Unix Socket MCP Server
Local MCP IPC guarded by socket-file permissions.
Availability
Implemented in the stable source; configuration and compatibility limits are described below.
Reviewed against stable v0.5.1. Rust candidate additions are labeled separately. Release status.
The pain this solves
- A network listener would expose terminal-control IPC beyond local socket access.
- Saying “no authentication” without describing file permissions hides the actual access boundary.
What ships with it
- The MCP listener uses ~/.chau7/mcp.sock, a local Unix domain socket.
- The socket file is created with mode 0600 for its owner.
- Same-user processes may access the socket; the path adds no separate MCP password or protection from that user.
Questions this answers
- How does Chau7's MCP server communicate with AI agents?
- Is the MCP connection secure if it runs locally?
- Does Chau7's MCP server expose any network ports?
- What transport does the MCP server use?
How it works
The stable MCP server listens at ~/.chau7/mcp.sock and uses a Unix domain socket rather than binding a TCP port for MCP clients.
The listener creates the socket with mode 0600, granting filesystem access to its owner. This is an OS permission boundary, not a separate MCP password or token; other processes running as that same user can generally access the socket.
A local bridge process connects configured clients to the socket. The socket is local IPC and should not be described as protection from all same-user processes or as a guarantee that data sent onward by a client remains local.
Why it matters
A Unix socket avoids exposing this MCP listener on a network interface and lets macOS file permissions restrict which user accounts can open it. It is important to describe the boundary precisely: same-user processes are within that OS account’s access scope.
Frequently asked questions
Does the MCP server listen on a network port?
The stable MCP listener uses a Unix socket at ~/.chau7/mcp.sock rather than a TCP listener.
Is no authentication needed?
The server uses a socket file with owner-only mode 0600. It has no separate MCP password in this path, and same-user processes may access the socket.
Does the socket keep all MCP data private from external providers?
No. It describes the local client-to-app transport. A client can separately send data to its configured providers.