oh-my-opencode-slim/docs/multiplexer-integration.md

Multiplexer Integration Guide

Complete guide for using terminal multiplexer integration (Tmux or Zellij) with oh-my-opencode-slim to watch agents work in real-time through automatic pane spawning.

Table of Contents

• Overview
• Supported Multiplexers
• Quick Setup
• Configuration
• Layout Options
• Usage Examples
• Troubleshooting
• Advanced Usage

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Overview

Watch your agents work in real-time. When the Orchestrator launches sub-agents or initiates background tasks, new panes automatically spawn in a dedicated tab showing each agent's live progress. No more waiting in the dark.

Key Benefits

• Real-time visibility into agent activities
• Automatic pane management - panes spawn and organize automatically
• Interactive debugging - you can jump into any agent's session
• Background task monitoring - see long-running work as it happens
• Multi-session support - different projects can have separate environments

⚠️ Temporary workaround: Start OpenCode with --port to enable multiplexer integration. The port must match the OPENCODE_PORT environment variable (default: 4096). This is required until the upstream issue is resolved. opencode#9099.

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Supported Multiplexers

Multiplexer	Status	Notes
Tmux	✅ Supported	Full layout control with main-vertical, main-horizontal, tiled, etc.
Zellij	✅ Supported	Creates dedicated "opencode-agents" tab, reuses default pane

---

Quick Setup

Step 1: Enable Multiplexer Integration

Edit ~/.config/opencode/oh-my-opencode-slim.json (or .jsonc):

For Tmux:

{
  "multiplexer": {
    "type": "tmux",
    "layout": "main-vertical",
    "main_pane_size": 60
  }
}

For Zellij:

{
  "multiplexer": {
    "type": "zellij"
  }
}

Auto-detect (recommended):

{
  "multiplexer": {
    "type": "auto",
    "layout": "main-vertical",
    "main_pane_size": 60
  }
}

Step 2: Run OpenCode Inside Your Multiplexer

Tmux:

# Start a new tmux session
tmux

# Start OpenCode with the default port (4096)
opencode --port 4096

Zellij:

# Start a new zellij session
zellij

# Start OpenCode with the default port (4096)
opencode --port 4096

That's it! Your agents will now spawn panes automatically.

---

Configuration

Multiplexer Settings

Configure multiplexer behavior in ~/.config/opencode/oh-my-opencode-slim.json (or .jsonc):

{
  "multiplexer": {
    "type": "auto",
    "layout": "main-vertical",
    "main_pane_size": 60
  }
}

Setting	Type	Default	Description
type	string	"none"	"auto", "tmux", "zellij", or "none"
layout	string	"main-vertical"	Layout preset (tmux only, see Layout Options)
main_pane_size	number	60	Main pane size as percentage (tmux only, 20-80)

Legacy Tmux Config (still supported)

{
  "tmux": {
    "enabled": true,
    "layout": "main-vertical",
    "main_pane_size": 60
  }
}

This is automatically converted to multiplexer.type: "tmux".

Layout Options (Tmux only)

Choose how panes are arranged:

Choose how panes are arranged:

Layout	Description
main-vertical	Your session on the left (60%), agents stacked on the right
main-horizontal	Your session on top (60%), agents stacked below
tiled	All panes in equal-sized grid
even-horizontal	All panes side by side
even-vertical	All panes stacked vertically

Example: Horizontal layout for wide screens:

{
  "tmux": {
    "enabled": true,
    "layout": "main-horizontal",
    "main_pane_size": 50
  }
}

Example: Tiled layout for maximum parallelism:

{
  "tmux": {
    "enabled": true,
    "layout": "tiled",
    "main_pane_size": 50
  }
}

---

Usage Examples

Basic Usage

1. Start tmux and OpenCode:

   tmux
   opencode --port 4096
   

2. Ask the Orchestrator to delegate work:

   Please analyze this codebase and create a documentation structure.
   

3. Watch panes spawn automatically:

   • The main OpenCode session stays visible
   • New panes appear showing agent activities
   • You can switch between panes to monitor progress

Navigating Panes

# List all panes (in another terminal)
tmux list-panes -a

# Switch to specific pane (in tmux)
Ctrl+B Arrow Keys    # Navigate between panes
Ctrl+B %             # Split pane horizontally
Ctrl+B "             # Split pane vertically
Ctrl+B z             # Zoom/unzoom pane
Ctrl+B c             # Create new window
Ctrl+B n/p           # Next/previous window

Detaching and Reattaching

# Detach from tmux session (keep it running)
Ctrl+B d

# Reattach to your session later
tmux attach

# Or specify which session
tmux attach -t 0

Monitoring Multiple Projects

For different projects on different ports:

# Project 1
tmux new -s project1
opencode --port 4096

# Detach and create Project 2
Ctrl+B d
tmux new -s project2
opencode --port 4097

# Switch between projects
tmux switch -t project1
tmux switch -t project2

Navigating Sessions

# List all sessions (in another terminal)
tmux list-sessions

# Switch to specific session (in tmux)
Ctrl+B s      # list sessions and select
Ctrl+B (      # switch to previous session
Ctrl+B )      # switch to next session
Ctrl+B $      # rename current session
Ctrl+B d      # detach from current session

---

Troubleshooting

Tmux Integration Not Working

Problem: No panes are spawning

Solutions:

1. Verify tmux integration is enabled:

   cat ~/.config/opencode/oh-my-opencode-slim.json | grep tmux # (or .jsonc)
   

2. Check port configuration:

   # Ensure port matches
   echo $OPENCODE_PORT  # Should be 4096 by default
   opencode --port 4096 # Should match
   

3. Verify you're running inside tmux:

   echo $TMUX  # Should show something, not empty
   

4. Check OpenCode logs:

   tail -f ~/.config/opencode/logs/opencode.log
   

Ghost Panes and Orphaned Processes

Problem: Tmux panes remain open after tasks complete, or opencode attach processes accumulate

This issue is fixed in the latest version. The session lifecycle now properly closes panes and terminates processes.

To verify the fix is working:

# After running some background tasks, check for orphans
ps aux | grep "opencode attach" | grep -v grep
# Should return no results

# Check active tmux panes
tmux list-panes
# Should only show your main session pane(s)

If you still see orphaned processes:

1. Kill all orphaned processes:

   pkill -f "opencode attach"
   

2. Close all ghost panes:

   # In tmux, close panes manually
   tmux kill-pane -t <pane-id>
   

3. Restart OpenCode with the updated plugin

Technical Details: The fix implements proper session lifecycle management:

• session.abort() is called after task completion
• Graceful shutdown with Ctrl+C before killing panes
• Event handlers for session.deleted events
• Automatic cleanup of tmux panes and processes

See AGENTS.md for implementation details.

Port Conflicts

Problem: "Port already in use" or agents not connecting

Solutions:

1. Use a different port:

   export OPENCODE_PORT=5000
   opencode --port 5000
   

2. Kill existing OpenCode processes:

   pkill -f "opencode"
   

3. Check for conflicting services:

   netstat -tulpn | grep 4096
   

Tmux Session Issues

Problem: Can't create or attach to tmux sessions

Solutions:

1. Install tmux: ```bash

   Ubuntu/Debian

   sudo apt install tmux

# macOS brew install tmux

# Or use the package manager that comes with your distribution

2. **Check tmux version:**
   ```bash
   tmux -V  # Should be 1.8 or higher

1. Reset tmux configuration: bash rm -f ~/.tmux.conf tmux kill-server tmux

Layout Problems

Problem: Panes don't arrange as expected

Solutions:

1. Try different layouts:

   {
    "tmux": {
      "enabled": true,
      "layout": "tiled",
      "main_pane_size": 40
    }
   }
   

2. Manual layout adjustment:

   # In tmux, resize panes
   Ctrl+B Alt+Arrow Keys
   

3. Clear all panes and restart:

   tmux kill-pane -a
   # Restart OpenCode
   

Performance Issues

Problem: Too many panes or slow performance

Solutions:

1. Reduce pane size for main window:

   {
    "tmux": {
      "enabled": true,
      "layout": "main-vertical",
      "main_pane_size": 40
    }
   }
   

2. Limit background tasks:

   # In OpenCode, use fewer parallel operations
   # Or configure agents to be more sequential
   

3. Clean up old panes:

   # Kill all panes except current
   tmux kill-pane -a
   

---

Advanced Usage

Custom Tmux Configuration

Create ~/.tmux.conf for custom behavior:

# Enable mouse support
set -g mouse on

# Custom key bindings
bind-key r source-file ~/.tmux.conf

# Better colors
set -g default-terminal "screen-256color"

# Status bar customization
set -g status-right "#H %Y-%m-%d %H:%M"

# Pane navigation
bind h select-pane -L
bind j select-pane -D
bind k select-pane -U
bind l select-pane -R

Monitoring Multiple Agents

Watch specific agents more closely:

# Monitor all agent panes
watch -n 1 'tmux list-panes -a -F "#{pane_current_command} (#{pane_index})"'

# Watch OpenCode output specifically
tmux list-panes -a | grep opencode

# Monitor background tasks
tmux list-panes -a | grep background

Integration with Background Tasks

The plugin provides background task tools that work seamlessly with tmux:

Tool	Description	Tmux Integration
background_task	Launch agents asynchronously	Spawns panes for monitoring
background_output	Check task results	Output appears in panes
background_cancel	Stop running tasks	Cleans up panes

Scripting and Automation

#!/bin/bash
# Auto-start script for OpenCode with tmux

# Create dedicated session
tmux new -d -s opencode

# Start OpenCode in the session
tmux send-keys -t opencode:0 'opencode --port 4096' Enter

# Wait and attach
sleep 2
tmux attach -t opencode

Log Monitoring

# Monitor OpenCode logs in real-time
tmux split-window -h
tmux send-keys 'tail -f ~/.config/opencode/logs/opencode.log' Enter

# Switch back to main pane
tmux select-pane -L

Custom Layouts

Create custom pane arrangements:

# In tmux, create a 3-pane layout
tmux split-window -h
tmux split-window -v
tmux select-pane -L

# Save the layout
tmux save-buffer ~/my-layout.txt

# Restore later
tmux load-buffer ~/my-layout.txt

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Best Practices

Session Management

• Use named sessions for different projects
• Detach when not actively monitoring
• Clean up unused sessions periodically

Performance

• Use main-vertical or main-horizontal layouts for better focus
• Adjust main_pane_size based on your screen resolution
• Limit parallel agent operations for complex tasks

Development Workflow

1. Start tmux session for your project
2. Launch OpenCode with tmux integration enabled
3. Monitor agent activities as they work
4. Detach when done, reattach to check progress
5. Clean up panes after completing work

Debugging

• Use Ctrl+B z to zoom into specific panes
• Check logs when agents aren't responding
• Verify port configuration when switching between projects

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Additional Resources

• Official Tmux Documentation: https://github.com/tmux/tmux/wiki
• Quick Reference: docs/quick-reference.md#tmux-integration
• Background Tasks: docs/quick-reference.md#background-tasks
• OpenCode Documentation: https://opencode.ai/docs