[BUG] Claude Code desktop causes kernel panic via memory exhaustion (WindowServer watchdog timeout)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Bug report: Claude Code (desktop) triggers kernel panic via memory exhaustion

Summary
Claude Code desktop app, latest build, causes the entire Mac to beach-ball then
force-restart when given a coding task. Reproduces even in a brand-new chat with
zero other applications open. Confirmed via kernel panic logs, not a subjective
"feels slow" report.

Environment

• Machine: MacBook Air (M1, MacBookAir10,1), 8GB RAM
• macOS: 26.6.1 (build 25G76)
• Claude.app version: 1.32885.1 (confirmed "latest version" via in-app check)
• App installed/updated: 2026-08-18 (build date), installed on this machine 2026-08-20

Reproduction

1. Open Claude Code desktop app, start a new chat (no other apps open).
2. Give it a task involving coding (previously worked fine for ~90% of a project

built over prior sessions with the same or heavier workflow — Xcode builds,
Simulator, Chrome all running simultaneously without issue).

1. App/system becomes unresponsive (beach ball).
2. After ~120 seconds, macOS force-restarts the machine.
3. Repeats reliably on "difficult" prompts; simple conversational prompts (no

coding) do not trigger it.

Evidence: kernel panic logs
8 panics captured in /Library/Logs/DiagnosticReports/panic-full-*.panic between
2026-08-19 and 2026-08-20 (5 on 2026-08-20 alone). All share the identical
signature:

panic(cpu N caller ...): userspace watchdog timeout: no successful
checkins from WindowServer (1-2 induced crashes) in 120-124 seconds
service returned not alive with context : is_alive_func returned
unhealthy : WindowServer initialization not complete (post IOKitWaitQuiet)

This is the standard macOS signature for WindowServer being starved of
CPU/memory long enough that the OS force-panics as a safety measure — i.e.
system-wide memory exhaustion, not an app-level crash.

Timestamps of captured panics:

• 2026-08-19 20:27
• 2026-08-19 20:54
• 2026-08-20 16:45
• 2026-08-20 17:02
• 2026-08-20 17:17
• 2026-08-20 18:48
• 2026-08-20 19:27

Supporting memory data

• At a quiescent moment (no Xcode build running), free memory was already low

and Chrome + Claude Code processes were consuming several GB combined, on
an 8GB machine — but user reports the crash reproduces even with *no other
apps open at all*, which points at Claude Code's own footprint, not
contention with other apps.

• User reports Activity Monitor shows Claude Code climbing to ~40GB (almost

certainly compressed-memory / swap accounting reflecting a leak, not literal
resident size) shortly before the freeze/restart.

• No custom MCP servers or extensions are configured

(extensions-installations.json is empty; claude_desktop_config.json has no
custom MCP entries) — ruling out a third-party extension as the cause.

Impact
User is mid-project (90% complete iOS app) and can no longer give the app any
non-trivial coding task without crashing the machine. Previously intermittent
("machine would recover for ~2 days after a restart"); now happens on nearly
every coding prompt, including fresh chats with no other apps running.

Request
Investigate for a memory leak in the Claude Code desktop app (or one of its
background helper processes) introduced around the 2026-08-18 build
(version 1.32885.1). Happy to provide the full .panic files and Activity
Monitor screenshots if useful.

What Should Happen?

panic(cpu N caller ...): userspace watchdog timeout: no successful checkins from WindowServer (1-2 induced crashes) in 120-124 seconds
service returned not alive with context : is_alive_func returned unhealthy : WindowServer initialization not complete (post IOKitWaitQuiet)

8 occurrences between 2026-08-19 and 2026-08-20 (5 on 2026-08-20 alone), all identical signature.
Claude.app version 1.32885.1, macOS 26.6.1, MacBook Air M1 8GB.
Reproduces on fresh chat with zero other apps open.

Error Messages/Logs

Steps to Reproduce

1. Open Claude Code desktop app (v1.32885.1) on macOS 26.6.1, MacBook Air M1, 8GB RAM.
2. Start a brand-new chat with zero other applications open.
3. Give it a coding task (works fine for simple conversational prompts; triggers reliably on non-trivial coding tasks — previously this workflow, even with Xcode/Simulator/Chrome running simultaneously, worked fine for most of a project).
4. App/system becomes unresponsive (beach ball).
5. After ~120 seconds, macOS force-restarts the machine.

Confirmed via 8 kernel panic logs captured 2026-08-19 to 2026-08-20 (5 on 2026-08-20 alone), all with identical signature:
"panic(...): userspace watchdog timeout: no successful checkins from WindowServer (1-2 induced crashes) in 120-124 seconds"

No custom MCP servers or extensions configured — ruling those out as the cause.

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

1.32885.1

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_