diff --git a/internal/agent/agent.go b/internal/agent/agent.go
new file mode 100644
index 0000000..c52235c
--- /dev/null
+++ b/internal/agent/agent.go
@@ -0,0 +1,139 @@
+package agent
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"log/slog"
+	"sync"
+	"time"
+
+	"git.db123.ir/db123/divacode/internal/companion"
+	"git.db123.ir/db123/divacode/internal/config"
+	"git.db123.ir/db123/divacode/internal/llama"
+	"git.db123.ir/db123/divacode/internal/memory"
+	"git.db123.ir/db123/divacode/internal/storage"
+	"git.db123.ir/db123/divacode/internal/tools"
+	"git.db123.ir/db123/divacode/pkg/types"
+)
+
+type Agent struct {
+	mu        sync.Mutex
+	cfg       *config.Config
+	llm       *llama.Client
+	mem       *memory.Store
+	store     *storage.DB
+	companion *companion.Engine
+	tools     *tools.Registry
+
+	conversationID string
+	messages       []types.Message
+}
+
+func New(cfg *config.Config, llm *llama.Client, store *storage.DB, mem *memory.Store, comp *companion.Engine, toolReg *tools.Registry) *Agent {
+	return &Agent{
+		cfg:       cfg,
+		llm:       llm,
+		store:     store,
+		mem:       mem,
+		companion: comp,
+		tools:     toolReg,
+	}
+}
+
+func (a *Agent) NewConversation() error {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	id := fmt.Sprintf("%x", time.Now().UnixNano())
+	a.conversationID = id
+	a.messages = nil
+	if err := a.store.Exec("INSERT INTO conversations (id) VALUES (?)", id); err != nil {
+		return fmt.Errorf("new conversation: %w", err)
+	}
+	slog.Info("new conversation", "id", id)
+	return nil
+}
+
+func (a *Agent) HandleMessage(ctx context.Context, content string) (string, error) {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+
+	userMsg := types.Message{
+		ID:        fmt.Sprintf("%x", time.Now().UnixNano()),
+		Role:      types.RoleUser,
+		Content:   content,
+		CreatedAt: time.Now(),
+	}
+	a.messages = append(a.messages, userMsg)
+	a.saveMessage(userMsg)
+
+	memories, err := a.mem.Search(ctx, content, a.cfg.MemoryTopK)
+	if err != nil {
+		slog.Warn("memory search failed", "error", err)
+	}
+
+	prompt, err := a.companion.BuildPrompt(ctx, &companion.PromptInput{
+		UserMessage:    content,
+		RecentMessages: a.messages,
+		Memories:       memories,
+	})
+	if err != nil {
+		return "", fmt.Errorf("build prompt: %w", err)
+	}
+
+	resp, err := a.llm.Complete(&llama.CompletionRequest{
+		Prompt:      prompt,
+		Temperature: a.cfg.Temperature,
+		TopP:        a.cfg.TopP,
+		MaxTokens:   a.cfg.MaxTokens,
+		Stream:      false,
+		CachePrompt: true,
+	})
+	if err != nil {
+		return "", fmt.Errorf("llm complete: %w", err)
+	}
+
+	assistantMsg := types.Message{
+		ID:        fmt.Sprintf("%x", time.Now().UnixNano()),
+		Role:      types.RoleAssistant,
+		Content:   resp.Content,
+		CreatedAt: time.Now(),
+	}
+	a.messages = append(a.messages, assistantMsg)
+	a.saveMessage(assistantMsg)
+
+	go func() {
+		if err := a.mem.Store(context.Background(), userMsg.Content, "conversation"); err != nil {
+			slog.Warn("memory store failed", "error", err)
+		}
+	}()
+
+	return resp.Content, nil
+}
+
+func (a *Agent) Messages() []types.Message {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return a.messages
+}
+
+func (a *Agent) ConversationID() string {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return a.conversationID
+}
+
+func (a *Agent) saveMessage(msg types.Message) {
+	toolCallJSON := ""
+	if msg.ToolCall != nil {
+		b, _ := json.Marshal(msg.ToolCall)
+		toolCallJSON = string(b)
+	}
+	err := a.store.Exec(
+		"INSERT INTO messages (id, conversation_id, role, content, tool_call, created_at) VALUES (?, ?, ?, ?, ?, ?)",
+		msg.ID, a.conversationID, string(msg.Role), msg.Content, toolCallJSON, msg.CreatedAt.Format(time.RFC3339),
+	)
+	if err != nil {
+		slog.Warn("failed to save message", "error", err)
+	}
+}
diff --git a/internal/agent/scheduler.go b/internal/agent/scheduler.go
new file mode 100644
index 0000000..b8a6c65
--- /dev/null
+++ b/internal/agent/scheduler.go
@@ -0,0 +1,69 @@
+package agent
+
+import (
+	"context"
+	"log/slog"
+	"time"
+)
+
+type Scheduler struct {
+	agent     *Agent
+	interval  time.Duration
+	diaryHour int
+	stopCh    chan struct{}
+}
+
+func NewScheduler(agent *Agent, interval time.Duration, diaryHour int) *Scheduler {
+	return &Scheduler{
+		agent:     agent,
+		interval:  interval,
+		diaryHour: diaryHour,
+		stopCh:    make(chan struct{}),
+	}
+}
+
+func (s *Scheduler) Start(ctx context.Context) {
+	slog.Info("scheduler started", "interval", s.interval)
+	ticker := time.NewTicker(s.interval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ctx.Done():
+			slog.Info("scheduler stopped via context")
+			return
+		case <-s.stopCh:
+			slog.Info("scheduler stopped via signal")
+			return
+		case <-ticker.C:
+			s.tick(ctx)
+		}
+	}
+}
+
+func (s *Scheduler) Stop() {
+	close(s.stopCh)
+}
+
+func (s *Scheduler) tick(ctx context.Context) {
+	mood := s.agent.companion.Mood()
+	lastContact := s.agent.companion.LastContactDuration()
+	trust := s.agent.companion.Trust()
+
+	slog.Debug("scheduler tick", "mood", mood, "lastContact", lastContact, "trust", trust)
+
+	if lastContact > 48*time.Hour && trust > 0.6 {
+		s.agent.companion.QueueAutonomousMessage(
+			"Haven't heard from you in a while. Everything okay?",
+		)
+	}
+
+	if s.agent.cfg.AutoDiary {
+		hour := time.Now().Hour()
+		if hour >= s.diaryHour || hour < 1 {
+			if err := s.agent.companion.WriteDiary(ctx); err != nil {
+				slog.Warn("diary write failed", "error", err)
+			}
+		}
+	}
+}