diff --git a/tools/cli/completion-main.go b/tools/cli/completion-main.go
index bc0948e02..d787c1e55 100644
--- a/tools/cli/completion-main.go
+++ b/tools/cli/completion-main.go
@@ -51,14 +51,6 @@ func RegisterExeForCompletion(x func(root *Command)) {
 	registered_exes = append(registered_exes, x)
 }
 
-func CompletionsForArgv(argv []string) *Completions {
-	var root = NewRootCommand()
-	for _, re := range registered_exes {
-		re(root)
-	}
-	return root.GetCompletions(argv, init_completions["json"])
-}
-
 func GenerateCompletions(args []string) error {
 	output_type := "json"
 	if len(args) > 0 {
diff --git a/tools/cmd/at/shell.go b/tools/cmd/at/shell.go
index 68d564d14..dc7f8365d 100644
--- a/tools/cmd/at/shell.go
+++ b/tools/cmd/at/shell.go
@@ -175,13 +175,19 @@ func exec_command(rl *readline.Readline, cmdline string) bool {
 	return true
 }
 
-func completions(before_cursor, after_cursor string) *cli.Completions {
-	text := "kitty @ " + before_cursor
-	argv, err := shlex.Split(text)
-	if err != nil {
-		return nil
+func completions(before_cursor, after_cursor string) (ans *cli.Completions) {
+	const prefix = "kitty @ "
+	text := prefix + before_cursor
+	argv, position_of_last_arg := shlex.SplitForCompletion(text)
+	if len(argv) == 0 || position_of_last_arg < len(prefix) {
+		return
 	}
-	return cli.CompletionsForArgv(argv)
+	root := cli.NewRootCommand()
+	c := root.AddSubCommand(&cli.Command{Name: "kitty-tool"})
+	EntryPoint(c)
+	ans = root.GetCompletions(argv, nil)
+	ans.CurrentWordIdx = position_of_last_arg - len(prefix)
+	return
 }
 
 func shell_main(cmd *cli.Command, args []string) (int, error) {
diff --git a/tools/tui/readline/actions_test.go b/tools/tui/readline/actions_test.go
index c3772a7ad..378ff3fc4 100644
--- a/tools/tui/readline/actions_test.go
+++ b/tools/tui/readline/actions_test.go
@@ -5,7 +5,9 @@ package readline
 import (
 	"container/list"
 	"fmt"
+	"kitty/tools/cli"
 	"kitty/tools/tui/loop"
+	"kitty/tools/utils/shlex"
 	"strconv"
 	"strings"
 	"testing"
@@ -481,7 +483,7 @@ func TestHistory(t *testing.T) {
 			t.Fatalf("Text before cursor not as expected:\n%s", diff)
 		}
 		if diff := cmp.Diff(after_cursor, aa); diff != "" {
-			t.Fatalf("Text before cursor not as expected:\n%s", diff)
+			t.Fatalf("Text after cursor not as expected:\n%s", diff)
 		}
 	}
 	add_item("xyz1")
@@ -512,3 +514,48 @@ func TestHistory(t *testing.T) {
 	rl.perform_action(ActionTerminateHistorySearchAndRestore, 1)
 	ah("a", "")
 }
+
+func TestReadlineCompletion(t *testing.T) {
+	lp, _ := loop.New()
+
+	completer := func(before_cursor, after_cursor string) (ans *cli.Completions) {
+		root := cli.NewRootCommand()
+		c := root.AddSubCommand(&cli.Command{Name: "test-completion"})
+		c.AddSubCommand(&cli.Command{Name: "a1"})
+		c.AddSubCommand(&cli.Command{Name: "a11"})
+		c.AddSubCommand(&cli.Command{Name: "a2"})
+		prefix := c.Name + " "
+		text := prefix + before_cursor
+		argv, position_of_last_arg := shlex.SplitForCompletion(text)
+		if len(argv) == 0 || position_of_last_arg < len(prefix) {
+			return
+		}
+		ans = root.GetCompletions(argv, nil)
+		ans.CurrentWordIdx = position_of_last_arg - len(prefix)
+		return
+
+	}
+	rl := New(lp, RlInit{Prompt: "$$ ", Completer: completer})
+
+	ah := func(before_cursor, after_cursor string) {
+		ab := rl.text_upto_cursor_pos()
+		aa := rl.text_after_cursor_pos()
+		if diff := cmp.Diff(before_cursor, ab); diff != "" {
+			t.Fatalf("Text before cursor not as expected:\n%s", diff)
+		}
+		if diff := cmp.Diff(after_cursor, aa); diff != "" {
+			t.Fatalf("Text after cursor not as expected:\n%s", diff)
+		}
+	}
+	rl.add_text("a")
+	rl.perform_action(ActionCompleteForward, 1)
+	ah("a", "")
+	rl.perform_action(ActionCompleteForward, 1)
+	ah("a1 ", "")
+	rl.perform_action(ActionCompleteForward, 1)
+	ah("a11 ", "")
+	rl.perform_action(ActionCompleteForward, 1)
+	ah("a2 ", "")
+	rl.perform_action(ActionCompleteBackward, 1)
+	ah("a11 ", "")
+}
diff --git a/tools/tui/readline/api.go b/tools/tui/readline/api.go
index 83c860579..90ee36922 100644
--- a/tools/tui/readline/api.go
+++ b/tools/tui/readline/api.go
@@ -181,6 +181,7 @@ func (self *Readline) ResetText() {
 	self.last_action = ActionNil
 	self.keyboard_state = KeyboardState{}
 	self.history_search = nil
+	self.completions.current = completion{}
 	self.cursor_y = 0
 }
 
diff --git a/tools/tui/readline/completion.go b/tools/tui/readline/completion.go
index acbb968fd..477b784b0 100644
--- a/tools/tui/readline/completion.go
+++ b/tools/tui/readline/completion.go
@@ -6,6 +6,7 @@ import (
 	"fmt"
 
 	"kitty/tools/cli"
+	"kitty/tools/utils"
 )
 
 var _ = fmt.Print
@@ -39,7 +40,11 @@ func (self *completion) current_match_text() string {
 		for _, g := range self.results.Groups {
 			for _, m := range g.Matches {
 				if i == self.current_match {
-					return m.Word
+					t := m.Word
+					if !g.NoTrailingSpace {
+						t += " "
+					}
+					return t
 				}
 				i++
 			}
@@ -83,6 +88,19 @@ func (self *Readline) complete(forwards bool, repeat_count uint) bool {
 	}
 	ct := c.current.current_match_text()
 	if ct != "" {
+		before := c.current.before_cursor[:c.current.results.CurrentWordIdx] + ct
+		after := c.current.after_cursor
+		self.input_state.lines = utils.Splitlines(before)
+		if len(self.input_state.lines) == 0 {
+			self.input_state.lines = []string{""}
+		}
+		self.input_state.cursor.Y = len(self.input_state.lines) - 1
+		self.input_state.cursor.X = len(self.input_state.lines[self.input_state.cursor.Y])
+		al := utils.Splitlines(after)
+		if len(al) > 0 {
+			self.input_state.lines[self.input_state.cursor.Y] += al[0]
+			self.input_state.lines = append(self.input_state.lines, al[1:]...)
+		}
 	}
 	if repeat_count > 0 {
 		self.complete(forwards, repeat_count)