diff --git a/config/fish/functions/cr.fish b/config/fish/functions/cr.fish
new file mode 100644
index 0000000..c2ab491
--- /dev/null
+++ b/config/fish/functions/cr.fish
@@ -0,0 +1,303 @@
+# cr.fish — Create and manage code review worktrees for Fish shell
+#
+# Synopsis:
+#   cr [OPTIONS] <source-branch>
+#   cr cleanup [OPTIONS]
+#
+# Description:
+#   Create a dedicated worktree for reviewing code based on a ticket ID
+#   extracted from a branch name, or clean up existing cr- worktrees.
+#
+# Constants:
+#   CR_DEFAULT_REMOTE      Default Git remote used when none specified
+#
+# Fish Requirements:
+#   Fish shell >= 3.1.0 for argparse builtin
+#
+# Based on work by ville6000 (https://github.com/ville6000)
+#
+# Examples:
+#   cr feature/1234-add-login
+#   cr -r upstream 5678
+#   cr cleanup --dry-run
+
+if not set -q CR_DEFAULT_REMOTE
+    set -g CR_DEFAULT_REMOTE origin
+end
+
+function __cr_show_help
+    echo 'Usage: cr [OPTIONS] <source-branch>'
+    echo '       cr cleanup [OPTIONS]'
+    echo
+    echo "  -r, --remote <name>        Git remote (default: $CR_DEFAULT_REMOTE)"
+    echo '  -d, --dry-run              Show actions without executing'
+    echo '  -f, --force                Skip confirmation prompts'
+    echo '  -k, --keep-branch          In cleanup, keep local branches'
+    echo '  -b, --branch-only <ticket> Create only the review branch (no worktree)'
+    echo '      --cleanup-branches-only In cleanup, delete branches only'
+    echo '  -h, --help                 Show this help'
+end
+
+function __cr_run_with_spinner --argument-names msg cmd
+    set -l tmp (mktemp)
+    eval $cmd >$tmp 2>&1 &
+    set -l pid $last_pid
+    set -l spin_chars '/-\|'
+    set -l i 1
+    while kill -0 $pid 2>/dev/null
+        printf "\r[%c] %s" (string sub -s $i -l 1 $spin_chars) "$msg"
+        set i (math (math $i % 4) + 1)
+        sleep 0.1
+    end
+    printf "\r%s\r" (string repeat -n (math (string length "$msg") + 5) " ")
+    wait $pid
+    set -l output (cat $tmp)
+    rm $tmp
+    # Remove any leading empty or all-whitespace lines (from spinner clear)
+    for line in $output
+        if test -n (string trim -- $line)
+            echo $line
+        end
+    end
+end
+
+function __cr_cleanup
+    argparse dry_run force keep_branch cleanup_branches_only -- $argv
+    or return
+
+    set -l dry_run (set -q _flag_dry_run; and echo 1; or echo 0)
+    set -l force (set -q _flag_force; and echo 1; or echo 0)
+    set -l keep_branch (set -q _flag_keep_branch; and echo 1; or echo 0)
+    set -l branches_only (set -q _flag_cleanup_branches_only; and echo 1; or echo 0)
+
+    set -l target_branch
+    if test (count $argv) -gt 0
+        set target_branch $argv[1]
+    end
+
+    git worktree prune
+
+    for wt in (git worktree list --porcelain | awk '/^worktree /{print $2}')
+        set -l base (basename $wt)
+        if string match -r '^cr-.*' $base
+            if test -n "$target_branch" -a "$base" != "$target_branch"
+                continue
+            end
+            if test "$branches_only" = 0
+                if test "$dry_run" = 1
+                    echo "[DRY-RUN] remove worktree: $wt"
+                else if test "$force" = 1
+                    git worktree remove --force $wt
+                else
+                    echo "git worktree remove --force $wt"
+                    echo "(!) Use --force to actually remove worktree: $wt."
+                end
+            end
+            if test "$keep_branch" = 0
+                if test "$branches_only" = 0
+                    if test "$dry_run" = 1
+                        echo "[DRY-RUN] delete branch: $base"
+                    else if test "$force" = 1
+                        git branch -D $base
+                    else
+                        echo "git branch -D $base"
+                        echo "(!) Use --force to actually delete branch: $base."
+                    end
+                end
+            end
+        end
+    end
+end
+
+# --- Main Entrypoint ---
+
+function cr --description 'Create or cleanup code-review worktrees'
+    if not git rev-parse --is-inside-work-tree >/dev/null 2>&1
+        echo "Not inside a git repository." >&2
+        return 1
+    end
+
+    set -l remotes (git remote)
+    if test (count $remotes) -eq 0
+        echo "No git remotes found. Please add a remote before using cr." >&2
+        return 1
+    end
+
+    if not type -q argparse
+        echo 'cr.fish requires the argparse builtin' >&2
+        return 1
+    end
+
+    argparse \
+        r/remote= \
+        h/help \
+        d/dry-run \
+        f/force \
+        y/yes \
+        k/keep-branch \
+        b/branch-only= \
+        cleanup-branches-only \
+        -- $argv
+    or return
+
+    if set -q _flag_h; or set -q _flag_help
+        __cr_show_help
+        return 0
+    end
+
+    set -l remote (set -q _flag_remote; and echo $_flag_remote[-1]; or echo $CR_DEFAULT_REMOTE)
+    if set -q _flag_yes
+        set -g _flag_force 1
+    end
+
+    if not contains $remote $remotes
+        echo "Remote '$remote' does not exist. Available remotes: $remotes" >&2
+        return 1
+    end
+
+    if test (count $argv) -gt 0 -a "$argv[1]" = cleanup
+        __cr_cleanup \
+            (set -q _flag_dry_run; and echo --dry_run) \
+            (set -q _flag_force; and echo --force) \
+            (set -q _flag_keep_branch; and echo --keep_branch) \
+            (set -q _flag_cleanup_branches_only; and echo --cleanup_branches_only)
+        return 0
+    end
+
+    set -l source_branch ""
+    if test (count $argv) -gt 0
+        set source_branch $argv[1]
+    else if type -q fzf
+        set -l branches (__cr_run_with_spinner "Fetching branches..." \
+            "git ls-remote --heads $remote | sed 's|.*refs/heads/||'")
+        printf "\n"
+        if test (count $branches) -eq 0
+            echo "No branches found on remote '$remote'." >&2
+            return 1
+        end
+        set -l exclude_branches main master develop dev trunk
+        set -l filtered_branches
+        for b in $branches
+            set b (string trim -- $b)
+            if not contains -- $b $exclude_branches
+                set filtered_branches $filtered_branches $b
+            end
+        end
+        set source_branch (printf '%s\n' $filtered_branches | fzf --prompt='Select branch: ')
+        echo "Selected branch: $source_branch"
+        if test $status -ne 0
+            echo 'Selection aborted' >&2
+            return 1
+        end
+        if test -z "$source_branch"
+            echo 'No branch selected' >&2
+            return 1
+        end
+    else
+        __cr_show_help >&2
+        return 1
+    end
+
+    # Extract ticket ID from branch name, or use slug if not found
+    set -l branch_tail (string split "/" $source_branch)[-1]
+    set -l ticket_id (printf '%s\n' $branch_tail | grep -o '[0-9]\+' | tail -n1)
+    set -l review_suffix ""
+    if test -z "$ticket_id"
+        # No numeric ticket, use slug of branch name as suffix
+        set review_suffix (string replace -ra '[^a-zA-Z0-9]+' '-' -- $source_branch)
+    else
+        set review_suffix $ticket_id
+    end
+    if set -q _flag_b; or set -q _flag_branch_only
+        set review_suffix $_flag_branch_only[-1]
+    end
+    set -l review_branch cr-$review_suffix
+    set -l folder ../$review_branch
+
+    # Branch-only mode
+    if set -q _flag_b; or set -q _flag_branch_only
+        if set -q _flag_dry_run
+            echo "[DRY-RUN] Create branch $review_branch from $remote/$source_branch"
+            return 0
+        end
+        __cr_run_with_spinner "Fetching from $remote..." \
+            "git fetch $remote $source_branch"
+        git branch $review_branch $remote/$source_branch
+        echo "Created branch $review_branch"
+        return 0
+    end
+
+    __cr_run_with_spinner "Checking remote branch..." \
+        "git ls-remote --exit-code --heads $remote $source_branch >/dev/null 2>&1"
+    if test $status -ne 0
+        echo "No remote branch $remote/$source_branch" >&2
+        return 1
+    end
+    if git show-ref --quiet refs/heads/$review_branch
+        echo "Local branch $review_branch exists" >&2
+        return 1
+    end
+    if test -d $folder
+        echo "Directory $folder exists" >&2
+        return 1
+    end
+
+    if set -q _flag_dry_run
+        echo "[DRY-RUN] Add worktree $folder -b $review_branch $remote/$source_branch"
+        return 0
+    end
+
+    __cr_run_with_spinner "Fetching from $remote..." \
+        "git fetch $remote $source_branch"
+    git worktree add $folder -b $review_branch $remote/$source_branch
+end
+
+# --- Completion Functions ---
+
+complete -c cr -l help -s h -f -d 'Show help'
+complete -c cr -l remote -s r -f -d 'Git remote' -a '(git remote)'
+complete -c cr -l dry-run -s d -f -d 'Dry run'
+complete -c cr -l force -s f -f -d 'Skip confirmations'
+complete -c cr -l keep-branch -s k -f -d 'Keep branches in cleanup'
+complete -c cr -l branch-only -s b -f -d 'Branch-only mode' \
+    -a '(__fish_cr_ticket_ids)'
+complete -c cr -l cleanup-branches-only -f -d 'Branches-only cleanup'
+complete -c cr -f -a cleanup -d 'Cleanup mode' \
+    -n 'not __fish_seen_subcommand_from cleanup'
+complete -c cr -n '__fish_seen_subcommand_from cleanup' -f \
+    -a '(__fish_cr_cleanup_branches)' -d 'cr-* branch'
+complete -c cr -n '__fish_seen_subcommand_from cleanup' -f
+complete -c cr -n 'not __fish_seen_subcommand_from cleanup' -f \
+    -a '(__fish_cr_branches)' -d 'Source branch'
+
+function __fish_cr_cleanup_branches
+    git worktree list --porcelain | awk '/^worktree /{print $2}' | while read -l wt
+        set base (basename $wt)
+        if string match -r '^cr-.*' $base
+            echo $base
+        end
+    end
+end
+
+function __fish_cr_branches --description 'List remote branches'
+    set -l exclude_branches main master develop dev trunk
+    set -l branches (git ls-remote --heads $CR_DEFAULT_REMOTE | \
+        sed 's|.*refs/heads/||')
+    for b in $branches
+        set b (string trim -- $b)
+        if not contains -- $b $exclude_branches
+            echo $b
+        end
+    end
+end
+
+function __fish_cr_ticket_ids --description 'List ticket IDs from remote branches'
+    for b in (git ls-remote --heads $CR_DEFAULT_REMOTE | \
+        sed 's|.*refs/heads/||')
+        set b (string trim -- $b)
+        set -l id (string match -r '[0-9]+' -- $b)
+        if test -n "$id"
+            echo $id
+        end
+    end
+end