Problem

Claude Code writes background task outputs and tool results to /private/tmp/claude-{UID}/ on macOS (or /tmp/claude-{UID}/ on Linux). These files are never cleaned up — not on session end, not on CLI exit, not on any lifecycle event.

Why this matters

• macOS does not auto-clean /tmp while the system is running. The periodic cleanup only runs on reboot, and desktop machines rarely reboot. Linux systemd-tmpfiles may help eventually, but default retention is 10 days — still too long for high-throughput use.
• In environments with many concurrent sessions (e.g. multi-agent orchestration, CI pipelines, or power users running several conversations), the accumulation is rapid.

Observed impact

• 107 GB accumulated across ~50+ session directories in /private/tmp/claude-502/ over a few days of multi-session use.
• Disk pressure caused other tools to fail and required manual intervention to recover.

Expected behavior

Claude Code should clean up task output files when sessions end, or implement a periodic reaper for stale files (e.g. files older than N minutes with no active session referencing them).

Workaround

Manual cron job:

# Clean up files older than 60 minutes
find /tmp/claude-$(id -u)/ -type f -mmin +60 -delete

Or a launchd plist / systemd timer equivalent for continuous cleanup.

Environment

• macOS (but applicable to any OS)
• Claude Code CLI (latest)
• High-session-count usage pattern (multi-agent orchestration)