diff --git a/README.md b/README.md
index ef66101..8f1ae36 100644
--- a/README.md
+++ b/README.md
@@ -23,6 +23,13 @@ go test ./...
 
 ## Status
 
+**M8 (Tier A) — Enforcement (window-minimize).** Drift finally costs something.
+A planning-screen "Enforce focus" toggle arms the new `enforce.Guard` port: when
+the drift judge confirms the active window is off-task, the daemon minimizes that
+window (native X11, no `xdotool`). It is unprivileged, per-session (the chosen
+enforcement level rides the snapshot), and degrades to today's advisory behavior
+when off, unwired, or on a platform without the X11 adapter.
+
 M7 (reflection): when a session ends, a fourth AI role — the reviewer —
 reflects on it, read against your recent sessions, and produces two short
 lines: a recap shown on the Review screen, and a carry-forward takeaway that
diff --git a/internal/web/static/app.css b/internal/web/static/app.css
index 8be65b2..ea4bf6e 100644
--- a/internal/web/static/app.css
+++ b/internal/web/static/app.css
@@ -124,3 +124,7 @@ input:focus { outline: 0; border-color: var(--accent); }
   background: none; border: none; padding: 0; font: inherit; font-size: 12px;
   color: var(--accent); cursor: pointer; text-decoration: underline;
 }
+
+.enforce-note { opacity: 0.8; font-size: 0.85em; }
+.enforce-toggle { display: flex; align-items: center; gap: 0.4em; }
+.hint { opacity: 0.7; font-size: 0.85em; margin: 0.2em 0 0.6em; }
diff --git a/internal/web/static/app.js b/internal/web/static/app.js
index 8117ab2..fe6cae3 100644
--- a/internal/web/static/app.js
+++ b/internal/web/static/app.js
@@ -73,6 +73,7 @@ function updateActiveDrift(state) {
     el.className = 'band statusband col';
     el.innerHTML = `<div><span class="pill">Drift</span></div>
       <div class="drift-reason">${drift.reason || 'This looks off task.'}</div>
+      ${drift.enforced ? '<div class="enforce-note">Off-task window minimized.</div>' : ''}
       <div class="band-actions">
         <button id="refocus" type="button" class="btn btn-primary">Back to task</button>
         <button id="ontask" type="button" class="btn btn-ghost">This is on task</button>
@@ -242,6 +243,8 @@ function render(state) {
         <label>Minutes</label><input id="mins" type="number" min="1" value="25">
         <label>Allowed apps (comma-separated window classes)</label>
         <input id="apps" placeholder="e.g. code, firefox">
+        <label class="enforce-toggle"><input id="enforce" type="checkbox"> Enforce focus</label>
+        <p class="hint">Minimize off-task windows when you drift.</p>
         <button id="start" class="btn btn-primary" disabled>Start commitment</button>
       </div>`;
     const na = document.getElementById('na'), sc = document.getElementById('sc'),
@@ -254,6 +257,7 @@ function render(state) {
       timebox_secs: Math.round(+mins.value * 60),
       allowed_window_classes: (document.getElementById('apps').value || '')
         .split(',').map(s => s.trim()).filter(Boolean),
+      enforce: document.getElementById('enforce').checked,
     });
     document.getElementById('sharpen').onclick = () => {
       const intent = document.getElementById('intent').value.trim();