Using Psalm’s Language Server

Psalm now has built-in Language Server Compatibility support so you can run it in your favourite IDE.

It currently supports diagnostics (i.e. finding errors and warnings), go-to-definition and hover, with limited support for autocompletion (PRs are welcome!).

It works well in a variety of editors (listed alphabetically):

Client configuration


I got it working with eglot

This is the config I used:

(when (file-exists-p "vendor/bin/psalm-language-server")
    (require 'php-mode)
    (require 'eglot)
    (add-to-list 'eglot-server-programs '(php-mode . ("php" "vendor/bin/psalm-language-server")))
    (add-hook 'php-mode-hook 'eglot-ensure)
    (advice-add 'eglot-eldoc-function :around
                (lambda (oldfun)
                  (let ((help (help-at-pt-kbd-string)))
                    (if help (message "%s" help) (funcall oldfun)))))


Native Support

As of PhpStorm 2020.3 support for psalm is supported and on by default, you can read more about that here

With LSP

Alternatively, psalm works with gtache/intellij-lsp plugin (Jetbrains-approved version, latest version).

Setup is done via a GUI.

When you install the plugin, you should see a "Language Server Protocol" section under the "Languages & Frameworks" tab.

In the "Server definitions" tab you should add a definition for Psalm:

  • Select Executable
  • Extension: php
  • Path: <path-to-php-binary> e.g. /usr/local/bin/php or C:\php\php.exe
    • this should be an absolute path, not just php
  • Args: vendor/bin/psalm-language-server (on Windows use vendor/vimeo/psalm/psalm-language-server, or for a 'global' install '%APPDATA%' + \Composer\vendor\vimeo\psalm\psalm-language-server, where the '%APPDATA%' environment variable is probably something like C:\Users\<homedir>\AppData\Roaming\)

In the "Timeouts" tab you can adjust the initialization timeout. This is important if you have a large project. You should set the "Init" value to the number of milliseconds you allow Psalm to scan your entire project and your project's dependencies. For opening a couple of projects that use large PHP frameworks, on a high-end business laptop, try 240000 milliseconds for Init.

Sublime Text

I use the excellent Sublime LSP plugin with the following config(Package Settings > LSP > Settings):

    "clients": {
        "psalm": {
            "command": ["php", "vendor/bin/psalm-language-server"],
            "selector": "source.php | embedding.php",
            "enabled": true

Vim & Neovim


ALE has support for Psalm (since v2.3.0).

let g:ale_linters = { 'php': ['php', 'psalm'] }


I also got it working with vim-lsp

This is the config I used (for Vim):

au User lsp_setup call lsp#register_server({
     \ 'name': 'psalm-language-server',
     \ 'cmd': {server_info->[expand('vendor/bin/psalm-language-server')]},
     \ 'allowlist': ['php'],
     \ })


It also works with coc.nvim.

Add settings to coc-settings.json:

  "languageserver": {
    "psalmls": {
      "command": "vendor/bin/psalm-language-server",
      "filetypes": ["php"],
      "rootPatterns": ["psalm.xml", "psalm.xml.dist"],
      "requireRootPattern": true

VS Code

Get the Psalm plugin here (Requires VS Code 1.26+):

Running the server in a docker container

Make sure you use --map-folder option. Using it without argument will map the server's CWD to the host's project root folder. You can also specify a custom mapping. For example:

docker-compose exec php /usr/share/php/psalm/psalm-language-server \
   -r=/var/www/html \