Session cleanup deletes same-day sessions unexpectedly

[derekmoreau]

Description

Sessions created on the same day are being deleted during startup cleanup, even though they should be retained based on the cleanupPeriodDays setting (default 30 days).

Environment

• Claude Code version: 2.1.12
• OS: macOS (Darwin 25.1.0)
• Platform: darwin

Steps to Reproduce

1. Start Claude Code and have several conversations throughout the day
2. Close terminal and reopen
3. Start a new Claude Code session
4. Run /resume - previous sessions are missing

Expected Behavior

Sessions created within the cleanupPeriodDays period (default 30 days) should be preserved and available via /resume.

Actual Behavior

All 5 sessions created the same day were deleted during startup. Debug logs show:

2026-01-17T18:16:05.137Z [DEBUG] Session index: added 1, updated 2, removed 0 (total: 5)
2026-01-17T20:19:27.848Z [DEBUG] Session index: added 0, updated 0, removed 5 (total: 0)

The cleanup at 20:19:27 removed all 5 sessions, despite them being created earlier the same day.

Additional Context

• cleanupPeriodDays was set to 36500 at 20:29:30 (after the cleanup had already run)
• However, even with the default 30-day retention, same-day sessions should not be deleted
• The history.jsonl file shows 8+ session IDs were used, but only 2 session files remained after the cleanup
• Sessions index file (sessions-index.json) went from 5 entries to 0 in a single startup

Debug Log Excerpt

From session 9d6e8a4a-cee8-41ae-be27-1a848fe3c74b.txt (the session that triggered the cleanup):

2026-01-17T20:19:27.843Z [DEBUG] [STARTUP] Running setup()...
2026-01-17T20:19:27.846Z [DEBUG] Stats cache is up to date
2026-01-17T20:19:27.846Z [DEBUG] Plugin autoupdate: skipped (auto-updater disabled)
2026-01-17T20:19:27.848Z [DEBUG] Session index: added 0, updated 0, removed 5 (total: 0)

The cleanup happened immediately during startup with no indication of why sessions were marked for removal.

Workaround

Setting cleanupPeriodDays to a high value (e.g., 36500) in ~/.claude/settings.json before any sessions are created may prevent this, but this does not explain why same-day sessions were deleted.

[github-actions]

Found 3 possible duplicate issues:

1. [BUG] Did 2.1.1 delete all of your *local* chat logs > 30 days old without asking? #16978
2. [Bug] Project files deleted despite cleanupPeriodDays set to 1825 #15935
3. [BUG] lost most session data in the past 24h #17794

This issue will be automatically closed as a duplicate in 3 days.

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🤖 Generated with Claude Code

[github-actions]

This issue has been automatically closed as a duplicate of #16978.

If this is incorrect, please re-open this issue or create a new one.

🤖 Generated with Claude Code

[github-actions]

This issue has been automatically locked since it was closed and has not had any activity for 7 days. If you're experiencing a similar issue, please file a new issue and reference this one if it's relevant.