diff --git a/src/lib/api.ts b/src/lib/api.ts
index e26f05b..53bc47f 100644
--- a/src/lib/api.ts
+++ b/src/lib/api.ts
@@ -52,6 +52,8 @@ export type Node = {
   total_tx: number
   month_rx: number
   month_tx: number
+  /** This period's usage as the plan meters it (`traffic_mode`). Absent on older hubs. */
+  month_used?: number
   month_start: string
   day_rx: number
   day_tx: number
diff --git a/src/lib/format.test.ts b/src/lib/format.test.ts
index e0858f5..93f3984 100644
--- a/src/lib/format.test.ts
+++ b/src/lib/format.test.ts
@@ -125,6 +125,7 @@ eq(duration(76 * 86400 + 5), "76 天", "超过一天只写天数")
   eq(monthUsage({ ...node, traffic_mode: "up" }), 5, "仅上行")
   eq(monthUsage({ ...node, traffic_mode: "down" }), 3, "仅下行")
   eq(monthUsage({ ...node, traffic_mode: "max" }), 5, "取较大值")
+  eq(monthUsage({ ...node, traffic_mode: "up", month_used: 7 }), 7, "hub 算好的值优先")
 }
 
 eq(osName("Debian GNU/Linux 12 (bookworm)"), "Debian 12", "发行版名去掉代号")
diff --git a/src/lib/format.ts b/src/lib/format.ts
index 24fbe76..9cf94cb 100644
--- a/src/lib/format.ts
+++ b/src/lib/format.ts
@@ -77,8 +77,12 @@ export function duration(seconds: number): string {
   return `${Math.floor(s / 3600)}:${pad(Math.floor((s % 3600) / 60))}:${pad(s % 60)}`
 }
 
-/** The month's usage counted the way the node's plan meters it. */
-export function monthUsage(node: { month_rx: number; month_tx: number; traffic_mode: string }): number {
+/**
+ * The month's usage counted the way the node's plan meters it. The hub computes
+ * it; the switch below serves only a hub from before `month_used`.
+ */
+export function monthUsage(node: { month_rx: number; month_tx: number; month_used?: number; traffic_mode: string }): number {
+  if (typeof node.month_used === "number") return node.month_used
   const { month_rx: rx, month_tx: tx } = node
   switch (node.traffic_mode) {
     case "up":