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+# codex-stdio-to-uds
+
+Traditionally, there are two transport mechanisms for an MCP server: stdio and HTTP.
+
+This crate helps enable a third, which is UNIX domain socket, because it has the advantages that:
+
+- The UDS can be attached to long-running process, like an HTTP server.
+- The UDS can leverage UNIX file permissions to restrict access.
+
+To that end, this crate provides an adapter between a UDS and stdio. The idea is that someone could start an MCP server that communicates over `/tmp/mcp.sock`. Then the user could specify this on the fly like so:
+
+```
+codex --config mcp_servers.example={command="codex-stdio-to-uds",args=["/tmp/mcp.sock"]}
+```
+
+Unfortunately, the Rust standard library does not provide support for UNIX domain sockets on Windows today even though support was added in October 2018 in Windows 10:
+
+https://github.com/rust-lang/rust/issues/56533
+
+As a workaround, this crate leverages https://crates.io/crates/uds_windows as a dependency on Windows.