diff --git a/packages/opencode/src/cli/cmd/tui/routes/session/sidebar.tsx b/packages/opencode/src/cli/cmd/tui/routes/session/sidebar.tsx
index a9ed042d1bb..caa7dd1a59e 100644
--- a/packages/opencode/src/cli/cmd/tui/routes/session/sidebar.tsx
+++ b/packages/opencode/src/cli/cmd/tui/routes/session/sidebar.tsx
@@ -1,8 +1,9 @@
 import { useSync } from "@tui/context/sync"
-import { createMemo, For, Show, Switch, Match } from "solid-js"
+import { createMemo, For, Show, Switch, Match, createResource, createEffect } from "solid-js"
 import { createStore } from "solid-js/store"
 import { useTheme } from "../../context/theme"
 import { Locale } from "@/util/locale"
+import { fetchPlanUsageWithCache, formatResetTime, getPercentage } from "@/provider/plan-usage"
 import path from "path"
 import type { AssistantMessage } from "@opencode-ai/sdk/v2"
 import { Global } from "@/global"
@@ -48,8 +49,12 @@ export function Sidebar(props: { sessionID: string }) {
     }).format(total)
   })
 
+  const lastAssistantMessage = createMemo(
+    () => messages().findLast((x) => x.role === "assistant" && x.tokens.output > 0) as AssistantMessage | undefined,
+  )
+
   const context = createMemo(() => {
-    const last = messages().findLast((x) => x.role === "assistant" && x.tokens.output > 0) as AssistantMessage
+    const last = lastAssistantMessage()
     if (!last) return
     const total =
       last.tokens.input + last.tokens.output + last.tokens.reasoning + last.tokens.cache.read + last.tokens.cache.write
@@ -57,9 +62,21 @@ export function Sidebar(props: { sessionID: string }) {
     return {
       tokens: total.toLocaleString(),
       percentage: model?.limit.context ? Math.round((total / model.limit.context) * 100) : null,
+      providerID: last.providerID,
     }
   })
 
+  const [planUsage, { refetch }] = createResource(
+    () => context()?.providerID,
+    (providerID) => fetchPlanUsageWithCache(providerID, sync.data.provider),
+  )
+
+  // Refetch plan usage when messages are added (user or assistant)
+  createEffect(() => {
+    messages().length
+    refetch()
+  })
+
   const directory = useDirectory()
   const kv = useKV()
 
@@ -96,6 +113,17 @@ export function Sidebar(props: { sessionID: string }) {
               <text fg={theme.textMuted}>{context()?.percentage ?? 0}% used</text>
               <text fg={theme.textMuted}>{cost()} spent</text>
             </box>
+            <Show when={planUsage()?.planUsage}>
+              {(data) => (
+                <box>
+                  <text fg={theme.text}>
+                    <b>Plan Usage</b>
+                  </text>
+                  <text fg={theme.textMuted}>{getPercentage(data())}% used</text>
+                  <text fg={theme.textMuted}>{formatResetTime(data().resetAt)}</text>
+                </box>
+              )}
+            </Show>
             <Show when={mcpEntries().length > 0}>
               <box>
                 <box
diff --git a/packages/opencode/src/provider/plan-usage.ts b/packages/opencode/src/provider/plan-usage.ts
new file mode 100644
index 00000000000..d62bea38ecc
--- /dev/null
+++ b/packages/opencode/src/provider/plan-usage.ts
@@ -0,0 +1,106 @@
+import { Log } from "@/util/log"
+
+const log = Log.create({ service: "plan-usage" })
+
+/**
+ * Generic plan usage interface that all providers should implement.
+ * Each provider converts their specific format to this common representation.
+ */
+export interface PlanUsage {
+  used: number
+  total: number
+  resetAt?: Date
+  percentage?: number // Provider-supplied percentage if more accurate than derived
+}
+
+export function getPercentage(planUsage: PlanUsage): number {
+  if (planUsage.percentage !== undefined) return planUsage.percentage
+  return planUsage.total > 0 ? Math.round((planUsage.used / planUsage.total) * 100) : 0
+}
+
+export interface PlanUsageData {
+  planUsage?: PlanUsage
+  error?: string
+}
+
+export type PlanUsageHandler = (config: { token: string; baseURL: string; timeout: number }) => Promise<PlanUsageData>
+
+const HANDLERS: Record<string, PlanUsageHandler> = {}
+
+export function registerProvider(id: string, handler: PlanUsageHandler) {
+  HANDLERS[id] = handler
+}
+
+// Load built-in providers
+import("./plan-usage/zai")
+
+type CacheEntry = { data: PlanUsageData; time: number }
+const cache = new Map<string, CacheEntry>()
+const CACHE_TTL_MS = 60 * 1000
+
+export async function fetchPlanUsage(
+  providerID: string,
+  providers: Array<Record<string, unknown>>,
+  timeout = 5000,
+): Promise<PlanUsageData> {
+  const config = await getProviderConfig(providerID, providers)
+  if (!config.token) {
+    log.debug("No API key configured for provider", { providerID })
+    return { error: `No API key configured for provider: ${providerID}` }
+  }
+  if (!config.baseURL) {
+    log.debug("No base URL configured for provider", { providerID })
+    return { error: `No base URL configured for provider: ${providerID}` }
+  }
+
+  const handler = HANDLERS[providerID]
+  if (!handler) {
+    log.debug("No plan usage handler for provider", { providerID })
+    return { error: `No plan usage handler for provider: ${providerID}` }
+  }
+
+  return handler({ token: config.token, baseURL: config.baseURL, timeout })
+}
+
+export async function fetchPlanUsageWithCache(
+  providerID: string,
+  providers: Array<Record<string, unknown>>,
+  timeout = 5000,
+): Promise<PlanUsageData> {
+  const key = `planUsage:${providerID}`
+  const cached = cache.get(key)
+  if (cached && Date.now() - cached.time < CACHE_TTL_MS) return cached.data
+
+  const data = await fetchPlanUsage(providerID, providers, timeout)
+  cache.set(key, { data, time: Date.now() })
+  return data
+}
+
+export function formatResetTime(date?: Date): string | null {
+  if (!date) return null
+
+  const now = Date.now()
+  const remaining = Math.max(0, date.getTime() - now) / 1000
+  const h = Math.floor(remaining / 3600)
+  const m = Math.floor((remaining % 3600) / 60)
+  const s = Math.floor(remaining % 60)
+
+  if (h > 24) return `Resets in ${Math.floor(h / 24)}d ${h % 24}h`
+  if (h > 0) return `Resets in ${h}h ${m}m`
+  if (m > 0) return `Resets in ${m}m`
+  if (s > 0) return `Resets in ${s}s`
+  return "Resets soon"
+}
+
+async function getProviderConfig(providerID: string, providers: Array<Record<string, unknown>>) {
+  const { Auth } = await import("@/auth")
+  const auth = await Auth.get(providerID)
+  const token = auth?.type === "api" ? auth.key : null
+
+  const provider = providers.find((p) => p.id === providerID)
+  const models = provider?.models as Record<string, { api?: { url?: string } }> | undefined
+  const firstModel = models ? Object.values(models)[0] : undefined
+  const baseURL = firstModel?.api?.url ?? null
+
+  return { token, baseURL }
+}
diff --git a/packages/opencode/src/provider/plan-usage/zai.ts b/packages/opencode/src/provider/plan-usage/zai.ts
new file mode 100644
index 00000000000..23727849eb7
--- /dev/null
+++ b/packages/opencode/src/provider/plan-usage/zai.ts
@@ -0,0 +1,115 @@
+import { Log } from "@/util/log"
+import { registerProvider, type PlanUsageHandler } from "../plan-usage"
+
+const log = Log.create({ service: "zai-plan-usage" })
+
+// z.ai specific types
+interface ZaiPlanUsageLimit {
+  type: string
+  unit: number
+  number: number
+  usage: number
+  currentValue: number
+  remaining: number
+  percentage: number
+  nextResetTime?: number
+}
+
+interface ZaiPlanUsageResponse {
+  data?: { limits?: ZaiPlanUsageLimit[] }
+  limits?: ZaiPlanUsageLimit[]
+}
+
+function selectLimit(limits: ZaiPlanUsageLimit[]): ZaiPlanUsageLimit | null {
+  return limits.find((l) => l.type === "TOKENS_LIMIT") ?? null
+}
+
+function fetchWithTimeout(url: string, headers: Record<string, string>, timeout: number): Promise<Response> {
+  const controller = new AbortController()
+  const id = setTimeout(() => controller.abort(), timeout)
+  return fetch(url, {
+    method: "GET",
+    headers,
+    signal: controller.signal,
+  }).then((response) => {
+    clearTimeout(id)
+    return response
+  })
+}
+
+async function parsePlanUsageResponse(
+  response: Response,
+): Promise<{ used: number; total: number; resetAt?: Date; percentage?: number } | { error: string }> {
+  if (!response.ok) {
+    const text = await response.text()
+    return { error: `HTTP ${response.status}: ${text}` }
+  }
+
+  const json = (await response.json()) as unknown
+  const limits = extractLimits(json)
+
+  if (!limits || !Array.isArray(limits) || limits.length === 0) {
+    return { error: "Invalid plan usage response format" }
+  }
+
+  const limit = selectLimit(limits)
+  if (!limit) {
+    return { error: "No token limit found in response" }
+  }
+
+  return {
+    used: limit.usage,
+    total: limit.number,
+    resetAt: limit.nextResetTime ? new Date(limit.nextResetTime) : undefined,
+    percentage: limit.percentage,
+  }
+}
+
+function extractLimits(json: unknown): ZaiPlanUsageLimit[] | undefined {
+  if (typeof json !== "object" || json === null) return undefined
+
+  const candidate = json as Record<string, unknown>
+
+  // Check for { data: { limits: [...] } }
+  if ("data" in candidate && typeof candidate.data === "object" && candidate.data !== null) {
+    const data = candidate.data as Record<string, unknown>
+    if ("limits" in data && Array.isArray(data.limits)) {
+      return data.limits as ZaiPlanUsageLimit[]
+    }
+  }
+
+  // Check for { limits: [...] }
+  if ("limits" in candidate && Array.isArray(candidate.limits)) {
+    return candidate.limits as ZaiPlanUsageLimit[]
+  }
+
+  return undefined
+}
+
+const zaiPlanUsageHandler: PlanUsageHandler = async ({ token, baseURL, timeout }) => {
+  if (!token) return { error: "No API key configured" }
+  if (!baseURL) return { error: "No base URL configured" }
+
+  const url = new URL(baseURL)
+  const endpoint = `${url.origin}/api/monitor/usage/quota/limit`
+
+  return fetchWithTimeout(
+    endpoint,
+    {
+      Authorization: token,
+      "Accept-Language": "en-US,en",
+      "Content-Type": "application/json",
+    },
+    timeout,
+  )
+    .then(parsePlanUsageResponse)
+    .then((result) => ("error" in result ? { error: result.error } : { planUsage: result }))
+    .catch((err) => {
+      const msg = err instanceof Error ? err.message : String(err)
+      log.debug("Failed to fetch plan usage", { provider: "zai-coding-plan", error: msg })
+      return { error: msg }
+    })
+}
+
+// Register on import
+registerProvider("zai-coding-plan", zaiPlanUsageHandler)