session-merge: Claude Code Session Merger

session-merge is a Claude Code skill that solves a common frustration: sessions splitting unexpectedly after cd operations, exit/resume cycles, or version updates. You end up with multiple sessions sharing the same name but containing fragments of what was supposed to be one conversation.

The tool works directly with the JSONL session files in ~/.claude/projects/, combining entries chronologically and producing a single unified session you can resume normally.

Key features:

• --find-splits — automatically detects all session groups that share the same name (i.e., sessions that split)
• --merge-splits — one-command fix to merge all split groups back together
• --dry-run — preview before committing
• Manual merge with --name for combining any sessions

How it works: Collects all JSONL entries from source sessions, sorts by timestamp, rewrites sessionId fields to a new merged UUID, copies subagent files, and updates the session index metadata.