  mkdir -p "$dir/cli" "$dir/control-plane/dashboard-ui"
+  printf '{"dependencies":{"left-pad":"1.0.0"}}\n' > "$dir/cli/package.json"
+  printf 'lock\n' > "$dir/cli/bun.lock"
+  printf '{"dependencies":{"react":"19.0.0"}}\n' > "$dir/control-plane/dashboard-ui/package.json"
+  printf 'lock\n' > "$dir/control-plane/dashboard-ui/bun.lock"
+  git -C "$dir" add .
+  git -C "$dir" commit -qm "initial"
+
+  printf '%s\n' "$dir"
+}
+
+with_fake_bun() {
+  local bin_dir="$1"
+  local log_file="$2"
+  local mode="${3:-clean}"
+
+  mkdir -p "$bin_dir"
+  cat > "$bin_dir/bun" <<'BUN'
+#!/usr/bin/env bash
+set -euo pipefail
+
+printf '%s|%s\n' "$PWD" "$*" >> "$FAKE_BUN_LOG"
+
+if [[ "${FAKE_BUN_MODE:-clean}" == "dirty-lock" ]]; then
+  printf 'changed by fake bun\n' >> bun.lock
+fi
+BUN
+  chmod +x "$bin_dir/bun"
+
+  export PATH="$bin_dir:$PATH"
+  export FAKE_BUN_LOG="$log_file"
+  export FAKE_BUN_MODE="$mode"
+}
+
+test_skips_when_no_package_manifest_is_staged() {
+  local repo bin_dir log_file
+  repo="$(new_repo)"
+  bin_dir="$(mktemp -d)"
+  log_file="$repo/bun.log"
+  with_fake_bun "$bin_dir" "$log_file"
+
+  printf 'docs\n' > "$repo/README.md"
+  git -C "$repo" add README.md
+
+  (cd "$repo" && "$SCRIPT")
+  if [[ -e "$log_file" ]]; then
+    echo "expected bun not to run for unrelated staged files" >&2
+    cat "$log_file" >&2
+    exit 1
+  fi
+}
+
+test_skips_unrelated_staged_files_without_bun() {
+  local repo
+  repo="$(new_repo)"
+
+  printf 'docs\n' > "$repo/README.md"
+  git -C "$repo" add README.md
+
+  (cd "$repo" && PATH="/usr/bin:/bin" "$SCRIPT")
+}
+
+test_checks_each_staged_manifest_workspace() {
+  local repo bin_dir log_file
+  repo="$(new_repo)"
+  bin_dir="$(mktemp -d)"
+  log_file="$repo/bun.log"
+  with_fake_bun "$bin_dir" "$log_file"
+
+  printf '{"dependencies":{"left-pad":"1.0.1"}}\n' > "$repo/cli/package.json"
+  git -C "$repo" add cli/package.json
+
+  (cd "$repo" && "$SCRIPT")
+  assert_file_contains "$log_file" "$repo/cli|install --frozen-lockfile"
+}
+
+test_fails_when_bun_changes_lockfile() {
+  local repo bin_dir log_file output
+  repo="$(new_repo)"
+  bin_dir="$(mktemp -d)"
+  log_file="$repo/bun.log"
+  output="$repo/output.log"
+  with_fake_bun "$bin_dir" "$log_file" "dirty-lock"
+
+  printf '{"dependencies":{"left-pad":"1.0.2"}}\n' > "$repo/cli/package.json"
+  git -C "$repo" add cli/package.json
+
+  if (cd "$repo" && "$SCRIPT") > "$output" 2>&1; then
+    echo "expected hook check to fail when bun.lock changes" >&2
+    exit 1
+  fi
+
+  assert_file_contains "$output" "cli/bun.lock changed after bun install --frozen-lockfile"
+}
+
+test_skips_when_no_package_manifest_is_staged
+test_skips_unrelated_staged_files_without_bun
+test_checks_each_staged_manifest_workspace
+test_fails_when_bun_changes_lockfile