rustaceanvim.md

rustaceanvim Integration

rustaceanvim is an LSP integration. It does not provide MCP tools; use Codex, Claude Code, or Generic MCP alongside it if you want agent-callable tools.

Primary Config Path

Use rustaceanvim's built-in lspmux support. When server.cmd is unset, rustaceanvim enables lspmux auto-discovery by default and tries to connect to a running lspmux server.

For TCP loopback:

vim.g.rustaceanvim = {
  server = {
    lspmux = {
      host = '127.0.0.1',
      port = 27631,
    },
  },
}

Do not set server.cmd unless you want to bypass rustaceanvim's lspmux auto-discovery. If auto-discovery cannot find the server, set server.lspmux.host and server.lspmux.port explicitly as above.

Transport

Use this lspmux config for the sandbox-friendly TCP path:

listen = "tcp://127.0.0.1:27631"
connect = "tcp://127.0.0.1:27631"

Unix sockets also work for local Neovim when the default lspmux config uses a socket path.

Verification

Open a Rust file and run:

:checkhealth vim.lsp

The active client should be rust-analyzer. Use :LspInfo only if your Neovim distribution still provides it through nvim-lspconfig.