[BUG] Past Conversations not showing in VSCode extension despite valid sessions-index.json

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?

Past Conversations are not appearing in the VSCode extension, even though all session files (.jsonl) and the sessions-index.json exist and are valid. After quitting and reopening VSCode, the conversation history is empty or missing sessions.

The extension logs reveal it's using a cached session index from a different project:
Using cached index entry for session: b186ea61-819c-4036-b856-26f113e06b80

This session ID belongs to Project A, but I'm working in Project B. The extension appears to cross-contaminate session caches between different workspace projects.

What Should Happen?

Sessions listed in ~/.claude/projects/{project-path}/sessions-index.json should appear in "Past Conversations" for that specific project. Each project's session index should be read independently without cache contamination from other projects.

Error Messages/Logs

From Claude VSCode.log (~/Library/Application Support/Code/logs/.../Anthropic.claude-code/):

2026-01-31 18:59:55.743 [info] From claude: 2026-01-31T17:59:55.743Z [DEBUG] Using cached index entry for session: b186ea61-819c-4036-b856-26f113e06b80

This session ID does not exist in the current project's sessions-index.json - it belongs to a completely different project workspace.

No other errors related to session loading are shown.

Steps to Reproduce

1. Open VSCode with multiple different project folders (separate windows)
2. Have conversations in each project
3. Quit VSCode completely (⌘+Q on macOS)
4. Reopen VSCode and open one of the projects
5. Check "Past Conversations" → list is empty or shows wrong/missing sessions
6. Verify that ~/.claude/projects/{project-path}/sessions-index.json contains valid entries
7. Verify that all .jsonl session files exist in the same directory

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.0.55 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

VS Code integrated terminal

Additional Information

Environment:

• Claude Code VSCode Extension: 2.1.27
• OS: macOS 15.2 (Darwin 25.2.0)
• Architecture: darwin-arm64

Verified manually:

• sessions-index.json is valid JSON (confirmed with python3 json.load)
• Contains 6 session entries with correct sessionId, fullPath, and metadata
• All referenced .jsonl files exist with correct permissions (600)
• File sizes range from 13KB to 21MB
• Removed macOS extended attributes with: xattr -cr ~/.claude/projects/{path}/

Workarounds attempted (none successful):

• Developer: Reload Window
• Full VSCode restart (⌘+Q and reopen)
• Manually editing/repairing sessions-index.json
• Removing macOS extended attributes
• Deleting lock files

The project folder is synced via Dropbox, but all files have correct permissions and no sync conflicts.