diff --git a/packages/cli/src/commands/handlers/stats.ts b/packages/cli/src/commands/handlers/stats.ts
index 3502ac5efe2..321007a73df 100644
--- a/packages/cli/src/commands/handlers/stats.ts
+++ b/packages/cli/src/commands/handlers/stats.ts
@@ -1,5 +1,7 @@
 import { ClientError, OpenCode, type SessionStatsInfo } from "@opencode-ai/client"
 import { Service } from "@opencode-ai/client/effect/service"
+import { TokenUsage } from "@opencode-ai/schema/token-usage"
+import { activityCalendar } from "@opencode-ai/util/activity-calendar"
 import { Effect, Option } from "effect"
 import { EOL } from "node:os"
 import { Commands } from "../commands"
@@ -91,7 +93,7 @@ type RenderOptions = {
 const colors = terminalPalette()
 
 export function renderStats(stats: SessionStatsInfo, options: RenderOptions) {
-  const totalTokens = tokenTotal(stats.tokens)
+  const totalTokens = TokenUsage.total(stats.tokens)
   const toolTotals = stats.tools.mode === "none" ? undefined : stats.tools.totals
   const terminalTools = toolTotals ? toolTotals.succeeded + toolTotals.failed : 0
   const toolRate = !toolTotals || terminalTools === 0 ? undefined : (toolTotals.succeeded / terminalTools) * 100
@@ -167,43 +169,23 @@ function renderActivity(
   color: boolean,
   width: number,
 ) {
-  const values = new Map(activity.map((day) => [day.date, day.steps]))
-  const rangeStart = dateOrdinal(new Date(from))
-  const rangeEnd = dateOrdinal(new Date(to - 1))
-  const end = new Date(to - 1)
-  end.setHours(12, 0, 0, 0)
-  end.setDate(end.getDate() + (7 - mondayIndex(end) - 1))
-  const start = new Date(from)
-  start.setHours(12, 0, 0, 0)
-  start.setDate(start.getDate() - mondayIndex(start))
-  const maxWeeks = Math.max(1, Math.min(53, width - 4))
-  const totalWeeks = Math.floor((dateOrdinal(end) - dateOrdinal(start)) / 7) + 1
-  const latest = new Date(end)
-  latest.setDate(latest.getDate() - (maxWeeks - 1) * 7)
-  if (start < latest) start.setTime(latest.getTime())
-
-  const active = [...values.values()].filter((value) => value > 0)
-  const levels = [...new Set(active)].sort((a, b) => a - b)
-  const weekStarts = Array.from({ length: Math.floor((dateOrdinal(end) - dateOrdinal(start)) / 7) + 1 }, (_, week) => {
-    const date = new Date(start)
-    date.setDate(date.getDate() + week * 7)
-    return date
-  })
-  const weeks = weekStarts.map((week) =>
-    Array.from({ length: 7 }, (_, day) => {
-      const date = new Date(week)
-      date.setDate(date.getDate() + day)
-      const ordinal = dateOrdinal(date)
-      if (ordinal < rangeStart || ordinal > rangeEnd) return " "
-      return activityGlyph(values.get(dateKey(date)) ?? 0, levels, color)
-    }),
-  )
+  const calendar = activityCalendar({ activity, from, to, maxWeeks: width - 4 })
+  const months = calendar.months
+    .map((month, index) =>
+      (index === calendar.months.length - 1 || month.label.length <= month.span ? month.label : "").padEnd(month.span),
+    )
+    .join("")
+    .trimEnd()
   const weekdays = ["Mo", "Tu", "We", "Th", "Fr", "Sa", "Su"]
   return [
-    style(totalWeeks > maxWeeks ? `activity · last ${maxWeeks} weeks` : "activity", `1;${colors.primary}`, color),
-    `   ${style(monthLabels(weekStarts), "2", color)}`,
+    style(
+      calendar.clipped ? `activity · last ${calendar.weeks.length} weeks` : "activity",
+      `1;${colors.primary}`,
+      color,
+    ),
+    `   ${style(months, "2", color)}`,
     ...weekdays.flatMap((label, day) => [
-      `${style(label, "2", color)} ${weeks.map((week) => week[day]).join("")}`,
+      `${style(label, "2", color)} ${calendar.weeks.map((week) => (week[day].level < 0 ? " " : paintActivity(week[day].level, color))).join("")}`,
       ...(day === weekdays.length - 1 ? [] : [""]),
     ]),
     "",
@@ -238,7 +220,7 @@ function renderModels(stats: SessionStatsInfo, limit: number, width: number) {
           `${item.model.providerID}/${item.model.id}${item.model.variant ? `#${item.model.variant}` : ""}`,
           width,
         ),
-        `  ${formatNumber(tokenTotal(item.tokens))} tokens · ${formatNumber(item.steps)} steps · $${item.cost.toFixed(2)}`,
+        `  ${formatNumber(TokenUsage.total(item.tokens))} tokens · ${formatNumber(item.steps)} steps · $${item.cost.toFixed(2)}`,
       ]),
       ...(more > 0 ? ["", `+${more.toLocaleString("en-US")} more model${more === 1 ? "" : "s"}`] : []),
     ]
@@ -248,7 +230,7 @@ function renderModels(stats: SessionStatsInfo, limit: number, width: number) {
     ...models.map((item) =>
       tableRow(
         `${item.model.providerID}/${item.model.id}${item.model.variant ? `#${item.model.variant}` : ""}`,
-        formatNumber(tokenTotal(item.tokens)),
+        formatNumber(TokenUsage.total(item.tokens)),
         formatNumber(item.steps),
         `$${item.cost.toFixed(2)}`,
       ),
@@ -310,10 +292,6 @@ function truncate(value: string, width: number) {
   return value.length <= width ? value : value.slice(0, width - 1) + "…"
 }
 
-function tokenTotal(tokens: SessionStatsInfo["tokens"]) {
-  return tokens.input + tokens.output + tokens.reasoning + tokens.cache.read + tokens.cache.write
-}
-
 function formatNumber(value: number) {
   if (value >= 1_000_000_000) return `${trimDecimal(value / 1_000_000_000)}b`
   if (value >= 1_000_000) return `${trimDecimal(value / 1_000_000)}m`
@@ -342,13 +320,6 @@ function style(value: string, code: string, color: boolean) {
   return color ? `\x1b[${code}m${value}\x1b[0m` : value
 }
 
-function activityGlyph(value: number, levels: number[], color: boolean) {
-  if (value === 0) return paintActivity(0, color)
-  const index = levels.indexOf(value)
-  const level = Math.max(1, Math.ceil(((index + 1) / levels.length) * 4))
-  return paintActivity(level, color)
-}
-
 function paintActivity(level: number, color: boolean) {
   const glyph = ["·", "░", "▒", "▓", "█"][level]
   if (!color) return glyph
@@ -370,39 +341,3 @@ function terminalPalette() {
     }
   return { primary: "36", activity: ["2;36", "36", "1;36", "1;96"] }
 }
-
-function monthLabels(weeks: Date[]) {
-  const line: string[] = []
-  weeks.reduce((previous, week, index) => {
-    const middle = new Date(week)
-    middle.setDate(middle.getDate() + 3)
-    const month = middle.getMonth()
-    if (month === previous) return previous
-    Intl.DateTimeFormat("en-US", { month: "short" })
-      .format(middle)
-      .split("")
-      .forEach((character, offset) => {
-        line[index + offset] = character
-      })
-    return month
-  }, -1)
-  return Array.from({ length: Math.max(weeks.length, line.length) }, (_, index) => line[index] ?? " ")
-    .join("")
-    .trimEnd()
-}
-
-function mondayIndex(date: Date) {
-  return (date.getDay() + 6) % 7
-}
-
-function dateKey(date: Date) {
-  return [
-    date.getFullYear(),
-    String(date.getMonth() + 1).padStart(2, "0"),
-    String(date.getDate()).padStart(2, "0"),
-  ].join("-")
-}
-
-function dateOrdinal(date: Date) {
-  return Math.floor(Date.UTC(date.getFullYear(), date.getMonth(), date.getDate()) / 86_400_000)
-}
diff --git a/packages/cli/test/stats.test.ts b/packages/cli/test/stats.test.ts
index 0fdea8ad08c..e3d3d81b09a 100644
--- a/packages/cli/test/stats.test.ts
+++ b/packages/cli/test/stats.test.ts
@@ -48,6 +48,20 @@ describe("stats rendering", () => {
     expect(output).not.toContain("$12.34")
   })
 
+  test("renders shared intensity levels and partial month labels", () => {
+    const output = renderStats(
+      {
+        ...stats,
+        range: { from: new Date(2026, 3, 29).getTime(), to: new Date(2026, 4, 20).getTime() },
+        activity: [{ date: "2026-04-29", steps: 1 }],
+      },
+      options(),
+    )
+    expect(output).toContain("    May")
+    expect(output).not.toContain("Apr")
+    expect(output.split(/\r?\n/).find((line) => line.startsWith("We "))).toContain("\u2588")
+  })
+
   test("renders only requested detail tables", () => {
     const output = renderStats(stats, options({ tools: true, cost: true }))
     expect(output).toContain("COST & TOKENS")
diff --git a/packages/core/src/session/stats.ts b/packages/core/src/session/stats.ts
index 057ca61fe44..0704d97bf6d 100644
--- a/packages/core/src/session/stats.ts
+++ b/packages/core/src/session/stats.ts
@@ -8,6 +8,7 @@ import { Project } from "@opencode-ai/schema/project"
 import { Provider } from "@opencode-ai/schema/provider"
 import { SessionEvent } from "@opencode-ai/schema/session-event"
 import { ToolMode } from "@opencode-ai/schema/session-stats"
+import { TokenUsage } from "@opencode-ai/schema/token-usage"
 import { Database } from "../database/database.js"
 import { EventTable } from "../event/sql.js"
 import { SessionMessageTable, SessionTable } from "./sql.js"
@@ -341,7 +342,7 @@ export const get = Effect.fn("SessionStats.get")(function* (input: Input = {}) {
     streak: longestStreak(days.map(([date]) => date)),
     activity: days.map(([date, steps]) => ({ date, steps })),
     models: [...models.values()]
-      .sort((a, b) => tokenTotal(b.tokens) - tokenTotal(a.tokens))
+      .sort((a, b) => TokenUsage.total(b.tokens) - TokenUsage.total(a.tokens))
       .map((model) => ({ ...model, cost: Money.USD.make(model.cost) })),
   }
 })
@@ -378,10 +379,6 @@ function addTokens(target: Tokens, source: Tokens) {
   target.cache.write += source.cache.write
 }
 
-function tokenTotal(tokens: Tokens) {
-  return tokens.input + tokens.output + tokens.reasoning + tokens.cache.read + tokens.cache.write
-}
-
 function addToolStatus(
   target: { calls: number; succeeded: number; failed: number; unfinished: number },
   status: string | null,
diff --git a/packages/schema/src/token-usage.ts b/packages/schema/src/token-usage.ts
index 6f08add0cc6..b8ce1d2ec9c 100644
--- a/packages/schema/src/token-usage.ts
+++ b/packages/schema/src/token-usage.ts
@@ -12,3 +12,7 @@ export const Info = Schema.Struct({
     write: Schema.Finite,
   }),
 }).annotate({ identifier: "TokenUsage.Info" })
+
+export function total(tokens: Info) {
+  return tokens.input + tokens.output + tokens.reasoning + tokens.cache.read + tokens.cache.write
+}
diff --git a/packages/schema/test/token-usage.test.ts b/packages/schema/test/token-usage.test.ts
new file mode 100644
index 00000000000..ee5e850cb71
--- /dev/null
+++ b/packages/schema/test/token-usage.test.ts
@@ -0,0 +1,18 @@
+import { expect, test } from "bun:test"
+import { TokenUsage } from "../src/token-usage.js"
+
+test("totals every token category", () => {
+  expect(TokenUsage.total({ input: 1, output: 2, reasoning: 4, cache: { read: 8, write: 16 } })).toBe(31)
+})
+
+test("supports zero and large usage totals without rounding", () => {
+  expect(TokenUsage.total({ input: 0, output: 0, reasoning: 0, cache: { read: 0, write: 0 } })).toBe(0)
+  expect(
+    TokenUsage.total({
+      input: 1_000_000_000,
+      output: 2_000_000_000,
+      reasoning: 3,
+      cache: { read: 4_000_000_000, write: 5 },
+    }),
+  ).toBe(7_000_000_008)
+})
diff --git a/packages/tui/src/app.tsx b/packages/tui/src/app.tsx
index b81c29b9b66..752830b5a77 100644
--- a/packages/tui/src/app.tsx
+++ b/packages/tui/src/app.tsx
@@ -1321,7 +1321,7 @@ function App(props: { pair?: DialogPairCredentials }) {
           <PaneResizeHandle resize={tabsResize} left={tabsResize.size() - 1} />
         </Show>
       </box>
-      <Show when={devtools()}>
+      <Show when={devtools() && !(route.data.type === "plugin" && route.data.id === "opencode.stats")}>
         <DevToolsBar />
       </Show>
       <Show when={!startup.skipInitialLoading}>
diff --git a/packages/tui/src/feature-plugins/system/stats-data.ts b/packages/tui/src/feature-plugins/system/stats-data.ts
new file mode 100644
index 00000000000..cafd2835320
--- /dev/null
+++ b/packages/tui/src/feature-plugins/system/stats-data.ts
@@ -0,0 +1,18 @@
+import type { SessionStatsInfo } from "@opencode-ai/client"
+import { TokenUsage } from "@opencode-ai/schema/token-usage"
+
+export function statsMetrics(stats: SessionStatsInfo) {
+  return [
+    {
+      label: "tokens",
+      value: TokenUsage.total(stats.tokens),
+    },
+    { label: "best streak", value: stats.streak },
+    { label: "active days", value: stats.activeDays },
+    { label: "sessions", value: stats.sessions },
+  ]
+}
+
+export function statsNumber(value: number) {
+  return new Intl.NumberFormat("en-US", { notation: "compact", maximumFractionDigits: 1 }).format(value)
+}
diff --git a/packages/tui/src/feature-plugins/system/stats.tsx b/packages/tui/src/feature-plugins/system/stats.tsx
new file mode 100644
index 00000000000..7cce828cf91
--- /dev/null
+++ b/packages/tui/src/feature-plugins/system/stats.tsx
@@ -0,0 +1,218 @@
+import type { SessionStatsInfo } from "@opencode-ai/client"
+import { Plugin } from "@opencode-ai/plugin/tui"
+import { activityCalendar } from "@opencode-ai/util/activity-calendar"
+import { TextAttributes } from "@opentui/core"
+import { useTerminalDimensions } from "@opentui/solid"
+import { createMemo, createResource, createSignal, For, Show } from "solid-js"
+import { Logo } from "../../component/logo"
+import { useTheme, useThemes } from "../../context/theme"
+import { tint } from "../../theme/color"
+import { statsMetrics, statsNumber } from "./stats-data"
+
+const digits: Record<string, string[]> = {
+  "0": ["111", "101", "101", "101", "111"],
+  "1": ["010", "110", "010", "010", "111"],
+  "2": ["111", "001", "111", "100", "111"],
+  "3": ["111", "001", "111", "001", "111"],
+  "4": ["101", "101", "111", "001", "001"],
+  "5": ["111", "100", "111", "001", "111"],
+  "6": ["111", "100", "111", "101", "111"],
+  "7": ["111", "001", "010", "010", "010"],
+  "8": ["111", "101", "111", "101", "111"],
+  "9": ["111", "101", "111", "001", "111"],
+  ".": ["0", "0", "0", "0", "1"],
+  K: ["101", "110", "100", "110", "101"],
+  M: ["10001", "11011", "10101", "10001", "10001"],
+  B: ["110", "101", "110", "101", "110"],
+  T: ["111", "010", "010", "010", "010"],
+}
+
+export function StatsPoster(props: { stats: SessionStatsInfo }) {
+  const dimensions = useTerminalDimensions()
+  const theme = useTheme()
+  const themes = useThemes()
+  const width = () => Math.max(12, Math.min(110, dimensions().width - 8))
+  const compact = () => dimensions().height < 38
+  const metrics = createMemo(() => statsMetrics(props.stats))
+  const number = () => statsNumber(metrics()[0].value)
+  const dates = createMemo(() =>
+    new Intl.DateTimeFormat("en-US", { month: "short", year: "numeric" }).formatRange(
+      new Date(props.stats.range.from),
+      new Date(Math.max(props.stats.range.from, props.stats.range.to - 1)),
+    ),
+  )
+  const letters = createMemo(() => Array.from(number()).map((char) => digits[char]))
+  const large = () =>
+    letters().every(Boolean) && letters().reduce((sum, char) => sum + char[0].length * 2 + 2, -2) <= width()
+  const calendar = createMemo(() =>
+    activityCalendar({
+      activity: props.stats.activity,
+      from: props.stats.range.from,
+      to: props.stats.range.to,
+      maxWeeks: Math.floor((width() - 4) / 2),
+    }),
+  )
+  const shades = createMemo(() => [
+    theme.text.subdued,
+    ...[0.3, 0.5, 0.75, 1].map((alpha) =>
+      tint(theme.background.default, theme.categorical[0][themes.mode() === "light" ? 800 : 200], alpha),
+    ),
+  ])
+
+  return (
+    <box width={width()} flexDirection="column" alignItems="center" flexShrink={0} gap={compact() ? 1 : 2}>
+      <box width="100%" flexDirection={width() < 44 ? "column" : "row"} justifyContent="space-between">
+        <text fg={theme.text.default} attributes={TextAttributes.BOLD}>
+          opencode / stats
+        </text>
+        <text fg={theme.text.subdued}>{dates()}</text>
+      </box>
+      <Show when={!compact()}>
+        <Logo />
+      </Show>
+      <box alignItems="center" gap={1}>
+        <Show
+          when={large()}
+          fallback={
+            <text fg={theme.text.default} attributes={TextAttributes.BOLD}>
+              {number()}
+            </text>
+          }
+        >
+          <box>
+            <For each={[0, 1, 2, 3, 4]}>
+              {(row) => (
+                <text fg={theme.text.default} selectable={false}>
+                  {letters()
+                    .map((char) => char[row].replaceAll("1", "\u2588\u2588").replaceAll("0", "  "))
+                    .join("  ")}
+                </text>
+              )}
+            </For>
+          </box>
+        </Show>
+        <text fg={theme.text.subdued}>TOKENS</text>
+      </box>
+      <box alignItems="center">
+        <text fg={theme.text.subdued}>
+          {"    " +
+            calendar()
+              .months.map((month) => (month.label.length <= month.span * 2 ? month.label : "").padEnd(month.span * 2))
+              .join("")}
+        </text>
+        <For each={["M", "T", "W", "T", "F", "S", "S"]}>
+          {(day, index) => (
+            <box flexDirection="row" height={1}>
+              <text fg={theme.text.subdued}>{day + "   "}</text>
+              <For each={calendar().weeks}>
+                {(week) => (
+                  <text fg={shades()[Math.max(0, week[index()].level)]} selectable={false}>
+                    {week[index()].level < 0 ? "  " : week[index()].level === 0 ? "\u00b7 " : "\u25a0 "}
+                  </text>
+                )}
+              </For>
+            </box>
+          )}
+        </For>
+        <Show when={calendar().clipped}>
+          <text fg={theme.text.subdued}>Your last {calendar().weeks.length} weeks</text>
+        </Show>
+      </box>
+      <box width="100%" flexDirection="row" justifyContent="space-around">
+        <For each={metrics().slice(1)}>
+          {(metric) => (
+            <box alignItems="center">
+              <text fg={theme.text.default} attributes={TextAttributes.BOLD}>
+                {statsNumber(metric.value)}
+                {metric.label === "best streak" ? " days" : ""}
+              </text>
+              <text fg={theme.text.subdued}>{metric.label}</text>
+            </box>
+          )}
+        </For>
+      </box>
+      <box width="100%" flexDirection="row" justifyContent="flex-end">
+        <text fg={theme.text.default}>opencode.ai</text>
+      </box>
+    </box>
+  )
+}
+
+function StatsPage(props: { context: Plugin.Context; onClose: () => void }) {
+  const [result] = createResource(() => {
+    const now = new Date()
+    return props.context.client.session.stats({
+      from: new Date(now.getFullYear(), 0, 1).getTime(),
+      timezone: Intl.DateTimeFormat().resolvedOptions().timeZone || "UTC",
+      tools: "none",
+    })
+  })
+  const theme = useTheme()
+
+  props.context.keymap.layer(() => ({
+    commands: [{ bind: "escape", title: "back", run: props.onClose }],
+  }))
+
+  return (
+    <box width="100%" height="100%" backgroundColor={theme.background.default}>
+      <scrollbox
+        flexGrow={1}
+        contentOptions={{
+          alignItems: "center",
+          justifyContent: "center",
+          minHeight: "100%",
+          paddingTop: 1,
+          paddingBottom: 1,
+        }}
+      >
+        <Show
+          when={!result.error}
+          fallback={
+            <text fg={theme.text.feedback.error.default}>Could not load stats. Reopen /stats to try again.</text>
+          }
+        >
+          <Show when={result()} fallback={<text fg={theme.text.subdued}>Gathering your stats...</text>}>
+            {(value) => <StatsPoster stats={value()} />}
+          </Show>
+        </Show>
+      </scrollbox>
+    </box>
+  )
+}
+
+export default Plugin.define({
+  id: "opencode.stats",
+  setup(context) {
+    const [previous, setPrevious] = createSignal({ ...context.ui.router.current() })
+    context.ui.router.register({
+      name: "stats",
+      render: () => <StatsPage context={context} onClose={() => context.ui.router.navigate(previous())} />,
+    })
+    context.ui.slot({
+      append: "app",
+      render() {
+        context.keymap.layer(() => ({
+          mode: "global",
+          commands: [
+            {
+              id: "stats.open",
+              title: "Usage statistics",
+              group: "System",
+              slash: { name: "stats" },
+              palette: true,
+              run() {
+                const current = context.ui.router.current()
+                if (current.type === "plugin" && current.name === "stats") return
+                // The router exposes a mutable store; retain the route before navigating.
+                setPrevious({ ...current })
+                context.ui.dialog.clear()
+                context.ui.router.navigate({ type: "plugin", name: "stats" })
+              },
+            },
+          ],
+        }))
+        return null
+      },
+    })
+  },
+})
diff --git a/packages/tui/src/plugin/builtins.ts b/packages/tui/src/plugin/builtins.ts
index fabfaff68f3..a2cacb8513b 100644
--- a/packages/tui/src/plugin/builtins.ts
+++ b/packages/tui/src/plugin/builtins.ts
@@ -7,6 +7,7 @@ import DiffViewer from "../feature-plugins/system/diff-viewer"
 import Notifications from "../feature-plugins/system/notifications"
 import Plugins from "../feature-plugins/system/plugins"
 import Storybook from "../feature-plugins/system/storybook"
+import Stats from "../feature-plugins/system/stats"
 import Latex from "@opencode-ai/latex/plugin"
 import Merman from "@opencode-ai/merman/plugin"
 
@@ -18,6 +19,7 @@ export const builtins = [
   SidebarFooter,
   Notifications,
   Plugins,
+  Stats,
   Merman,
   Latex,
   // The storybook is a development tool; keep its route and palette commands out of
diff --git a/packages/tui/test/stats.test.ts b/packages/tui/test/stats.test.ts
new file mode 100644
index 00000000000..a694fec854f
--- /dev/null
+++ b/packages/tui/test/stats.test.ts
@@ -0,0 +1,33 @@
+import { describe, expect, test } from "bun:test"
+import type { SessionStatsInfo } from "@opencode-ai/client"
+import { statsMetrics, statsNumber } from "../src/feature-plugins/system/stats-data"
+
+const stats: SessionStatsInfo = {
+  range: { from: new Date(2026, 0, 1).getTime(), to: new Date(2026, 0, 8).getTime() },
+  sessions: 12,
+  subagents: 99,
+  prompts: 24,
+  steps: 50,
+  activeDays: 2,
+  streak: 2,
+  tokens: { input: 1, output: 2, reasoning: 3, cache: { read: 4, write: 5 } },
+  cost: 0,
+  tools: { mode: "none" },
+  models: [],
+  activity: [
+    { date: "2026-01-01", steps: 1 },
+    { date: "2026-01-02", steps: 50 },
+  ],
+}
+
+describe("stats poster", () => {
+  test("includes all token categories and replaces subagents with tokens", () => {
+    expect(statsMetrics(stats)).toEqual([
+      { label: "tokens", value: 15 },
+      { label: "best streak", value: 2 },
+      { label: "active days", value: 2 },
+      { label: "sessions", value: 12 },
+    ])
+    expect([0, 685, 5284, 9_200_000_000].map(statsNumber)).toEqual(["0", "685", "5.3K", "9.2B"])
+  })
+})
diff --git a/packages/tui/test/stats.view.test.tsx b/packages/tui/test/stats.view.test.tsx
new file mode 100644
index 00000000000..c5f1f222b9d
--- /dev/null
+++ b/packages/tui/test/stats.view.test.tsx
@@ -0,0 +1,90 @@
+import { expect, test } from "bun:test"
+import { createTestRenderer } from "@opentui/core/testing"
+import { Global } from "@opencode-ai/util/global"
+import { Effect, FileSystem } from "effect"
+import { createEventStream, createFetch, json } from "./fixture/tui-client"
+import { tmpdir } from "./fixture/fixture"
+
+test("stats shows only this year and returns after errors or success", async () => {
+  await using state = await tmpdir()
+  const setup = await createTestRenderer({ width: 100, height: 34, useThread: false, kittyKeyboard: true })
+  setup.renderer.start()
+  const requests: URL[] = []
+  const calls = createFetch((url) => {
+    if (url.pathname !== "/api/session/stats") return undefined
+    requests.push(url)
+    if (requests.length === 1) return json({ message: "offline" }, { status: 503 })
+    return json({
+      data: {
+        range: { from: new Date(new Date().getFullYear(), 0, 1).getTime(), to: Date.now() },
+        sessions: 123,
+        subagents: 0,
+        prompts: 1,
+        steps: 1,
+        tokens: { input: 10, output: 5, reasoning: 2, cache: { read: 20, write: 0 } },
+        cost: 0,
+        tools: { mode: "none" },
+        activeDays: 1,
+        streak: 1,
+        activity: [{ date: `${new Date().getFullYear()}-01-01`, steps: 1 }],
+        models: [],
+      },
+    })
+  }, createEventStream())
+  const server = Bun.serve({ port: 0, idleTimeout: 0, fetch: (request) => calls.fetch(request) })
+  const { run } = await import("../src/app")
+  const task = Effect.runPromise(
+    run({
+      app: { name: "test", version: "test", channel: "test" },
+      server: { endpoint: { url: server.url.toString() } },
+      config: {
+        get: async () => ({ animations: false, tabs: { enabled: false } }),
+        update: async () => ({}),
+      },
+      packages: { resolve: async () => undefined },
+      terminalHandoff: async () => ({ renderer: setup.renderer, mode: "dark", complete: () => {} }),
+      args: {},
+      log: () => {},
+    }).pipe(Effect.provide(Global.layerWith({ state: state.path })), Effect.provide(FileSystem.layerNoop({}))),
+  )
+  try {
+    await setup.waitForFrame((frame) => frame.includes("commands"))
+    await setup.mockInput.typeText("/stats")
+    await setup.waitForFrame((frame) => frame.includes("Usage statistics"))
+    setup.mockInput.pressKey("RETURN")
+    await setup.waitForFrame((frame) => frame.includes("Could not load stats"))
+    setup.mockInput.pressKey("ESCAPE")
+    await setup.waitForFrame((frame) => frame.includes("commands") && !frame.includes("Could not load stats"))
+    await setup.mockInput.typeText("/stats")
+    await setup.waitForFrame((frame) => frame.includes("Usage statistics"))
+    setup.mockInput.pressKey("RETURN")
+    await setup.waitForFrame((frame) => frame.includes("TOKENS") && frame.includes("123"))
+    expect(requests[1].searchParams.get("tools")).toBe("none")
+    expect(Number(requests[1].searchParams.get("from"))).toBe(new Date(new Date().getFullYear(), 0, 1).getTime())
+    expect(requests[1].searchParams.has("to")).toBe(false)
+    expect(setup.captureCharFrame()).not.toContain("all time")
+    expect(setup.captureCharFrame()).not.toContain("All projects")
+    expect(setup.captureCharFrame()).not.toContain("show this year")
+    expect(setup.captureCharFrame()).not.toContain("esc")
+    expect(
+      setup
+        .captureCharFrame()
+        .split("\n")
+        .find((line) => line.includes("opencode / stats")),
+    ).not.toContain("tab")
+    setup.mockInput.pressKey("RETURN")
+    setup.mockInput.pressKey("SPACE")
+    await setup.mockInput.typeText("rhp")
+    setup.mockInput.pressKey("TAB")
+    setup.mockInput.pressKey("RIGHT")
+    await setup.waitForVisualIdle()
+    expect(requests).toHaveLength(2)
+    expect(setup.captureCharFrame()).toContain("TOKENS")
+    expect(setup.captureCharFrame()).not.toContain("headline")
+    setup.mockInput.pressKey("ESCAPE")
+    await setup.waitForFrame((frame) => frame.includes("commands") && !frame.includes("opencode / stats"))
+  } finally {
+    if (!setup.renderer.isDestroyed) setup.renderer.destroy()
+    await task.finally(() => server.stop(true))
+  }
+})
diff --git a/packages/util/src/activity-calendar.test.ts b/packages/util/src/activity-calendar.test.ts
new file mode 100644
index 00000000000..07458905f3b
--- /dev/null
+++ b/packages/util/src/activity-calendar.test.ts
@@ -0,0 +1,136 @@
+import { describe, expect, test } from "bun:test"
+import { activityCalendar } from "./activity-calendar.js"
+
+const input = {
+  from: new Date(2026, 0, 1).getTime(),
+  to: new Date(2026, 0, 8).getTime(),
+  maxWeeks: 53,
+  activity: [
+    { date: "2026-01-01", steps: 1 },
+    { date: "2026-01-02", steps: 50 },
+  ],
+}
+
+describe("activity calendar", () => {
+  test("aligns Monday-first weeks and excludes cells outside the end-exclusive range", () => {
+    const calendar = activityCalendar(input)
+    expect(calendar.clipped).toBe(false)
+    expect(calendar.weeks).toHaveLength(2)
+    expect(calendar.weeks[0][0]).toEqual({ date: "2025-12-29", steps: 0, level: -1 })
+    expect(calendar.weeks[0][3]).toEqual({ date: "2026-01-01", steps: 1, level: 2 })
+    expect(calendar.weeks[0][4]).toEqual({ date: "2026-01-02", steps: 50, level: 4 })
+    expect(calendar.weeks[1][2]).toEqual({ date: "2026-01-07", steps: 0, level: 0 })
+    expect(calendar.weeks[1][3].level).toBe(-1)
+    expect(calendar.months).toEqual([{ week: 0, label: "Jan", span: 2 }])
+  })
+
+  test("clips to the latest weeks and keeps empty days distinct from out-of-range cells", () => {
+    const calendar = activityCalendar({ ...input, activity: [], maxWeeks: 1 })
+    expect(calendar.clipped).toBe(true)
+    expect(calendar.weeks).toHaveLength(1)
+    expect(calendar.weeks[0][0]).toEqual({ date: "2026-01-05", steps: 0, level: 0 })
+    expect(calendar.weeks[0][3].level).toBe(-1)
+  })
+
+  test("caps long histories at 53 weeks", () => {
+    const calendar = activityCalendar({ ...input, from: new Date(2020, 0, 1).getTime(), maxWeeks: 200 })
+    expect(calendar.clipped).toBe(true)
+    expect(calendar.weeks).toHaveLength(53)
+    expect(calendar.weeks.at(-1)?.[2].date).toBe("2026-01-07")
+    expect(calendar.months.reduce((sum, month) => sum + month.span, 0)).toBe(53)
+  })
+
+  test("returns month positions and spans for partial first and last months", () => {
+    const calendar = activityCalendar({
+      ...input,
+      from: new Date(2026, 3, 29).getTime(),
+      to: new Date(2026, 4, 20).getTime(),
+    })
+    expect(calendar.months).toEqual([
+      { week: 0, label: "Apr", span: 1 },
+      { week: 1, label: "May", span: 3 },
+    ])
+    const partial = activityCalendar({
+      ...input,
+      from: new Date(2026, 3, 1).getTime(),
+      to: new Date(2026, 3, 2).getTime(),
+    })
+    expect(partial.months).toEqual([{ week: 0, label: "Apr", span: 1 }])
+  })
+
+  test("places month labels across a year boundary", () => {
+    const calendar = activityCalendar({
+      ...input,
+      from: new Date(2025, 11, 22).getTime(),
+      to: new Date(2026, 0, 12).getTime(),
+    })
+    expect(calendar.months).toEqual([
+      { week: 0, label: "Dec", span: 1 },
+      { week: 1, label: "Jan", span: 2 },
+    ])
+  })
+
+  test("keeps exactly seven distinct cells per week across DST and leap days", () => {
+    const calendar = activityCalendar({
+      from: new Date(2024, 1, 26).getTime(),
+      to: new Date(2024, 2, 12).getTime(),
+      maxWeeks: 53,
+      activity: [
+        { date: "2024-02-29", steps: 1 },
+        { date: "2024-03-10", steps: 1 },
+      ],
+    })
+    expect(calendar.weeks).toHaveLength(3)
+    expect(
+      calendar.weeks
+        .flat()
+        .filter((day) => day.steps > 0)
+        .map((day) => day.date),
+    ).toEqual(["2024-02-29", "2024-03-10"])
+    expect(new Set(calendar.weeks.flat().map((day) => day.date)).size).toBe(21)
+  })
+
+  test("uses the highest intensity for a single distinct positive count", () => {
+    const calendar = activityCalendar({ ...input, activity: input.activity.map((day) => ({ ...day, steps: 10 })) })
+    expect(
+      calendar.weeks
+        .flat()
+        .filter((day) => day.steps > 0)
+        .map((day) => day.level),
+    ).toEqual([4, 4])
+  })
+
+  test("ranks distinct activity counts in four levels", () => {
+    const calendar = activityCalendar({
+      ...input,
+      to: new Date(2026, 0, 10).getTime(),
+      activity: Array.from({ length: 8 }, (_, index) => ({ date: `2026-01-0${index + 1}`, steps: index + 1 })),
+    })
+    expect(
+      calendar.weeks
+        .flat()
+        .filter((day) => day.steps > 0)
+        .map((day) => day.level),
+    ).toEqual([1, 1, 2, 2, 3, 3, 4, 4])
+  })
+
+  test("keeps intensity relative to the requested range when older weeks are clipped", () => {
+    const calendar = activityCalendar({
+      ...input,
+      maxWeeks: 1,
+      activity: [
+        { date: "2026-01-01", steps: 50 },
+        { date: "2026-01-05", steps: 1 },
+      ],
+    })
+    expect(calendar.weeks[0][0].level).toBe(2)
+  })
+
+  test("returns an empty calendar for an empty range", () => {
+    expect(activityCalendar({ ...input, to: input.from, activity: [] })).toEqual({
+      weeks: [],
+      months: [],
+      clipped: false,
+    })
+  })
+})
diff --git a/packages/util/src/activity-calendar.ts b/packages/util/src/activity-calendar.ts
new file mode 100644
index 00000000000..eb89d1cb23b
--- /dev/null
+++ b/packages/util/src/activity-calendar.ts
@@ -0,0 +1,50 @@
+export function activityCalendar(input: {
+  activity: readonly { date: string; steps: number }[]
+  from: number
+  to: number
+  maxWeeks: number
+}) {
+  // Extract local dates first, then use UTC ordinals so DST cannot add or drop cells.
+  const ordinal = (time: number) => {
+    const date = new Date(time)
+    return Date.UTC(date.getFullYear(), date.getMonth(), date.getDate()) / 86_400_000
+  }
+  const from = ordinal(input.from)
+  const to = ordinal(input.to - 1)
+  const monday = from - ((new Date(from * 86_400_000).getUTCDay() + 6) % 7)
+  const total = input.to <= input.from ? 0 : Math.floor((to - monday) / 7) + 1
+  const count = Math.min(total, 53, Math.max(1, Math.floor(input.maxWeeks)))
+  const start = monday + Math.max(0, total - count) * 7
+  const values = new Map(input.activity.map((day) => [day.date, day.steps]))
+  const levels = [...new Set([...values.values()].filter((steps) => steps > 0))].sort((a, b) => a - b)
+  const weeks = Array.from({ length: count }, (_, week) =>
+    Array.from({ length: 7 }, (_, day) => {
+      const date = start + week * 7 + day
+      const key = new Date(date * 86_400_000).toISOString().slice(0, 10)
+      const steps = values.get(key) ?? 0
+      return {
+        date: key,
+        steps,
+        level:
+          date < from || date > to
+            ? -1
+            : steps === 0
+              ? 0
+              : Math.max(1, Math.ceil(((levels.indexOf(steps) + 1) / levels.length) * 4)),
+      }
+    }),
+  )
+  const formatter = new Intl.DateTimeFormat("en-US", { month: "short", timeZone: "UTC" })
+  // Thursday identifies the month owning most of a week; partial edge weeks stay inside the range.
+  const months = weeks
+    .map((_, week) => ({
+      week,
+      label: formatter.format(Math.min(to, Math.max(from, start + week * 7 + 3)) * 86_400_000),
+    }))
+    .filter((month, index, months) => index === 0 || month.label !== months[index - 1].label)
+  return {
+    weeks,
+    months: months.map((month, index) => ({ ...month, span: (months[index + 1]?.week ?? count) - month.week })),
+    clipped: count < total,
+  }
+}