diff --git a/internal/client/ui/core/chat/chat.go b/internal/client/ui/core/chat/chat.go
index 04eedb7..a93272f 100644
--- a/internal/client/ui/core/chat/chat.go
+++ b/internal/client/ui/core/chat/chat.go
@@ -23,7 +23,7 @@ func New() Model {
 		return lineNumber + " ┃ "
 	}
 
-	vi.SetLines(viminput.Line("test"), viminput.Line("best"))
+	vi.SetLines([]rune("test"), []rune("best"))
 	// ta.Cursor.SetChar()
 
 	// vi.CharLimit = 280
@@ -54,8 +54,10 @@ func (m Model) Update(msg tea.Msg) (Model, tea.Cmd) {
 
 func (m *Model) Focus() {
 	m.focus = true
+	m.vi.Focus()
 }
 
 func (m *Model) Blur() {
 	m.focus = false
+	m.vi.Blur()
 }
diff --git a/internal/client/ui/viminput/viminput.go b/internal/client/ui/viminput/viminput.go
index 94c5413..1c3d8a9 100644
--- a/internal/client/ui/viminput/viminput.go
+++ b/internal/client/ui/viminput/viminput.go
@@ -1,31 +1,38 @@
 package viminput
 
 import (
+	"slices"
 	"strings"
 
 	tea "github.com/charmbracelet/bubbletea"
 	"github.com/charmbracelet/lipgloss"
+	"github.com/kyren223/eko/internal/client/ui/colors"
 )
 
+var DefaultCursorStyle = lipgloss.NewStyle().Background(colors.White).Foreground(colors.Background)
+
 type (
-	Keymap         struct{}
 	LineDecoration = func(lnum int, m Model) string
 )
 
-type Line []byte
+const (
+	NormalMode = iota
+	InsertMode
+	VisualMode
+)
 
 type Model struct {
-	keymap Keymap
-
 	PlaceholderStyle lipgloss.Style
 	PromptStyle      lipgloss.Style
 
 	Placeholder    string
 	LineDecoration LineDecoration
 
-	lines      []Line
-	CursorLine int
-	CursorColumn int
+	lines        [][]rune
+	cursorLine   int
+	cursorColumn int
+	goalColumn   int
+	mode         int
 
 	width  int
 	height int
@@ -34,11 +41,15 @@ type Model struct {
 
 func New(width, height int) Model {
 	return Model{
-		keymap:           Keymap{},
 		PlaceholderStyle: lipgloss.NewStyle(),
 		PromptStyle:      lipgloss.NewStyle(),
 		Placeholder:      "",
 		LineDecoration:   EmptyLineDecoration,
+		lines:            [][]rune{},
+		cursorLine:       0,
+		cursorColumn:     0,
+		goalColumn:       -1,
+		mode:             NormalMode,
 		width:            width,
 		height:           height,
 		focus:            false,
@@ -50,10 +61,10 @@ func (m Model) Init() tea.Cmd {
 }
 
 func (m Model) View() string {
-	var lines []Line
+	var lines [][]rune
 	if len(m.lines) == 0 {
 		placeholder := m.PlaceholderStyle.Render(m.Placeholder)
-		lines = append(lines, Line(placeholder))
+		lines = append(lines, []rune(placeholder))
 	} else {
 		lines = m.lines
 	}
@@ -62,7 +73,18 @@ func (m Model) View() string {
 	for i, line := range lines {
 		lineDecoration := m.LineDecoration(i, m)
 		builder.WriteString(lineDecoration)
-		builder.Write(line)
+
+		if m.CursorLine() != i {
+			builder.WriteString(string(line))
+		} else if m.CursorColumn() == len(m.lines[m.CursorLine()]) {
+			builder.WriteString(string(line))
+			builder.WriteString(DefaultCursorStyle.Render(" "))
+		} else {
+			builder.WriteString(string(line[:m.CursorColumn()]))
+			builder.WriteString(DefaultCursorStyle.Render(string(line[m.CursorColumn()])))
+			builder.WriteString(string(line[m.CursorColumn()+1:]))
+		}
+
 		builder.WriteByte('\n')
 	}
 
@@ -77,6 +99,12 @@ func (m Model) Update(msg tea.Msg) (Model, tea.Cmd) {
 		return m, nil
 	}
 
+	switch msg := msg.(type) {
+	case tea.KeyMsg:
+		cmd := m.handleKeys(msg)
+		return m, cmd
+	}
+
 	return m, nil
 }
 
@@ -104,14 +132,90 @@ func (m *Model) Blur() {
 	m.focus = false
 }
 
-func (m *Model) SetLines(lines ...Line) {
+func (m *Model) SetLines(lines ...[]rune) {
 	m.lines = lines
 }
 
-func (m *Model) SetLine(lnum int, line Line) {
+func (m *Model) SetLine(lnum int, line []rune) {
 	m.lines[lnum] = line
 }
 
-func (m *Model) Line(lnum int) Line {
+func (m *Model) Line(lnum int) []rune {
 	return m.lines[lnum]
 }
+
+func (m *Model) SetCursorColumn(col int) {
+	m.cursorColumn = col
+	m.goalColumn = -1
+}
+
+func (m *Model) SetCursorLine(line int) {
+	fromLength := m.CursorColumn()
+	toLength := len(m.lines[line])
+	if fromLength > toLength && m.goalColumn == -1 {
+		m.goalColumn = fromLength
+	}
+	if m.goalColumn != -1 {
+		m.cursorColumn = min(toLength-1, m.goalColumn)
+	}
+	m.cursorLine = line
+}
+
+func (m *Model) CursorColumn() int {
+	return m.cursorColumn
+}
+
+func (m *Model) CursorLine() int {
+	return m.cursorLine
+}
+
+func (m *Model) handleKeys(key tea.KeyMsg) tea.Cmd {
+	switch m.mode {
+	case NormalMode:
+		return m.handleNormalModeKeys(key)
+	case InsertMode:
+		return m.handleInsertModeKeys(key)
+	}
+
+	return nil
+}
+
+func (m *Model) handleNormalModeKeys(key tea.KeyMsg) tea.Cmd {
+	switch key.String() {
+	case "h":
+		m.SetCursorColumn(max(m.CursorColumn()-1, 0))
+	case "j":
+		m.SetCursorLine(min(m.CursorLine()+1, len(m.lines)-1))
+	case "k":
+		m.SetCursorLine(max(m.CursorLine()-1, 0))
+	case "l":
+		m.SetCursorColumn(min(m.CursorColumn()+1, len(m.lines[m.CursorLine()])-1))
+	case "i":
+		m.mode = InsertMode
+	case "a":
+		m.mode = InsertMode
+		m.SetCursorColumn(m.CursorColumn() + 1)
+	case "0":
+		m.SetCursorColumn(0)
+	}
+
+	return nil
+}
+
+func (m *Model) handleInsertModeKeys(key tea.KeyMsg) tea.Cmd {
+	if key.Type == tea.KeyEscape {
+		m.SetCursorColumn(max(m.CursorColumn()-1, 0))
+		m.mode = NormalMode
+		return nil
+	}
+
+	keyStr := key.String()
+	length := len(keyStr)
+	if length == 1 && 32 <= keyStr[0] && keyStr[0] <= 126 {
+		line := m.lines[m.CursorLine()]
+		m.lines[m.CursorLine()] = slices.Insert(line, m.CursorColumn(), rune(keyStr[0]))
+		m.SetCursorColumn(m.CursorColumn() + 1)
+	}
+
+	return nil
+}