From 5bd05c9e0f8d4a203d58213605eefa06985da437 Mon Sep 17 00:00:00 2001
From: Garry Tan <garrytan@gmail.com>
Date: Sun, 5 Apr 2026 22:54:33 -0700
Subject: [PATCH] fix(browse): terminate orphan server when parent process
 exits (#808)

Community PR #808 by @mmporong. Passes BROWSE_PARENT_PID to the spawned
server process. The server polls every 15s with signal 0 and calls
shutdown() if the parent is gone. Prevents orphaned chrome-headless-shell
processes when Claude Code sessions exit abnormally.

Co-Authored-By: mmporong <mmporong@users.noreply.github.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 browse/src/cli.ts    |  4 ++--
 browse/src/server.ts | 17 +++++++++++++++++
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/browse/src/cli.ts b/browse/src/cli.ts
index 10c2646d..96051847 100644
--- a/browse/src/cli.ts
+++ b/browse/src/cli.ts
@@ -232,7 +232,7 @@ async function startServer(extraEnv?: Record<string, string>): Promise<ServerSta
     // when the CLI exits, the server dies with it. Use Node's child_process.spawn
     // with { detached: true } instead, which is the gold standard for Windows
     // process independence. Credit: PR #191 by @fqueiro.
-    const extraEnvStr = JSON.stringify({ BROWSE_STATE_FILE: config.stateFile, ...(extraEnv || {}) });
+    const extraEnvStr = JSON.stringify({ BROWSE_STATE_FILE: config.stateFile, BROWSE_PARENT_PID: String(process.pid), ...(extraEnv || {}) });
     const launcherCode =
       `const{spawn}=require('child_process');` +
       `spawn(process.execPath,[${JSON.stringify(NODE_SERVER_SCRIPT)}],` +
@@ -243,7 +243,7 @@ async function startServer(extraEnv?: Record<string, string>): Promise<ServerSta
     // macOS/Linux: Bun.spawn + unref works correctly
     proc = Bun.spawn(['bun', 'run', SERVER_SCRIPT], {
       stdio: ['ignore', 'pipe', 'pipe'],
-      env: { ...process.env, BROWSE_STATE_FILE: config.stateFile, ...extraEnv },
+      env: { ...process.env, BROWSE_STATE_FILE: config.stateFile, BROWSE_PARENT_PID: String(process.pid), ...extraEnv },
     });
     proc.unref();
   }
diff --git a/browse/src/server.ts b/browse/src/server.ts
index 12d44625..8d94c18f 100644
--- a/browse/src/server.ts
+++ b/browse/src/server.ts
@@ -691,6 +691,23 @@ const idleCheckInterval = setInterval(() => {
   }
 }, 60_000);
 
+// ─── Parent-Process Watchdog ────────────────────────────────────────
+// When the spawning CLI process (e.g. a Claude Code session) exits, this
+// server can become an orphan — keeping chrome-headless-shell alive and
+// causing console-window flicker on Windows. Poll the parent PID every 15s
+// and self-terminate if it is gone.
+const BROWSE_PARENT_PID = parseInt(process.env.BROWSE_PARENT_PID || '0', 10);
+if (BROWSE_PARENT_PID > 0) {
+  setInterval(() => {
+    try {
+      process.kill(BROWSE_PARENT_PID, 0); // signal 0 = existence check only, no signal sent
+    } catch {
+      console.log(`[browse] Parent process ${BROWSE_PARENT_PID} exited, shutting down`);
+      shutdown();
+    }
+  }, 15_000);
+}
+
 // ─── Command Sets (from commands.ts — single source of truth) ───
 import { READ_COMMANDS, WRITE_COMMANDS, META_COMMANDS } from './commands';
 export { READ_COMMANDS, WRITE_COMMANDS, META_COMMANDS };