[BUG] VSCode Extension 2.1.20 - Critical Memory Leak: 11.6GB per conversation window on macOS

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?

What's Wrong?

The Claude Code VSCode extension version 2.1.20 (released January 27, 2026) has a critical memory leak. Opening a single new conversation window immediately spawns two "claude" processes, each consuming approximately 11.6GB of RAM (23.2GB total).

Environment

• Extension Version: 2.1.20
• VS Code Version: 1.108.2 (Universal)
• Operating System: macOS
• System RAM: 24GB physical memory
• Issue Start Date: January 27, 2026 (same day as 2.1.20 release)

Steps to Reproduce

1. Install Claude Code extension version 2.1.20 from VSCode Marketplace
2. Open VSCode
3. Click to open a new Claude Code conversation window
4. Open Activity Monitor (macOS)
5. Observe two "claude" processes immediately appearing

Expected Behavior

• Processes should use approximately 200-400MB each (as in previous versions like 2.1.16)
• Total memory usage should remain under 1GB for a new conversation window

Actual Behavior

• Two "claude" processes spawn immediately
• Each process consumes ~11.6GB RAM
• Total memory consumption: ~23.2GB
• System becomes nearly unusable
• Swap usage increases to 10GB+
• Memory pressure becomes critical (red zone)
• Example PIDs: 2399 and 2384

Screenshots

Activity Monitor showing memory usage:

• Process name: "claude"
• Memory per process: 11.60 GB and 11.59 GB
• Total system memory used: 19.37 GB / 24.00 GB
• Swap used: 10.04 GB

<img width="735" height="177" alt="Image" src="https://github.com/user-attachments/assets/f543e4e0-034d-47bd-a238-6f723ede73c2" />

]

Process Details

Running ps aux | grep -i claude shows:

kefei  11376  1.1  1.0  1865763536  263472  ??  S  4:58PM  0:19.58 /Applications/Claude.app/Contents/MacOS/Claude

Multiple Claude Helper (Renderer) processes are spawned, but the main issue is the two processes consuming 11.6GB each.

Additional Context

• Version 2.1.16 worked perfectly - this is a regression specific to version 2.1.20
• Problem occurs immediately upon opening a conversation window
• No active conversation needed to trigger the leak
• Problem occurs before any user input or interaction
• Affects all projects and workspaces
• The memory leak appears instantly, not gradually
• Closing the conversation window does not free the memory - processes must be manually killed

Workaround

Rolling back to version 2.1.16 completely resolves the issue:

1. Open VSCode Extensions
2. Click the gear icon next to Claude Code
3. Select "Install Another Version..."
4. Choose version 2.1.16
5. Click the gear icon again and select "Disable Auto Update"

After rollback, memory usage returns to normal (~200-400MB per process).

Impact

This bug makes the VSCode extension completely unusable:

• Consumes all available system memory instantly
• Forces system into swap, making everything extremely slow
• Requires manual process termination to recover
• Prevents any productive use of Claude Code in VSCode

Related Issues

This appears to be related to but more severe than:

• #16508 - Memory leak in closed session tabs (~400MB per session)
• #20777 - Memory leak on Linux (20GB+)
• #20696 - macOS IDE memory issue

However, the severity in 2.1.20 is significantly worse - 11.6GB per process vs. the 400MB-3GB reported in other issues.

Request

Given the severity of this issue and that it affects the latest release, could the team:

1. Investigate the 2.1.20 release for regression
2. Consider rolling back 2.1.20 or releasing a hotfix 2.1.21
3. Provide guidance on recommended version until fixed

Thank you for your attention to this critical issue.

What Should Happen?

What Should Happen?

When opening a new Claude Code conversation window in VSCode, the extension should:

1. Normal Memory Usage: Claude processes should consume approximately 200-400MB of RAM each, similar to version 2.1.16
2. Stable Performance: The system should remain responsive with no significant impact on available memory
3. No Memory Leaks: Memory usage should remain stable and not grow unboundedly
4. Reasonable Resource Consumption: Total Claude Code memory footprint should stay under 1GB for a new, empty conversation window

The extension should initialize and be ready to use without causing system memory pressure or requiring swap usage.

Error Messages/Logs

Steps to Reproduce

1. Install Claude Code extension version 2.1.20 from VSCode Marketplace
2. Launch Visual Studio Code (Version 1.108.2)
3. Open any project or workspace (the issue occurs with all projects)
4. Click the Claude Code icon to open a new conversation window
5. Open macOS Activity Monitor (Applications → Utilities → Activity Monitor)
6. Sort processes by Memory usage
7. Observe two "claude" processes immediately appearing, each consuming ~11.6GB RAM

Note: The memory leak occurs instantly upon opening the conversation window, before any user interaction or conversation begins. The issue is 100% reproducible.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.15

Claude Code Version

2.1.20

Platform

Other

Operating System

macOS

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_