diff --git a/files/config/fish/go-task.fish b/files/config/fish/go-task.fish
new file mode 100644
index 0000000..6c7e2cf
--- /dev/null
+++ b/files/config/fish/go-task.fish
@@ -0,0 +1,37 @@
+set GO_TASK_PROGNAME task
+
+function __task_get_tasks --description "Prints all available tasks with their description"
+    # Read the list of tasks (and potential errors)
+    $GO_TASK_PROGNAME --list-all 2>&1 | read -lz rawOutput
+
+    # Return on non-zero exit code (for cases when there is no Taskfile found or etc.)
+    if test $status -ne 0
+        return
+    end
+
+    # Grab names and descriptions (if any) of the tasks
+    set -l output (echo $rawOutput | sed -e '1d; s/\* \(.*\):\s*\(.*\)\s*(aliases.*/\1\t\2/' -e 's/\* \(.*\):\s*\(.*\)/\1\t\2/'| string split0)
+    if test $output
+        echo $output
+    end
+end
+
+complete -c $GO_TASK_PROGNAME -d 'Runs the specified task(s). Falls back to the "default" task if no task name was specified, or lists all tasks if an unknown task name was
+    specified.' -xa "(__task_get_tasks)"
+
+complete -c $GO_TASK_PROGNAME -s c -l color -d 'colored output (default true)'
+complete -c $GO_TASK_PROGNAME -s d -l dir -d 'sets directory of execution'
+complete -c $GO_TASK_PROGNAME -l dry -d 'compiles and prints tasks in the order that they would be run, without executing them'
+complete -c $GO_TASK_PROGNAME -s f -l force -d 'forces execution even when the task is up-to-date'
+complete -c $GO_TASK_PROGNAME -s h -l help -d 'shows Task usage'
+complete -c $GO_TASK_PROGNAME -s i -l init -d 'creates a new Taskfile.yml in the current folder'
+complete -c $GO_TASK_PROGNAME -s l -l list -d 'lists tasks with description of current Taskfile'
+complete -c $GO_TASK_PROGNAME -s o -l output -d 'sets output style: [interleaved|group|prefixed]' -xa "interleaved group prefixed"
+complete -c $GO_TASK_PROGNAME -s p -l parallel -d 'executes tasks provided on command line in parallel'
+complete -c $GO_TASK_PROGNAME -s s -l silent -d 'disables echoing'
+complete -c $GO_TASK_PROGNAME -l status -d 'exits with non-zero exit code if any of the given tasks is not up-to-date'
+complete -c $GO_TASK_PROGNAME -l summary -d 'show summary about a task'
+complete -c $GO_TASK_PROGNAME -s t -l taskfile -d 'choose which Taskfile to run. Defaults to "Taskfile.yml"'
+complete -c $GO_TASK_PROGNAME -s v -l verbose -d 'enables verbose mode'
+complete -c $GO_TASK_PROGNAME -l version -d 'show Task version'
+complete -c $GO_TASK_PROGNAME -s w -l watch -d 'enables watch of the given task'
diff --git a/files/config/fish/jj.fish b/files/config/fish/jj.fish
new file mode 100644
index 0000000..9a6257e
--- /dev/null
+++ b/files/config/fish/jj.fish
@@ -0,0 +1,338 @@
+# TODO: passthru other args? E.g.. --at-operation, --repository
+function __jj
+    command jj --ignore-working-copy --color=never --quiet $argv 2>/dev/null
+end
+
+# Aliases
+# Based on https://github.com/fish-shell/fish-shell/blob/cd71359c42f633d9d71a63591ae16d150407a2b2/share/completions/git.fish#L625.
+#
+# Aliases are stored in global variables.
+# `__jj_aliases` is a list of all aliases and `__jj_alias_$alias` is the command line for the alias.
+function __jj_add_alias
+    set -l alias $argv[1]
+    set -l alias_escaped (string escape --style=var -- $alias)
+    set -g __jj_alias_$alias_escaped $argv
+    set --append -g __jj_aliases $alias
+end
+
+__jj config list aliases -T 'concat(name, "\t", value, "\n")' --include-defaults | while read -l config_alias
+    set -l parsed (string match --regex '^aliases\.(.+)\t(.*)$' --groups-only -- $config_alias)
+    set -l alias $parsed[1]
+    set -l command $parsed[2]
+    set -l args $alias
+    # Replace wrapping `[]` if any
+    set -l command (string replace -r --all '^\[|]$' ""  -- $command)
+    while test (string length -- $command) -gt 0
+        set -l parsed (string match -r '^"((?:\\\"|[^"])*?)"(?:,\s)?(.*)$' --groups-only  -- $command)
+        set --append args $parsed[1]
+        set command $parsed[2]
+    end
+    __jj_add_alias $args
+end
+
+__jj_add_alias ci commit
+__jj_add_alias desc describe
+__jj_add_alias op operation
+__jj_add_alias st status
+
+# Resolve aliases that call another alias.
+for alias in $__jj_aliases
+    set -l handled $alias
+
+    while true
+        set -l alias_escaped (string escape --style=var -- $alias)
+        set -l alias_varname __jj_alias_$alias_escaped
+        set -l aliased_command $$alias_varname[1][2]
+        set -l aliased_escaped (string escape --style=var -- $aliased_command)
+        set -l aliased_varname __jj_alias_$aliased_escaped
+        set -q $aliased_varname
+        or break
+
+        # Prevent infinite recursion
+        contains $aliased_escaped $handled
+        and break
+
+        # Expand alias in cmdline
+        set -l aliased_cmdline $$aliased_varname[1][2..-1]
+        set --append aliased_cmdline $$alias_varname[1][3..-1]
+        set -g $alias_varname $$alias_varname[1][1] $aliased_cmdline
+        set --append handled $aliased_escaped
+    end
+end
+
+function __jj_aliases_with_descriptions
+    for alias in $__jj_aliases
+        set -l alias_escaped (string escape --style=var -- $alias)
+        set -l alias_varname __jj_alias_$alias_escaped
+        set -l aliased_cmdline (string join " " -- $$alias_varname[1][2..-1] | string replace -r --all '\\\"' '"')
+        printf "%s\talias: %s\n" $alias $aliased_cmdline
+    end
+end
+
+# Based on https://github.com/fish-shell/fish-shell/blob/2d4e42ee93327b9cfd554a0d809f85e3d371e70e/share/functions/__fish_seen_subcommand_from.fish.
+# Test to see if we've seen a subcommand from a list.
+# This logic may seem backwards, but the commandline will often be much shorter than the list.
+function __jj_seen_subcommand_from
+    set -l cmd (commandline -opc)
+    set -e cmd[1]
+
+    # Check command line arguments first.
+    for i in $cmd
+        if contains -- $i $argv
+            return 0
+        end
+    end
+
+    # Check aliases.
+    set -l alias $cmd[1]
+    set -l alias_escaped (string escape --style=var -- $alias)
+    set -l varname __jj_alias_$alias_escaped
+    set -q $varname
+    or return 1
+
+    for i in $$varname[1][2..-1]
+        if contains -- $i $argv
+            return 0
+        end
+    end
+
+    return 1
+end
+
+function __jj_changes
+    __jj log --no-graph --limit 1000 -r $argv[1] \
+        -T 'separate("\t", change_id.shortest(), if(description, description.first_line(), "(no description set)")) ++ "\n"'
+end
+
+function __jj_bookmarks
+    set -f filter $argv[1]
+    if string length --quiet -- $argv[2]
+        __jj bookmark list --all-remotes -r "$argv[2]" \
+            -T "if($filter, name ++ if(remote, \"@\" ++ remote) ++ \"\t\" ++ if(normal_target, normal_target.change_id().shortest() ++ \": \" ++ if(normal_target.description(), normal_target.description().first_line(), \"(no description set)\"), \"(conflicted bookmark)\") ++ \"\n\")"
+    else
+        __jj bookmark list --all-remotes \
+            -T "if($filter, name ++ if(remote, \"@\" ++ remote) ++ \"\t\" ++ if(normal_target, normal_target.change_id().shortest() ++ \": \" ++ if(normal_target.description(), normal_target.description().first_line(), \"(no description set)\"), \"(conflicted bookmark)\") ++ \"\n\")"
+    end
+end
+
+function __jj_all_bookmarks
+    __jj_bookmarks '!remote || !remote.starts_with("git")' $argv[1]
+end
+
+function __jj_local_bookmarks
+    __jj_bookmarks '!remote' ''
+end
+
+function __jj_remote_bookmarks
+    __jj_bookmarks 'remote && !remote.starts_with("git")' ''
+end
+
+function __jj_all_changes
+    if string length --quiet -- $argv[1]
+        set -f REV $argv[1]
+    else
+        set -f REV "all()"
+    end
+    __jj_changes $REV
+    __jj_all_bookmarks $REV
+end
+
+function __jj_mutable_changes
+    set -f REV "mutable()"
+    __jj_changes $REV
+    __jj_all_bookmarks $REV
+end
+
+function __jj_revision_modified_files
+    if test $argv[1] = "@"
+        set -f suffix ""
+    else
+        set -l change_id (__jj log --no-graph --limit 1 -T 'change_id.shortest()')
+        set -f suffix " in $change_id"
+    end
+
+    __jj diff -r $argv[1] --summary | while read -l line
+        set -l file (string split " " -m 1 -- $line)
+        switch $file[1]
+            case M
+                set -f change Modified
+            case D
+                set -f change Deleted
+            case A
+                set -f change Added
+        end
+        printf "%s\t%s%s\n" $file[2] $change $suffix
+    end
+end
+
+function __jj_remotes
+    __jj git remote list | while read -l remote
+        printf "%s\t%s\n" (string split " " -m 1 -- $remote)
+    end
+end
+
+function __jj_operations
+    __jj operation log --no-graph --limit 1000 -T 'separate("\t", id.short(), description) ++ "\n"'
+end
+
+function __jj_parse_revision
+    set -l cmd (commandline -opc)
+    set -e cmd[1]
+    set -l return_next false
+    set -l return_value 1
+
+    # Check aliases.
+    set -l alias $cmd[1]
+    set -l alias_escaped (string escape --style=var -- $alias)
+    set -l varname __jj_alias_$alias_escaped
+
+    if set -q $varname
+        set cmd $$varname[1][2..-1] $cmd[2..-1]
+    end
+
+    # Check command line arguments first.
+    for i in $cmd
+        if $return_next
+            echo $i
+            set return_value 0
+        else if contains -- $i -r --revision --from
+            set return_next true
+        else
+            set -l match (string match --regex '^(?:-r=?|--revision=|--from=)(.+)\s*$' --groups-only -- $i)
+            if set -q match[1]
+                echo $match[1]
+                set return_value 0
+            end
+        end
+    end
+
+    return $return_value
+end
+
+function __jj_revision_files
+    set -l description (__jj log --no-graph --limit 1 -r $argv[1] -T 'change_id.shortest() ++ ": " ++ coalesce(description.first_line().substr(0, 30), "(no description set)")')
+    __jj file list -r $argv[1] | while read -l file
+        printf "%s\t%s\n" $file $description
+    end
+end
+
+function __jj_revision_conflicted_files
+    __jj resolve --list -r $argv[1] | while read -l line
+        set -l file (string split " " -m 1 -- $line)
+        printf "%s\t%s\n" $file[1] $file[2]
+    end
+end
+
+function __jj_parse_revision_files
+    set -l rev (__jj_parse_revision)
+    if test $status -eq 1
+        set rev "@"
+    end
+    __jj_revision_files $rev
+end
+
+function __jj_parse_revision_conflicted_files
+    set -l rev (__jj_parse_revision)
+    if test $status -eq 1
+        set rev "@"
+    end
+    __jj_revision_conflicted_files $rev
+end
+
+function __jj_parse_revision_files_or_wc_modified_files
+    set -l revs (__jj_parse_revision)
+    if test $status -eq 1
+        __jj_revision_modified_files "@"
+    else
+        for rev in $revs
+            __jj_revision_files $rev
+        end
+    end
+end
+
+function __jj_parse_revision_modified_files_or_wc_modified_files
+    set -l revs (__jj_parse_revision)
+    if test $status -eq 1
+        __jj_revision_modified_files "@"
+    else
+        for rev in $revs
+            __jj_revision_modified_files $rev
+        end
+    end
+end
+
+# Aliases.
+complete -f -c jj -n __fish_use_subcommand -a '(__jj_aliases_with_descriptions)'
+
+# Files.
+complete -f -c jj -n '__jj_seen_subcommand_from file; and __jj_seen_subcommand_from show' -ka '(__jj_parse_revision_files)'
+complete -f -c jj -n '__jj_seen_subcommand_from file; and __jj_seen_subcommand_from chmod' -ka '(__jj_parse_revision_files)'
+complete -f -c jj -n '__jj_seen_subcommand_from commit' -ka '(__jj_revision_modified_files "@")'
+complete -c jj -n '__jj_seen_subcommand_from diff' -ka '(__jj_parse_revision_files_or_wc_modified_files)'
+complete -c jj -n '__jj_seen_subcommand_from interdiff' -ka '(__jj_parse_revision_files)'
+complete -f -c jj -n '__jj_seen_subcommand_from resolve' -ka '(__jj_parse_revision_conflicted_files)'
+complete -f -c jj -n '__jj_seen_subcommand_from restore' -ka '(__jj_parse_revision_files_or_wc_modified_files)'
+complete -f -c jj -n '__jj_seen_subcommand_from split' -ka '(__jj_parse_revision_modified_files_or_wc_modified_files)'
+complete -f -c jj -n '__jj_seen_subcommand_from squash' -ka '(__jj_parse_revision_modified_files_or_wc_modified_files)'
+complete -f -c jj -n '__jj_seen_subcommand_from untrack' -ka '(__jj_parse_revision_files_or_wc_modified_files)'
+
+# Revisions.
+complete -f -c jj -n '__jj_seen_subcommand_from abandon' -ka '(__jj_mutable_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from backout' -s r -l revision -rka '(__jj_all_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from backout' -s d -l destination -rka '(__jj_all_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from file; and __jj_seen_subcommand_from show' -s r -l revision -rka '(__jj_all_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from chmod' -s r -l revision -rka '(__jj_mutable_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from describe' -ka '(__jj_mutable_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from diff' -s r -l revision -rka '(__jj_all_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from diff' -l from -rka '(__jj_all_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from diff' -l to -rka '(__jj_all_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from diffedit' -s r -l revision -rka '(__jj_mutable_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from diffedit' -l from -rka '(__jj_all_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from diffedit' -l to -rka '(__jj_mutable_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from duplicate' -ka '(__jj_all_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from edit' -ka '(__jj_mutable_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from file; and __jj_seen_subcommand_from list' -s r -l revision -rka '(__jj_all_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from interdiff' -l from -rka '(__jj_all_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from interdiff' -l to -rka '(__jj_all_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from log' -s r -rka '(__jj_all_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from new' -ka '(__jj_all_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from new' -s A -l after -l insert-after -rka '(__jj_all_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from new' -s B -l before -l insert-before -rka '(__jj_mutable_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from obslog' -s r -l revision -rka '(__jj_all_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from parallelize' -ka '(__jj_mutable_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from rebase' -s r -l revisions -rka '(__jj_mutable_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from rebase' -s s -l source -rka '(__jj_mutable_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from rebase' -s b -l bookmark -rka '(__jj_mutable_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from rebase' -s d -l destination -rka '(__jj_all_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from rebase' -s A -l after -l insert-after -rka '(__jj_all_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from rebase' -s B -l before -l insert-before -rka '(__jj_mutable_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from resolve' -s r -l revision -rka '(__jj_mutable_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from restore' -l from -rka '(__jj_all_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from restore' -l to -rka '(__jj_mutable_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from restore' -s c -l changes-in -rka '(__jj_all_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from show' -ka '(__jj_all_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from split' -s r -l revision -rka '(__jj_mutable_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from squash' -s r -l revision -rka '(__jj_mutable_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from squash' -l from -rka '(__jj_mutable_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from squash' -l to -l into -rka '(__jj_mutable_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from unsquash' -s r -l revision -rka '(__jj_mutable_changes)'
+
+# Bookmarks
+complete -f -c jj -n '__jj_seen_subcommand_from bookmark; and __jj_seen_subcommand_from delete forget rename set d f r s' -ka '(__jj_local_bookmarks)'
+complete -f -c jj -n '__jj_seen_subcommand_from bookmark; and __jj_seen_subcommand_from track t' -ka '(__jj_bookmarks "remote && !tracked" "")'
+complete -f -c jj -n '__jj_seen_subcommand_from bookmark; and __jj_seen_subcommand_from untrack' -ka '(__jj_bookmarks "remote && tracked && !remote.starts_with(\"git\")" "")'
+complete -f -c jj -n '__jj_seen_subcommand_from bookmark; and __jj_seen_subcommand_from create move set c m s' -s r -l revision -kra '(__jj_all_changes)'
+complete -f -c jj -n '__jj_seen_subcommand_from bookmark; and __jj_seen_subcommand_from move' -l from -rka '(__jj_changes "all()")'
+complete -f -c jj -n '__jj_seen_subcommand_from bookmark; and __jj_seen_subcommand_from move' -l to -rka '(__jj_changes "all()")'
+
+# Git.
+complete -f -c jj -n '__jj_seen_subcommand_from git; and __jj_seen_subcommand_from push' -s c -l change -kra '(__jj_changes "all()")'
+complete -f -c jj -n '__jj_seen_subcommand_from git; and __jj_seen_subcommand_from push' -s r -l revisions -kra '(__jj_changes "all()")'
+complete -f -c jj -n '__jj_seen_subcommand_from git; and __jj_seen_subcommand_from fetch push' -s b -l bookmark -rka '(__jj_local_bookmarks)'
+complete -f -c jj -n '__jj_seen_subcommand_from git; and __jj_seen_subcommand_from fetch push' -l remote -rka '(__jj_remotes)'
+complete -f -c jj -n '__jj_seen_subcommand_from git; and __jj_seen_subcommand_from remote; and __jj_seen_subcommand_from remove rename set-url' -ka '(__jj_remotes)'
+
+# Operations.
+complete -f -c jj -l at-op -l at-operation -rka '(__jj_operations)'
+complete -f -c jj -n '__jj_seen_subcommand_from undo' -ka '(__jj_operations)'
+complete -f -c jj -n '__jj_seen_subcommand_from operation; and __jj_seen_subcommand_from abandon undo restore' -ka '(__jj_operations)'
diff --git a/files/config/fish/vcs.fish b/files/config/fish/vcs.fish
index 0fa3e43..f3c179e 100644
--- a/files/config/fish/vcs.fish
+++ b/files/config/fish/vcs.fish
@@ -64,7 +64,3 @@ bind \ea vcs_log
 bind \ee vcs_broot
 bind \eS vcs_diff
 bind \es vcs_status
-
-# jj completions
-
-COMPLETE=fish jj | source
diff --git a/home/common/fish.nix b/home/common/fish.nix
index e5d1c45..03cf86f 100644
--- a/home/common/fish.nix
+++ b/home/common/fish.nix
@@ -3,6 +3,7 @@
   programs.fish = {
     enable = true;
 
+
     plugins = [
       {
         name = "transient";
@@ -56,42 +57,42 @@
       '';
 
       fish_jj_prompt.body = ''
-          if not command -sq jj || not jj root --quiet &>/dev/null
-            return 1
-          end
+        if not command -sq jj || not jj root --quiet &>/dev/null
+          return 1
+        end
 
-        jj log --ignore-working-copy --no-graph --color never -r @ -T '
-          surround(
-            " \e[2;3m",
-            "\e[0m",
-            separate(
-              " ",
-              surround(
-                "\e[0;2;3m",
-                "\e[0m",
-                coalesce(
-                  surround(
-                    "\e[1;2;3m❝",
-                    "❞\e[0m",
-                    if(
-                      description.first_line().substr(0, 80).starts_with(description.first_line()),
-                      description.first_line().substr(0, 80),
-                      description.first_line().substr(0, 79) ++ "…"
-                    )
-                  ),
-                  "…"
+      jj log --ignore-working-copy --no-graph --color never -r @ -T '
+        surround(
+          " \e[2;3m",
+          "\e[0m",
+          separate(
+            " ",
+            surround(
+              "\e[0;2;3m",
+              "\e[0m",
+              coalesce(
+                surround(
+                  "\e[1;2;3m❝",
+                  "❞\e[0m",
+                  if(
+                    description.first_line().substr(0, 80).starts_with(description.first_line()),
+                    description.first_line().substr(0, 80),
+                    description.first_line().substr(0, 79) ++ "…"
+                  )
                 ),
+                "…"
               ),
-              surround("\e[0;1;95m ", "\e[0;2;3m", change_id.shortest()),
-              surround("\e[0;35m󰸕 ", "\e[0m", bookmarks.join("╱")),
-              surround("\e[0;34m ",   "\e[0;2;3m", commit_id.shortest()),
-              if(conflict,  "󰂭"),
-              if(empty,     ""),
-              if(divergent, ""),
-              if(hidden,    "󰘓"),
-            )
+            ),
+            surround("\e[0;1;95m ", "\e[0;2;3m", change_id.shortest()),
+            surround("\e[0;35m󰸕 ", "\e[0m", bookmarks.join("╱")),
+            surround("\e[0;34m ",   "\e[0;2;3m", commit_id.shortest()),
+            if(conflict,  "󰂭"),
+            if(empty,     ""),
+            if(divergent, ""),
+            if(hidden,    "󰘓"),
           )
-        '
+        )
+      '
       '';
 
       fish_prompt.body = ''
@@ -116,6 +117,8 @@
     interactiveShellInit = lib.concatStringsSep "\n" [
       (builtins.readFile ../../files/config/fish/config.fish)
       (builtins.readFile ../../files/config/fish/semantic-prompt.fish)
+      (builtins.readFile ../../files/config/fish/go-task.fish)
+      (builtins.readFile ../../files/config/fish/jj.fish)
       (builtins.readFile ../../files/config/fish/vcs.fish)
     ];