[BUG] sessions-index.json stops updating - new sessions not appearing in /resume picker (Linux/WSL2)

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?

Description

The sessions-index.json file stops updating at some point, causing new sessions to not appear in the /resume
picker. Session .jsonl files are correctly written to disk, but they are never registered in the index file.

## Steps to Reproduce

1. Use Claude Code normally over multiple sessions across several days
2. Run /resume to see the list of past conversations
3. Notice that recent sessions (last 2-3 days) are missing from the list
4. Verify that the .jsonl session files exist on disk:

```bash
ls -lt ~/.claude/projects/<project-path>/*.jsonl | head -10

1. Check sessions-index.json and confirm it has not been updated:

cat ~/.claude/projects/<project-path>/sessions-index.json

Expected Behavior

All sessions should appear in /resume. The sessions-index.json file should be updated every time a new session is
created.

Actual Behavior

sessions-index.json stopped updating on Feb 3rd. Sessions from Feb 3, 4, and 5 exist as .jsonl files (including one
that is 6.6 MB) but are not in the index. The last indexed session is from Jan 29.

The sessions can still be resumed manually using:
claude --resume <session-id>

This has happened repeatedly - sessions keep "disappearing" from /resume.

Diagnostic Data

• 5 session files on disk not present in sessions-index.json
• sessions-index.json last meaningful update: Jan 29, file mtime: Feb 3
• Largest missing session: 6.6 MB (e60db920-8e16-4f8d-855a-2a8f48ed1802.jsonl)
• Index contains 11 entries, but at least 16 session files exist

Environment

• Claude Code version: 2.1.31
• OS: Linux (WSL2) - Linux 6.6.87.2-microsoft-standard-WSL2
• Platform: Ubuntu on Windows WSL2
• Shell: bash

Related Issues

• #23375 - /resume only shows a few recent conversations
• #23302 - /resume command shows incomplete session list
• #23358 - Sessions not appearing in resume list (closed/completed)

### Labels (seleccionalos en la barra lateral)

• bug
• area:core
• platform:linux

---

What Should Happen?

Every time a new Claude Code session is created, it should be registered in the sessions-index.json file so it appears in the /resume picker. All sessions should be visible and resumable from the /resume list.

Error Messages/Logs

Steps to Reproduce

1. Use Claude Code on a project over multiple days with several sessions
2. After a few days, run /resume to list past conversations
3. Notice that recent sessions (last 2-3 days) are missing from the picker
4. Verify session files exist on disk but are not indexed:

# Session .jsonl files exist:
ls -lt ~/.claude/projects/<project-path>/*.jsonl | head -10
# Shows files from Feb 3, 4, 5

# But sessions-index.json only has entries up to Jan 29:
cat ~/.claude/projects/<project-path>/sessions-index.json
# Last entry is from Jan 29, 11 entries total
# Meanwhile there are at least 16 .jsonl session files on disk

1. Sessions CAN be resumed manually with: claude --resume <session-id>

This confirms the session data is intact, just not indexed.

In my case, 5 sessions across 3 days were written to disk but never added
to sessions-index.json. The largest missing session is 6.6 MB. This issue
has happened repeatedly - it's not a one-time occurrence.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.32 (Claude Code)

Platform

Anthropic API

Operating System

Other Linux

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_