v0.0.4: add sessions and refine tui

.gitignore

@@ -2,3 +2,4 @@ agentu*.yaml
 /agentu
 /coverage.out
 *.swp
+chat-history.txt

cmd/agentu/main.go

@@ -9,6 +9,7 @@ import (
 	"net/http"
 	"os"
 	"os/signal"
+	"path/filepath"
 	"strings"
 
 	"agentu/internal/agent"
@@ -31,6 +32,7 @@ func run() error {
 	yolo := flag.Bool("yolo", false, "also enable automatic file writes and shell execution")
 	plain := flag.Bool("plain", false, "use the simple line-based REPL instead of the TUI")
 	themeName := flag.String("theme", "light", "TUI theme: light or dark")
+	resumeID := flag.String("resume", "", "resume a specific session by ID")
 	flag.Parse()
 
 	themeMode, err := tui.ParseThemeMode(*themeName)
@@ -75,27 +77,52 @@ func run() error {
 		ToolRegistry:    registry,
 		ToolTimeout:     cfg.Agent.ToolTimeout,
 	})
-	modelManager, err := session.NewManager(cfg, assistant, http.DefaultClient)
+
+	// Initialize session store
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return fmt.Errorf("resolve home dir: %w", err)
+	}
+	sessionsDir := filepath.Join(home, ".agentu", "sessions")
+	store, err := session.NewStore(sessionsDir)
+	if err != nil {
+		return fmt.Errorf("init session store: %w", err)
+	}
+
+	modelManager, err := session.NewManager(cfg, assistant, http.DefaultClient, store)
 	if err != nil {
 		return err
 	}
 
+	// Resume session
+	if *resumeID != "" {
+		if err := modelManager.Resume(*resumeID); err != nil {
+			return fmt.Errorf("resume session: %w", err)
+		}
+	} else {
+		if err := modelManager.ResumeLatest(); err != nil {
+			return fmt.Errorf("resume latest session: %w", err)
+		}
+	}
+
 	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt)
 	defer stop()
 
 	if !*plain {
-		return tui.Run(ctx, assistant, tui.Options{
+		err := tui.Run(ctx, assistant, tui.Options{
 			ModelName:    providerConfig.Model,
 			Yolo:         *yolo,
 			ThemeMode:    themeMode,
 			ModelManager: modelManager,
 		})
+		printExitSession(modelManager)
+		return err
 	}
 
-	return repl(ctx, assistant)
+	return repl(ctx, assistant, modelManager)
 }
 
-func repl(ctx context.Context, assistant *agent.Agent) error {
+func repl(ctx context.Context, assistant *agent.Agent, modelManager *session.Manager) error {
 	scanner := bufio.NewScanner(os.Stdin)
 	scanner.Buffer(make([]byte, 0, 64*1024), 1024*1024)
 
@@ -108,6 +135,7 @@ func repl(ctx context.Context, assistant *agent.Agent) error {
 				return err
 			}
 			fmt.Println()
+			printExitSession(modelManager)
 			return nil
 		}
 
@@ -116,6 +144,7 @@ func repl(ctx context.Context, assistant *agent.Agent) error {
 		case "":
 			continue
 		case "/exit", "/quit":
+			printExitSession(modelManager)
 			return nil
 		case "/clear":
 			assistant.Clear()
@@ -126,6 +155,24 @@ func repl(ctx context.Context, assistant *agent.Agent) error {
 		if err := assistant.RunTurn(ctx, input, os.Stdout, os.Stderr); err != nil {
 			fmt.Fprintln(os.Stderr, "\nerror:", err)
 		}
+		_ = modelManager.Save()
 		fmt.Println()
 	}
 }
+
+func printExitSession(m *session.Manager) {
+	if m == nil {
+		return
+	}
+	_ = m.Save()
+	id := m.CurrentSessionID()
+	name := m.CurrentSessionName()
+	if id != "" {
+		if name != "" && name != id {
+			fmt.Fprintf(os.Stderr, "session: %s (%s)\n", id, name)
+		} else {
+			fmt.Fprintf(os.Stderr, "session: %s\n", id)
+		}
+		fmt.Fprintf(os.Stderr, "resume:  agentu --resume %s\n", id)
+	}
+}

internal/agent/agent.go

@@ -117,6 +117,18 @@ func (a *Agent) Clear() {
 	}
 }
 
+// Messages returns a copy of the current conversation messages.
+func (a *Agent) Messages() []llm.Message {
+	out := make([]llm.Message, len(a.messages))
+	copy(out, a.messages)
+	return out
+}
+
+// SetMessages replaces the conversation messages (used for session restore).
+func (a *Agent) SetMessages(messages []llm.Message) {
+	a.messages = append([]llm.Message(nil), messages...)
+}
+
 func (a *Agent) RunTurn(ctx context.Context, input string, out io.Writer, logs io.Writer) error {
 	input = strings.TrimSpace(input)
 	if input == "" {

internal/session/manager.go

@@ -5,6 +5,7 @@ import (
 	"net/http"
 	"sort"
 	"strings"
+	"time"
 
 	"agentu/internal/agent"
 	"agentu/internal/config"
@@ -12,14 +13,16 @@ import (
 )
 
 type Manager struct {
-	cfg          *config.Config
+	cfg            *config.Config
-	agent        *agent.Agent
+	agent          *agent.Agent
-	httpClient   *http.Client
+	httpClient     *http.Client
-	providerName string
+	providerName   string
-	provider     config.ProviderConfig
+	provider       config.ProviderConfig
+	store          *Store
+	currentSession *Session
 }
 
-func NewManager(cfg *config.Config, assistant *agent.Agent, httpClient *http.Client) (*Manager, error) {
+func NewManager(cfg *config.Config, assistant *agent.Agent, httpClient *http.Client, store *Store) (*Manager, error) {
 	if httpClient == nil {
 		httpClient = http.DefaultClient
 	}
@@ -28,13 +31,160 @@ func NewManager(cfg *config.Config, assistant *agent.Agent, httpClient *http.Cli
 	if !ok {
 		return nil, fmt.Errorf("no provider is configured")
 	}
-	return &Manager{
+	m := &Manager{
 		cfg:          cfg,
 		agent:        assistant,
 		httpClient:   httpClient,
 		providerName: providerName,
 		provider:     provider,
-	}, nil
+		store:        store,
+	}
+	return m, nil
+}
+
+// ResumeLatest loads the most recent session, or creates a new one.
+func (m *Manager) ResumeLatest() error {
+	if m.store == nil {
+		return nil
+	}
+	metas, err := m.store.List()
+	if err != nil {
+		return err
+	}
+	if len(metas) > 0 {
+		return m.Resume(metas[0].ID)
+	}
+	m.newSession()
+	return nil
+}
+
+// Resume loads a session by ID and restores it into the agent.
+func (m *Manager) Resume(id string) error {
+	if m.store == nil {
+		return fmt.Errorf("session storage is not configured")
+	}
+	sess, err := m.store.Load(id)
+	if err != nil {
+		return err
+	}
+	m.currentSession = sess
+	m.agent.SetMessages(sess.Messages)
+	return nil
+}
+
+// Save persists the current session to disk.
+func (m *Manager) Save() error {
+	if m.store == nil || m.currentSession == nil {
+		return nil
+	}
+	m.currentSession.Messages = m.agent.Messages()
+	m.currentSession.Provider = m.providerName
+	m.currentSession.Model = m.provider.Model
+	// Auto-name if empty
+	if m.currentSession.Name == "" {
+		m.currentSession.Name = DefaultName(m.currentSession.Messages)
+	}
+	return m.store.Save(m.currentSession)
+}
+
+// Rename changes the current session name and saves.
+func (m *Manager) Rename(name string) (string, error) {
+	name = strings.TrimSpace(name)
+	if name == "" {
+		return "", fmt.Errorf("name is required")
+	}
+	if m.currentSession == nil {
+		return "", fmt.Errorf("no active session")
+	}
+	m.currentSession.Name = name
+	if err := m.Save(); err != nil {
+		return "", err
+	}
+	return fmt.Sprintf("Renamed session to %q.", name), nil
+}
+
+// Sessions returns a formatted list of all sessions.
+func (m *Manager) Sessions() (string, error) {
+	if m.store == nil {
+		return "", fmt.Errorf("session storage is not configured")
+	}
+	metas, err := m.store.List()
+	if err != nil {
+		return "", err
+	}
+	if len(metas) == 0 {
+		return "No saved sessions.", nil
+	}
+	var b strings.Builder
+	b.WriteString("Sessions:\n")
+	for _, meta := range metas {
+		name := meta.Name
+		if name == "" {
+			name = "(unnamed)"
+		}
+		current := ""
+		if m.currentSession != nil && meta.ID == m.currentSession.ID {
+			current = " (current)"
+		}
+		ts := meta.UpdatedAt.Local().Format("2006-01-02 15:04")
+		fmt.Fprintf(&b, "  %s  %-30s  %s  %d msgs%s\n", meta.ID, fitName(name, 30), ts, meta.MessageCount, current)
+	}
+	return b.String(), nil
+}
+
+// NewSession starts a fresh session, saving the current one first.
+func (m *Manager) NewSession() (string, error) {
+	// Save current if it has user messages
+	if m.currentSession != nil {
+		msgs := m.agent.Messages()
+		hasUser := false
+		for _, msg := range msgs {
+			if msg.Role == llm.RoleUser {
+				hasUser = true
+				break
+			}
+		}
+		if hasUser {
+			m.currentSession.Messages = msgs
+			m.currentSession.Provider = m.providerName
+			m.currentSession.Model = m.provider.Model
+			if m.currentSession.Name == "" {
+				m.currentSession.Name = DefaultName(msgs)
+			}
+			if m.store != nil {
+				_ = m.store.Save(m.currentSession)
+			}
+		}
+	}
+	m.newSession()
+	return "Session saved. Starting new session.", nil
+}
+
+func (m *Manager) newSession() {
+	m.currentSession = &Session{
+		ID:        GenerateID(),
+		CreatedAt: time.Now().UTC(),
+		Provider:  m.providerName,
+		Model:     m.provider.Model,
+	}
+	m.agent.Clear()
+}
+
+func (m *Manager) CurrentSessionID() string {
+	if m.currentSession == nil {
+		return ""
+	}
+	return m.currentSession.ID
+}
+
+func (m *Manager) CurrentSessionName() string {
+	if m.currentSession == nil {
+		return ""
+	}
+	if m.currentSession.Name != "" {
+		return m.currentSession.Name
+	}
+	return m.currentSession.ID
 }
 
 func (m *Manager) CurrentProvider() string {
@@ -140,3 +290,10 @@ func contains(values []string, value string) bool {
 	}
 	return false
 }
+
+func fitName(name string, width int) string {
+	if len(name) <= width {
+		return name
+	}
+	return name[:width-3] + "..."
+}

internal/session/manager_test.go

@@ -2,6 +2,7 @@ package session
 
 import (
 	"context"
+	"path/filepath"
 	"strings"
 	"testing"
 
@@ -19,8 +20,8 @@ func (p *recordingProvider) ChatStream(ctx context.Context, req llm.ChatRequest,
 	return emit(llm.StreamEvent{Content: "ok"})
 }
 
-func TestManagerSwitchesModelAndThinking(t *testing.T) {
+func testConfig() *config.Config {
-	cfg := &config.Config{
+	return &config.Config{
 		Providers: map[string]config.ProviderConfig{
 			"one": {
 				Name:               "one",
@@ -34,6 +35,11 @@ func TestManagerSwitchesModelAndThinking(t *testing.T) {
 			},
 		},
 	}
+}
+
+func testManager(t *testing.T) (*Manager, *agent.Agent, *recordingProvider) {
+	t.Helper()
+	cfg := testConfig()
 	provider := &recordingProvider{}
 	assistant := agent.New(agent.Options{
 		Provider:        provider,
@@ -43,10 +49,19 @@ func TestManagerSwitchesModelAndThinking(t *testing.T) {
 		ThinkingParam:   "thinking",
 		ThinkingEnabled: true,
 	})
-	manager, err := NewManager(cfg, assistant, nil)
+	store, err := NewStore(filepath.Join(t.TempDir(), "sessions"))
 	if err != nil {
 		t.Fatal(err)
 	}
+	manager, err := NewManager(cfg, assistant, nil, store)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return manager, assistant, provider
+}
+
+func TestManagerSwitchesModelAndThinking(t *testing.T) {
+	manager, assistant, provider := testManager(t)
 
 	if _, err := manager.SetModel("model-b"); err != nil {
 		t.Fatal(err)
@@ -80,7 +95,8 @@ func TestManagerRejectsUnknownModelAndThinking(t *testing.T) {
 		},
 	}
 	assistant := agent.New(agent.Options{Provider: &recordingProvider{}, Model: "model-a"})
-	manager, err := NewManager(cfg, assistant, nil)
+	store, _ := NewStore(filepath.Join(t.TempDir(), "sessions"))
+	manager, err := NewManager(cfg, assistant, nil, store)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -92,3 +108,159 @@ func TestManagerRejectsUnknownModelAndThinking(t *testing.T) {
 		t.Fatal("expected invalid thinking error")
 	}
 }
+
+func TestManagerSaveAndResume(t *testing.T) {
+	manager, assistant, _ := testManager(t)
+
+	// Start new session and have a conversation
+	manager.newSession()
+	var out strings.Builder
+	assistant.RunTurn(context.Background(), "hello world", &out, nil)
+
+	// Save
+	if err := manager.Save(); err != nil {
+		t.Fatalf("save: %v", err)
+	}
+	savedID := manager.CurrentSessionID()
+	if savedID == "" {
+		t.Fatal("expected session ID after save")
+	}
+	// Name should be auto-derived from first user message
+	if manager.CurrentSessionName() != "hello world" {
+		t.Fatalf("session name = %q, want %q", manager.CurrentSessionName(), "hello world")
+	}
+
+	// Start a new session
+	manager.newSession()
+	if manager.CurrentSessionID() == savedID {
+		t.Fatal("new session should have different ID")
+	}
+
+	// Resume
+	if err := manager.Resume(savedID); err != nil {
+		t.Fatalf("resume: %v", err)
+	}
+	if manager.CurrentSessionID() != savedID {
+		t.Fatalf("after resume, ID = %q, want %q", manager.CurrentSessionID(), savedID)
+	}
+	msgs := assistant.Messages()
+	hasUser := false
+	for _, m := range msgs {
+		if m.Role == llm.RoleUser && m.Content == "hello world" {
+			hasUser = true
+		}
+	}
+	if !hasUser {
+		t.Fatal("resumed session should contain original user message")
+	}
+}
+
+func TestManagerRename(t *testing.T) {
+	manager, _, _ := testManager(t)
+	manager.newSession()
+
+	msg, err := manager.Rename("my cool session")
+	if err != nil {
+		t.Fatalf("rename: %v", err)
+	}
+	if !strings.Contains(msg, "my cool session") {
+		t.Fatalf("rename message = %q", msg)
+	}
+	if manager.CurrentSessionName() != "my cool session" {
+		t.Fatalf("name = %q", manager.CurrentSessionName())
+	}
+
+	// Verify persisted
+	_, err = manager.store.Load(manager.CurrentSessionID())
+	if err != nil {
+		t.Fatalf("load after rename: %v", err)
+	}
+}
+
+func TestManagerRenameEmpty(t *testing.T) {
+	manager, _, _ := testManager(t)
+	manager.newSession()
+	_, err := manager.Rename("  ")
+	if err == nil {
+		t.Fatal("expected error for empty name")
+	}
+}
+
+func TestManagerSessions(t *testing.T) {
+	manager, _, _ := testManager(t)
+
+	// No sessions yet
+	out, err := manager.Sessions()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.Contains(out, "No saved sessions") {
+		t.Fatalf("expected 'no saved sessions', got: %s", out)
+	}
+
+	// Create and save a session
+	manager.newSession()
+	manager.Save()
+
+	out, err = manager.Sessions()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if strings.Contains(out, "No saved sessions") {
+		t.Fatal("expected session list")
+	}
+}
+
+func TestManagerNewSession(t *testing.T) {
+	manager, assistant, _ := testManager(t)
+	manager.newSession()
+	var out strings.Builder
+	assistant.RunTurn(context.Background(), "first message", &out, nil)
+
+	msg, err := manager.NewSession()
+	if err != nil {
+		t.Fatalf("new session: %v", err)
+	}
+	if !strings.Contains(msg, "Starting new session") {
+		t.Fatalf("message = %q", msg)
+	}
+	// Old session should be saved
+	metas, _ := manager.store.List()
+	if len(metas) != 1 {
+		t.Fatalf("expected 1 saved session, got %d", len(metas))
+	}
+}
+
+func TestManagerResumeLatest(t *testing.T) {
+	manager, assistant, _ := testManager(t)
+
+	// Create two sessions
+	manager.newSession()
+	var out strings.Builder
+	assistant.RunTurn(context.Background(), "session one", &out, nil)
+	manager.Save()
+	id1 := manager.CurrentSessionID()
+
+	manager.NewSession()
+	assistant.RunTurn(context.Background(), "session two", &out, nil)
+	manager.Save()
+	id2 := manager.CurrentSessionID()
+
+	// Clear and resume latest
+	manager.newSession()
+	if err := manager.ResumeLatest(); err != nil {
+		t.Fatalf("resume latest: %v", err)
+	}
+	// Should resume the most recently updated (id2)
+	if manager.CurrentSessionID() != id2 {
+		t.Fatalf("expected to resume %s, got %s", id2, manager.CurrentSessionID())
+	}
+
+	// Also verify id1 is resumable
+	if err := manager.Resume(id1); err != nil {
+		t.Fatalf("resume id1: %v", err)
+	}
+	if manager.CurrentSessionID() != id1 {
+		t.Fatalf("expected %s, got %s", id1, manager.CurrentSessionID())
+	}
+}

internal/session/store.go

@@ -0,0 +1,173 @@
+package session
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+	"time"
+
+	"agentu/internal/llm"
+)
+
+// Session represents a persisted conversation.
+type Session struct {
+	ID        string        `json:"id"`
+	Name      string        `json:"name"`
+	CreatedAt time.Time     `json:"created_at"`
+	UpdatedAt time.Time     `json:"updated_at"`
+	Provider  string        `json:"provider"`
+	Model     string        `json:"model"`
+	Messages  []llm.Message `json:"messages"`
+}
+
+// SessionMeta is a lightweight summary for listing.
+type SessionMeta struct {
+	ID           string    `json:"id"`
+	Name         string    `json:"name"`
+	CreatedAt    time.Time `json:"created_at"`
+	UpdatedAt    time.Time `json:"updated_at"`
+	Provider     string    `json:"provider"`
+	Model        string    `json:"model"`
+	MessageCount int       `json:"message_count"`
+}
+
+// Store manages session files under a directory.
+type Store struct {
+	dir string
+}
+
+// NewStore creates a store, ensuring the directory exists.
+func NewStore(dir string) (*Store, error) {
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		return nil, fmt.Errorf("create session dir: %w", err)
+	}
+	return &Store{dir: dir}, nil
+}
+
+// Save writes a session to disk.
+func (s *Store) Save(sess *Session) error {
+	if sess.ID == "" {
+		return fmt.Errorf("session ID is required")
+	}
+	sess.UpdatedAt = time.Now().UTC()
+	if sess.CreatedAt.IsZero() {
+		sess.CreatedAt = sess.UpdatedAt
+	}
+	data, err := json.MarshalIndent(sess, "", "  ")
+	if err != nil {
+		return fmt.Errorf("marshal session: %w", err)
+	}
+	path := s.filePath(sess.ID)
+	if err := os.WriteFile(path, data, 0o644); err != nil {
+		return fmt.Errorf("write session: %w", err)
+	}
+	return nil
+}
+
+// Load reads a session by ID.
+func (s *Store) Load(id string) (*Session, error) {
+	path := s.filePath(id)
+	data, err := os.ReadFile(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, fmt.Errorf("session %q not found", id)
+		}
+		return nil, fmt.Errorf("read session: %w", err)
+	}
+	var sess Session
+	if err := json.Unmarshal(data, &sess); err != nil {
+		return nil, fmt.Errorf("parse session: %w", err)
+	}
+	return &sess, nil
+}
+
+// List returns metadata for all sessions, sorted by updated_at descending.
+func (s *Store) List() ([]SessionMeta, error) {
+	entries, err := os.ReadDir(s.dir)
+	if err != nil {
+		return nil, fmt.Errorf("read session dir: %w", err)
+	}
+	var metas []SessionMeta
+	for _, entry := range entries {
+		if entry.IsDir() || !strings.HasSuffix(entry.Name(), ".json") {
+			continue
+		}
+		path := filepath.Join(s.dir, entry.Name())
+		data, err := os.ReadFile(path)
+		if err != nil {
+			continue
+		}
+		var sess Session
+		if err := json.Unmarshal(data, &sess); err != nil {
+			continue
+		}
+		metas = append(metas, SessionMeta{
+			ID:           sess.ID,
+			Name:         sess.Name,
+			CreatedAt:    sess.CreatedAt,
+			UpdatedAt:    sess.UpdatedAt,
+			Provider:     sess.Provider,
+			Model:        sess.Model,
+			MessageCount: len(sess.Messages),
+		})
+	}
+	sort.Slice(metas, func(i, j int) bool {
+		return metas[i].UpdatedAt.After(metas[j].UpdatedAt)
+	})
+	return metas, nil
+}
+
+// Delete removes a session file.
+func (s *Store) Delete(id string) error {
+	path := s.filePath(id)
+	if err := os.Remove(path); err != nil {
+		if os.IsNotExist(err) {
+			return fmt.Errorf("session %q not found", id)
+		}
+		return fmt.Errorf("delete session: %w", err)
+	}
+	return nil
+}
+
+func (s *Store) filePath(id string) string {
+	return filepath.Join(s.dir, id+".json")
+}
+
+// GenerateID creates a random 8-character hex session ID.
+func GenerateID() string {
+	b := make([]byte, 4)
+	_, _ = rand.Read(b)
+	return hex.EncodeToString(b)
+}
+
+// DefaultName derives a session name from the first user message.
+func DefaultName(messages []llm.Message) string {
+	for _, msg := range messages {
+		if msg.Role != llm.RoleUser {
+			continue
+		}
+		text := strings.TrimSpace(msg.Content)
+		if text == "" {
+			continue
+		}
+		// Take first line, truncate at 40 chars at word boundary
+		if idx := strings.IndexByte(text, '\n'); idx >= 0 {
+			text = text[:idx]
+		}
+		text = strings.TrimSpace(text)
+		if len(text) > 40 {
+			text = text[:40]
+			if idx := strings.LastIndexByte(text, ' '); idx > 20 {
+				text = text[:idx]
+			}
+			text += "..."
+		}
+		return text
+	}
+	return ""
+}

internal/session/store_test.go

@@ -0,0 +1,170 @@
+package session
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"agentu/internal/llm"
+)
+
+func tempStore(t *testing.T) *Store {
+	t.Helper()
+	dir := t.TempDir()
+	store, err := NewStore(dir)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return store
+}
+
+func TestSaveAndLoad(t *testing.T) {
+	store := tempStore(t)
+	sess := &Session{
+		ID:       GenerateID(),
+		Name:     "test session",
+		Provider: "loveuer",
+		Model:    "deepseek-v4-flash",
+		Messages: []llm.Message{
+			{Role: llm.RoleSystem, Content: "you are helpful"},
+			{Role: llm.RoleUser, Content: "hello"},
+			{Role: llm.RoleAssistant, Content: "hi there"},
+		},
+	}
+	if err := store.Save(sess); err != nil {
+		t.Fatalf("save: %v", err)
+	}
+
+	loaded, err := store.Load(sess.ID)
+	if err != nil {
+		t.Fatalf("load: %v", err)
+	}
+	if loaded.ID != sess.ID {
+		t.Errorf("ID = %q, want %q", loaded.ID, sess.ID)
+	}
+	if loaded.Name != sess.Name {
+		t.Errorf("Name = %q, want %q", loaded.Name, sess.Name)
+	}
+	if len(loaded.Messages) != 3 {
+		t.Errorf("Messages len = %d, want 3", len(loaded.Messages))
+	}
+	if loaded.Messages[1].Content != "hello" {
+		t.Errorf("Messages[1].Content = %q, want %q", loaded.Messages[1].Content, "hello")
+	}
+	if loaded.UpdatedAt.IsZero() {
+		t.Error("UpdatedAt should be set")
+	}
+}
+
+func TestLoadNotFound(t *testing.T) {
+	store := tempStore(t)
+	_, err := store.Load("nonexistent")
+	if err == nil {
+		t.Fatal("expected error for nonexistent session")
+	}
+}
+
+func TestList(t *testing.T) {
+	store := tempStore(t)
+	// Empty list
+	metas, err := store.List()
+	if err != nil {
+		t.Fatalf("list: %v", err)
+	}
+	if len(metas) != 0 {
+		t.Errorf("expected empty list, got %d", len(metas))
+	}
+
+	// Save two sessions
+	store.Save(&Session{ID: "aaa", Name: "first", Messages: []llm.Message{{Role: "user", Content: "a"}}})
+	store.Save(&Session{ID: "bbb", Name: "second", Messages: []llm.Message{{Role: "user", Content: "b"}, {Role: "assistant", Content: "c"}}})
+
+	metas, err = store.List()
+	if err != nil {
+		t.Fatalf("list: %v", err)
+	}
+	if len(metas) != 2 {
+		t.Fatalf("expected 2 sessions, got %d", len(metas))
+	}
+	// Sorted by updated_at desc
+	if metas[0].ID != "bbb" && metas[0].ID != "aaa" {
+		t.Errorf("unexpected first session ID: %q", metas[0].ID)
+	}
+}
+
+func TestDelete(t *testing.T) {
+	store := tempStore(t)
+	store.Save(&Session{ID: "todelete", Name: "temp"})
+
+	if err := store.Delete("todelete"); err != nil {
+		t.Fatalf("delete: %v", err)
+	}
+	_, err := store.Load("todelete")
+	if err == nil {
+		t.Fatal("expected error after delete")
+	}
+}
+
+func TestDeleteNotFound(t *testing.T) {
+	store := tempStore(t)
+	err := store.Delete("nonexistent")
+	if err == nil {
+		t.Fatal("expected error for nonexistent delete")
+	}
+}
+
+func TestSaveRequiresID(t *testing.T) {
+	store := tempStore(t)
+	err := store.Save(&Session{Name: "no id"})
+	if err == nil {
+		t.Fatal("expected error for empty ID")
+	}
+}
+
+func TestGenerateID(t *testing.T) {
+	id := GenerateID()
+	if len(id) != 8 {
+		t.Errorf("ID length = %d, want 8", len(id))
+	}
+	id2 := GenerateID()
+	if id == id2 {
+		t.Error("expected unique IDs")
+	}
+}
+
+func TestDefaultName(t *testing.T) {
+	tests := []struct {
+		name     string
+		messages []llm.Message
+		want     string
+	}{
+		{"empty", nil, ""},
+		{"no user msg", []llm.Message{{Role: "system", Content: "hi"}}, ""},
+		{"short", []llm.Message{{Role: "user", Content: "hello world"}}, "hello world"},
+		{"long", []llm.Message{{Role: "user", Content: "this is a really long message that should be truncated at some point in the middle"}}, "this is a really long message that..."},
+		{"multiline", []llm.Message{{Role: "user", Content: "first line\nsecond line"}}, "first line"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := DefaultName(tt.messages)
+			if got != tt.want {
+				t.Errorf("DefaultName = %q, want %q", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestNewStoreCreatesDir(t *testing.T) {
+	dir := filepath.Join(t.TempDir(), "nested", "sessions")
+	store, err := NewStore(dir)
+	if err != nil {
+		t.Fatalf("NewStore: %v", err)
+	}
+	info, err := os.Stat(store.dir)
+	if err != nil {
+		t.Fatalf("stat: %v", err)
+	}
+	if !info.IsDir() {
+		t.Error("expected directory")
+	}
+}

internal/tui/app.go

@@ -9,6 +9,7 @@ import (
 	"strings"
 
 	"agentu/internal/agent"
+	"agentu/internal/llm"
 
 	"github.com/charmbracelet/bubbles/spinner"
 	"github.com/charmbracelet/bubbles/textarea"
@@ -33,10 +34,17 @@ type ModelManager interface {
 	CurrentProvider() string
 	CurrentModel() string
 	CurrentThinking() string
+	CurrentSessionID() string
+	CurrentSessionName() string
 	Info() string
 	SetProvider(name string) (string, error)
 	SetModel(model string) (string, error)
 	SetThinking(level string) (string, error)
+	Save() error
+	Resume(id string) error
+	Rename(name string) (string, error)
+	Sessions() (string, error)
+	NewSession() (string, error)
 }
 
 func Run(ctx context.Context, assistant *agent.Agent, opts Options) error {
@@ -81,6 +89,18 @@ type model struct {
 	running  bool
 	cancel   context.CancelFunc
 	events   <-chan tea.Msg
+
+	// Session picker state
+	picking      bool
+	pickerItems  []pickerItem
+	pickerCursor int
+}
+
+type pickerItem struct {
+	id        string
+	name      string
+	detail    string
+	isCurrent bool
 }
 
 type assistantChunkMsg string
@@ -90,6 +110,8 @@ type turnDoneMsg struct {
 	err error
 }
 
+var errOpenPicker = fmt.Errorf("open picker")
+
 type slashCommand struct {
 	Name        string
 	Description string
@@ -100,6 +122,10 @@ var slashCommands = []slashCommand{
 	{Name: "/exit", Description: "quit"},
 	{Name: "/quit", Description: "quit"},
 	{Name: "/model", Description: "model/provider/thinking"},
+	{Name: "/sessions", Description: "list sessions"},
+	{Name: "/resume", Description: "resume session"},
+	{Name: "/rename", Description: "rename session"},
+	{Name: "/new", Description: "new session"},
 }
 
 func newModel(ctx context.Context, assistant *agent.Agent, opts Options) model {
@@ -144,9 +170,35 @@ func newModel(ctx context.Context, assistant *agent.Agent, opts Options) model {
 }
 
 func (m model) Init() tea.Cmd {
+	m.syncMessages()
 	return textarea.Blink
 }
 
+// syncMessages rebuilds the TUI display messages from the agent's conversation history.
+func (m *model) syncMessages() {
+	if m.agent == nil {
+		return
+	}
+	msgs := m.agent.Messages()
+	m.messages = m.messages[:0]
+	for _, msg := range msgs {
+		switch msg.Role {
+		case llm.RoleUser:
+			m.messages = append(m.messages, message{role: roleUser, content: msg.Content})
+		case llm.RoleAssistant:
+			if msg.Content != "" {
+				m.messages = append(m.messages, message{role: roleAssistant, content: msg.Content})
+			}
+		case llm.RoleTool:
+			text := cleanToolLog(msg.Content)
+			if text != "" {
+				m.messages = append(m.messages, message{role: roleTool, content: text})
+			}
+		}
+	}
+	m.refreshViewport(true)
+}
+
 func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 	var cmds []tea.Cmd
 
@@ -167,6 +219,9 @@ func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		return m, cmd
 
 	case tea.KeyMsg:
+		if m.picking {
+			return m.updatePicker(msg)
+		}
 		switch msg.String() {
 		case "ctrl+c":
 			if m.cancel != nil {
@@ -213,6 +268,10 @@ func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		} else {
 			m.status = "ready"
 		}
+		// Auto-save session after turn completes
+		if m.models != nil {
+			_ = m.models.Save()
+		}
 		m.resize()
 		m.refreshViewport(true)
 		cmds = append(cmds, textarea.Blink)
@@ -252,7 +311,14 @@ func (m model) View() string {
 		return "agentu"
 	}
 
-	parts := []string{m.headerView(), m.viewport.View()}
+	if m.picking {
+		parts := []string{m.viewport.View()}
+		parts = append(parts, m.pickerView(), m.modelMetaView(), m.footerView())
+		body := lipgloss.JoinVertical(lipgloss.Left, parts...)
+		return m.styles.App.Width(m.width).Height(m.height).Render(body)
+	}
+
+	parts := []string{m.viewport.View()}
 	if activity := m.activityView(); activity != "" {
 		parts = append(parts, activity)
 	}
@@ -354,11 +420,10 @@ func (m *model) appendAssistantChunk(chunk string) {
 
 func (m *model) resize() {
 	width := max(40, m.width)
-	inputWidth := max(20, width-4)
+	inputWidth := max(20, width-m.styles.InputBox.GetHorizontalFrameSize())
 	m.input.SetWidth(inputWidth)
 	m.syncInputHeight()
 
-	headerHeight := 1
 	activityHeight := 0
 	if m.running {
 		activityHeight = 1
@@ -366,7 +431,7 @@ func (m *model) resize() {
 	inputHeight := m.inputBlockHeight()
 	footerHeight := 2
 	m.viewport.Width = width
-	m.viewport.Height = max(4, m.height-headerHeight-activityHeight-inputHeight-footerHeight)
+	m.viewport.Height = max(4, m.height-activityHeight-inputHeight-footerHeight)
 	m.viewport.Style = m.styles.Viewport
 }
 
@@ -379,7 +444,7 @@ func (m *model) refreshViewport(bottom bool) {
 
 func (m model) renderMessages() string {
 	width := max(40, m.width)
-	contentWidth := max(20, width-6)
+	contentWidth := width
 	parts := make([]string, 0, len(m.messages))
 	for _, msg := range m.messages {
 		content := strings.TrimRight(msg.content, "\n")
@@ -397,12 +462,11 @@ func (m model) renderMessages() string {
 func (m model) messageView(r role, content string, width int) string {
 	label := roleLabel(r)
 	style := m.styles.AssistantMsg
-	labelStyle := m.styles.AssistantLabel
+	labelStyle := m.styles.SystemLabel
 
 	switch r {
 	case roleUser:
 		style = m.styles.UserMessage
-		labelStyle = m.styles.UserLabel
 	case roleTool:
 		style = m.styles.ToolMessage
 		labelStyle = m.styles.ToolLabel
@@ -420,17 +484,33 @@ func (m model) messageView(r role, content string, width int) string {
 		bodyContent = renderMarkdown(content, bodyWidth, m.theme)
 	}
 
+	bodyWidth := messageBodyWidth(bodyContent, width, style)
+	if r == roleUser {
+		bodyWidth = width
+	}
+	body := style.Width(bodyWidth).Render(bodyContent)
+	if label == "" {
+		return body
+	}
 	labelLine := labelStyle.Render(label)
-	body := style.Width(width).Render(bodyContent)
 	return lipgloss.JoinVertical(lipgloss.Left, labelLine, body)
 }
 
+func messageBodyWidth(content string, maxWidth int, style lipgloss.Style) int {
+	maxWidth = max(1, maxWidth)
+	contentWidth := 1
+	for _, line := range strings.Split(content, "\n") {
+		contentWidth = max(contentWidth, lipgloss.Width(line))
+	}
+	return min(maxWidth, contentWidth+style.GetHorizontalFrameSize())
+}
+
 func roleLabel(r role) string {
 	switch r {
 	case roleUser:
-		return "You"
+		return ""
 	case roleAssistant:
-		return "Agentu"
+		return ""
 	case roleTool:
 		return "Tool"
 	case roleError:
@@ -442,13 +522,6 @@ func roleLabel(r role) string {
 	}
 }
 
-func (m model) headerView() string {
-	title := m.styles.Title.Render("agentu")
-	meta := m.styles.Muted.Render("local agent")
-	line := lipgloss.JoinHorizontal(lipgloss.Center, title, "  ", meta)
-	return m.styles.Header.Width(max(1, m.width)).Render(line)
-}
-
 func (m model) modelMetaView() string {
 	mode := "read-only tools"
 	if m.yolo {
@@ -457,6 +530,9 @@ func (m model) modelMetaView() string {
 	modelName := m.modelName
 	parts := []string{}
 	if m.models != nil {
+		if sessionName := m.models.CurrentSessionName(); sessionName != "" {
+			parts = append(parts, "session "+sessionName)
+		}
 		if provider := m.models.CurrentProvider(); provider != "" {
 			parts = append(parts, "provider "+provider)
 		}
@@ -571,11 +647,25 @@ func (m model) desiredInputHeight() int {
 func (m model) inputBlockHeight() int {
 	height := m.input.Height() + m.styles.InputBox.GetVerticalFrameSize()
 	if m.showSlashSuggestions() {
-		height++
+		height += m.slashSuggestionCount()
 	}
 	return height
 }
 
+func (m model) slashSuggestionCount() int {
+	prefix := strings.TrimSpace(m.input.Value())
+	count := 0
+	for _, command := range slashCommands {
+		if strings.HasPrefix(command.Name, prefix) {
+			count++
+		}
+	}
+	if count == 0 {
+		count = 1 // "No matching commands"
+	}
+	return count
+}
+
 func (m model) showSlashSuggestions() bool {
 	value := strings.TrimSpace(m.input.Value())
 	return strings.HasPrefix(value, "/") && !strings.Contains(value, " ")
@@ -596,7 +686,7 @@ func (m model) slashSuggestionsView() string {
 	if len(parts) == 0 {
 		parts = append(parts, "No matching commands")
 	}
-	return m.styles.CommandHint.Width(max(20, m.width-2)).Render(strings.Join(parts, "  "))
+	return m.styles.CommandHint.Width(max(20, m.width-2)).Render(strings.Join(parts, "\n"))
 }
 
 func (m model) modelInfo() string {
@@ -635,6 +725,10 @@ func fitLine(text string, width int) string {
 
 func (m *model) runLocalCommand(input string) (tea.Model, tea.Cmd) {
 	output, err := m.handleLocalCommand(input)
+	if err == errOpenPicker {
+		m.openSessionPicker()
+		return *m, nil
+	}
 	role := roleSystem
 	status := "command"
 	if err != nil {
@@ -642,10 +736,13 @@ func (m *model) runLocalCommand(input string) (tea.Model, tea.Cmd) {
 		role = roleError
 		status = "command error"
 	}
-	m.messages = append(m.messages, message{role: role, content: output})
 	m.input.SetValue("")
 	m.afterInputChanged()
 	m.status = status
+	// Rebuild display from agent history (matters after /resume and /new)
+	m.syncMessages()
+	// Append command output after synced history
+	m.messages = append(m.messages, message{role: role, content: output})
 	m.refreshViewport(true)
 	return *m, nil
 }
@@ -658,6 +755,14 @@ func (m model) handleLocalCommand(input string) (string, error) {
 	switch fields[0] {
 	case "/model":
 		return m.handleModelCommand(fields[1:])
+	case "/sessions":
+		return m.handleSessionsCommand()
+	case "/resume":
+		return m.handleResumeCommand(fields[1:])
+	case "/rename":
+		return m.handleRenameCommand(fields[1:])
+	case "/new":
+		return m.handleNewCommand()
 	default:
 		return "", fmt.Errorf("unknown command: %s", fields[0])
 	}
@@ -697,4 +802,150 @@ func (m model) handleModelCommand(args []string) (string, error) {
 	}
 }
 
+func (m model) handleSessionsCommand() (string, error) {
+	if m.models == nil {
+		return "", fmt.Errorf("session management is not configured")
+	}
+	return m.models.Sessions()
+}
+
+func (m model) handleResumeCommand(args []string) (string, error) {
+	if m.models == nil {
+		return "", fmt.Errorf("session management is not configured")
+	}
+	if len(args) > 0 {
+		id := strings.TrimSpace(args[0])
+		if err := m.models.Resume(id); err != nil {
+			return "", err
+		}
+		return fmt.Sprintf("Resumed session %q.", m.models.CurrentSessionName()), nil
+	}
+	// No args — open interactive picker (handled in runLocalCommand)
+	return "", errOpenPicker
+}
+
+func (m model) handleRenameCommand(args []string) (string, error) {
+	if m.models == nil {
+		return "", fmt.Errorf("session management is not configured")
+	}
+	if len(args) == 0 {
+		return "", fmt.Errorf("usage: /rename <name>")
+	}
+	name := strings.Join(args, " ")
+	return m.models.Rename(name)
+}
+
+func (m model) handleNewCommand() (string, error) {
+	if m.models == nil {
+		return "", fmt.Errorf("session management is not configured")
+	}
+	return m.models.NewSession()
+}
+
+func (m *model) openSessionPicker() {
+	if m.models == nil {
+		return
+	}
+	output, err := m.models.Sessions()
+	if err != nil {
+		m.messages = append(m.messages, message{role: roleError, content: err.Error()})
+		return
+	}
+	// Parse session list into picker items
+	m.pickerItems = m.pickerItems[:0]
+	m.pickerCursor = 0
+	for _, line := range strings.Split(output, "\n") {
+		line = strings.TrimSpace(line)
+		if line == "" || line == "Sessions:" || strings.HasPrefix(line, "No saved") {
+			continue
+		}
+		// Format: "  id  name  date  msgs (current)"
+		fields := strings.Fields(line)
+		if len(fields) < 2 {
+			continue
+		}
+		id := fields[0]
+		isCurrent := strings.Contains(line, "(current)")
+		// Reconstruct display
+		m.pickerItems = append(m.pickerItems, pickerItem{
+			id:        id,
+			name:      line,
+			isCurrent: isCurrent,
+		})
+	}
+	if len(m.pickerItems) == 0 {
+		m.messages = append(m.messages, message{role: roleSystem, content: "No saved sessions."})
+		m.refreshViewport(true)
+		return
+	}
+	// Skip current session in picker, pre-select next one
+	for i, item := range m.pickerItems {
+		if !item.isCurrent {
+			m.pickerCursor = i
+			break
+		}
+	}
+	m.picking = true
+	m.input.SetValue("")
+	m.input.Blur()
+	m.refreshViewport(true)
+}
+
+func (m *model) updatePicker(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
+	switch msg.String() {
+	case "ctrl+c", "esc":
+		m.picking = false
+		m.input.Focus()
+		return *m, textarea.Blink
+	case "up", "k":
+		if m.pickerCursor > 0 {
+			m.pickerCursor--
+		}
+		return *m, nil
+	case "down", "j":
+		if m.pickerCursor < len(m.pickerItems)-1 {
+			m.pickerCursor++
+		}
+		return *m, nil
+	case "enter":
+		if m.pickerCursor >= 0 && m.pickerCursor < len(m.pickerItems) {
+			item := m.pickerItems[m.pickerCursor]
+			m.picking = false
+			m.input.Focus()
+			if err := m.models.Resume(item.id); err != nil {
+				m.messages = append(m.messages, message{role: roleError, content: err.Error()})
+			} else {
+				m.syncMessages()
+				m.messages = append(m.messages, message{role: roleSystem, content: fmt.Sprintf("Resumed session %q.", m.models.CurrentSessionName())})
+			}
+			m.refreshViewport(true)
+		}
+		return *m, textarea.Blink
+	}
+	return *m, nil
+}
+
+func (m model) pickerView() string {
+	if !m.picking || len(m.pickerItems) == 0 {
+		return ""
+	}
+	width := max(40, m.width-4)
+	var b strings.Builder
+	b.WriteString(m.styles.Muted.Render("Select a session (↑/↓ navigate, enter select, esc cancel)"))
+	b.WriteString("\n\n")
+	for i, item := range m.pickerItems {
+		line := item.name
+		if item.isCurrent {
+			line += " (current)"
+		}
+		if i == m.pickerCursor {
+			b.WriteString(m.styles.UserLabel.Render("▸ " + line))
+		} else {
+			b.WriteString(m.styles.Muted.Render("  " + line))
+		}
+		b.WriteString("\n")
+	}
+	return m.styles.InputBox.Width(width).Render(b.String())
+}
+
 var _ io.Writer = eventWriter{}

internal/tui/app_test.go

@@ -6,18 +6,65 @@ import (
 	"testing"
 
 	tea "github.com/charmbracelet/bubbletea"
+	"github.com/charmbracelet/lipgloss"
 )
 
 func TestModelRendersChatShell(t *testing.T) {
 	m := newModel(context.Background(), nil, Options{ModelName: "test-model", Yolo: true})
 	next, _ := m.Update(tea.WindowSizeMsg{Width: 100, Height: 30})
-	rendered := next.(model).View()
+	m = next.(model)
+	rendered := m.View()
 
-	for _, want := range []string{"agentu", "test-model", "yolo tools", "light", "ctrl+j", "alt+enter"} {
+	for _, want := range []string{"test-model", "yolo tools", "light", "ctrl+j", "alt+enter"} {
 		if !strings.Contains(rendered, want) {
 			t.Fatalf("rendered view missing %q:\n%s", want, rendered)
 		}
 	}
+	if strings.Contains(rendered, "local agent") {
+		t.Fatalf("top header should not render:\n%s", rendered)
+	}
+	if _, ok := m.styles.App.GetBackground().(lipgloss.NoColor); !ok {
+		t.Fatalf("app should not paint a global background")
+	}
+	if _, ok := m.styles.Viewport.GetBackground().(lipgloss.NoColor); !ok {
+		t.Fatalf("viewport should not paint an assistant background")
+	}
+}
+
+func TestInputTextDoesNotPaintBackground(t *testing.T) {
+	m := newModel(context.Background(), nil, Options{ModelName: "test-model"})
+	for name, color := range map[string]any{
+		"input box":           m.styles.InputBox.GetBackground(),
+		"focused base":        m.input.FocusedStyle.Base.GetBackground(),
+		"focused cursor line": m.input.FocusedStyle.CursorLine.GetBackground(),
+		"blurred base":        m.input.BlurredStyle.Base.GetBackground(),
+		"blurred cursor line": m.input.BlurredStyle.CursorLine.GetBackground(),
+	} {
+		if _, ok := color.(lipgloss.NoColor); !ok {
+			t.Fatalf("%s should not paint input text background", name)
+		}
+	}
+}
+
+func TestInputBoxIsRoomier(t *testing.T) {
+	m := newModel(context.Background(), nil, Options{ModelName: "test-model"})
+	next, _ := m.Update(tea.WindowSizeMsg{Width: 100, Height: 30})
+	m = next.(model)
+
+	if got := m.styles.InputBox.GetVerticalFrameSize(); got != 2 {
+		t.Fatalf("input box vertical frame should stay compact, got %d", got)
+	}
+	if got := m.styles.InputBox.GetHorizontalFrameSize(); got < 6 {
+		t.Fatalf("input box horizontal frame should include roomier padding, got %d", got)
+	}
+	if got, want := m.input.Width(), 100-m.styles.InputBox.GetHorizontalFrameSize(); got != want {
+		t.Fatalf("input content width = %d, want %d", got, want)
+	}
+	rendered := m.inputView()
+	line := strings.Split(rendered, "\n")[0]
+	if got := lipgloss.Width(line); got != 100 {
+		t.Fatalf("input box rendered width = %d, want 100:\n%s", got, rendered)
+	}
 }
 
 func TestModelMetaRendersBelowInput(t *testing.T) {
@@ -63,36 +110,87 @@ func TestRunningStateRendersActivityIndicator(t *testing.T) {
 	}
 }
 
-func TestUserMessageRendersOnLeft(t *testing.T) {
+func TestUserMessageRendersFullWidthBubble(t *testing.T) {
 	m := newModel(context.Background(), nil, Options{ModelName: "test-model"})
 	next, _ := m.Update(tea.WindowSizeMsg{Width: 100, Height: 30})
 	m = next.(model)
 
-	rendered := m.messageView(roleUser, "hello", 80)
+	rendered := m.messageView(roleUser, "hi", 80)
-	if strings.HasPrefix(rendered, " ") {
+	if !strings.Contains(rendered, "hi") {
-		t.Fatalf("user message should not be right-aligned:\n%q", rendered)
-	}
-	if !strings.Contains(rendered, "You") || !strings.Contains(rendered, "hello") {
 		t.Fatalf("user message missing content:\n%s", rendered)
 	}
+	if strings.Contains(rendered, "You") {
+		t.Fatalf("user message should not render label:\n%s", rendered)
+	}
+	if !strings.Contains(rendered, " hi") || !strings.Contains(rendered, "hi ") {
+		t.Fatalf("user message should have horizontal padding:\n%q", rendered)
+	}
+	lines := strings.Split(rendered, "\n")
+	if len(lines) < 3 {
+		t.Fatalf("user message background should include vertical padding:\n%q", rendered)
+	}
+	for _, line := range lines {
+		if got := lipgloss.Width(line); got != 80 {
+			t.Fatalf("user message background should span full width, line width = %d:\n%q", got, rendered)
+		}
+	}
+	m.width = 80
+	m.messages = []message{{role: roleUser, content: "hi"}}
+	rendered = m.renderMessages()
+	for _, line := range strings.Split(rendered, "\n") {
+		if got := lipgloss.Width(line); got != 80 {
+			t.Fatalf("rendered user transcript should span full width, line width = %d:\n%q", got, rendered)
+		}
+	}
 }
 
-func TestAssistantMessagesRenderMarkdown(t *testing.T) {
+func TestAssistantMessagesRenderMarkdownWithoutChrome(t *testing.T) {
 	m := newModel(context.Background(), nil, Options{ModelName: "test-model"})
 	next, _ := m.Update(tea.WindowSizeMsg{Width: 100, Height: 30})
 	m = next.(model)
 
 	rendered := m.messageView(roleAssistant, "# Title\n\n- item", 80)
-	for _, want := range []string{"Agentu", "Title", "item"} {
+	for _, want := range []string{"Title", "item"} {
 		if !strings.Contains(rendered, want) {
 			t.Fatalf("assistant markdown missing %q:\n%s", want, rendered)
 		}
 	}
+	for _, unwanted := range []string{"Agentu", "│", "┃", "|"} {
+		if strings.Contains(rendered, unwanted) {
+			t.Fatalf("assistant message should not render chrome %q:\n%s", unwanted, rendered)
+		}
+	}
 	if strings.Contains(rendered, "# Title") {
 		t.Fatalf("assistant markdown heading was not rendered:\n%s", rendered)
 	}
 }
 
+func TestAssistantMessageRendersPaddedBodyWithoutBackground(t *testing.T) {
+	m := newModel(context.Background(), nil, Options{ModelName: "test-model"})
+	next, _ := m.Update(tea.WindowSizeMsg{Width: 100, Height: 30})
+	m = next.(model)
+	if _, ok := m.styles.AssistantMsg.GetBackground().(lipgloss.NoColor); !ok {
+		t.Fatalf("assistant message should not set a background color")
+	}
+
+	rendered := m.messageView(roleAssistant, "hello", 80)
+	if !strings.Contains(rendered, "hello") {
+		t.Fatalf("assistant message missing content:\n%s", rendered)
+	}
+	lines := strings.Split(rendered, "\n")
+	if len(lines) < 3 {
+		t.Fatalf("assistant message should include vertical padding:\n%q", rendered)
+	}
+	if got := lipgloss.Width(rendered); got <= len("hello") {
+		t.Fatalf("assistant message should be wider than text, width = %d:\n%q", got, rendered)
+	}
+	for _, line := range lines {
+		if got := lipgloss.Width(line); got >= 80 {
+			t.Fatalf("assistant message should not fill the row, line width = %d:\n%q", got, rendered)
+		}
+	}
+}
+
 func TestUserMessagesDoNotRenderMarkdown(t *testing.T) {
 	m := newModel(context.Background(), nil, Options{ModelName: "test-model"})
 	next, _ := m.Update(tea.WindowSizeMsg{Width: 100, Height: 30})
@@ -106,7 +204,7 @@ func TestUserMessagesDoNotRenderMarkdown(t *testing.T) {
 	}
 }
 
-func TestMessageRoleLabels(t *testing.T) {
+func TestMessageRoleLabelsDoNotLabelUserOrAssistant(t *testing.T) {
 	m := newModel(context.Background(), nil, Options{ModelName: "test-model"})
 	next, _ := m.Update(tea.WindowSizeMsg{Width: 100, Height: 30})
 	m = next.(model)
@@ -116,9 +214,14 @@ func TestMessageRoleLabels(t *testing.T) {
 	}
 
 	rendered := m.renderMessages()
-	for _, want := range []string{"You", "Agentu"} {
+	for _, want := range []string{"hello", "hi"} {
 		if !strings.Contains(rendered, want) {
-			t.Fatalf("messages missing %q:\n%s", want, rendered)
+			t.Fatalf("messages missing content %q:\n%s", want, rendered)
+		}
+	}
+	for _, unwanted := range []string{"You", "Agentu"} {
+		if strings.Contains(rendered, unwanted) {
+			t.Fatalf("message should not render label %q:\n%s", unwanted, rendered)
 		}
 	}
 }
@@ -197,9 +300,11 @@ func TestModelThinkingCommand(t *testing.T) {
 }
 
 type fakeModelManager struct {
-	provider string
+	provider    string
-	model    string
+	model       string
-	thinking string
+	thinking    string
+	sessionName string
+	saved       bool
 }
 
 func (f *fakeModelManager) CurrentProvider() string {
@@ -217,6 +322,17 @@ func (f *fakeModelManager) CurrentThinking() string {
 	return f.thinking
 }
 
+func (f *fakeModelManager) CurrentSessionID() string {
+	return "test-id"
+}
+
+func (f *fakeModelManager) CurrentSessionName() string {
+	if f.sessionName == "" {
+		return "test-session"
+	}
+	return f.sessionName
+}
+
 func (f *fakeModelManager) Info() string {
 	return "provider: " + f.CurrentProvider() + "\nmodel: " + f.model + "\nthinking: " + f.thinking
 }
@@ -236,6 +352,28 @@ func (f *fakeModelManager) SetThinking(level string) (string, error) {
 	return f.Info(), nil
 }
 
+func (f *fakeModelManager) Save() error {
+	f.saved = true
+	return nil
+}
+
+func (f *fakeModelManager) Resume(id string) error {
+	return nil
+}
+
+func (f *fakeModelManager) Rename(name string) (string, error) {
+	f.sessionName = name
+	return "Renamed.", nil
+}
+
+func (f *fakeModelManager) Sessions() (string, error) {
+	return "No sessions.", nil
+}
+
+func (f *fakeModelManager) NewSession() (string, error) {
+	return "New session.", nil
+}
+
 func TestParseThemeMode(t *testing.T) {
 	for input, want := range map[string]ThemeMode{
 		"":      ThemeLight,

internal/tui/markdown.go

@@ -2,6 +2,8 @@ package tui
 
 import (
 	"strings"
+	"unicode"
+	"unicode/utf8"
 
 	"github.com/charmbracelet/glamour"
 	"github.com/charmbracelet/glamour/ansi"
@@ -24,7 +26,7 @@ func renderMarkdown(content string, width int, th theme) string {
 	if err != nil {
 		return content
 	}
-	return strings.TrimRight(rendered, "\n")
+	return trimRenderedMarkdown(rendered)
 }
 
 func markdownStyle(th theme) ansi.StyleConfig {
@@ -32,6 +34,7 @@ func markdownStyle(th theme) ansi.StyleConfig {
 	if th.Mode == ThemeDark {
 		cfg = glamstyles.DarkStyleConfig
 	}
+	clearMarkdownBackgrounds(&cfg)
 
 	zero := uint(0)
 	cfg.Document.Margin = &zero
@@ -51,7 +54,7 @@ func markdownStyle(th theme) ansi.StyleConfig {
 	cfg.LinkText.Color = stringPtr(th.User)
 
 	cfg.Code.Color = stringPtr(th.Tool)
-	cfg.Code.BackgroundColor = stringPtr(th.SurfaceAlt)
+	cfg.Code.BackgroundColor = nil
 	cfg.CodeBlock.Color = stringPtr(th.Text)
 	cfg.CodeBlock.BackgroundColor = nil
 	cfg.CodeBlock.Margin = &zero
@@ -59,6 +62,93 @@ func markdownStyle(th theme) ansi.StyleConfig {
 	return cfg
 }
 
+func clearMarkdownBackgrounds(cfg *ansi.StyleConfig) {
+	cfg.Document.BackgroundColor = nil
+	cfg.BlockQuote.BackgroundColor = nil
+	cfg.Paragraph.BackgroundColor = nil
+	cfg.Heading.BackgroundColor = nil
+	cfg.H1.BackgroundColor = nil
+	cfg.H2.BackgroundColor = nil
+	cfg.H3.BackgroundColor = nil
+	cfg.H4.BackgroundColor = nil
+	cfg.H5.BackgroundColor = nil
+	cfg.H6.BackgroundColor = nil
+	cfg.Text.BackgroundColor = nil
+	cfg.Strikethrough.BackgroundColor = nil
+	cfg.Emph.BackgroundColor = nil
+	cfg.Strong.BackgroundColor = nil
+	cfg.HorizontalRule.BackgroundColor = nil
+	cfg.Item.BackgroundColor = nil
+	cfg.Enumeration.BackgroundColor = nil
+	cfg.Task.BackgroundColor = nil
+	cfg.Link.BackgroundColor = nil
+	cfg.LinkText.BackgroundColor = nil
+	cfg.Image.BackgroundColor = nil
+	cfg.ImageText.BackgroundColor = nil
+	cfg.Code.BackgroundColor = nil
+	cfg.CodeBlock.BackgroundColor = nil
+	cfg.Table.BackgroundColor = nil
+	cfg.DefinitionList.BackgroundColor = nil
+	cfg.DefinitionTerm.BackgroundColor = nil
+	cfg.DefinitionDescription.BackgroundColor = nil
+	cfg.HTMLBlock.BackgroundColor = nil
+	cfg.HTMLSpan.BackgroundColor = nil
+}
+
+func trimRenderedMarkdown(value string) string {
+	lines := strings.Split(strings.TrimRight(value, "\n"), "\n")
+	for i, line := range lines {
+		lines[i] = trimStyledTrailingSpaces(line)
+	}
+	return strings.Join(lines, "\n")
+}
+
+func trimStyledTrailingSpaces(line string) string {
+	cut := 0
+	seenNonSpace := false
+	seenWhitespaceAfterLastNonSpace := false
+	for i := 0; i < len(line); {
+		if end, ok := ansiSequenceEnd(line, i); ok {
+			if seenNonSpace && !seenWhitespaceAfterLastNonSpace {
+				cut = end
+			}
+			i = end
+			continue
+		}
+
+		r, size := utf8.DecodeRuneInString(line[i:])
+		if r == utf8.RuneError && size == 0 {
+			break
+		}
+		end := i + size
+		if unicode.IsSpace(r) {
+			if seenNonSpace {
+				seenWhitespaceAfterLastNonSpace = true
+			}
+		} else {
+			seenNonSpace = true
+			seenWhitespaceAfterLastNonSpace = false
+			cut = end
+		}
+		i = end
+	}
+	if cut == 0 {
+		return ""
+	}
+	return line[:cut]
+}
+
+func ansiSequenceEnd(value string, start int) (int, bool) {
+	if start+2 >= len(value) || value[start] != '\x1b' || value[start+1] != '[' {
+		return 0, false
+	}
+	for i := start + 2; i < len(value); i++ {
+		if value[i] >= 0x40 && value[i] <= 0x7e {
+			return i + 1, true
+		}
+	}
+	return 0, false
+}
 func stringPtr(value string) *string {
 	return &value
 }

internal/tui/markdown_test.go

@@ -37,6 +37,26 @@ func TestRenderMarkdownSupportsThemesAndNarrowWidth(t *testing.T) {
 	}
 }
 
+func TestRenderMarkdownDoesNotEmitBackgroundColors(t *testing.T) {
+	content := "# Title\n\n`inline`\n\n```go\nfmt.Println(\"x\")\n```"
+	for _, mode := range []ThemeMode{ThemeLight, ThemeDark} {
+		rendered := renderMarkdown(content, 80, themeForMode(mode))
+		if backgroundPattern.MatchString(rendered) {
+			t.Fatalf("markdown output for %s should not emit background colors:\n%q", mode, rendered)
+		}
+	}
+}
+
+func TestRenderMarkdownTrimsGlamourTrailingSpaces(t *testing.T) {
+	rendered := renderMarkdown("hello", 80, themeForMode(ThemeLight))
+	plain := stripANSI(rendered)
+	if plain != "hello" {
+		t.Fatalf("markdown should not pad a plain assistant line:\n%q", plain)
+	}
+}
+
+var backgroundPattern = regexp.MustCompile(`\x1b\[[0-9;:]*48[;:][0-9;:]*m`)
+
 var ansiPattern = regexp.MustCompile(`\x1b\[[0-9;:]*[A-Za-z]`)
 
 func stripANSI(value string) string {

internal/tui/theme.go

@@ -45,26 +45,23 @@ type theme struct {
 }
 
 type styles struct {
-	App            lipgloss.Style
+	App           lipgloss.Style
-	Header         lipgloss.Style
+	Muted         lipgloss.Style
-	Title          lipgloss.Style
+	Activity      lipgloss.Style
-	Muted          lipgloss.Style
+	ModelMeta     lipgloss.Style
-	Activity       lipgloss.Style
+	Footer        lipgloss.Style
-	ModelMeta      lipgloss.Style
+	Viewport      lipgloss.Style
-	Footer         lipgloss.Style
+	InputBox      lipgloss.Style
-	Viewport       lipgloss.Style
+	CommandHint   lipgloss.Style
-	InputBox       lipgloss.Style
+	UserLabel     lipgloss.Style
-	CommandHint    lipgloss.Style
+	ToolLabel     lipgloss.Style
-	UserLabel      lipgloss.Style
+	ErrorLabel    lipgloss.Style
-	AssistantLabel lipgloss.Style
+	SystemLabel   lipgloss.Style
-	ToolLabel      lipgloss.Style
+	UserMessage   lipgloss.Style
-	ErrorLabel     lipgloss.Style
+	AssistantMsg  lipgloss.Style
-	SystemLabel    lipgloss.Style
+	ToolMessage   lipgloss.Style
-	UserMessage    lipgloss.Style
+	ErrorMessage  lipgloss.Style
-	AssistantMsg   lipgloss.Style
+	SystemMessage lipgloss.Style
-	ToolMessage    lipgloss.Style
-	ErrorMessage   lipgloss.Style
-	SystemMessage  lipgloss.Style
 }
 
 func themeForMode(mode ThemeMode) theme {
@@ -113,17 +110,7 @@ func darkTheme() theme {
 func (t theme) styles() styles {
 	return styles{
 		App: lipgloss.NewStyle().
-			Foreground(lipgloss.Color(t.Text)).
+			Foreground(lipgloss.Color(t.Text)),
-			Background(lipgloss.Color(t.Background)),
-
-		Header: lipgloss.NewStyle().
-			Foreground(lipgloss.Color(t.Text)).
-			Background(lipgloss.Color(t.SurfaceAlt)).
-			Padding(0, 1),
-
-		Title: lipgloss.NewStyle().
-			Bold(true).
-			Foreground(lipgloss.Color(t.Title)),
 
 		Muted: lipgloss.NewStyle().
 			Foreground(lipgloss.Color(t.Muted)),
@@ -141,36 +128,32 @@ func (t theme) styles() styles {
 
 		Footer: lipgloss.NewStyle().
 			Foreground(lipgloss.Color(t.Muted)).
-			Background(lipgloss.Color(t.Background)).
 			Padding(0, 1),
 
 		Viewport: lipgloss.NewStyle().
-			Foreground(lipgloss.Color(t.Text)).
+			Foreground(lipgloss.Color(t.Text)),
-			Background(lipgloss.Color(t.Background)),
 
 		InputBox: lipgloss.NewStyle().
 			Foreground(lipgloss.Color(t.Text)).
-			Background(lipgloss.Color(t.Surface)).
+			Border(lipgloss.ThickBorder()).
-			Border(lipgloss.NormalBorder()).
 			BorderForeground(lipgloss.Color(t.Border)).
-			Padding(0, 1),
+			Padding(0, 2),
 
 		CommandHint: lipgloss.NewStyle().
 			Foreground(lipgloss.Color(t.Muted)).
 			Background(lipgloss.Color(t.SurfaceAlt)).
 			Padding(0, 1),
 
-		UserLabel:      labelStyle(t.User),
+		UserLabel:   labelStyle(t.User),
-		AssistantLabel: labelStyle(t.Assistant),
+		ToolLabel:   labelStyle(t.Tool),
-		ToolLabel:      labelStyle(t.Tool),
+		ErrorLabel:  labelStyle(t.Error),
-		ErrorLabel:     labelStyle(t.Error),
+		SystemLabel: labelStyle(t.System),
-		SystemLabel:    labelStyle(t.System),
 
-		UserMessage:   messageStyle(t.Text, t.User),
+		UserMessage:   bubbleMessageStyle(t.Text, t.SurfaceAlt),
-		AssistantMsg:  messageStyle(t.Text, t.Assistant),
+		AssistantMsg:  assistantMessageStyle(t.Text),
-		ToolMessage:   messageStyle(t.Text, t.Tool),
+		ToolMessage:   messageStyle(t.Text),
-		ErrorMessage:  messageStyle(t.Error, t.Error),
+		ErrorMessage:  messageStyle(t.Error),
-		SystemMessage: lipgloss.NewStyle().Foreground(lipgloss.Color(t.System)).PaddingLeft(1),
+		SystemMessage: lipgloss.NewStyle().Foreground(lipgloss.Color(t.System)).Padding(0, 1),
 	}
 }
 
@@ -180,21 +163,30 @@ func labelStyle(color string) lipgloss.Style {
 		Foreground(lipgloss.Color(color))
 }
 
-func messageStyle(textColor, accentColor string) lipgloss.Style {
+func messageStyle(textColor string) lipgloss.Style {
 	return lipgloss.NewStyle().
 		Foreground(lipgloss.Color(textColor)).
-		Border(lipgloss.ThickBorder(), false, false, false, true).
+		Padding(0, 1)
-		BorderForeground(lipgloss.Color(accentColor)).
+}
-		PaddingLeft(1)
+
+func assistantMessageStyle(textColor string) lipgloss.Style {
+	return lipgloss.NewStyle().
+		Foreground(lipgloss.Color(textColor)).
+		Padding(1, 2)
+}
+
+func bubbleMessageStyle(textColor, backgroundColor string) lipgloss.Style {
+	return lipgloss.NewStyle().
+		Foreground(lipgloss.Color(textColor)).
+		Background(lipgloss.Color(backgroundColor)).
+		Padding(1, 2)
 }
 
 func applyTextareaTheme(input *textarea.Model, t theme) {
 	focused := textarea.Style{
 		Base: lipgloss.NewStyle().
-			Foreground(lipgloss.Color(t.Text)).
+			Foreground(lipgloss.Color(t.Text)),
-			Background(lipgloss.Color(t.Surface)),
+		CursorLine: lipgloss.NewStyle(),
-		CursorLine: lipgloss.NewStyle().
-			Background(lipgloss.Color(t.Surface)),
 		Placeholder: lipgloss.NewStyle().
 			Foreground(lipgloss.Color(t.Muted)),
 		Prompt: lipgloss.NewStyle().
@@ -205,7 +197,7 @@ func applyTextareaTheme(input *textarea.Model, t theme) {
 			Foreground(lipgloss.Color(t.Surface)),
 	}
 	blurred := focused
-	blurred.CursorLine = lipgloss.NewStyle().Background(lipgloss.Color(t.Surface))
+	blurred.CursorLine = lipgloss.NewStyle()
 
 	input.FocusedStyle = focused
 	input.BlurredStyle = blurred