diff --git a/README.md b/README.md
index b1d3a0a..02c4489 100644
--- a/README.md
+++ b/README.md
@@ -74,6 +74,7 @@ Environment variables (prefix `WHENCE_`):
 | Tool | Operations |
 |---|---|
 | `pass` | show, insert, generate, edit |
+| `bitwarden` / `bw` | authenticate (YubiKey OTP 2FA) |
 | `sops` | encrypt, decrypt, edit, rotate |
 | `age` / `rage` | encrypt, decrypt |
 | `git` | push, pull, fetch, clone, signed commit |
diff --git a/e2e/README.md b/e2e/README.md
index ed33d27..bc55604 100644
--- a/e2e/README.md
+++ b/e2e/README.md
@@ -43,6 +43,7 @@ a PASS / FAIL / SKIP matrix and exits non-zero if anything failed.
 | `ssh` | `ssh-keygen -t ed25519-sk` | FIDO2 PIN set on the key |
 | `age` | `age -d` via `age-plugin-yubikey` | PIV identity (best-effort) |
 | browser | opens webauthn.io in your default browser | a passkey/WebAuthn credential |
+| `bitwarden` | manual: unlock / login using YubiKey OTP 2FA | a Bitwarden account with YubiKey OTP 2FA |
 
 The watcher is granted only the eBPF caps (`cap_bpf`, `cap_perfmon`,
 `cap_sys_admin`). An agent-mediated touch (gpg, pass, sops, …) is attributed to
diff --git a/e2e/run.sh b/e2e/run.sh
index 242e9ab..fd367e5 100755
--- a/e2e/run.sh
+++ b/e2e/run.sh
@@ -309,8 +309,19 @@ test_browser() {
 	show_stack
 }
 
+test_bitwarden() {
+	if [ ! -t 0 ]; then record bitwarden SKIP "manual test needs a TTY"; return; fi
+	ask_run "bitwarden — unlock / log in using your YubiKey OTP 2FA (desktop app or 'bw')" || { record bitwarden SKIP "skipped"; return; }
+	command -v bw >/dev/null 2>&1 || say "('bw' CLI not found — use the Bitwarden desktop app instead)"
+	say "In Bitwarden, do an unlock/login that uses the YubiKey OTP 2FA method"
+	say "(desktop app or 'bw login --method 0') and touch the key to emit the code."
+	mark
+	read -r -p "   press Enter once the Bitwarden touch is done… " _
+	finish bitwarden bitwarden
+}
+
 # --- driver -------------------------------------------------------------------
-ALL=(gpg pass gopass sops git ssh age browser)
+ALL=(gpg pass gopass sops git ssh age browser bitwarden)
 if [ "$#" -gt 0 ]; then SELECTED=("$@"); else SELECTED=("${ALL[@]}"); fi
 
 say "Testing: ${SELECTED[*]}"
diff --git a/flake.nix b/flake.nix
index f9266c3..5fc8019 100644
--- a/flake.nix
+++ b/flake.nix
@@ -36,6 +36,7 @@
             pkgs.age                # age
             pkgs.rage               # rage
             pkgs.git                # git
+            pkgs.bitwarden-cli      # bw (Bitwarden CLI)
             pkgs.yubikey-manager    # ykman (key diagnostics)
             pkgs.age-plugin-yubikey # age + YubiKey via PIV
             pkgs.libfido2           # fido2-token etc. for FIDO diagnostics
diff --git a/internal/classifier/rules/all.go b/internal/classifier/rules/all.go
index 74bdf43..de9e5a6 100644
--- a/internal/classifier/rules/all.go
+++ b/internal/classifier/rules/all.go
@@ -11,6 +11,7 @@ func All() []classifier.Rule {
 		SOPS{},
 		Gopass{},
 		Pass{},
+		Bitwarden{},
 		Age{},
 		Git{},
 		GPG{},
diff --git a/internal/classifier/rules/bitwarden.go b/internal/classifier/rules/bitwarden.go
new file mode 100644
index 0000000..b1a1018
--- /dev/null
+++ b/internal/classifier/rules/bitwarden.go
@@ -0,0 +1,27 @@
+package rules
+
+import (
+	"github.com/Talgarr/Whence-Touche/internal/classifier"
+)
+
+// Bitwarden matches Bitwarden (https://bitwarden.com/) vault unlocks that
+// touch the key. Bitwarden offers a YubiKey OTP two-factor method: both the
+// desktop app (the `bitwarden` Electron binary) and the `bw` CLI prompt for
+// the YubiKey OTP, and the key emits the one-time code on touch (HID OTP).
+// (WebAuthn/passkey unlock goes through the browser and is out of scope here.)
+type Bitwarden struct{}
+
+func (Bitwarden) Match(tree []classifier.Process) (classifier.Classification, bool) {
+	// "bw" is the CLI and is a short name, but a rule only fires inside a
+	// confirmed YubiKey-touch process tree, so false positives are unlikely.
+	idx, _, ok := classifier.FindFirst(tree, "bitwarden", "bw")
+	if !ok {
+		return classifier.Classification{}, false
+	}
+	return classifier.Classification{
+		Tool:     "bitwarden",
+		Action:   "authenticate",
+		Resource: "Bitwarden vault",
+		Depth:    idx,
+	}, true
+}
diff --git a/internal/classifier/rules/bitwarden_test.go b/internal/classifier/rules/bitwarden_test.go
new file mode 100644
index 0000000..17b56db
--- /dev/null
+++ b/internal/classifier/rules/bitwarden_test.go
@@ -0,0 +1,67 @@
+package rules
+
+import (
+	"testing"
+
+	"github.com/Talgarr/Whence-Touche/internal/classifier"
+)
+
+func TestBitwardenMatch(t *testing.T) {
+	cases := []struct {
+		name      string
+		tree      []classifier.Process
+		wantOK    bool
+		wantDepth int
+	}{
+		{
+			name: "desktop bitwarden matches",
+			tree: []classifier.Process{
+				{PID: 1, Comm: "systemd", Args: []string{"/usr/lib/systemd/systemd"}},
+				{PID: 2, Comm: "bitwarden", Args: []string{"/opt/Bitwarden/bitwarden"}},
+			},
+			wantOK:    true,
+			wantDepth: 1,
+		},
+		{
+			name: "bw CLI matches",
+			tree: []classifier.Process{
+				{PID: 1, Comm: "bash", Args: []string{"/bin/bash"}},
+				{PID: 2, Comm: "bw", Args: []string{"bw", "unlock"}},
+			},
+			wantOK:    true,
+			wantDepth: 1,
+		},
+		{
+			name: "tree without bitwarden returns false",
+			tree: []classifier.Process{
+				{PID: 1, Comm: "bash", Args: []string{"/bin/bash"}},
+				{PID: 2, Comm: "ssh", Args: []string{"ssh", "host"}},
+			},
+			wantOK: false,
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			got, ok := Bitwarden{}.Match(tc.tree)
+			if ok != tc.wantOK {
+				t.Fatalf("Match() ok = %v, want %v", ok, tc.wantOK)
+			}
+			if !ok {
+				return
+			}
+			if got.Tool != "bitwarden" {
+				t.Errorf("Tool = %q, want %q", got.Tool, "bitwarden")
+			}
+			if got.Action != "authenticate" {
+				t.Errorf("Action = %q, want %q", got.Action, "authenticate")
+			}
+			if got.Resource != "Bitwarden vault" {
+				t.Errorf("Resource = %q, want %q", got.Resource, "Bitwarden vault")
+			}
+			if got.Depth != tc.wantDepth {
+				t.Errorf("Depth = %d, want %d", got.Depth, tc.wantDepth)
+			}
+		})
+	}
+}