diff --git a/internal/tui/commands_test.go b/internal/tui/commands_test.go
index 385bd24..c03b381 100644
--- a/internal/tui/commands_test.go
+++ b/internal/tui/commands_test.go
@@ -3,6 +3,8 @@ package tui
 import (
 	"strings"
 	"testing"
+
+	tea "github.com/charmbracelet/bubbletea"
 )
 
 func TestCommandPrefix(t *testing.T) {
@@ -128,6 +130,36 @@ func TestCommandCompletion(t *testing.T) {
 	}
 }
 
+// While the command popup is open, plain keys must keep flowing into the
+// input (narrowing the filter) instead of being swallowed.
+func TestCommandPopupKeepsTyping(t *testing.T) {
+	m := wired(t)
+	m.Update(key("/")) // opens the command popup
+	if !m.ac.open || m.ac.mode != acCmd {
+		t.Fatalf("command popup not open: %+v", m.ac)
+	}
+	m.Update(key("h")) // must reach the input, not be swallowed
+	if got := m.ta.Value(); got != "/h" {
+		t.Fatalf("input after typing = %q, want %q", got, "/h")
+	}
+	if !m.ac.open || m.ac.mode != acCmd {
+		t.Fatal("popup should stay open while the name is typed")
+	}
+	if len(m.ac.items) != 1 || m.ac.items[0].ID != "/help" {
+		t.Errorf("popup should re-filter to /help: %+v", m.ac.items)
+	}
+	// Backspace edits the input too.
+	m.Update(tea.KeyMsg{Type: tea.KeyBackspace})
+	if got := m.ta.Value(); got != "/" {
+		t.Errorf("input after backspace = %q, want %q", got, "/")
+	}
+	// ctrl+c still quits while the popup has capture.
+	m.Update(key("ctrl+c"))
+	if !m.quitting {
+		t.Error("ctrl+c should quit while the popup is open")
+	}
+}
+
 func TestCommandPopupEnterExecutes(t *testing.T) {
 	m := wired(t)
 	m.msgs = append(m.msgs, message{role: roleUser, content: "x"})
diff --git a/internal/tui/input.go b/internal/tui/input.go
index b50ffec..6988c71 100644
--- a/internal/tui/input.go
+++ b/internal/tui/input.go
@@ -39,8 +39,16 @@ func (m *Model) handleACKey(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
 	case "esc":
 		m.closeAC()
 		return m, nil
-	}
-	return m, nil
+	case "ctrl+c":
+		m.quitting = true
+		return m, tea.Quit
+	}
+	// Any other key is plain input: forward it to the textarea, then
+	// re-evaluate the popup against the new value — typing narrows the
+	// filter, backspace widens it, a space ends command completion.
+	var cmd tea.Cmd
+	m.ta, cmd = m.ta.Update(msg)
+	return m, tea.Batch(cmd, m.syncAC())
 }
 
 // acMode selects what the completion popup is completing.