Concurrent Sessions
Run multiple Claude CLI instances simultaneously with different accounts. Each profile runs in an isolated environment with independent credentials, sessions, and state.
Overview
# Terminal 1
ccs work "implement feature X"
# Terminal 2 (simultaneously)
ccs personal "research topic Y"
# Both run at the same time with isolated state
Architecture
CCS uses CLAUDE_CONFIG_DIR to create isolated instances:
~/.ccs/instances/work/ # Work account
~/.ccs/instances/personal/ # Personal account
ccs work "task":
- Sets
CLAUDE_CONFIG_DIR=~/.ccs/instances/work/
- Claude loads credentials from that directory
- All state stays isolated
Instance Structure
Each profile gets its own directory:
~/.ccs/instances/work/
├── .credentials.json # OAuth credentials
├── session-env/ # Chat history
├── todos/ # Task lists
├── logs/ # Execution logs
├── commands/ # Custom commands
└── skills/ # Custom skills
| Metric | First Use | Subsequent |
|---|
| Activation | ~20-35ms | ~5-10ms |
| Memory | ~3-5 KB per activation | - |
| Disk | ~200-700 KB per profile | - |
Limitations
Running the same profile in multiple terminals causes conflicts.
# This conflicts:
ccs work "task1" # Terminal 1
ccs work "task2" # Terminal 2 - same files!
# Do this instead:
ccs work "task1" # Terminal 1
ccs personal "task2" # Terminal 2
Other Limitations
CLAUDE_CONFIG_DIR is undocumented (keep Claude CLI updated)- Commands/skills copied on creation, not synced later
- Sessions/logs accumulate (manual cleanup if needed)
Sync Commands Manually
If you update ~/.claude/commands/ after creating a profile:
# Option 1: Recreate instance
rm -rf ~/.ccs/instances/work
ccs work "task" # Recreates with latest
# Option 2: Manual copy
cp -r ~/.claude/commands/* ~/.ccs/instances/work/commands/
Cleanup
# Check sizes
du -sh ~/.ccs/instances/*
# Clear sessions
rm -rf ~/.ccs/instances/work/session-env/*
# Clear logs
rm -rf ~/.ccs/instances/work/logs/*
