Tact Language Server

January 9, 2026 · View on GitHub

Developed by TON Studio, powered by the community.

Features • Installation • Community • Troubleshooting

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This language server and an extension for VSCode-based editors provide support for the Tact programming language. Tact is a next-generation programming language for building secure, scalable, and maintainable smart contracts on TON blockchain.

For support of FunC, TL-B, Fift assembly, TASM and TON Bag-of-Cells (BoC), use the official TON extension.

Features

Quick start

The easiest way to get started with Tact is to use VS Code or editors based on it:

  1. Install the Tact language extension in VS Code or in VS Code-based editors
  2. That's it!

The extension automatically detects your Tact compiler installation. If you need to work with multiple Tact versions or custom-builds, check out the toolchain management guide.

editor.png

Installation

VS Code / VSCodium / Cursor / Windsurf

  1. Get the latest .vsix file from releases from VS Code marketplace or from Open VSX Registry
  2. In VS Code:
    • Open the Command Palette (Ctrl+Shift+P or Cmd+Shift+P)
    • Type "Install from VSIX"
    • Select the downloaded .vsix file
    • Reload VS Code

Other Editors

Via NPM

  1. Install the language server via NPM:

    npm install -g @tact-lang/tact-language-server

    After installation, you can use tact-language-server executable to run the language server.

  2. Configure your editor to use the language server (see editor-specific instructions below).

Note

If for some reason your editor rejects tact-language-server executable, run where tact-language-server to find the path to the executable and then configure your editor to run node <path-to-js-file>.

Manually

  1. Get the latest archive from releases:
    • tact-language-server-*.tar.gz for Linux/macOS
    • tact-language-server-*.zip for Windows
  2. Extract it to a convenient location
  3. Configure your editor to use the language server (see editor-specific instructions below)

Building from Source

If you want to build the language server yourself:

git clone https://github.com/tact-lang/tact-language-server
cd tact-language-server
yarn install
yarn build

To obtain the .vsix package with the VS Code extension, additionally run:

yarn package

Then run either of those to install the extension from the .vsix package:

# VSCode, replace VERSION with the actual version from package.json
code --install-extension vscode-tact-VERSION.vsix

# VSCodium, replace VERSION with the actual version from package.json
codium --install-extension vscode-tact-VERSION.vsix

Editor Setup

Sublime Text

  1. Install LSP package:

    • Open Command Palette (Ctrl+Shift+P or Cmd+Shift+P)
    • Select "Package Control: Install Package"
    • Search for and select "LSP"

  2. For syntax highlighting, install the Tact package via Package Control in a similar manner:

    • Open Command Palette (Ctrl+Shift+P or Cmd+Shift+P)
    • Select "Package Control: Install Package"
    • Search for and select "Tact"

  3. Add the following configuration to your LSP settings (Preferences > Package Settings > LSP > Settings):

    {
    "clients": {
        "tact": {
            "enabled": true,
            // If you installed the language server via NPM, use the following command:
            "command": ["tact-language-server", "--stdio"],
            // If you installed the language server manually, use the following command:
            "command": ["node", "path/to/language-server/dist/server.js", "--stdio"],
            "selector": "source.tact",
        },
    },
    "inhibit_snippet_completions": true,
    "semantic_highlighting": true,
}

  4. Add the following setting to your settings to enable highlighting of Tact code blocks in hover documentation ( Preferences > Settings):

    {
    // ...
    "mdpopups.sublime_user_lang_map": {
        "tact": [["tact"], ["Tact/package/Tact"]],
    },
}

  5. Create a new file or open an existing file with the .tact extension to verify the setup

Neovim

Prerequisites:

Setup steps:

  1. Add tact.lua to your lua/lspconfig/server_configurations directory with the following content:

    local util = require 'lspconfig.util'

return {
  default_config = {
    -- If you installed the language server via NPM, use the following command:
    cmd = { 'tact-language-server', '--stdio' },
    -- If you installed the language server manually, use the following command:
    cmd = { 'node', '/absolute/path/to/language-server/dist/server.js', '--stdio' },
    filetypes = { 'tact' },
    root_dir = util.root_pattern('package.json', '.git'),
  },
  docs = {
    description = [[
      Tact Language Server
      https://github.com/tact-lang/tact-language-server
    ]],
    default_config = {
      root_dir = [[root_pattern("package.json", ".git")]],
    },
  },
}

  2. Add the following to your init.lua:

    require'lspconfig'.tact.setup {}

Vim

Prerequisites:

  • Vim 8 or newer
  • Async LSP Client for Vim: vim-lsp
  • Plugin for Tact: tact.vim

Recommended, but not required:

Setup steps:

  1. Install the tact.vim if it hasn't already been installed. Use a non-built-in plugin manager to simplify the update process.

  2. Install the vim-lsp plugin if it isn't already installed. For that, use vim-plug or the built-in package manager of Vim 8+, see :help packages.

  • If it wasn't installed before, you should set up basic keybindings with the language client. Add the following to your ~/.vimrc (or ~/_vimrc if you're on Windows):

    function! s:on_lsp_buffer_enabled() abort
    setlocal omnifunc=lsp#complete
    setlocal signcolumn=yes
    if exists('+tagfunc') | setlocal tagfunc=lsp#tagfunc | endif
    nmap <buffer> gd <plug>(lsp-definition)
    nmap <buffer> gs <plug>(lsp-document-symbol-search)
    nmap <buffer> gS <plug>(lsp-workspace-symbol-search)
    nmap <buffer> gr <plug>(lsp-references)
    nmap <buffer> gi <plug>(lsp-implementation)
    nmap <buffer> gt <plug>(lsp-type-definition)
    nmap <buffer> <leader>rn <plug>(lsp-rename)
    nmap <buffer> [g <plug>(lsp-previous-diagnostic)
    nmap <buffer> ]g <plug>(lsp-next-diagnostic)
    nmap <buffer> K <plug>(lsp-hover)
    nnoremap <buffer> <expr><c-f> lsp#scroll(+4)
    nnoremap <buffer> <expr><c-d> lsp#scroll(-4)

    let g:lsp_format_sync_timeout = 1000
    autocmd! BufWritePre *.rs,*.go call execute('LspDocumentFormatSync')

    " Refer to the doc to add more commands:
    " https://github.com/prabirshrestha/vim-lsp#supported-commands
endfunction

augroup lsp_install
    au!
    " call s:on_lsp_buffer_enabled only for languages that have the server registered.
    autocmd User lsp_buffer_enabled call s:on_lsp_buffer_enabled()
augroup END

  1. Add the following to your ~/.vimrc (or ~/_vimrc if you're on Windows):

    if executable('node')
  au User lsp_setup call lsp#register_server({
        \ 'name': 'tact',
        # If you installed the language server via NPM, use the following command:
        \ 'cmd': {server_info->['tact-language-server', '--stdio']},
        # If you installed the language server manually, use the following command:
        \ 'cmd': {server_info->['node', '/absolute/path/to/language-server/dist/server.js', '--stdio']},
        \ 'allowlist': ['tact'],
        \ })
endif

Helix

  1. Add the following configuration to your ~/.config/helix/languages.toml:

    [[language]]
name = "tact"
language-servers = ["tact-language-server"]

[language-server.tact-language-server]

# If you installed the language server via NPM, use the following command:
command = "tact-language-server"
args = ["--stdio"]
# If you installed the language server manually, use the following command:
command = "node"
args = ["/absolute/path/to/language-server/dist/server.js", "--stdio"]

  2. Replace path/to/language-server with the actual path where you cloned the repository

  3. Restart Helix for changes to take effect

Community

Troubleshooting

See TROUBLESHOOTING.md.

License

MIT