diff --git a/apps/web/src/components/BranchToolbar.tsx b/apps/web/src/components/BranchToolbar.tsx
index ffab9cbdf86..bee8478a4b7 100644
--- a/apps/web/src/components/BranchToolbar.tsx
+++ b/apps/web/src/components/BranchToolbar.tsx
@@ -248,7 +248,7 @@ export const BranchToolbar = memo(function BranchToolbar({
   if (!hasActiveThread || !activeProject) return null;
 
   return (
-    <div className="chat-composer-context-strip -mt-4 mx-auto flex w-[calc(100%-1.5rem)] max-w-[calc(48rem-1.5rem)] items-center gap-2 pt-5 pb-1 ps-1">
+    <div className="chat-composer-context-strip -mt-4 mx-auto flex w-[calc(100%-2.75rem)] max-w-[calc(48rem-2.75rem)] items-center gap-2 px-1 pt-5 pb-1">
       {isMobile ? (
         <MobileRunContextSelector
           envLocked={envLocked}
diff --git a/apps/web/src/components/BranchToolbarBranchSelector.tsx b/apps/web/src/components/BranchToolbarBranchSelector.tsx
index 08ee713a932..763de56d8c4 100644
--- a/apps/web/src/components/BranchToolbarBranchSelector.tsx
+++ b/apps/web/src/components/BranchToolbarBranchSelector.tsx
@@ -731,7 +731,7 @@ export function BranchToolbarBranchSelector({
         >
           <ComboboxTrigger
             render={<Button variant="ghost" size="xs" />}
-            className="min-w-0 text-muted-foreground/70 hover:text-foreground/80"
+            className="min-w-0 max-w-full text-muted-foreground/70 hover:text-foreground/80"
             disabled={isInitialBranchesLoadPending || isBranchActionPending}
           >
             <GitBranchIcon className="size-3 shrink-0 opacity-70" />
diff --git a/apps/web/src/components/ChatView.tsx b/apps/web/src/components/ChatView.tsx
index e2437a465d7..9a3eb10a18d 100644
--- a/apps/web/src/components/ChatView.tsx
+++ b/apps/web/src/components/ChatView.tsx
@@ -2352,6 +2352,7 @@ function ChatViewContent(props: ChatViewProps) {
     terminalUiLaunchContext?.threadId === activeThreadId ? terminalUiLaunchContext : null;
   // Default true while loading to avoid toolbar flicker.
   const isGitRepo = gitStatusQuery.data?.isRepo ?? true;
+  const showComposerContextStrip = isGitRepo && activeProject !== null;
   const initialDiffPanelGitScope =
     gitStatusQuery.data?.hasWorkingTreeChanges === true ? "unstaged" : "branch";
   const diffPanelGitStatusResolutionKey = gitStatusQuery.data ? "resolved" : "pending";
@@ -5592,119 +5593,128 @@ function ChatViewContent(props: ChatViewProps) {
                         : undefined
                     }
                   >
-                    <div className="chat-composer-glass-host relative z-10 mx-auto w-full max-w-3xl rounded-[22px]">
-                      <div ref={attachDraftHeroComposerAnchorRef} className="relative z-10">
-                        <ChatComposer
-                          composerRef={composerRef}
-                          composerDraftTarget={composerDraftTarget}
-                          environmentId={environmentId}
-                          routeKind={routeKind}
-                          routeThreadRef={routeThreadRef}
-                          draftId={draftId}
-                          activeThreadId={activeThreadId}
-                          activeThreadEnvironmentId={activeThread?.environmentId}
-                          activeThread={activeThread}
-                          isServerThread={isServerThread}
-                          isLocalDraftThread={isLocalDraftThread}
-                          forceExpandedOnMobile={forceExpandedMobileComposer && isDraftHeroState}
-                          projectSelectionRequired={isLocalDraftThread && activeProject === null}
-                          phase={phase}
-                          isConnecting={isConnecting}
-                          isSendBusy={isSendBusy}
-                          isPreparingWorktree={isPreparingWorktree}
-                          environmentUnavailable={activeEnvironmentUnavailableState}
-                          activePendingApproval={activePendingApproval}
-                          pendingApprovals={pendingApprovals}
-                          pendingUserInputs={pendingUserInputs}
-                          activePendingProgress={activePendingProgress}
-                          activePendingResolvedAnswers={activePendingResolvedAnswers}
-                          activePendingIsResponding={activePendingIsResponding}
-                          activePendingDraftAnswers={activePendingDraftAnswers}
-                          activePendingQuestionIndex={activePendingQuestionIndex}
-                          respondingRequestIds={respondingRequestIds}
-                          showPlanFollowUpPrompt={showPlanFollowUpPrompt}
-                          activeProposedPlan={activeProposedPlan}
-                          activePlan={activePlan as { turnId?: TurnId } | null}
-                          sidebarProposedPlan={sidebarProposedPlan as { turnId?: TurnId } | null}
-                          planSidebarLabel={planSidebarLabel}
-                          planSidebarOpen={planSidebarOpen}
-                          runtimeMode={runtimeMode}
-                          interactionMode={interactionMode}
-                          lockedProvider={lockedProvider}
-                          providerStatuses={providerStatuses as ServerProvider[]}
-                          activeProjectDefaultModelSelection={activeProject?.defaultModelSelection}
-                          activeThreadModelSelection={activeThread?.modelSelection}
-                          activeThreadActivities={activeThread?.activities}
-                          resolvedTheme={resolvedTheme}
-                          settings={settings}
-                          keybindings={keybindings}
-                          terminalOpen={Boolean(terminalUiState.terminalOpen)}
-                          gitCwd={gitCwd}
-                          promptRef={promptRef}
-                          composerImagesRef={composerImagesRef}
-                          composerTerminalContextsRef={composerTerminalContextsRef}
-                          composerElementContextsRef={composerElementContextsRef}
-                          onSend={onSend}
-                          onInterrupt={onInterrupt}
-                          onImplementPlanInNewThread={onImplementPlanInNewThread}
-                          onRespondToApproval={onRespondToApproval}
-                          onSelectActivePendingUserInputOption={
-                            onSelectActivePendingUserInputOption
-                          }
-                          onAdvanceActivePendingUserInput={onAdvanceActivePendingUserInput}
-                          onPreviousActivePendingUserInputQuestion={
-                            onPreviousActivePendingUserInputQuestion
-                          }
-                          onChangeActivePendingUserInputCustomAnswer={
-                            onChangeActivePendingUserInputCustomAnswer
-                          }
-                          onProviderModelSelect={onProviderModelSelect}
-                          getModelDisabledReason={getModelDisabledReason}
-                          toggleInteractionMode={toggleInteractionMode}
-                          handleRuntimeModeChange={handleRuntimeModeChange}
-                          handleInteractionModeChange={handleInteractionModeChange}
-                          togglePlanSidebar={togglePlanSidebar}
-                          focusComposer={focusComposer}
-                          scheduleComposerFocus={scheduleComposerFocus}
-                          setThreadError={setThreadError}
-                          onExpandImage={onExpandTimelineImage}
-                        />
+                    <div
+                      className={cn(
+                        "chat-composer-glass-shell relative mx-auto w-full max-w-3xl",
+                        showComposerContextStrip && "chat-composer-glass-shell-with-context",
+                      )}
+                    >
+                      <div className="chat-composer-glass-host relative z-10 w-full rounded-[22px]">
+                        <div ref={attachDraftHeroComposerAnchorRef} className="relative z-10">
+                          <ChatComposer
+                            composerRef={composerRef}
+                            composerDraftTarget={composerDraftTarget}
+                            environmentId={environmentId}
+                            routeKind={routeKind}
+                            routeThreadRef={routeThreadRef}
+                            draftId={draftId}
+                            activeThreadId={activeThreadId}
+                            activeThreadEnvironmentId={activeThread?.environmentId}
+                            activeThread={activeThread}
+                            isServerThread={isServerThread}
+                            isLocalDraftThread={isLocalDraftThread}
+                            forceExpandedOnMobile={forceExpandedMobileComposer && isDraftHeroState}
+                            projectSelectionRequired={isLocalDraftThread && activeProject === null}
+                            phase={phase}
+                            isConnecting={isConnecting}
+                            isSendBusy={isSendBusy}
+                            isPreparingWorktree={isPreparingWorktree}
+                            environmentUnavailable={activeEnvironmentUnavailableState}
+                            activePendingApproval={activePendingApproval}
+                            pendingApprovals={pendingApprovals}
+                            pendingUserInputs={pendingUserInputs}
+                            activePendingProgress={activePendingProgress}
+                            activePendingResolvedAnswers={activePendingResolvedAnswers}
+                            activePendingIsResponding={activePendingIsResponding}
+                            activePendingDraftAnswers={activePendingDraftAnswers}
+                            activePendingQuestionIndex={activePendingQuestionIndex}
+                            respondingRequestIds={respondingRequestIds}
+                            showPlanFollowUpPrompt={showPlanFollowUpPrompt}
+                            activeProposedPlan={activeProposedPlan}
+                            activePlan={activePlan as { turnId?: TurnId } | null}
+                            sidebarProposedPlan={sidebarProposedPlan as { turnId?: TurnId } | null}
+                            planSidebarLabel={planSidebarLabel}
+                            planSidebarOpen={planSidebarOpen}
+                            runtimeMode={runtimeMode}
+                            interactionMode={interactionMode}
+                            lockedProvider={lockedProvider}
+                            providerStatuses={providerStatuses as ServerProvider[]}
+                            activeProjectDefaultModelSelection={
+                              activeProject?.defaultModelSelection
+                            }
+                            activeThreadModelSelection={activeThread?.modelSelection}
+                            activeThreadActivities={activeThread?.activities}
+                            resolvedTheme={resolvedTheme}
+                            settings={settings}
+                            keybindings={keybindings}
+                            terminalOpen={Boolean(terminalUiState.terminalOpen)}
+                            gitCwd={gitCwd}
+                            promptRef={promptRef}
+                            composerImagesRef={composerImagesRef}
+                            composerTerminalContextsRef={composerTerminalContextsRef}
+                            composerElementContextsRef={composerElementContextsRef}
+                            onSend={onSend}
+                            onInterrupt={onInterrupt}
+                            onImplementPlanInNewThread={onImplementPlanInNewThread}
+                            onRespondToApproval={onRespondToApproval}
+                            onSelectActivePendingUserInputOption={
+                              onSelectActivePendingUserInputOption
+                            }
+                            onAdvanceActivePendingUserInput={onAdvanceActivePendingUserInput}
+                            onPreviousActivePendingUserInputQuestion={
+                              onPreviousActivePendingUserInputQuestion
+                            }
+                            onChangeActivePendingUserInputCustomAnswer={
+                              onChangeActivePendingUserInputCustomAnswer
+                            }
+                            onProviderModelSelect={onProviderModelSelect}
+                            getModelDisabledReason={getModelDisabledReason}
+                            toggleInteractionMode={toggleInteractionMode}
+                            handleRuntimeModeChange={handleRuntimeModeChange}
+                            handleInteractionModeChange={handleInteractionModeChange}
+                            togglePlanSidebar={togglePlanSidebar}
+                            focusComposer={focusComposer}
+                            scheduleComposerFocus={scheduleComposerFocus}
+                            setThreadError={setThreadError}
+                            onExpandImage={onExpandTimelineImage}
+                          />
+                        </div>
                       </div>
-                    </div>
-                    <div className="min-h-0">
-                      <div
-                        data-terminal-open={terminalUiState.terminalOpen ? "true" : undefined}
-                        className="relative z-0"
-                      >
-                        {isGitRepo && (
-                          <div className="pointer-events-auto">
-                            <BranchToolbar
-                              environmentId={activeThread.environmentId}
-                              threadId={activeThread.id}
-                              {...(routeKind === "draft" && draftId ? { draftId } : {})}
-                              onEnvModeChange={onEnvModeChange}
-                              startFromOrigin={startFromOrigin}
-                              onStartFromOriginChange={onStartFromOriginChange}
-                              {...(canOverrideServerThreadEnvMode
-                                ? { effectiveEnvModeOverride: envMode }
-                                : {})}
-                              {...(canOverrideServerThreadEnvMode
-                                ? {
-                                    activeThreadBranchOverride: activeThreadBranch,
-                                    onActiveThreadBranchOverrideChange:
-                                      setPendingServerThreadBranch,
-                                  }
-                                : {})}
-                              envLocked={envLocked}
-                              onComposerFocusRequest={scheduleComposerFocus}
-                              {...(canCheckoutPullRequestIntoThread
-                                ? { onCheckoutPullRequestRequest: openPullRequestDialog }
-                                : {})}
-                              {...(hasMultipleEnvironments ? { onEnvironmentChange } : {})}
-                              availableEnvironments={logicalProjectEnvironments}
-                            />
-                          </div>
-                        )}
+                      <div className="min-h-0">
+                        <div
+                          data-terminal-open={terminalUiState.terminalOpen ? "true" : undefined}
+                          className="relative z-0"
+                        >
+                          {showComposerContextStrip && (
+                            <div className="pointer-events-auto">
+                              <BranchToolbar
+                                environmentId={activeThread.environmentId}
+                                threadId={activeThread.id}
+                                {...(routeKind === "draft" && draftId ? { draftId } : {})}
+                                onEnvModeChange={onEnvModeChange}
+                                startFromOrigin={startFromOrigin}
+                                onStartFromOriginChange={onStartFromOriginChange}
+                                {...(canOverrideServerThreadEnvMode
+                                  ? { effectiveEnvModeOverride: envMode }
+                                  : {})}
+                                {...(canOverrideServerThreadEnvMode
+                                  ? {
+                                      activeThreadBranchOverride: activeThreadBranch,
+                                      onActiveThreadBranchOverrideChange:
+                                        setPendingServerThreadBranch,
+                                    }
+                                  : {})}
+                                envLocked={envLocked}
+                                onComposerFocusRequest={scheduleComposerFocus}
+                                {...(canCheckoutPullRequestIntoThread
+                                  ? { onCheckoutPullRequestRequest: openPullRequestDialog }
+                                  : {})}
+                                {...(hasMultipleEnvironments ? { onEnvironmentChange } : {})}
+                                availableEnvironments={logicalProjectEnvironments}
+                              />
+                            </div>
+                          )}
+                        </div>
                       </div>
                     </div>
                     <div
diff --git a/apps/web/src/index.css b/apps/web/src/index.css
index abe150db588..fefa86c741b 100644
--- a/apps/web/src/index.css
+++ b/apps/web/src/index.css
@@ -377,21 +377,20 @@ html[data-mobile-composer-route-transition="true"]::view-transition-old(t3-mobil
     backdrop-filter: blur(var(--glass-blur)) saturate(var(--glass-saturation));
   }
 
-  .chat-composer-glass-host {
+  .chat-composer-glass-shell {
     --chat-composer-glass-surface: var(--card);
+    --chat-composer-outline: rgb(0 0 0 / 8%);
 
     position: relative;
-    box-shadow:
-      0 0 0 1px rgb(0 0 0 / 8%),
-      0 12px 28px -18px rgb(0 0 0 / 40%);
+    isolation: isolate;
   }
 
-  .chat-composer-glass-host::before {
+  .chat-composer-glass-shell::before {
     pointer-events: none;
     position: absolute;
     z-index: 0;
     inset: 0;
-    border-radius: inherit;
+    border-radius: 22px;
     background: color-mix(
       in srgb,
       var(--chat-composer-glass-surface) var(--glass-opacity),
@@ -402,9 +401,73 @@ html[data-mobile-composer-route-transition="true"]::view-transition-old(t3-mobil
     content: "";
   }
 
-  .chat-composer-context-strip {
-    --chat-composer-context-surface: var(--card);
+  .chat-composer-glass-shell-with-context {
+    --chat-composer-context-extension: 2.25rem;
+  }
+
+  .chat-composer-glass-shell-with-context::before {
+    border-radius: 0;
+    /*
+     * One continuous glass layer: a 22px composer joined to a 16px strip,
+     * whose visible sides align with the composer's bottom tangents.
+     */
+    clip-path: shape(
+      from 0 22px,
+      curve to 22px 0 with 0 9.85px / 9.85px 0,
+      line to calc(100% - 22px) 0,
+      curve to 100% 22px with calc(100% - 9.85px) 0 / 100% 9.85px,
+      line to 100% calc(100% - var(--chat-composer-context-extension) - 22px),
+      curve to calc(100% - 22px) calc(100% - var(--chat-composer-context-extension)) with 100%
+        calc(100% - var(--chat-composer-context-extension) - 9.85px) / calc(100% - 9.85px)
+        calc(100% - var(--chat-composer-context-extension)),
+      line to calc(100% - 22px) calc(100% - 16px),
+      curve to calc(100% - 38px) 100% with calc(100% - 22px) calc(100% - 7.16px) /
+        calc(100% - 29.16px) 100%,
+      line to 38px 100%,
+      curve to 22px calc(100% - 16px) with 29.16px 100% / 22px calc(100% - 7.16px),
+      line to 22px calc(100% - var(--chat-composer-context-extension)),
+      curve to 0 calc(100% - var(--chat-composer-context-extension) - 22px) with 9.85px
+        calc(100% - var(--chat-composer-context-extension)) / 0
+        calc(100% - var(--chat-composer-context-extension) - 9.85px),
+      line to 0 22px,
+      close
+    );
+  }
+
+  @media (min-width: 40rem) {
+    .chat-composer-glass-shell-with-context {
+      /* The xs toolbar controls shrink by 4px at Tailwind's sm breakpoint. */
+      --chat-composer-context-extension: 2rem;
+    }
+  }
+
+  .chat-composer-glass-host {
+    position: relative;
+    box-shadow: 0 12px 28px -18px rgb(0 0 0 / 40%);
+  }
+
+  .chat-composer-glass-host::after {
+    pointer-events: none;
+    position: absolute;
+    z-index: 1;
+    inset: 0;
+    border: 1px solid var(--chat-composer-outline);
+    border-radius: inherit;
+    /* Keep the attachment seam open; the strip continues the outer outline below. */
+    clip-path: polygon(
+      0 0,
+      100% 0,
+      100% 100%,
+      calc(100% - 22px) 100%,
+      calc(100% - 22px) calc(100% - 2px),
+      22px calc(100% - 2px),
+      22px 100%,
+      0 100%
+    );
+    content: "";
+  }
 
+  .chat-composer-context-strip {
     position: relative;
     isolation: isolate;
   }
@@ -413,27 +476,39 @@ html[data-mobile-composer-route-transition="true"]::view-transition-old(t3-mobil
     position: absolute;
     z-index: -1;
     inset: 0;
+    border: 1px solid var(--chat-composer-outline);
     border-radius: 0 0 16px 16px;
-    background: color-mix(
-      in srgb,
-      var(--chat-composer-context-surface) var(--glass-opacity),
-      transparent
-    );
+    /* Start the strip outline exactly where the composer's 22px curve reaches its tangent. */
     -webkit-mask-image: linear-gradient(to bottom, transparent 0 1rem, black 1rem);
     mask-image: linear-gradient(to bottom, transparent 0 1rem, black 1rem);
     box-shadow: 0 12px 28px -18px rgb(0 0 0 / 40%);
     content: "";
-    -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(var(--glass-saturation));
-    backdrop-filter: blur(var(--glass-blur)) saturate(var(--glass-saturation));
   }
 
-  .dark .chat-composer-glass-host {
+  .dark .chat-composer-glass-shell {
     --chat-composer-glass-surface: color-mix(in srgb, var(--background) 96%, var(--color-white));
+    --chat-composer-outline: color-mix(in srgb, var(--color-white) 5%, transparent);
+    --chat-composer-highlight: rgb(255 255 255 / 3%);
+  }
 
+  .dark .chat-composer-glass-host {
     box-shadow: none;
   }
 
+  .dark .chat-composer-glass-host::after {
+    box-shadow: inset 0 1px var(--chat-composer-highlight);
+  }
+
   .dark .chat-composer-context-strip::before {
+    border-color: rgb(255 255 255 / 7%);
+    background:
+      linear-gradient(
+        to bottom,
+        transparent 0 1rem,
+        rgb(0 0 0 / 18%) 1rem,
+        transparent calc(1rem + 10px)
+      ),
+      rgb(255 255 255 / 2%);
     box-shadow: 0 14px 32px -18px rgb(0 0 0 / 75%);
   }
 
@@ -641,7 +716,7 @@ html[data-mobile-composer-route-transition="true"]::view-transition-old(t3-mobil
       background: var(--background) !important;
     }
 
-    .chat-composer-glass-host::before {
+    .chat-composer-glass-shell::before {
       background: var(--chat-composer-glass-surface);
     }