Editor setup for noyalib-lsp

The noyalib LSP server speaks the standard Language Server Protocol over stdio, so any editor with LSP client support can wire it up. This page collects the working configurations for the major editors.

For the full list of methods the server implements, see protocol-coverage.md.

Install

cargo install noyalib-lsp

The binary lands in ~/.cargo/bin/noyalib-lsp. The remainder of this document assumes that path is on PATH; if not, substitute the absolute path in each editor’s config.

VS Code

The recommended path is the noyalib VS Code extension, which drives the LSP server and configures it automatically. Install it from the Marketplace:

ext install sebastienrousseau.noyalib

The listing goes live with the first release published under the sebastienrousseau publisher. Until then, every CI run attaches a .vsix you can install with “Extensions: Install from VSIX…”.

For a manual setup (e.g. you want to drive your own LSP client), add to settings.json:

{
  "yaml.server.path": "noyalib-lsp",
  "[yaml]": {
    "editor.defaultFormatter": "sebastienrousseau.noyalib",
    "editor.formatOnSave": true
  }
}

Neovim

nvim-lspconfig

-- ~/.config/nvim/init.lua
local lspconfig = require("lspconfig")
local configs = require("lspconfig.configs")

if not configs.noyalib then
  configs.noyalib = {
    default_config = {
      cmd = { "noyalib-lsp" },
      filetypes = { "yaml" },
      root_dir = lspconfig.util.find_git_ancestor,
      single_file_support = true,
    },
  }
end

lspconfig.noyalib.setup({
  on_attach = function(client, bufnr)
    -- Format on save.
    vim.api.nvim_create_autocmd("BufWritePre", {
      buffer = bufnr,
      callback = function()
        vim.lsp.buf.format({ bufnr = bufnr })
      end,
    })
  end,
})

Native vim.lsp (Neovim 0.11+)

vim.lsp.config.noyalib = {
  cmd = { "noyalib-lsp" },
  filetypes = { "yaml" },
  root_markers = { ".git" },
}
vim.lsp.enable({ "noyalib" })

Helix

~/.config/helix/languages.toml:

[[language]]
name = "yaml"
language-servers = ["noyalib-lsp"]
auto-format = true

[language-server.noyalib-lsp]
command = "noyalib-lsp"

Zed

~/.config/zed/settings.json:

{
  "lsp": {
    "noyalib-lsp": {
      "binary": {
        "path": "noyalib-lsp",
        "arguments": []
      }
    }
  },
  "languages": {
    "YAML": {
      "language_servers": ["noyalib-lsp"],
      "format_on_save": "on"
    }
  }
}

Emacs

lsp-mode

;; ~/.emacs.d/init.el
(with-eval-after-load 'lsp-mode
  (add-to-list 'lsp-language-id-configuration '(yaml-mode . "yaml"))
  (lsp-register-client
   (make-lsp-client :new-connection (lsp-stdio-connection "noyalib-lsp")
                    :major-modes '(yaml-mode yaml-ts-mode)
                    :server-id 'noyalib-lsp)))

(add-hook 'yaml-mode-hook #'lsp-deferred)
(add-hook 'before-save-hook #'lsp-format-buffer)

eglot (Emacs 29+)

(with-eval-after-load 'eglot
  (add-to-list 'eglot-server-programs
               '((yaml-mode yaml-ts-mode) . ("noyalib-lsp"))))

(add-hook 'yaml-mode-hook 'eglot-ensure)
(add-hook 'yaml-ts-mode-hook 'eglot-ensure)

Sublime Text

Install the LSP package, then add to Preferences → Package Settings → LSP → Settings:

{
  "clients": {
    "noyalib-lsp": {
      "enabled": true,
      "command": ["noyalib-lsp"],
      "selector": "source.yaml"
    }
  }
}

Kakoune

~/.config/kak/kakrc:

hook global WinSetOption filetype=yaml %{
  lsp-enable-window
  set-option global lsp_servers %{
    [noyalib-lsp]
    root_globs = [".git"]
    args = []
  }
}

JetBrains IDEs (IntelliJ, RustRover, GoLand, etc.)

Install the LSP4IJ plugin, then in Settings → LSP:

• Add a new server named noyalib-lsp
• Command: noyalib-lsp
• File mappings: *.yaml, *.yml

Verifying the server is working

echo '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"capabilities":{}}}' \
  | noyalib-lsp

Should respond with a JSON-RPC result containing the server’s capabilities. If it hangs or errors, verify:

1. which noyalib-lsp returns a path
2. The binary is executable (chmod +x if needed)
3. The version matches your editor’s expectations (noyalib-lsp --version)

Troubleshooting

Diagnostics don’t appear

Most editors require the LSP client to be configured for the YAML file type. Confirm with:

:LspInfo            " Neovim with nvim-lspconfig
:lsp-info           " Helix
M-x lsp-describe-session   " Emacs / lsp-mode

Format-on-save doesn’t run

The server provides textDocument/formatting. If the editor doesn’t trigger it on save, set the editor’s “format on save” option and ensure the LSP client is the registered formatter for YAML (some editors prefer the built-in tree-sitter formatter unless told otherwise — see each editor’s section above for the explicit override).

Hover descriptions show null

Hover content depends on a JSON Schema being available for the document. Configure the schema via the editor’s standard YAML schema mapping (e.g. yaml.schemas in VS Code, or the yaml-language-server schema selector inline pragma). With no schema, hover returns the parsed value type only.

High CPU on large files

Large YAML files (>10 MB) trigger a full-document re-parse on every keystroke under the default didChange debounce. Either:

• Increase the debounce in your editor’s LSP client settings
• Use --max-document-length to refuse very large files
• File an issue if the parse is structurally slow — the bench numbers in crates/noyalib-lsp/benches/lsp_handlers.rs are the reference

Related

• Protocol coverage — which LSP methods are implemented
• Crate README — full server overview