cc: Multi-session awareness for Claude Code CLI.

When you run multiple Claude Code sessions on the same machine, they don't know about each other. You end up manually relaying context between terminals. cc fixes that using Claude Code's own /tmp directories.

What it does

Every time you send a prompt, cc reminds your current session who else is working:

[cc] 3 sessions active on 'vector-seo'
  -> vector-seo-2 (feat/api) editing: src/routes.ts, lib/seo.ts — "fixing crawl endpoint" — 12m ago
  -> vector-seo-3 editing: tests/api.test.ts — "writing integration tests" — 3m ago
  !! vector-seo-2 is also touching src/routes.ts

• See all active sessions on the same project
• File conflict warnings when two sessions touch the same file
• Send messages between sessions via /cc
• Dead sessions are detected instantly (no stale data)

How it works

┌─────────────────────────────────────────────────────────┐
│  Claude Code Session A          Session B          ...  │
│       │                            │                    │
│  UserPromptSubmit             UserPromptSubmit          │
│       │                            │                    │
│       ▼                            ▼                    │
│  ┌─────────┐                  ┌─────────┐              │
│  │  cc.py   │◄── reads ──────►│  cc.py   │              │
│  │  roster  │                 │  roster  │              │
│  └────┬─────┘                 └────┬─────┘              │
│       │ writes                     │ writes             │
│       ▼                            ▼                    │
│  ~/.claude/cc/sessions/       ~/.claude/cc/sessions/    │
│    {session-a}.json              {session-b}.json       │
│                                                         │
│  Liveness: /tmp/claude-{uid}/{project}/{session-uuid}/  │
│  (managed by Claude Code — exists only while running)   │
└─────────────────────────────────────────────────────────┘

Liveness detection uses Claude Code's /tmp directories. These directories exist only while a session is running — when it ends (or crashes), the directory disappears. No PIDs, no heartbeats, no TTLs (near instant).

Metadata (session name, files being edited, current task) is stored in ~/.claude/cc/sessions/ as one JSON file per session. Each session writes only its own file and reads everyone else's.

Install

claude plugin add anipotts/cc

Usage

cc works automatically once installed. Every prompt shows a roster if there are other sessions on the same project.

/cc command

Command	What it does
/cc	Show all active sessions with details
/cc <name>	Pull in context from another session's transcript
/cc <name> <message>	Send a message to another session (delivered on their next prompt)

Plugin structure

cc/
├── .claude-plugin/plugin.json   Plugin manifest
├── hooks/
│   ├── cc.py                    Core logic (roster, touch, cleanup)
│   └── hooks.json               Hook registration
├── commands/cc.md               /cc command definition
└── evals/test_cc.py             Test suite (69 tests)

Hooks

Event	Handler	What it does
UserPromptSubmit	roster	Register session + show peer roster + file conflict warnings
PostToolUse (Edit/Write)	touch	Track which files this session is editing
SessionEnd	cleanup	Remove session metadata file

Requirements

• Claude Code v2.1+
• Python 3.10+
• macOS or Linux

License

MIT