[BUG] VSCode Extension Crashes in Restart Loop with Large Conversation History (500+ sessions, 488MB)Retry #12221

Preflight Checklist

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

What's Wrong?

Bug Description

The Claude Code VSCode Extension becomes completely unresponsive and enters a crash-reboot loop when the conversation history in ~/.claude/projects/ becomes large (500+ sessions, ~488MB).

What Should Happen?

Symptoms

1. Extension Non-Responsive: Extension UI becomes completely unresponsive after loading
2. Abnormal Termination and Restart Loop: Extension repeatedly crashes and attempts to restart
3. MCP Server Initialization Failure: Console shows MCP error -32601: Method not found for the internal claude-vscode MCP server
4. VSCode Hangs: In severe cases, VSCode itself becomes sluggish or unresponsive

Error Messages/Logs

### Error Logs

[ERROR] MCP server "claude-vscode" Failed to fetch tools: MCP error -32601: Method not found

Steps to Reproduce

Steps to Reproduce

1. Use Claude Code CLI extensively over time (create 500+ conversation sessions)
2. Accumulate ~488MB of conversation history in ~/.claude/projects/
3. Install and launch Claude Code VSCode Extension
4. Extension fails to initialize properly and enters crash-reboot loop
5. Extension becomes unresponsive, VSCode may hang

Claude Model

Sonnet (default)

Is this a regression?

No, this never worked

Last Working Version

• not working after long commination

Claude Code Version

latest

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

Root Cause

The extension appears to attempt loading ALL conversation history on startup without:

• Pagination
• Lazy loading
• Timeout handling
• Size limits

With 500+ sessions (488MB), this causes the initialization process to fail, resulting in MCP server errors and extension crashes.

Workaround

Delete conversation history folders:

rm -rf ~/.claude/projects/
rm -rf ~/.claude/debug/
rm -rf ~/.claude/todos/
rm -rf ~/.claude/shell-snapshots/

This freed 488MB and immediately resolved all issues.

Expected Behavior

The extension should:

1. Implement pagination/lazy loading for conversation history
2. Add size/count limits for history loading
3. Provide graceful degradation when history is large
4. Show meaningful error messages (not misleading MCP errors)
5. Offer built-in history cleanup/archival functionality

Additional Notes

This is an edge case that only affects power users who extensively use Claude Code CLI. Most users won't encounter this issue, which may be why it hasn't been caught in testing.

However,