Add session-management plugin: fork/move conversations across directories

[mmostagirbhuiyan]

Summary

Adds a session-management plugin with /fork, /move, and /sessions commands that let users relocate conversations to a different working directory while preserving full history.

• /fork <path> — copies the current conversation to a new directory (original stays intact)
• /move <path> — moves the conversation (removes from original location)
• /sessions [path] — lists all stored sessions for a directory with timestamps and previews

Motivation

This is one of the most consistently requested features in the repo, going back 9 months across 10+ issues and 37+ thumbs-up reactions:

Issue	Title	Status	Reactions	Since
#1516	Ability to move directories and not break --continue	Closed (autoclose)	👍 5, 💬 10	Jun 2025
#5768	Resuming sessions only works from the directory they were started	Open	👍 11, 💬 15	Aug 2025
#12629	Session Branching / Conversation Forking	Open	👍 12, 💬 5	Nov 2025
#12941	Clone/duplicate conversation to try different approaches	Open	👍 9, 💬 3	Dec 2025
#24745	Cannot rename project directory	Open	💬 2	Feb 2026
#26766	Allow seamless session resumption by name across directories	Open	👍 1, 💬 3	Feb 2026
#27473	Session resume should support moved/renamed project directories	Closed	💬 1	Feb 2026
#27883	--resume fails to find session from different directory	Open	💬 1	Feb 2026
#28745	Allow resuming conversations from different directories	Open	💬 1	Feb 2026
#28766	Fork/move conversation to a different working directory	Open	—	Feb 2026

Directly addresses #28766 and provides a plugin-based solution for #5768, #12629, #12941, #24745, #26766, #27473, #27883, #28745.

How it works

Claude Code stores conversations as JSONL files in ~/.claude/projects/, keyed by the working directory path (with / replaced by -). When users move their project files, the conversation stays tied to the old path.

This plugin:

1. Locates the session JSONL file for the current conversation
2. Copies/moves it (and companion data: subagent logs, tool results) to the target directory's storage
3. Uses Python str.replace() to safely update cwd references in the JSONL
4. Notifies the user about memory files (CLAUDE.md, memory/) that may need manual copying

Security hardening

• No eval — tilde expansion uses case-based pattern matching, not eval echo
• No sed injection — cwd replacement uses Python str.replace() via sys.argv (no shell interpolation of path characters like |, &, \)
• Scoped tool access — Bash(*) for fork/move, specific Bash(ls:*), Bash(du:*) etc. for read-only sessions command
• Absolute path validation — rejects relative paths after expansion
• Error handling — all cp/mv/mkdir operations guarded with || exit 1
• Cross-platform — macOS stat -f with GNU stat -c fallback, sed -i.bak for portability

Tested on real data

Validated by forking a 9MB conversation (4,543 cwd references) from one project to another. Confirmed:

• All cwd references updated correctly (including variant paths from devcontainer sessions)
• JSONL integrity preserved (valid JSON on every line)
• Companion directory (52 subagent logs + tool results) copied
• claude --resume works from the target directory

Test plan

• Install the plugin and verify /fork, /move, /sessions commands appear
• Run /sessions to list existing conversations
• Run /fork ~/test-dir to fork a conversation, verify claude --resume works from target
• Run /move ~/test-dir to move a conversation, verify original removed and resume works
• Test edge cases: non-existent target (prompts to create), empty args (prompts for path), paths with spaces

🤖 Generated with Claude Code