diff --git a/shell/open_sess.sh b/shell/open_sess.sh
new file mode 100755
index 0000000..76274a8
--- /dev/null
+++ b/shell/open_sess.sh
@@ -0,0 +1,37 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+PROJECT_DIR=$(find ~/projects -mindepth 1 -maxdepth 1 -type d | fzf --prompt='Select project: ')
+[ -z "$PROJECT_DIR" ] && exit 0
+
+SESSION_NAME=$(basename "$PROJECT_DIR")
+
+# If session exists, switch or attach depending on context
+if tmux has-session -t "$SESSION_NAME" 2>/dev/null; then
+    if [ -n "${TMUX:-}" ]; then
+        tmux switch-client -t "$SESSION_NAME"
+    else
+        tmux attach -t "$SESSION_NAME"
+    fi
+    exit 0
+fi
+
+# Choose startup command
+if [ -f "$PROJECT_DIR/shell.nix" ]; then
+    START_CMD="cd \"$PROJECT_DIR\" && nix-shell"
+else
+    START_CMD="cd \"$PROJECT_DIR\""
+fi
+
+# Create a new detached session
+tmux new-session -d -s "$SESSION_NAME" "bash -c '$START_CMD; exec bash'"
+
+# Create a second window running Neovim
+tmux new-window -t "$SESSION_NAME" -n nvim "bash -c 'cd \"$PROJECT_DIR\" && nvim'"
+
+# Attach or switch, depending on whether we're inside tmux
+if [ -n "${TMUX:-}" ]; then
+    tmux switch-client -t "$SESSION_NAME"
+else
+    tmux attach -t "$SESSION_NAME"
+fi