Two engineers. Two Claude Code instances. One shared brain.

A Claude Code plugin for live collaborative coding sessions where each engineer has their own Claude instance, sharing context through git and a .mob/ directory. No external services. No databases. Just git and markdown.

This repo is a Claude Code plugin. Install it once and the mob skill is available in every repo you work in.

Run this inside any Claude Code session:

/plugin marketplace add mumby0168/mob
/plugin install mob@mumby0168/mob

The skill will be available as /mob in every repo.

If you only want the skill in one repo:

/plugin install mob@mumby0168/mob --scope project

This adds the plugin to that project's .claude/settings.json so teammates get it when they pull.

git clone https://github.com/mumby0168/mob.git

Claude Code will discover the skill from the sibling directory.

Check out a mobbing/* branch — that prefix is the signal that mob mode is active:

git checkout -b mobbing/auth-refactor
git push -u origin mobbing/auth-refactor

Start Claude Code. It detects the branch automatically and enters mob mode. The other engineer pulls the branch and starts their own Claude Code instance. Done.

Run the init script to scaffold the .mob/ context directory:

./mob-init.sh alice "Ship the auth refactor"
git add -A && git commit -m "mob: init" && git push

Other engineer: git pull && ./mob-init.sh bob

If you prefer not to use the plugin system, copy CLAUDE-MOB.md content into your repo's CLAUDE.md. This gives Claude the mob workflow without installing anything.

Each Claude instance:

• Pulls every 2 turns and reads .mob/ context files
• Writes a context update + turn log entry on every commit
• Commits and pushes as one action, frequently
• Detects when updating the session plan vs writing code
• References turn log entries in commit messages for traceability

The .mob/ directory holds all shared state:

.mob/
└── <session-name>/
    ├── session.md      # Goal, plan, decisions, scope
    ├── alice.md        # Alice's current focus and notes
    ├── bob.md          # Bob's current focus and notes
    └── log.md          # Append-only turn log

mob/
├── .claude/
│   └── skills/
│       ├── mob.md              # The Claude Code skill
│       └── references/
│           ├── init.md         # New session & resume flows
│           ├── context-format.md   # Engineer context file format
│           ├── log-format.md   # Turn log format
│           └── sessions.md     # Multi-session management
├── .claude-plugin/
│   ├── plugin.json             # Plugin manifest
│   └── marketplace.json        # Marketplace metadata
├── docs/
│   └── index.html              # Landing page (served via GitHub Pages)
├── CLAUDE-MOB.md               # Standalone CLAUDE.md instructions (no plugin needed)
├── mob-init.sh                 # Quick-start shell script
└── README.md                   # This file

Every commit follows this loop:

pull → read .mob/ → work → update context → write log → commit → push

Small, atomic commits. Frequent pushes. Both engineers stay in sync through the shared .mob/ context rather than long explanations in chat.

The landing page is at mumby0168.github.io/mob — a shareable explanation of the concept.