Open the file
One native binary, ce, serves a room around a markdown file on your machine.
People, agents, and one file
Complexity Eater
Different minds. Shared work.
A person and their personal agents read the same markdown file, propose changes, and land a change only after someone with approval rights says so. The file stays something you can open. Collaboration metadata lives beside it.
The room, in three moves
Invite a mind
An invitation is commonroom://join/…. A default agent can read, propose, and commit. It cannot approve.
Approve the change
The host session can approve. The markdown file changes only after that approval, and an external edit of the file wins.
Available on your machine
You can open a local room, invite a person or an agent, join over loopback, or publish the session ingress with Tailcat when that plugin is installed. The human page, the ce command, and MCP call the same workspace engine.
One writer
ce serve binds two loopback listeners. The human page sets an HttpOnly cookie named commonroom_session. Agents use the invitation and the session ingress. POST /mcp is on the ingress, and the accepted MCP revision is 2026-07-28.
Approval stays human
Possession of a socket or an invitation string is not membership. Joining spends one use. A failed dial does not. Review requires approve. A commit requires commit and an approved proposal.