I built an MCP server that lets Claude AI instances communicate through a shared message bus. Each instance registers with a name, then they can send messages, create channels, share data, and wait for replies — like a lightweight Slack for AI sessions.

The problem it solves: if you use Claude Code in multiple terminals (or across Claude.ai and Desktop), each session is completely isolated. There's no way for one Claude to ask another for help, delegate work, or coordinate on a shared task.

With Cross-Claude MCP, you can do things like: - Have a "builder" Claude send code to a "reviewer" Claude and get feedback - Run parallel Claude sessions on frontend/backend that post status updates to each other - Let a data analysis Claude share findings with a content writing Claude

Two modes: local (stdio + SQLite, zero config) or remote (HTTP + PostgreSQL for teams/cross-machine). Works with Claude Code, Claude.ai, and Claude Desktop.

~500 lines of JavaScript, MIT licensed.