diff --git a/.env.example b/.env.example
new file mode 100644
index 0000000..366d35b
--- /dev/null
+++ b/.env.example
@@ -0,0 +1,6 @@
+OPENAI_API_KEY=sk-your-api-key-here
+OPENAI_BASE_URL=https://api.openai.com/v1
+OPENAI_MODEL=gpt-4o
+OPENAI_EMBED_MODEL=text-embedding-3-small
+DATA_DIR=./data
+PORT=8080
diff --git a/config/config.go b/config/config.go
new file mode 100644
index 0000000..8167c51
--- /dev/null
+++ b/config/config.go
@@ -0,0 +1,30 @@
+package config
+
+import "os"
+
+type Config struct {
+	OpenAIAPIKey     string
+	OpenAIBaseURL    string
+	OpenAIModel      string
+	OpenAIEmbedModel string
+	DataDir          string
+	Port             string
+}
+
+func Load() *Config {
+	return &Config{
+		OpenAIAPIKey:     getEnv("OPENAI_API_KEY", ""),
+		OpenAIBaseURL:    getEnv("OPENAI_BASE_URL", "https://api.openai.com/v1"),
+		OpenAIModel:      getEnv("OPENAI_MODEL", "gpt-4o"),
+		OpenAIEmbedModel: getEnv("OPENAI_EMBED_MODEL", "text-embedding-3-small"),
+		DataDir:          getEnv("DATA_DIR", "./data"),
+		Port:             getEnv("PORT", "8080"),
+	}
+}
+
+func getEnv(key, fallback string) string {
+	if v := os.Getenv(key); v != "" {
+		return v
+	}
+	return fallback
+}
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..28b9fa5
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module eino-test
+
+go 1.23.6
diff --git a/internal/store/memory.go b/internal/store/memory.go
new file mode 100644
index 0000000..6bfcc86
--- /dev/null
+++ b/internal/store/memory.go
@@ -0,0 +1,83 @@
+package store
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"sync"
+)
+
+type MemoryNoteStore struct {
+	mu    sync.RWMutex
+	notes map[string]*Note
+}
+
+func NewMemoryNoteStore() *MemoryNoteStore {
+	return &MemoryNoteStore{
+		notes: make(map[string]*Note),
+	}
+}
+
+func (s *MemoryNoteStore) GetByID(_ context.Context, id string) (*Note, error) {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+	n, ok := s.notes[id]
+	if !ok {
+		return nil, fmt.Errorf("note not found: %s", id)
+	}
+	return n, nil
+}
+
+func (s *MemoryNoteStore) List(_ context.Context) ([]*Note, error) {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+	result := make([]*Note, 0, len(s.notes))
+	for _, n := range s.notes {
+		result = append(result, n)
+	}
+	return result, nil
+}
+
+func (s *MemoryNoteStore) Create(_ context.Context, note *Note) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if _, exists := s.notes[note.ID]; exists {
+		return fmt.Errorf("note already exists: %s", note.ID)
+	}
+	s.notes[note.ID] = note
+	return nil
+}
+
+func (s *MemoryNoteStore) Update(_ context.Context, note *Note) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if _, exists := s.notes[note.ID]; !exists {
+		return fmt.Errorf("note not found: %s", note.ID)
+	}
+	s.notes[note.ID] = note
+	return nil
+}
+
+func (s *MemoryNoteStore) Delete(_ context.Context, id string) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if _, exists := s.notes[id]; !exists {
+		return fmt.Errorf("note not found: %s", id)
+	}
+	delete(s.notes, id)
+	return nil
+}
+
+func (s *MemoryNoteStore) SearchByKeyword(_ context.Context, keyword string) ([]*Note, error) {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+	keyword = strings.ToLower(keyword)
+	var result []*Note
+	for _, n := range s.notes {
+		if strings.Contains(strings.ToLower(n.Title), keyword) ||
+			strings.Contains(strings.ToLower(n.Content), keyword) {
+			result = append(result, n)
+		}
+	}
+	return result, nil
+}
diff --git a/internal/store/models.go b/internal/store/models.go
new file mode 100644
index 0000000..c8607ce
--- /dev/null
+++ b/internal/store/models.go
@@ -0,0 +1,25 @@
+package store
+
+import "time"
+
+type Note struct {
+	ID        string    `json:"id"`
+	Title     string    `json:"title"`
+	Content   string    `json:"content"`
+	Tags      []string  `json:"tags"`
+	FilePath  string    `json:"file_path"`
+	CreatedAt time.Time `json:"created_at"`
+	UpdatedAt time.Time `json:"updated_at"`
+}
+
+type Chunk struct {
+	NoteID    string
+	Index     int
+	Content   string
+	Embedding []float64
+}
+
+type SearchResult struct {
+	Note  *Note   `json:"note"`
+	Score float64 `json:"score"`
+}
diff --git a/internal/store/store.go b/internal/store/store.go
new file mode 100644
index 0000000..64a5efe
--- /dev/null
+++ b/internal/store/store.go
@@ -0,0 +1,12 @@
+package store
+
+import "context"
+
+type NoteStore interface {
+	GetByID(ctx context.Context, id string) (*Note, error)
+	List(ctx context.Context) ([]*Note, error)
+	Create(ctx context.Context, note *Note) error
+	Update(ctx context.Context, note *Note) error
+	Delete(ctx context.Context, id string) error
+	SearchByKeyword(ctx context.Context, keyword string) ([]*Note, error)
+}
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..ea57497
--- /dev/null
+++ b/main.go
@@ -0,0 +1,18 @@
+package main
+
+import (
+	"fmt"
+	"log"
+
+	"eino-test/config"
+	"eino-test/internal/store"
+)
+
+func main() {
+	cfg := config.Load()
+	noteStore := store.NewMemoryNoteStore()
+	_ = noteStore
+
+	log.Printf("Server starting on port %s (data dir: %s)", cfg.Port, cfg.DataDir)
+	fmt.Println("Knowledge Assistant ready")
+}