diff --git a/apps/web/src/components/sidebar/SidebarChrome.tsx b/apps/web/src/components/sidebar/SidebarChrome.tsx
index 4f115a751422..32c9b9cf7c98 100644
--- a/apps/web/src/components/sidebar/SidebarChrome.tsx
+++ b/apps/web/src/components/sidebar/SidebarChrome.tsx
@@ -5,7 +5,7 @@ import {
   SettingsIcon,
 } from "lucide-react";
 import type { ReactNode } from "react";
-import { memo, useCallback } from "react";
+import { memo, useCallback, useId } from "react";
 import { Link, useCanGoBack, useLocation, useNavigate } from "@tanstack/react-router";
 
 import { useEnvironmentIdentificationMode } from "../../hooks/useSettings";
@@ -30,6 +30,7 @@ import {
   useSidebar,
 } from "../ui/sidebar";
 import { Tooltip, TooltipPopup, TooltipTrigger } from "../ui/tooltip";
+import { UsageLimitsTooltip } from "../usage/UsageLimitsTooltip";
 import { readPullRequestListPreferences } from "../pullRequest/pullRequestListPreferences";
 import { SidebarProviderUpdatePill } from "./SidebarProviderUpdatePill";
 import { SidebarUpdateArchitectureWarning, SidebarUpdatePill } from "./SidebarUpdatePill";
@@ -110,22 +111,30 @@ function SidebarUtilityItem({
   icon,
   label,
   onClick,
+  renderTooltip,
 }: {
   icon: ReactNode;
   label: string;
   onClick: () => void;
+  renderTooltip?: (id: string) => ReactNode;
 }) {
+  const tooltipId = useId();
   return (
     <SidebarMenuItem className="shrink-0">
       <Tooltip>
         <TooltipTrigger
           render={
-            <SidebarMenuButton aria-label={label} onClick={onClick} size="icon">
+            <SidebarMenuButton
+              aria-label={label}
+              aria-describedby={renderTooltip ? tooltipId : undefined}
+              onClick={onClick}
+              size="icon"
+            >
               {icon}
             </SidebarMenuButton>
           }
         />
-        <TooltipPopup side="top">{label}</TooltipPopup>
+        {renderTooltip ? renderTooltip(tooltipId) : <TooltipPopup side="top">{label}</TooltipPopup>}
       </Tooltip>
     </SidebarMenuItem>
   );
@@ -213,6 +222,7 @@ export const SidebarUtilityMenu = memo(function SidebarUtilityMenu() {
             icon={<ChartNoAxesColumnIcon />}
             label="Usage"
             onClick={handleUsageClick}
+            renderTooltip={(id) => <UsageLimitsTooltip id={id} />}
           />
         </>
       )}
diff --git a/apps/web/src/components/usage/UsageLimits.tsx b/apps/web/src/components/usage/UsageLimits.tsx
index e50547b66008..25be99cdcb9e 100644
--- a/apps/web/src/components/usage/UsageLimits.tsx
+++ b/apps/web/src/components/usage/UsageLimits.tsx
@@ -5,7 +5,6 @@ import {
   ServerProvider,
   ServerProviderResetCredits,
   ServerProviderUsageWindow,
-  UsageProviderKind,
 } from "@t3tools/contracts";
 import { useAtomValue } from "@effect/atom-react";
 import {
@@ -36,7 +35,7 @@ import {
 import { Button } from "../ui/button";
 import { Tooltip, TooltipPopup, TooltipTrigger } from "../ui/tooltip";
 import { UsageLimitsPooled } from "./UsageLimitsPooled";
-import { PROVIDER_PRESENTATION } from "./usageProviders";
+import { barColor } from "./usageProviders";
 
 const PACE: Record<LimitPace, { readonly label: string; readonly icon: typeof GaugeIcon }> = {
   ahead: { label: "Ahead of pace: spending faster than the window elapses", icon: TrendingUpIcon },
@@ -44,13 +43,6 @@ const PACE: Record<LimitPace, { readonly label: string; readonly icon: typeof Ga
   under: { label: "Under pace: headroom left for the rest of the window", icon: TrendingDownIcon },
 };
 
-/** The series colour the cost chart uses for this driver, so the two views read as one. */
-export function barColor(driver: ServerProvider["driver"]): string {
-  const kind: UsageProviderKind | undefined =
-    driver === "codex" ? "codex" : driver === "claudeAgent" ? "claude" : undefined;
-  return kind ? PROVIDER_PRESENTATION[kind].color : "var(--foreground)";
-}
-
 /** Pace as a glyph with the words on hover. */
 export function PaceIcon({ pace }: { readonly pace: LimitPace }) {
   const Icon = PACE[pace].icon;
diff --git a/apps/web/src/components/usage/UsageLimitsPooled.tsx b/apps/web/src/components/usage/UsageLimitsPooled.tsx
index 37654140c282..e5932684d538 100644
--- a/apps/web/src/components/usage/UsageLimitsPooled.tsx
+++ b/apps/web/src/components/usage/UsageLimitsPooled.tsx
@@ -21,13 +21,8 @@ import { getDriverOption } from "../settings/providerDriverMeta";
 import { RedactedSensitiveText } from "../settings/RedactedSensitiveText";
 import { Button } from "../ui/button";
 import { Popover, PopoverPopup, PopoverTrigger } from "../ui/popover";
-import {
-  PaceIcon,
-  ResetCreditDialog,
-  barColor,
-  resetCreditsSummary,
-  useResetCredit,
-} from "./UsageLimits";
+import { PaceIcon, ResetCreditDialog, resetCreditsSummary, useResetCredit } from "./UsageLimits";
+import { barColor } from "./usageProviders";
 
 /** `someone@example.com` → `SE`: enough to tell accounts apart, too little to identify one. */
 function accountInitials(email: string): string {
diff --git a/apps/web/src/components/usage/UsageLimitsTooltip.tsx b/apps/web/src/components/usage/UsageLimitsTooltip.tsx
new file mode 100644
index 000000000000..394f89578e86
--- /dev/null
+++ b/apps/web/src/components/usage/UsageLimitsTooltip.tsx
@@ -0,0 +1,91 @@
+import { useAtomValue } from "@effect/atom-react";
+import {
+  collectLimitAccounts,
+  collectLimitNotices,
+  collectLimitPools,
+  formatDuration,
+} from "@t3tools/shared/usageLimits";
+import { useState } from "react";
+
+import { environmentPresentations } from "../../state/presentation";
+import { getDriverOption } from "../settings/providerDriverMeta";
+import { TooltipPopup } from "../ui/tooltip";
+import { barColor } from "./usageProviders";
+
+/** Reads the existing config snapshots only while the tooltip content is mounted. */
+function UsageLimitsSummary() {
+  const presentations = useAtomValue(environmentPresentations.presentationsAtom);
+  const [now] = useState(() => Date.now());
+  const pools = collectLimitPools(collectLimitAccounts(presentations), now);
+  const notices = collectLimitNotices(presentations);
+
+  return (
+    <div className="flex max-h-[min(28rem,60vh)] flex-col gap-4 overflow-y-auto p-2 text-xs">
+      <h2 className="text-sm font-medium">Usage limits</h2>
+      {pools.map((pool) => (
+        <section key={pool.driver} className="flex flex-col gap-2">
+          <h3 className="flex items-baseline justify-between gap-3 font-medium">
+            <span>{getDriverOption(pool.driver)?.label ?? String(pool.driver)}</span>
+            {pool.accounts.length > 1 ? (
+              <span className="font-normal text-muted-foreground">
+                {pool.accounts.length} accounts
+              </span>
+            ) : null}
+          </h3>
+          {pool.windows.map((window) => {
+            const nextRefill = window.resets.find((reset) => reset.restoresPercent > 0);
+            return (
+              <div key={`${window.kind}:${window.id}`} className="flex flex-col gap-1">
+                <div className="flex items-baseline justify-between gap-3">
+                  <span className="min-w-0 break-words">{window.label}</span>
+                  <span className="shrink-0 font-medium tabular-nums">
+                    {window.remainingPercent}% left
+                  </span>
+                </div>
+                <div aria-hidden className="h-1 overflow-hidden rounded-sm bg-muted">
+                  <div
+                    className="h-full rounded-sm"
+                    style={{
+                      width: `${window.remainingPercent}%`,
+                      backgroundColor: barColor(pool.driver),
+                    }}
+                  />
+                </div>
+                {nextRefill ? (
+                  <span className="text-muted-foreground tabular-nums">
+                    +{nextRefill.restoresPercent}%{" "}
+                    {nextRefill.at <= now ? "now" : `in ${formatDuration(nextRefill.at - now)}`}
+                  </span>
+                ) : null}
+              </div>
+            );
+          })}
+        </section>
+      ))}
+      {pools.length === 0 && notices.length === 0 ? <p>No subscription limits reported.</p> : null}
+      {notices.length > 0 ? (
+        <ul className="flex flex-col gap-1 text-muted-foreground">
+          {notices.map((notice) => (
+            <li key={notice} className="break-words">
+              {notice}
+            </li>
+          ))}
+        </ul>
+      ) : null}
+    </div>
+  );
+}
+
+export function UsageLimitsTooltip({ id }: { readonly id: string }) {
+  return (
+    <TooltipPopup
+      id={id}
+      role="tooltip"
+      side="top"
+      align="start"
+      className="pointer-events-auto w-72 max-w-[calc(100vw-2rem)] text-wrap"
+    >
+      <UsageLimitsSummary />
+    </TooltipPopup>
+  );
+}
diff --git a/apps/web/src/components/usage/usageProviders.ts b/apps/web/src/components/usage/usageProviders.ts
index efad95e531ad..43d5b6f6e8d7 100644
--- a/apps/web/src/components/usage/usageProviders.ts
+++ b/apps/web/src/components/usage/usageProviders.ts
@@ -1,4 +1,4 @@
-import type { UsageProviderKind } from "@t3tools/contracts";
+import type { ServerProvider, UsageProviderKind } from "@t3tools/contracts";
 
 import { ClaudeAI, GrokIcon, type Icon, OpenAI } from "../Icons";
 
@@ -32,6 +32,13 @@ export const PROVIDER_PRESENTATION = {
   },
 } satisfies Record<UsageProviderKind, UsageProviderPresentation>;
 
+/** The series colour the cost chart uses for this driver, so the two views read as one. */
+export function barColor(driver: ServerProvider["driver"]): string {
+  const kind: UsageProviderKind | undefined =
+    driver === "codex" ? "codex" : driver === "claudeAgent" ? "claude" : undefined;
+  return kind ? PROVIDER_PRESENTATION[kind].color : "var(--foreground)";
+}
+
 /** Stable provider reading order across charts, summaries, tables, and hover rows. */
 export const PROVIDER_ORDER = Object.keys(PROVIDER_PRESENTATION) as UsageProviderKind[];