Fix new-window context leak showing previous session ctx%

Stop tmux status from falling back to global status files, seed new
tmux instances at 0%, rank live sessions by opened_at instead of
signals.json keepalive mtime, and bind Grok pids to tmux more reliably.

CHANGELOG.md

@@ -1,5 +1,16 @@
 # Changelog
 
+## 0.3.13
+
+### Fixes
+- **New window context leak**: brand-new Terminal no longer shows the previous
+  session’s high ctx%. Root causes fixed:
+  1. tmux status **no longer falls back** to global `~/.grok/hud/tmux-*.txt`
+  2. new tmux instances are **seeded at ctx 0%**
+  3. session ranking ignores `signals.json` mtime keepalive and prefers newest
+     `opened_at` among live sessions
+  4. stronger pid/tty → tmux binding via `resolveTmuxSessionForGrok`
+
 ## 0.3.12
 
 ### Repo / docs

package.json

@@ -1,6 +1,6 @@
 {
   "name": "grok-build-hud",
-  "version": "0.3.12",
+  "version": "0.3.13",
   "description": "第三方 Grok Build 状态条（非 xAI 官方）：同窗口上下文/配额/token/工具；plugin + CLI + tmux HUD",
   "type": "module",
   "main": "dist/src/index.js",

plugin.json

@@ -1,6 +1,6 @@
 {
   "name": "grok-build-hud",
-  "version": "0.3.12",
+  "version": "0.3.13",
   "description": "第三方 Grok Build 状态条（非官方）：同窗口上下文/配额/token/工具/待办；tmux HUD + 会话斜杠命令",
   "author": {
     "name": "Redredchen01"

src/dashboard.ts

@@ -18,7 +18,7 @@ import {
 } from "./session.js";
 import { getCreditUsage } from "./billing.js";
 import { writeStatusFiles, formatCompactLine } from "./status.js";
-import { findTmuxSessionForPid } from "./multi-session.js";
+import { resolveTmuxSessionForGrok } from "./multi-session.js";
 import type { SessionSnapshot, UsageSnapshot } from "./types.js";
 
 export function dashboardPidPath(grokHome = defaultGrokHome()): string {
@@ -178,17 +178,17 @@ export async function refreshDashboard(options: {
     /* ignore */
   }
 
-  // Write per-tmux-session status so each Terminal bar shows ITS own Grok
-  // Layout adapts to each window's client width.
+  // Write per-tmux-session status so each Terminal bar shows ITS own Grok.
+  // New windows are seeded at ctx 0% and never read global status (tmux-hud).
   for (const snap of targets) {
-    const tmuxSession = findTmuxSessionForPid(snap.pid);
+    const tmuxSession = resolveTmuxSessionForGrok(snap.pid, grokHome);
     const tty = ttyForPid(snap.pid);
     const isPrimary =
       primary != null && snap.sessionId === primary.sessionId;
     writeStatusFiles(snap, usage, grokHome, {
       tmuxSession,
       ttyPath: tty,
-      // Only primary overwrites global status.* (hooks / grok-hud status)
+      // Only primary overwrites global status.* (hooks / grok-hud status CLI)
       writeGlobal: isPrimary || targets.length === 1,
     });
 
@@ -202,7 +202,7 @@ export async function refreshDashboard(options: {
   // If somehow no primary write happened, write one
   if (primary && !targets.some((t) => t.sessionId === primary!.sessionId)) {
     writeStatusFiles(primary, usage, grokHome, {
-      tmuxSession: findTmuxSessionForPid(primary.pid),
+      tmuxSession: resolveTmuxSessionForGrok(primary.pid, grokHome),
       writeGlobal: true,
     });
   }

src/hook.ts

@@ -173,7 +173,18 @@ export async function runHookTick(
       }
     }
 
-    const written = writeStatusFiles(snap, usage, grokHome);
+    // Bind to THIS Terminal's tmux instance when env is set (set by grok wrap).
+    // Avoid overwriting global status with a stale high-ctx session from another tab
+    // when this hook is for a brand-new session.
+    const tmuxSession =
+      env.GROK_HUD_TMUX_SESSION?.trim() ||
+      env.GROK_TMUX_SESSION?.trim() ||
+      null;
+    const written = writeStatusFiles(snap, usage, grokHome, {
+      tmuxSession,
+      // Always refresh global for CLI `grok-hud status`, but per-tmux is authoritative in UI
+      writeGlobal: true,
+    });
     const annotate =
       options.forceAnnotate || shouldEmitAnnotation(String(event), grokHome);
     if (annotate) {

src/multi-session.ts

@@ -163,6 +163,70 @@ export function findTmuxSessionForPid(grokPid?: number): string | null {
   return null;
 }
 
+/** tty device base for a pid (e.g. ttys012), or null. */
+export function ttyBaseForPid(pid?: number): string | null {
+  if (!pid || pid <= 0) return null;
+  try {
+    const out = execFileSync("ps", ["-p", String(pid), "-o", "tty="], {
+      encoding: "utf8",
+      stdio: ["ignore", "pipe", "ignore"],
+      timeout: 1000,
+    }).trim();
+    if (!out || out === "??" || out === "-") return null;
+    return out.replace(/^\/dev\//, "");
+  } catch {
+    return null;
+  }
+}
+
+/**
+ * Resolve tmux session for a live Grok process.
+ * 1) process tree → pane
+ * 2) meta.json launcherPid / tty match (set at `grok` wrap time)
+ * Never invent a name — caller must treat null as "do not write global for this".
+ */
+export function resolveTmuxSessionForGrok(
+  grokPid?: number,
+  grokHome = defaultGrokHome(),
+): string | null {
+  const byTree = findTmuxSessionForPid(grokPid);
+  if (byTree) return byTree;
+
+  if (!grokPid || grokPid <= 0) return null;
+
+  const tty = ttyBaseForPid(grokPid);
+  const root = path.join(grokHome, "hud", "tmux");
+  if (!fs.existsSync(root)) return null;
+
+  try {
+    for (const name of fs.readdirSync(root)) {
+      const metaPath = path.join(root, name, "meta.json");
+      if (!fs.existsSync(metaPath)) continue;
+      let meta: TmuxInstanceMeta;
+      try {
+        meta = JSON.parse(fs.readFileSync(metaPath, "utf8")) as TmuxInstanceMeta;
+      } catch {
+        continue;
+      }
+      if (meta.launcherPid && isInProcessTree(grokPid, meta.launcherPid)) {
+        return meta.tmuxSession || name;
+      }
+      if (meta.launcherPid === grokPid) {
+        return meta.tmuxSession || name;
+      }
+      if (tty && meta.tty) {
+        const mt = meta.tty.replace(/^\/dev\//, "");
+        if (mt && (tty === mt || tty.endsWith(mt) || mt.endsWith(tty))) {
+          return meta.tmuxSession || name;
+        }
+      }
+    }
+  } catch {
+    /* ignore */
+  }
+  return null;
+}
+
 /** List instance dirs under hud/tmux/ that look like our sessions. */
 export function listHudTmuxSessions(grokHome = defaultGrokHome()): string[] {
   const root = path.join(grokHome, "hud", "tmux");

src/session.ts

@@ -96,6 +96,10 @@ export function parseTimeMs(value?: string | null): number {
  * After /new, both old and new Grok processes can stay live; array order in
  * active_sessions.json is insertion order (oldest first), so we must rank by
  * activity — not by list position.
+ *
+ * IMPORTANT: do NOT rank by signals.json mtime alone. An older live session
+ * keeps rewriting signals while a brand-new Terminal is still at ctx 0%, and
+ * that made the HUD "stick" on the old high context.
  */
 export function sessionRecencyMs(
   session: SessionSnapshot,
@@ -105,13 +109,19 @@ export function sessionRecencyMs(
   const lastActive = parseTimeMs(session.summary?.last_active_at);
   const updated = parseTimeMs(session.summary?.updated_at);
   const created = parseTimeMs(session.summary?.created_at);
+  // User-facing activity only (not signals keepalive rewrites)
+  const semantic = Math.max(opened, lastActive, updated, created);
   const fileM = Math.max(
-    mtimeMs(path.join(session.sessionDir, "signals.json")),
     mtimeMs(path.join(session.sessionDir, "summary.json")),
     mtimeMs(path.join(session.sessionDir, "updates.jsonl")),
     mtimeMs(path.join(session.sessionDir, "chat_history.jsonl")),
   );
-  return Math.max(opened, lastActive, updated, created, fileM);
+  // Prefer semantic timestamps; use file mtime only as a weak boost when
+  // semantic exists (never let signals-only rewrites dominate).
+  if (semantic > 0) {
+    return Math.max(semantic, fileM);
+  }
+  return fileM;
 }
 
 /** live first, then most recently active. */
@@ -136,6 +146,10 @@ export function sortSessionsByRecency(
 /**
  * Prefer the newest live session among active_sessions.
  * Fixes HUD stuck on an older tab's ctx% after the user runs /new.
+ *
+ * When several sessions are live, break ties with opened_at (newest Terminal
+ * /newest /new wins) so a brand-new window at ctx 0% is not displaced by an
+ * older busy session that still rewrites signals.
  */
 export function pickFromActiveSessions(
   grokHome: string,
@@ -162,12 +176,54 @@ export function pickFromActiveSessions(
 
   const ranked = sortSessionsByRecency(snaps, active);
   if (options.preferLive !== false) {
-    const live = ranked.find((s) => s.live);
-    if (live) return live;
+    const live = ranked.filter((s) => s.live);
+    if (live.length === 1) return live[0]!;
+    if (live.length > 1) {
+      // Newest open wins among live (new window / /new)
+      return [...live].sort((a, b) => {
+        const ae = active.find((x) => x.session_id === a.sessionId);
+        const be = active.find((x) => x.session_id === b.sessionId);
+        const ao = parseTimeMs(ae?.opened_at);
+        const bo = parseTimeMs(be?.opened_at);
+        if (ao !== bo) return bo - ao;
+        return sessionRecencyMs(b, be) - sessionRecencyMs(a, ae);
+      })[0]!;
+    }
   }
   return ranked[0] ?? null;
 }
 
+/** Minimal snapshot for a brand-new Terminal (ctx 0%, no session yet). */
+export function emptySessionSnapshot(
+  overrides: Partial<SessionSnapshot> = {},
+): SessionSnapshot {
+  return {
+    sessionId: "—",
+    sessionDir: "",
+    cwd: "",
+    model: "—",
+    live: false,
+    contextPercent: 0,
+    contextTokensUsed: 0,
+    contextWindowTokens: 0,
+    turnCount: 0,
+    userMessageCount: 0,
+    toolCallCount: 0,
+    toolFailureCount: 0,
+    errorCount: 0,
+    durationSeconds: 0,
+    agentLinesAdded: 0,
+    agentLinesRemoved: 0,
+    compactionCount: 0,
+    avgTtftMs: 0,
+    tools: [],
+    agents: [],
+    todos: [],
+    signals: {},
+    ...overrides,
+  };
+}
+
 export function loadSnapshotFromDir(
   sessionDir: string,
   options: {

src/tmux-hud.ts

@@ -13,11 +13,31 @@ import { resolveTheme, tmuxStatusChrome } from "./theme.js";
 import { loadHudConfig } from "./hud-config.js";
 import { installGrokCommandWrap } from "./grok-wrap.js";
 import {
+  detectControllingTtyBase,
   hudTmuxDir,
   uniqueTmuxSessionName,
   writeTmuxInstanceMeta,
 } from "./multi-session.js";
 
+/** Brand-new Terminal status: ctx 0%, no leakage from previous windows. */
+export function seedIdleTmuxStatus(instDir: string): void {
+  fs.mkdirSync(instDir, { recursive: true });
+  const idleSingle = "窗 ░░░░░░░░░░ 0% · —\n";
+  const idleLines = [
+    "— · —",
+    "窗 ░░░░░░░░░░ 0% · —",
+    "",
+  ].join("\n") + "\n";
+  fs.writeFileSync(path.join(instDir, "tmux-status.txt"), idleSingle, "utf8");
+  fs.writeFileSync(path.join(instDir, "tmux-lines.txt"), idleLines, "utf8");
+  fs.writeFileSync(path.join(instDir, "status-line.txt"), "[hud] ctx 0%\n", "utf8");
+}
+
+function detectControllingTtyPath(): string | null {
+  const base = detectControllingTtyBase();
+  return base ? `/dev/${base}` : null;
+}
+
 export function isInsideTmux(env: NodeJS.ProcessEnv = process.env): boolean {
   return Boolean(env.TMUX && env.TMUX.length > 0);
 }
@@ -61,8 +81,9 @@ export function tmuxStatusCommands(grokHome = defaultGrokHome()): string[][] {
   // #{session_name} expanded by tmux before running #() — one bar per session
   const scopedLines = `${instRoot}/#{session_name}/tmux-lines.txt`;
   const scopedSingle = `${instRoot}/#{session_name}/tmux-status.txt`;
-  const fallbackLines = path.join(grokHome, "hud", "tmux-lines.txt");
-  const fallbackSingle = path.join(grokHome, "hud", "tmux-status.txt");
+  // NEVER fall back to global ~/.grok/hud/tmux-*.txt — that leaked the previous
+  // Terminal's high ctx% into brand-new windows (should show 0% / idle).
+  const idleSingle = "窗 ░░░░░░░░░░ 0% · —";
   // Up to 3 status rows in the SAME terminal window
   const statusLines = Math.max(
     1,
@@ -91,15 +112,20 @@ export function tmuxStatusCommands(grokHome = defaultGrokHome()): string[][] {
       "set",
       "-g",
       "status-format[0]",
-      `#[align=left]#(cat ${scopedSingle} 2>/dev/null || cat ${fallbackSingle} 2>/dev/null)`,
+      `#[align=left]#(cat ${scopedSingle} 2>/dev/null || printf '%s' '${idleSingle}')`,
     ]);
   } else {
     for (let i = 0; i < statusLines; i++) {
+      // Line 0 gets idle placeholder; other rows blank when scoped missing
+      const idle =
+        i === 0
+          ? `printf '%s' '${idleSingle}'`
+          : `printf ''`;
       cmds.push([
         "set",
         "-g",
         `status-format[${i}]`,
-        `#[align=left]#(sed -n '${i + 1}p' ${scopedLines} 2>/dev/null || sed -n '${i + 1}p' ${fallbackLines} 2>/dev/null)`,
+        `#[align=left]#(sed -n '${i + 1}p' ${scopedLines} 2>/dev/null || ${idle})`,
       ]);
     }
   }
@@ -180,22 +206,14 @@ export function execGrokInSameWindowTmux(options: {
 
   const instDir = hudTmuxDir(session, grokHome);
   fs.mkdirSync(instDir, { recursive: true });
-  const statusFile = path.join(instDir, "tmux-status.txt");
-  if (!fs.existsSync(statusFile)) {
-    fs.writeFileSync(statusFile, "ctx … · quota …\n", "utf8");
-  }
-  // Also ensure global fallback placeholders
-  fs.mkdirSync(path.join(grokHome, "hud"), { recursive: true });
-  const globalStatus = path.join(grokHome, "hud", "tmux-status.txt");
-  if (!fs.existsSync(globalStatus)) {
-    fs.writeFileSync(globalStatus, "ctx … · quota …\n", "utf8");
-  }
+  // Seed THIS tmux only with ctx 0% — never copy global / previous window state
+  seedIdleTmuxStatus(instDir);
 
   writeTmuxInstanceMeta({
     tmuxSession: session,
     launcherPid: process.pid,
     startedAt: new Date().toISOString(),
-    tty: process.env.TTY ?? null,
+    tty: process.env.TTY ?? detectControllingTtyPath() ?? null,
   }, grokHome);
   writeTmuxConfFile(grokHome);
 

tests/dashboard.test.ts

@@ -62,6 +62,95 @@ describe("dashboard", () => {
     fs.rmSync(tmp, { recursive: true, force: true });
   });
 
+  it("new window: old live session with fresher signals mtime does not steal primary", async () => {
+    // Repro: old tab still live and signals.json keeps updating; new tab has
+    // later opened_at but no/low context — must pick new (ctx ~0), not old 78%.
+    const tmp = fs.mkdtempSync(path.join(os.tmpdir(), "hud-newwin-"));
+    const cwd = "/Users/dex/AI FILM SPACE/0717";
+    const oldId = "old-busy-78";
+    const newId = "new-window-zero";
+    const enc = encodeURIComponent(cwd);
+    const oldDir = path.join(tmp, "sessions", enc, oldId);
+    const newDir = path.join(tmp, "sessions", enc, newId);
+    fs.mkdirSync(oldDir, { recursive: true });
+    fs.mkdirSync(newDir, { recursive: true });
+
+    const oldSignals = {
+      contextWindowUsage: 78,
+      contextTokensUsed: 392180,
+      contextWindowTokens: 500000,
+      turnCount: 18,
+      toolCallCount: 344,
+      primaryModelId: "grok-4.5",
+    };
+    fs.writeFileSync(path.join(oldDir, "signals.json"), JSON.stringify(oldSignals));
+    fs.writeFileSync(
+      path.join(oldDir, "summary.json"),
+      JSON.stringify({
+        info: { id: oldId, cwd },
+        last_active_at: "2026-07-17T06:00:00.000Z",
+        updated_at: "2026-07-17T06:00:00.000Z",
+        created_at: "2026-07-17T04:00:00.000Z",
+        current_model_id: "grok-4.5",
+      }),
+    );
+    // Touch signals again so mtime is "now" (old session keepalive)
+    const now = Date.now();
+    fs.utimesSync(path.join(oldDir, "signals.json"), new Date(now), new Date(now));
+
+    fs.writeFileSync(
+      path.join(newDir, "summary.json"),
+      JSON.stringify({
+        info: { id: newId, cwd },
+        last_active_at: "2026-07-17T08:00:00.000Z",
+        updated_at: "2026-07-17T08:00:00.000Z",
+        created_at: "2026-07-17T08:00:00.000Z",
+        current_model_id: "grok-4.5",
+      }),
+    );
+    // Explicit empty/low context for new window
+    fs.writeFileSync(
+      path.join(newDir, "signals.json"),
+      JSON.stringify({
+        contextWindowUsage: 0,
+        contextTokensUsed: 0,
+        contextWindowTokens: 500000,
+        turnCount: 0,
+        toolCallCount: 0,
+        primaryModelId: "grok-4.5",
+      }),
+    );
+
+    fs.writeFileSync(
+      path.join(tmp, "active_sessions.json"),
+      JSON.stringify([
+        {
+          session_id: oldId,
+          pid: process.pid,
+          cwd,
+          opened_at: "2026-07-17T04:00:00.000Z",
+        },
+        {
+          session_id: newId,
+          pid: process.pid,
+          cwd,
+          opened_at: "2026-07-17T08:00:00.000Z",
+        },
+      ]),
+    );
+
+    const r = await refreshDashboard({ grokHome: tmp, noUsage: true });
+    assert.ok(r.session);
+    assert.equal(r.session!.sessionId, newId);
+    assert.ok(
+      Math.round(r.session!.contextPercent) < 5,
+      `new window must be ~0% ctx, got ${r.session!.contextPercent}`,
+    );
+    assert.doesNotMatch(r.title, /78%/);
+
+    fs.rmSync(tmp, { recursive: true, force: true });
+  });
+
   it("after /new: prefers newest active session, not first-listed old 78%", async () => {
     // Repro: active_sessions keeps old tab first; new tab second with low/no signals.
     const tmp = fs.mkdtempSync(path.join(os.tmpdir(), "hud-new-"));

tests/multi-session.test.ts

@@ -1,11 +1,14 @@
 import { describe, it } from "node:test";
 import assert from "node:assert/strict";
+import os from "node:os";
+import path from "node:path";
 import {
   uniqueTmuxSessionName,
   sanitizeId,
   isInProcessTree,
   parentPid,
 } from "../src/multi-session.js";
+import { tmuxStatusCommands } from "../src/tmux-hud.js";
 
 describe("multi-session isolation", () => {
   it("uniqueTmuxSessionName never returns fixed grok-hud", () => {
@@ -48,4 +51,23 @@ describe("multi-session isolation", () => {
       assert.equal(isInProcessTree(process.pid, pp), true);
     }
   });
+
+  it("tmux status format never falls back to global status (new window isolation)", () => {
+    const home = path.join(os.tmpdir(), "hud-fake-home");
+    const cmds = tmuxStatusCommands(home);
+    const formats = cmds
+      .filter((a) => a[0] === "set" && String(a[2] ?? "").startsWith("status-format"))
+      .map((a) => a.slice(3).join(" "));
+    assert.ok(formats.length >= 1);
+    for (const f of formats) {
+      // Must only read per-session path; global fallback leaked old ctx%
+      assert.match(f, /hud\/tmux\/#\{session_name\}/);
+      assert.doesNotMatch(
+        f,
+        /hud\/tmux-lines\.txt|hud\/tmux-status\.txt(?!\/)/,
+      );
+      // No "|| cat …/hud/tmux-status" style global fallback
+      assert.doesNotMatch(f, /\|\|\s*cat\s+\S*\/hud\/tmux-/);
+    }
+  });
 });