diff --git a/system/public/aesthetic.computer/bios.mjs b/system/public/aesthetic.computer/bios.mjs
index 70453a619d..7a7d3a4d6c 100644
--- a/system/public/aesthetic.computer/bios.mjs
+++ b/system/public/aesthetic.computer/bios.mjs
@@ -816,6 +816,7 @@ async function boot(parsed, bpm = 60, resolution, debug) {
   preservedParams = {};
   if (resolution.gap === 0) preservedParams.nogap = "true"; // gap: 0 means nogap was true
   if (resolution.nolabel === true) preservedParams.nolabel = "true";
+  if (resolution.shellhtml === true) preservedParams.shellhtml = "true";
   if (resolution.tv === true) preservedParams.tv = "true";
   if (resolution.device === true) preservedParams.device = "true";
   if (resolution.solo === true) preservedParams.solo = "true";
@@ -13866,6 +13867,9 @@ async function boot(parsed, bpm = 60, resolution, debug) {
       if (preservedParams.nolabel) {
         currentUrl.searchParams.set("nolabel", preservedParams.nolabel);
       }
+      if (preservedParams.shellhtml) {
+        currentUrl.searchParams.set("shellhtml", preservedParams.shellhtml);
+      }
       if (preservedParams.duration) {
         currentUrl.searchParams.set("duration", preservedParams.duration);
       }
diff --git a/system/public/aesthetic.computer/boot.mjs b/system/public/aesthetic.computer/boot.mjs
index 85a8699f3b..6ed3db1c97 100644
--- a/system/public/aesthetic.computer/boot.mjs
+++ b/system/public/aesthetic.computer/boot.mjs
@@ -528,7 +528,7 @@ if (window.max?.outlet) {
 // List of legitimate query parameters that should be preserved
 const LEGITIMATE_PARAMS = [
   'icon', 'preview', 'signup', 'supportSignUp', 'success', 'code', 
-  'supportForgotPassword', 'message', 'vscode', 'nogap', 'nolabel', 
+  'supportForgotPassword', 'message', 'vscode', 'nogap', 'nolabel', 'shellhtml',
   'density', 'zoom', 'duration', 'session-aesthetic', 'session-sotce', 'notice', 'tv', 'highlight',
   'noauth', 'nocache', 'daw', 'width', 'height', 'desktop', 'device', 'perf', 'auto-scale', 'solo',
   'crossfade', 'maxfps'
@@ -1109,6 +1109,10 @@ const nogap = params.has("nogap") || params.has("desktop") || location.search.in
 // Check for nolabel parameter (no localStorage persistence)
 const nolabel = params.has("nolabel") || params.has("desktop") || location.search.includes("nolabel");
 
+// 🐚 shellhtml — an HTML shell (prompt.ac) hosts the runtime and owns the
+// prompt/corner chrome in DOM; the composited equivalents stand down.
+const shellhtml = params.has("shellhtml") || location.search.includes("shellhtml");
+
 // Check for desktop mode (Electron app) - combines nogap + nolabel
 const desktop = params.has("desktop") || location.search.includes("desktop");
 
@@ -1237,7 +1241,7 @@ if (window.acVSCODE) {
 
 // Pass the parameters directly without stripping them
 bootLog(`booting: ${parsed?.text || 'prompt'}`);
-boot(parsed, bpm, { gap: nogap ? 0 : undefined, nolabel, density, zoom, duration, tv, highlight, desktop, device, perf, autoScale, solo, maxfps, spoofaudio }, debug);
+boot(parsed, bpm, { gap: nogap ? 0 : undefined, nolabel, shellhtml, density, zoom, duration, tv, highlight, desktop, device, perf, autoScale, solo, maxfps, spoofaudio }, debug);
 
 // Start processing any early kidlisp messages that arrived before boot completed
 processEarlyKidlispQueue();
diff --git a/system/public/aesthetic.computer/lib/disk.mjs b/system/public/aesthetic.computer/lib/disk.mjs
index e6297bc780..ab055aa19c 100644
--- a/system/public/aesthetic.computer/lib/disk.mjs
+++ b/system/public/aesthetic.computer/lib/disk.mjs
@@ -970,6 +970,10 @@ function fillExpandedWithFadePixels(screen, width, height, oldWidth, oldHeight,
 }
 
 const projectionMode = location.search.indexOf("nolabel") > -1; // Skip loading noise.
+// 🐚 shellhtml mode — the runtime is hosted by an HTML shell (prompt.ac) that
+// owns the prompt + return-to-prompt chrome in crisp DOM above the pixel
+// buffer. The composited typable prompt and corner label stand down here.
+const shellHTMLMode = location.search.indexOf("shellhtml") > -1;
 
 import { setDebug } from "../disks/common/debug.mjs";
 import { customAlphabet } from "../dep/nanoid/nanoid.js";
@@ -3675,6 +3679,9 @@ const $commonApi = {
     data: {},
   },
   system: {
+    // 🐚 True when an HTML shell (prompt.ac) hosts the runtime and owns the
+    // prompt / corner chrome in DOM — pieces skip their own low-res chrome.
+    shellhtml: shellHTMLMode,
     // prompt: { input: undefined }, Gets set in `prompt_boot`.
     // 🎵 ac-electron drag-drop: set when a file is dropped onto the app
     // (Dock icon or running window). Pieces (notably `play`) read this on
@@ -9662,7 +9669,7 @@ async function load(
 
       sim = ($) => {
         module.sim?.($);
-        prompt.prompt_sim($);
+        if (!shellHTMLMode) prompt.prompt_sim($);
       };
 
       paint = ($) => {
@@ -9675,7 +9682,9 @@ async function load(
           noPaint = true;
         }
 
-        const promptPainted = prompt.prompt_paint($);
+        // shellhtml: the host page's DOM bar IS the prompt — never composite
+        // the low-res typable input over the buffer.
+        const promptPainted = shellHTMLMode ? false : prompt.prompt_paint($);
         return noPaint || promptPainted;
       };
 
@@ -9683,7 +9692,7 @@ async function load(
 
       act = ($) => {
         module.act?.($);
-        prompt.prompt_act($);
+        if (!shellHTMLMode) prompt.prompt_act($); // shell DOM owns typing
       };
 
       leave = ($) => {
@@ -9884,6 +9893,7 @@ async function load(
     const searchParams = new URLSearchParams(parsed.search);
     if (searchParams.has("nolabel")) hideLabel = true;
   }
+  if (shellHTMLMode) hideLabel = true; // the shell's DOM corner overlay replaces it
 
     currentColon = colon;
     currentParams = params;
diff --git a/system/public/aesthetic.computer/lib/parse.mjs b/system/public/aesthetic.computer/lib/parse.mjs
index f33c56b75c..d63cdcdc8d 100644
--- a/system/public/aesthetic.computer/lib/parse.mjs
+++ b/system/public/aesthetic.computer/lib/parse.mjs
@@ -18,6 +18,7 @@ const LEGITIMATE_PARAMS = [
   "vscode",
   "nogap",
   "nolabel",
+  "shellhtml",
   "noboot",
   "density",
   "zoom",
diff --git a/system/public/prompt.ac/index.html b/system/public/prompt.ac/index.html
index 232172b13d..03739f6958 100644
--- a/system/public/prompt.ac/index.html
+++ b/system/public/prompt.ac/index.html
@@ -50,6 +50,22 @@
   }
   .loading.gone { opacity: 0; }
 
+  /* ── DOM corner overlay — the crisp return-to-prompt chip that replaces the
+     runtime's composited corner label while in shellhtml mode. ───────────── */
+  .corner {
+    position: absolute; top: 8px; left: 8px; z-index: 2;
+    display: none; align-items: center; gap: 6px;
+    padding: 4px 9px; cursor: pointer; user-select: none;
+    background: color-mix(in srgb, var(--bar) 82%, transparent);
+    border: 1px solid var(--edge); border-radius: 6px;
+    color: var(--text); font-family: var(--font); font-size: 13px;
+    backdrop-filter: blur(6px); -webkit-backdrop-filter: blur(6px);
+    text-shadow: 0 1px 2px rgba(0,0,0,.6);
+  }
+  .corner.on { display: flex; }
+  .corner:hover { border-color: var(--accent); }
+  .corner .back { color: var(--accent); font-weight: 700; }
+
   /* token colors (for the suggestion/echo line, shared class names with moat) */
   .t-handle { color: #ffb0a0; } .t-kidlisp { color: #ff8cc8; } .t-clock { color: #ffd24b; }
 </style>
@@ -63,6 +79,7 @@
   </div>
   <div class="stage">
     <iframe id="ac" title="Aesthetic Computer" allow="microphone; camera; midi; autoplay; clipboard-read; clipboard-write; fullscreen; xr-spatial-tracking"></iframe>
+    <div class="corner" id="corner" title="back to prompt"><span class="back">&lsaquo;</span><span id="cornerName"></span></div>
     <div class="loading" id="loading">booting aesthetic computer…</div>
   </div>
 
@@ -73,6 +90,8 @@ const $cmd = document.getElementById("cmd");
 const $here = document.getElementById("here");
 const $dot = document.getElementById("dot");
 const $loading = document.getElementById("loading");
+const $corner = document.getElementById("corner");
+const $cornerName = document.getElementById("cornerName");
 const frame = new ACFrame(document.getElementById("ac"));
 
 // Deep-link support that doesn't fight Caddy: prompt.ac/#clock stays on the
@@ -80,7 +99,9 @@ const frame = new ACFrame(document.getElementById("ac"));
 const initial = decodeURIComponent(location.hash.slice(1)) || "prompt";
 
 $dot.title = "booting…";
-frame.boot(initial);
+// shellhtml: the runtime's composited prompt + corner label stand down — this
+// page's DOM bar and corner chip are that chrome, at native resolution.
+frame.boot(initial, "nogap=true&nolabel=true&shellhtml=true");
 
 frame.onReady(() => {
   $dot.className = "dot ok"; $dot.title = "live";
@@ -88,14 +109,23 @@ frame.onReady(() => {
   $cmd.focus();
 });
 
-// Keep the bar + URL hash in sync with whatever the runtime is showing.
+// Keep the bar + URL hash + corner chip in sync with the runtime.
 frame.onPiece((slug) => {
   const name = slug || "prompt";
   $here.textContent = name;
   document.title = name === "prompt" ? "prompt.ac" : name + " · prompt.ac";
+  const onPiece = name !== "prompt";
+  $corner.classList.toggle("on", onPiece); // chip only overlays pieces
+  $cornerName.textContent = name;
   const h = "#" + name;
-  if (location.hash !== h && name !== "prompt") history.replaceState(null, "", h);
-  else if (name === "prompt" && location.hash) history.replaceState(null, "", location.pathname);
+  if (location.hash !== h && onPiece) history.replaceState(null, "", h);
+  else if (!onPiece && location.hash) history.replaceState(null, "", location.pathname);
+});
+
+// Corner chip → back to the prompt (the DOM twin of the composited label).
+$corner.addEventListener("click", () => {
+  frame.load("prompt");
+  $cmd.focus();
 });
 
 // Command bar → in-place piece load.