vyper-language-server 0.2.2

Language server for Vyper, a pythonic smart contract language

Vyper Language Server

A language server for Vyper, a pythonic smart contract language for the EVM.

Forked from vyperlang/vyper-lsp.

Requirements

• Python >= 3.12
• Vyper >= 0.4.1

The Vyper version installed in your virtual environment must be capable of compiling your contract for full support.

Installation

This language server imports Vyper as a library, so it should be installed in the same environment as your project's Vyper.

As a project dev dependency (recommended)

# pyproject.toml
[dependency-groups]
dev = [
    "vyper-language-server",
]

[tool.uv.sources]
vyper-language-server = { git = "https://github.com/latticafi/vyper-language-server" }

Then uv sync.

Via pipx (global)

pipx install git+https://github.com/latticafi/vyper-language-server.git

Note: when installed globally, the server will use whatever Vyper version is in its own environment, which may not match your project.

Verify

which vyper-language-server

Editor Setup

Neovim

Add to ~/.config/nvim/init.lua:

vim.api.nvim_create_autocmd({ "BufEnter" }, {
  pattern = { "*.vy" },
  callback = function()
    vim.lsp.start({
      name = "vyper-language-server",
      cmd = { "vyper-language-server" },
      root_dir = vim.fs.dirname(vim.fs.find({ ".git" }, { upward = true })[1])
    })
  end,
})

If installed as a project dep, point to the venv binary:

vim.api.nvim_create_autocmd({ "BufEnter" }, {
  pattern = { "*.vy" },
  callback = function()
    local venv = vim.fs.find({ ".venv" }, { upward = true })[1]
    local cmd = venv and (venv .. "/bin/vyper-language-server") or "vyper-language-server"
    vim.lsp.start({
      name = "vyper-language-server",
      cmd = { cmd },
      root_dir = vim.fs.dirname(vim.fs.find({ ".git" }, { upward = true })[1])
    })
  end,
})

Emacs

(define-derived-mode vyper-mode python-mode "Vyper" "Major mode for editing Vyper.")

(add-to-list 'auto-mode-alist '("\\.vy\\'" . vyper-mode))

(with-eval-after-load 'lsp-mode
  (add-to-list 'lsp-language-id-configuration
               '(vyper-mode . "vyper"))
  (lsp-register-client
   (make-lsp-client :new-connection
                    (lsp-stdio-connection `(,(executable-find "vyper-language-server")))
                    :activation-fn (lsp-activate-on "vyper")
                    :server-id 'vyper-language-server)))

Features

• Diagnostics (compile errors and warnings)
• Completions (state variables, functions, decorators, types, imports)
• Hover information
• Go to definition / declaration
• Find references
• Signature help

Development

Setup

1. Install uv (Fast Python package installer and resolver)

   pip install uv
   # Or on macOS with Homebrew
   brew install uv

2. Clone and install

   git clone https://github.com/latticafi/vyper-language-server.git
   cd vyper-language-server
   uv sync

Commands

uv run pytest                  # run tests
uv run ruff check .            # lint
uv run ruff format .           # format
uv run coverage run -m pytest  # test with coverage
uv run coverage report         # view coverage

License

MIT