diff --git a/frontend/packages/dashboard/src/common.js b/frontend/packages/dashboard/src/common.js
index 8998ff46..5b59da4f 100644
--- a/frontend/packages/dashboard/src/common.js
+++ b/frontend/packages/dashboard/src/common.js
@@ -216,6 +216,7 @@ export const Panel = (() => {
   let root = null;
   let titleEl = null;
   let bodyEl = null;
+  let drawer = null;
   /** Owner key set by `openNamed` (e.g. 'inbox'). `refresh(name, …)`
    *  is a no-op when the current owner doesn't match, so live
    *  updates can re-render an open view without grabbing focus
@@ -229,6 +230,7 @@ export const Panel = (() => {
       root = $('side-panel');
       titleEl = $('side-panel-title');
       bodyEl = $('side-panel-body');
+      drawer = root && root.querySelector('.side-panel-drawer');
     }
     return root != null;
   }
@@ -256,6 +258,79 @@ export const Panel = (() => {
     root.classList.remove('open');
     root.setAttribute('aria-hidden', 'true');
   }
+  // #451: drag-to-resize the drawer's width. Listens on a thin
+  // hit-strip glued to the drawer's left edge; mousedown captures
+  // pointermove + pointerup on the document so the drag continues
+  // even if the cursor strays outside the 6px handle band. Width
+  // persists to localStorage so it survives page reload. The CSS
+  // clamps the value (min-width: 320px, max-width: 96vw) — drop
+  // unparseable / out-of-range stored values silently.
+  const WIDTH_KEY = 'hyperhive:side-panel-width';
+  const WIDTH_MIN = 320;
+  function clampWidth(w) {
+    const max = Math.floor(window.innerWidth * 0.96);
+    return Math.max(WIDTH_MIN, Math.min(max, w));
+  }
+  function applyStoredWidth() {
+    if (!drawer) return;
+    const raw = (() => {
+      try { return localStorage.getItem(WIDTH_KEY); }
+      catch { return null; }
+    })();
+    if (!raw) return;
+    const parsed = parseInt(raw, 10);
+    if (!Number.isFinite(parsed) || parsed <= 0) return;
+    drawer.style.setProperty('--side-panel-w', clampWidth(parsed) + 'px');
+  }
+  function bindResize() {
+    if (!drawer) return;
+    const handle = document.createElement('div');
+    handle.className = 'side-panel-resize';
+    handle.setAttribute('role', 'separator');
+    handle.setAttribute('aria-orientation', 'vertical');
+    handle.setAttribute('aria-label', 'drag to resize side panel');
+    handle.title = 'drag to resize';
+    drawer.prepend(handle);
+    let dragging = false;
+    handle.addEventListener('pointerdown', (e) => {
+      e.preventDefault();
+      dragging = true;
+      document.body.classList.add('side-panel-resizing');
+      // Capture so we keep getting pointermove even when the cursor
+      // outpaces the handle band (drag-fast-then-pause loses the
+      // handle's :hover state otherwise).
+      try { handle.setPointerCapture(e.pointerId); } catch { /* legacy */ }
+    });
+    document.addEventListener('pointermove', (e) => {
+      if (!dragging) return;
+      // Drawer is anchored to the right edge — width = viewport - pointer X.
+      const w = clampWidth(window.innerWidth - e.clientX);
+      drawer.style.setProperty('--side-panel-w', w + 'px');
+    });
+    function stopDrag() {
+      if (!dragging) return;
+      dragging = false;
+      document.body.classList.remove('side-panel-resizing');
+      // Persist the final width. Read the actual rendered width
+      // rather than re-deriving so the stored value matches what
+      // the operator saw at mouseup.
+      const w = drawer.getBoundingClientRect().width;
+      try { localStorage.setItem(WIDTH_KEY, String(Math.round(w))); }
+      catch { /* localStorage unavailable — width is session-only */ }
+    }
+    document.addEventListener('pointerup', stopDrag);
+    document.addEventListener('pointercancel', stopDrag);
+    // Re-clamp on viewport resize so a persisted width that exceeds
+    // 96vw doesn't push the drawer off-screen after a window shrink.
+    window.addEventListener('resize', () => {
+      if (dragging) return;
+      const cur = drawer.getBoundingClientRect().width;
+      const clamped = clampWidth(cur);
+      if (clamped !== Math.round(cur)) {
+        drawer.style.setProperty('--side-panel-w', clamped + 'px');
+      }
+    });
+  }
   function bind() {
     if (!ensure()) return;
     $('side-panel-close').addEventListener('click', close);
@@ -263,6 +338,8 @@ export const Panel = (() => {
     document.addEventListener('keydown', (e) => {
       if (e.key === 'Escape' && root.classList.contains('open')) close();
     });
+    applyStoredWidth();
+    bindResize();
   }
   return { open, openNamed, refresh, close, bind };
 })();
diff --git a/frontend/packages/dashboard/src/dashboard.css b/frontend/packages/dashboard/src/dashboard.css
index 3caffb1c..1ca6a9bf 100644
--- a/frontend/packages/dashboard/src/dashboard.css
+++ b/frontend/packages/dashboard/src/dashboard.css
@@ -1111,8 +1111,10 @@ summary:hover { color: var(--purple); }
   background: var(--bg-elev);
   border: 1px solid var(--border);
   padding: 0.5em 0.8em;
-  max-height: 24em;
-  overflow-y: auto;
+  /* #450: no max-height cap — let the inbox grow to fill the
+     side-panel-body which already scrolls (`overflow: auto`). The
+     pre-#450 24em cap clamped the list well short of the available
+     panel height even on tall viewports. */
 }
 .inbox li {
   padding: 0.25em 0;
@@ -1297,7 +1299,19 @@ footer .banner-thin {
   top: 0;
   right: 0;
   bottom: 0;
-  width: min(760px, 94vw);
+  /* #451: width is a CSS variable so the drag handle (added by
+     Panel.bind) can update it live, and so localStorage-persisted
+     widths apply on first paint. Default min(760px, 94vw) preserves
+     the pre-#451 behaviour for operators who never drag. The body
+     adds `data-spw="<px>"` once persisted; CSS doesn't read it
+     directly — JS sets `--side-panel-w` via inline style on the
+     drawer. */
+  width: var(--side-panel-w, min(760px, 94vw));
+  /* Clamp so a stored width can never push the drawer off-screen
+     or shrink it past readability. min content width matches the
+     panel-head's natural width with the close button visible. */
+  min-width: 320px;
+  max-width: 96vw;
   display: flex;
   flex-direction: column;
   background: var(--bg-elev);
@@ -1309,6 +1323,36 @@ footer .banner-thin {
 .side-panel.open { pointer-events: auto; }
 .side-panel.open .side-panel-backdrop { opacity: 1; }
 .side-panel.open .side-panel-drawer { transform: translateX(0); }
+/* #451: drag-to-resize handle on the drawer's left edge. The handle
+   itself is invisible until hover/drag so it doesn't compete with the
+   2px mauve `border-left` for the visual boundary. Pointer-cursor
+   tells the operator the edge is grabbable; the brighter glow during
+   drag (`body.side-panel-resizing`) is the affordance the eye
+   tracks. */
+.side-panel-resize {
+  position: absolute;
+  top: 0;
+  left: 0;
+  bottom: 0;
+  width: 6px;
+  margin-left: -3px;
+  cursor: ew-resize;
+  z-index: 1;
+  background: transparent;
+  transition: background 120ms ease;
+}
+.side-panel-resize:hover,
+body.side-panel-resizing .side-panel-resize {
+  background: rgba(203, 166, 247, 0.55);
+}
+/* While dragging: kill text selection + force the resize cursor
+   page-wide so the cursor doesn't flip back to default the moment it
+   leaves the 6px handle band. */
+body.side-panel-resizing {
+  cursor: ew-resize !important;
+  user-select: none;
+}
+body.side-panel-resizing * { cursor: ew-resize !important; }
 .side-panel-head {
   flex: 0 0 auto;
   display: flex;