lsp-fish: Add support for fish-lsp. (#5027)

Author: Dietr1ch

CHANGELOG.org

@@ -78,6 +78,7 @@
   * Add support for ~~crates-lsp~~
   * Remove outdated Ruff option and add new lint-related options
   * Add new Nextflow client customizations
+  * Add support for ~~fish-lsp~~
 
 ** 9.0.0
   * Add language server config for QML (Qt Modeling Language) using qmlls.

clients/lsp-fish.el

@@ -0,0 +1,53 @@
+;;; lsp-fish.el --- lsp-mode fish-shell integration -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2025-2026 lsp-mode maintainers
+
+;; Author: lsp-mode maintainers
+;; Keywords: languages
+
+;; This program is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;;  Client for fish, the user-friendly command line shell (https://github.com/fish-shell/fish-shell/)
+
+;;; Code:
+
+(require 'lsp-mode)
+
+(defgroup lsp-fish nil
+  "Settings for the fish-shell Language Server."
+  :group 'lsp-mode
+  :link '(url-link "https://fish-lsp.dev/")
+  :package-version '(lsp-mode . "9.0.1"))
+
+(defcustom lsp-fish-executable '("fish-lsp" "start")
+  "Command to run the fish-shell language server."
+  :group 'lsp-fish
+  :risky t
+  :type '(repeat string))
+
+(lsp-dependency 'fish-language-server
+                '(:system "fish-lsp"))
+
+(lsp-register-client
+ (make-lsp-client :server-id 'fish-lsp
+                  :new-connection (lsp-stdio-connection (lambda () lsp-fish-executable))
+                  :activation-fn (lsp-activate-on "fish")
+                  :major-modes '(fish-mode)))
+
+(lsp-consistency-check lsp-fish)
+
+(provide 'lsp-fish)
+;;; lsp-fish.el ends here

docs/lsp-clients.json

@@ -367,6 +367,14 @@
     "lsp-install-server": "fsac",
     "debugger": "Yes (netcoredbg)"
   },
+  {
+    "name": "fish",
+    "full-name": "Fish shell",
+    "server-name": "fish-lsp",
+    "server-url": "https://fish-lsp.dev/",
+    "installation-url": "https://github.com/ndonfris/fish-lsp#installation",
+    "debugger": "Not available"
+  },
   {
     "name": "fortitude",
     "full-name": "Fortran",

lsp-mode.el

@@ -179,7 +179,7 @@ As defined by the Language Server Protocol 3.16."
      lsp-clojure lsp-cmake lsp-cobol lsp-credo lsp-crystal lsp-csharp lsp-c3
      lsp-css lsp-copilot lsp-crates lsp-cucumber lsp-cypher lsp-d lsp-dart
      lsp-dhall lsp-docker lsp-dockerfile lsp-earthly lsp-elixir lsp-elm lsp-emmet
-     lsp-erlang lsp-eslint lsp-fortitude lsp-fortran lsp-futhark lsp-fsharp lsp-gdscript
+     lsp-erlang lsp-eslint lsp-fortitude lsp-fortran lsp-futhark lsp-fsharp lsp-fish lsp-gdscript
      lsp-gleam lsp-glsl lsp-go lsp-golangci-lint lsp-grammarly lsp-graphql
      lsp-groovy lsp-hack lsp-haskell lsp-haxe lsp-idris lsp-java lsp-javascript
      lsp-just lsp-jq lsp-json lsp-kotlin lsp-kubernetes-helm lsp-latex lsp-lisp
@@ -864,6 +864,7 @@ Changes take effect only when a new session is started."
     (ebuild-mode . "shellscript")
     (pkgbuild-mode . "shellscript")
     (envrc-file-mode . "shellscript")
+    (fish-mode . "fish")
     (scala-mode . "scala")
     (scala-ts-mode . "scala")
     (julia-mode . "julia")

mkdocs.yml

@@ -87,6 +87,7 @@ nav:
     - Erlang (ELP): page/lsp-erlang-elp.md
     - ESLint: page/lsp-eslint.md
     - F#: page/lsp-fsharp.md
+    - Fish (fish-lsp): page/lsp-fish.md
     - Fortran (fortls): page/lsp-fortran.md
     - Fortran (fortitude): page/lsp-fortitude.md
     - Futhark: page/lsp-futhark.md