diff --git a/.macos b/.macos
index 227589cd82..6e44bb761d 100755
--- a/.macos
+++ b/.macos
@@ -33,6 +33,40 @@ else
 	echo "Skipping computer name configuration (COMPUTER_NAME not set)."
 fi
 
+# Touch ID for sudo. /etc/pam.d/sudo_local is Apple's own hook for this: it
+# survives OS updates where /etc/pam.d/sudo does not, and the template beside
+# it ships with the pam_tid line commented out. Created from the template when
+# missing, appended to when present without the line, left alone otherwise.
+if ! grep -Eqs '^auth[[:space:]]+sufficient[[:space:]]+pam_tid\.so' /etc/pam.d/sudo_local; then
+	if [[ -f /etc/pam.d/sudo_local ]]; then
+		printf 'auth       sufficient     pam_tid.so\n' | sudo tee -a /etc/pam.d/sudo_local >/dev/null
+	elif [[ -f /etc/pam.d/sudo_local.template ]]; then
+		sed 's/^#auth/auth/' /etc/pam.d/sudo_local.template | sudo tee /etc/pam.d/sudo_local >/dev/null
+	else
+		echo "Skipping Touch ID for sudo (no /etc/pam.d/sudo_local.template on this macOS)."
+	fi
+fi
+
+# One touch for everything. sudo caches a tty-less authorisation per parent
+# process, so a tool that runs sudo once per step from fresh processes
+# (Ansible's local connection, say) raises a Touch ID prompt for every step —
+# measured at ten in one run. A global timestamp makes one touch cover every
+# sudo on the machine. The timeout is taste, not part of the fix: `global`
+# alone cures the per-process prompts; export SUDO_TIMESTAMP_TIMEOUT (minutes)
+# to override the 60 here. The file is validated by visudo BEFORE it is
+# installed, at the 0440 sudo expects, so a bad file never reaches sudoers.d.
+if ! sudo grep -qs 'timestamp_type=global' /etc/sudoers.d/timestamp \
+	|| [[ "$(stat -f %Lp /etc/sudoers.d/timestamp 2>/dev/null)" != 440 ]]; then
+	sudoers_tmp="$(mktemp)"
+	printf 'Defaults timestamp_type=global\nDefaults timestamp_timeout=%s\n' "${SUDO_TIMESTAMP_TIMEOUT:-60}" > "$sudoers_tmp"
+	if visudo -cf "$sudoers_tmp" >/dev/null 2>&1; then
+		sudo install -m 0440 -o root -g wheel "$sudoers_tmp" /etc/sudoers.d/timestamp
+	else
+		echo "Skipping the global sudo timestamp: visudo rejected the generated file."
+	fi
+	rm -f "$sudoers_tmp"
+fi
+
 # Disable the sound effects on boot (Apple Silicon)
 sudo nvram StartupMute=%01
 
diff --git a/CLAUDE.md b/CLAUDE.md
index 19f35e6315..ce2306a3b8 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -100,7 +100,7 @@ VMs; the test skips everywhere else unless `MACOS_APPLY_OK=1` is set.
 - **`.chezmoiignore`** — target paths chezmoi must not manage (repo-level files everywhere, `CLAUDE.md` and `com.googlecode.iterm2.plist` among them; macOS GUI config off-mac; identity/secrets on `ephemeral`)
 - **`bootstrap.sh`** — deprecated wrapper around `chezmoi init --source . --apply`
 - **`docs/watchlist.md`** — tools evaluated and parked as "not yet", each with what would make it worth another look; check it before re-evaluating something, and add to it when an evaluation ends in "not yet"
-- **`.macos`** — macOS `defaults write` settings; reads `$COMPUTER_NAME` env var for machine-specific naming
+- **`.macos`** — macOS `defaults write` settings; reads `$COMPUTER_NAME` env var for machine-specific naming; also enables Touch ID for sudo (via `/etc/pam.d/sudo_local`, Apple's update-proof hook) and a global sudo timestamp (`/etc/sudoers.d/timestamp`, `visudo`-checked before install, mode 0440), because a per-process cache plus Touch ID means one prompt per step for anything that runs sudo from fresh processes; the 60-minute timeout is a preference, overridable with `$SUDO_TIMESTAMP_TIMEOUT`
 - **`Brewfile`** — Homebrew formulae, casks, and Mac App Store apps (macOS only; `.chezmoiscripts/darwin/` runs `brew bundle` when it changes)
 - **`packages-apt.txt`** — Debian/Ubuntu/WSL package list (`.chezmoiscripts/linux/` installs it when it changes; skips gracefully without apt or sudo)
 - **`packages-apt-wsl.txt`** — WSL-only additions, installed on top of the shared list when the machine class is `wsl`
diff --git a/tests/macos-apply.bats b/tests/macos-apply.bats
index ca7ca98368..eb17b40dc2 100644
--- a/tests/macos-apply.bats
+++ b/tests/macos-apply.bats
@@ -30,3 +30,21 @@ setup() {
 @test "highlight color is set" {
   [ "$(defaults read NSGlobalDomain AppleHighlightColor)" = "0.764700 0.976500 0.568600" ]
 }
+
+@test "Touch ID for sudo is enabled in sudo_local" {
+  grep -Eq '^auth[[:space:]]+sufficient[[:space:]]+pam_tid\.so' /etc/pam.d/sudo_local
+}
+
+@test "the global sudo timestamp is in effect and its file parses" {
+  sudo -n visudo -cf /etc/sudoers.d/timestamp
+  sudo -n -l | grep -q 'timestamp_type=global'
+}
+
+@test ".macos is idempotent for the sudo settings" {
+  cd "$BATS_TEST_DIRNAME/.."
+  ./.macos > "$BATS_TEST_TMPDIR/macos2.log" 2>&1
+  # Anchored: the template's commented-out line also says pam_tid.so.
+  [ "$(grep -Ec '^auth[[:space:]]+sufficient[[:space:]]+pam_tid\.so' /etc/pam.d/sudo_local)" = 1 ]
+  [ "$(sudo -n grep -c 'timestamp_type' /etc/sudoers.d/timestamp)" = 1 ]
+  [ "$(stat -f %Lp /etc/sudoers.d/timestamp)" = 440 ]
+}
diff --git a/tests/macos.bats b/tests/macos.bats
index bdd5bb184d..8efe2c705f 100644
--- a/tests/macos.bats
+++ b/tests/macos.bats
@@ -19,3 +19,20 @@
   run grep -q 'AppleHighlightColor -string "0.764700 0.976500 0.568600"' "$BATS_TEST_DIRNAME/../.macos"
   [ "$status" -eq 0 ]
 }
+
+@test "macos enables Touch ID for sudo through sudo_local, never /etc/pam.d/sudo" {
+  run grep -q 'pam_tid.so' "$BATS_TEST_DIRNAME/../.macos"
+  [ "$status" -eq 0 ]
+  run grep -E 'tee.*/etc/pam\.d/sudo([^_]|$)' "$BATS_TEST_DIRNAME/../.macos"
+  [ "$status" -ne 0 ]
+}
+
+@test "macos makes one sudo authorisation cover every process, and validates the sudoers file" {
+  run grep -q 'Defaults timestamp_type=global' "$BATS_TEST_DIRNAME/../.macos"
+  [ "$status" -eq 0 ]
+  # Validated before it is installed, and installed at the mode sudo wants.
+  run grep -q 'visudo -cf "$sudoers_tmp"' "$BATS_TEST_DIRNAME/../.macos"
+  [ "$status" -eq 0 ]
+  run grep -q 'install -m 0440 -o root -g wheel "$sudoers_tmp" /etc/sudoers.d/timestamp' "$BATS_TEST_DIRNAME/../.macos"
+  [ "$status" -eq 0 ]
+}