From 789ff23cc13c8ac0b3d49c377e85193f1e3f32e6 Mon Sep 17 00:00:00 2001
From: Stephen <939775+thecodeassassin@users.noreply.github.com>
Date: Mon, 22 Jun 2026 23:27:12 +0000
Subject: [PATCH] fix: use tmux-256color default-terminal so tmux exposes
 extended keys

---
 static/build/docker-entrypoint         | 14 ++++++++++--
 static/build/docker-entrypoint_test.sh | 31 ++++++++++++++++++++++++++
 2 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/static/build/docker-entrypoint b/static/build/docker-entrypoint
index 13240d0..ee0c040 100755
--- a/static/build/docker-entrypoint
+++ b/static/build/docker-entrypoint
@@ -65,15 +65,25 @@ update_tmux_status() {
 
 write_tmux_conf() {
     local conf="/tmp/exitbox-tmux.conf"
-    local display ws_name ver session_name
+    local display ws_name ver session_name default_term
     display="$(agent_display_name "$AGENT")"
     ws_name="${EXITBOX_WORKSPACE_NAME:-default}"
     ver="${EXITBOX_VERSION:-dev}"
     session_name="${EXITBOX_SESSION_NAME:-default}"
 
+    # Present tmux-256color to inner apps: unlike xterm-256color, its terminfo
+    # declares the extended-key capabilities tmux needs to forward modified keys
+    # (Shift+Enter, etc.) to Kitty-protocol TUIs like Pi. Fall back to
+    # xterm-256color if that terminfo entry isn't installed.
+    if infocmp tmux-256color >/dev/null 2>&1; then
+        default_term="tmux-256color"
+    else
+        default_term="xterm-256color"
+    fi
+
     cat > "$conf" <<TMUXEOF
 # ExitBox tmux configuration
-set -g default-terminal "xterm-256color"
+set -g default-terminal "${default_term}"
 # Forward modified keys (e.g. Shift+Enter / Alt+Enter) to agent TUIs that request
 # them (Kitty keyboard protocol). The "*" pattern advertises extkeys for every
 # outer terminal that supports it, not just xterm-named ones, so Shift+Enter
diff --git a/static/build/docker-entrypoint_test.sh b/static/build/docker-entrypoint_test.sh
index 43f7a9e..80b4707 100644
--- a/static/build/docker-entrypoint_test.sh
+++ b/static/build/docker-entrypoint_test.sh
@@ -749,6 +749,36 @@ test_write_tmux_conf_scroll_settings() {
     assert_contains "write_tmux_conf shows session shortcut" "$output" 'C-M-s: sessions'
 }
 
+# ============================================================================
+# Test: write_tmux_conf default-terminal prefers tmux-256color (extended keys)
+# ============================================================================
+test_write_tmux_conf_default_terminal() {
+    # When tmux-256color terminfo is available, it must be the default-terminal
+    # (its terminfo declares the extended-key capabilities Pi needs).
+    local with_tmux
+    with_tmux="$(
+        AGENT="pi"; EXITBOX_WORKSPACE_NAME="default"; EXITBOX_VERSION="test"
+        unset EXITBOX_KEYBINDINGS
+        eval "$PARSE_KB_FUNC"; parse_keybindings
+        eval "$DISPLAY_FUNC"; eval "$TMUX_CONF_FUNC"
+        infocmp() { return 0; }
+        cat "$(write_tmux_conf)"
+    )" 2>/dev/null
+    assert_contains "default-terminal prefers tmux-256color" "$with_tmux" 'set -g default-terminal "tmux-256color"'
+
+    # When it is NOT available, fall back to xterm-256color (no breakage).
+    local without_tmux
+    without_tmux="$(
+        AGENT="pi"; EXITBOX_WORKSPACE_NAME="default"; EXITBOX_VERSION="test"
+        unset EXITBOX_KEYBINDINGS
+        eval "$PARSE_KB_FUNC"; parse_keybindings
+        eval "$DISPLAY_FUNC"; eval "$TMUX_CONF_FUNC"
+        infocmp() { return 1; }
+        cat "$(write_tmux_conf)"
+    )" 2>/dev/null
+    assert_contains "default-terminal falls back to xterm-256color" "$without_tmux" 'set -g default-terminal "xterm-256color"'
+}
+
 # ============================================================================
 # Test: parse_keybindings defaults (no env var)
 # ============================================================================
@@ -847,6 +877,7 @@ test_should_exec_raw_detects_auth_keywords
 test_run_raw_command_prefixes_agent
 test_build_agent_loop_command_passthrough
 test_write_tmux_conf_scroll_settings
+test_write_tmux_conf_default_terminal
 test_parse_keybindings_default
 test_parse_keybindings_custom
 test_parse_keybindings_partial