diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..3f599ae
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,17 @@
+.PHONY: build test run clean
+
+BINARY_NAME=mend
+BUILD_DIR=bin
+
+build:
+	@mkdir -p $(BUILD_DIR)
+	go build -o $(BUILD_DIR)/$(BINARY_NAME) .
+
+test:
+	go test ./...
+
+run:
+	go run .
+
+clean:
+	rm -rf $(BUILD_DIR)
diff --git a/README.md b/README.md
index ff25d2d..f67a56f 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,10 @@
 my take on how notes and srs should be combind and simplified
 
-# Tests
+## Usage
 
-Run tests with `go test ./...`
+The project includes a `Makefile` for common tasks:
+
+- **Build**: `make build` (creates binary in `bin/mend`)
+- **Test**: `make test`
+- **Run**: `make run`
+- **Clean**: `make clean`
diff --git a/fs.go b/fs.go
deleted file mode 100644
index 3e6ed00..0000000
--- a/fs.go
+++ /dev/null
@@ -1,103 +0,0 @@
-/*
-This file has the raw file io operations that are used by FsTree
-- ruinivist, 30Dec25
-*/
-
-package main
-
-import (
-	"errors"
-	"os"
-	"path/filepath"
-)
-
-func walkFileSystemAndBuildTree(rootPath string, node *FsNode) error {
-	if node == nil {
-		return errors.New("node cannot be nil")
-	}
-	if len(node.children) > 0 {
-		return errors.New("node already has children")
-	}
-
-	entries, err := os.ReadDir(rootPath)
-	if err != nil {
-		return err
-	}
-
-	files := make([]os.DirEntry, 0)
-	folders := make([]os.DirEntry, 0)
-
-	for _, entry := range entries {
-		// dot folders and files skipped
-		if len(entry.Name()) > 0 && entry.Name()[0] == '.' {
-			continue
-		}
-
-		if entry.IsDir() {
-			folders = append(folders, entry)
-		} else {
-			files = append(files, entry)
-		}
-	}
-
-	for _, file := range files {
-		newNode := &FsNode{
-			nodeType: FileNode,
-			path:     filepath.Join(rootPath, file.Name()),
-			children: make([]*FsNode, 0),
-			parent:   node,
-			expanded: false,
-		}
-		node.children = append(node.children, newNode)
-	}
-
-	for _, folder := range folders {
-		newNode := &FsNode{
-			nodeType: FolderNode,
-			path:     filepath.Join(rootPath, folder.Name()),
-			children: make([]*FsNode, 0),
-			parent:   node,
-			expanded: true, // all expanded by default
-		}
-		node.children = append(node.children, newNode)
-		walkFileSystemAndBuildTree(newNode.path, newNode)
-	}
-
-	return nil
-}
-
-func createFile(path string, content []byte) error {
-	if path == "" {
-		return errors.New("file path cannot be empty")
-	}
-
-	if _, err := os.Stat(path); err == nil {
-		return errors.New("file already exists")
-	}
-
-	return os.WriteFile(path, content, 0644)
-}
-
-func createFolder(path string) error {
-	if path == "" {
-		return errors.New("folder path cannot be empty")
-	}
-
-	if _, err := os.Stat(path); err == nil {
-		return errors.New("folder already exists")
-	}
-
-	return os.Mkdir(path, 0755)
-}
-
-func deletePath(path string) error {
-	if path == "" {
-		return errors.New("path cannot be empty")
-	}
-
-	if _, err := os.Stat(path); os.IsNotExist(err) {
-		return errors.New("path does not exist")
-	}
-
-	return os.RemoveAll(path)
-}
diff --git a/internal/filesystem/fs.go b/internal/filesystem/fs.go
new file mode 100644
index 0000000..80d558d
--- /dev/null
+++ b/internal/filesystem/fs.go
@@ -0,0 +1,42 @@
+package filesystem
+
+import (
+	"errors"
+	"os"
+)
+
+func CreateFile(path string, content []byte) error {
+	if path == "" {
+		return errors.New("file path cannot be empty")
+	}
+
+	if _, err := os.Stat(path); err == nil {
+		return errors.New("file already exists")
+	}
+
+	return os.WriteFile(path, content, 0644)
+}
+
+func CreateFolder(path string) error {
+	if path == "" {
+		return errors.New("folder path cannot be empty")
+	}
+
+	if _, err := os.Stat(path); err == nil {
+		return errors.New("folder already exists")
+	}
+
+	return os.Mkdir(path, 0755)
+}
+
+func DeletePath(path string) error {
+	if path == "" {
+		return errors.New("path cannot be empty")
+	}
+
+	if _, err := os.Stat(path); os.IsNotExist(err) {
+		return errors.New("path does not exist")
+	}
+
+	return os.RemoveAll(path)
+}
diff --git a/fs_test.go b/internal/filesystem/fs_test.go
similarity index 85%
rename from fs_test.go
rename to internal/filesystem/fs_test.go
index 217e246..0924444 100644
--- a/fs_test.go
+++ b/internal/filesystem/fs_test.go
@@ -1,4 +1,4 @@
-package main
+package filesystem
 
 import (
 	"os"
@@ -16,7 +16,7 @@ func TestCreateFile(t *testing.T) {
 
 	// test valid creation
 	filePath := filepath.Join(tmpDir, "test.md")
-	err = createFile(filePath, []byte("content"))
+	err = CreateFile(filePath, []byte("content"))
 	if err != nil {
 		t.Errorf("expected no error, got %v", err)
 	}
@@ -26,13 +26,13 @@ func TestCreateFile(t *testing.T) {
 	}
 
 	// test creation failure (exists)
-	err = createFile(filePath, []byte("content"))
+	err = CreateFile(filePath, []byte("content"))
 	if err == nil {
 		t.Error("expected error for existing file, got nil")
 	}
 
 	// test empty path
-	err = createFile("", []byte{})
+	err = CreateFile("", []byte{})
 	if err == nil {
 		t.Error("expected error for empty path, got nil")
 	}
@@ -47,7 +47,7 @@ func TestCreateFolder(t *testing.T) {
 	defer os.RemoveAll(tmpDir)
 
 	folderPath := filepath.Join(tmpDir, "subfolder")
-	err = createFolder(folderPath)
+	err = CreateFolder(folderPath)
 	if err != nil {
 		t.Errorf("expected no error, got %v", err)
 	}
@@ -61,13 +61,13 @@ func TestCreateFolder(t *testing.T) {
 	}
 
 	// test creation failure (exists)
-	err = createFolder(folderPath)
+	err = CreateFolder(folderPath)
 	if err == nil {
 		t.Error("expected error for existing folder, got nil")
 	}
 
 	// test empty path
-	err = createFolder("")
+	err = CreateFolder("")
 	if err == nil {
 		t.Error("expected error for empty path, got nil")
 	}
@@ -86,7 +86,7 @@ func TestDeletePath(t *testing.T) {
 	fileInSubDir := filepath.Join(subDir, "file.txt")
 	os.WriteFile(fileInSubDir, []byte("data"), 0644)
 
-	err = deletePath(subDir)
+	err = DeletePath(subDir)
 	if err != nil {
 		t.Errorf("expected no error, got %v", err)
 	}
@@ -96,13 +96,13 @@ func TestDeletePath(t *testing.T) {
 	}
 
 	// test delete non-existent
-	err = deletePath(filepath.Join(tmpDir, "nonexistent"))
+	err = DeletePath(filepath.Join(tmpDir, "nonexistent"))
 	if err == nil {
 		t.Error("expected error for nonexistent path, got nil")
 	}
 
 	// test empty path
-	err = deletePath("")
+	err = DeletePath("")
 	if err == nil {
 		t.Error("expected error for empty path, got nil")
 	}
diff --git a/fstree.go b/internal/ui/fstree/model.go
similarity index 65%
rename from fstree.go
rename to internal/ui/fstree/model.go
index b8f8c32..11a2d0e 100644
--- a/fstree.go
+++ b/internal/ui/fstree/model.go
@@ -1,16 +1,16 @@
 /*
 This file contains the implementation of an in-memory tree of files and folders that the app used.
 It is initialised at startup and used for state changes in UI and later persisted to disk.
-
-- ruinivist, 30Dec25
 */
 
-package main
+package fstree
 
 import (
 	"errors"
+	"mend/internal/filesystem"
 	"mend/styles"
 	"mend/utils"
+	"os"
 	"path/filepath"
 	"strings"
 
@@ -30,28 +30,28 @@ const (
 // a single node, Fs => deals with file system related info mostly
 // a name for example can be content derived as well
 type FsNode struct {
-	nodeType FsNodeType
-	path     string
-	children []*FsNode
-	parent   *FsNode // for fast traversal up the tree
-	expanded bool    // makes sense only for folder nodes
-	// these are populated by buildLines for fast access
+	Type     FsNodeType
+	Path     string
+	Children []*FsNode
+	Parent   *FsNode // for fast traversal up the tree
+	Expanded bool    // makes sense only for folder nodes
+	// these are populated by BuildLines for fast access
 	line int
 	prev *FsNode
 	next *FsNode
 }
 
 func (n *FsNode) FileName() string {
-	name := filepath.Base(n.path)
-	if n.nodeType == FileNode {
+	name := filepath.Base(n.Path)
+	if n.Type == FileNode {
 		return strings.TrimSuffix(name, ".md")
 	}
 	return name
 }
 
 // ================== messages ===================
-type nodeSelected struct {
-	path string
+type NodeSelectedMsg struct {
+	Path string
 }
 
 type FsActionType int
@@ -73,11 +73,11 @@ type PerformActionMsg struct {
 
 // ==================== FsNode definition ====================
 type FsTree struct {
-	root         *FsNode
+	Root         *FsNode
 	lines        map[int]*FsNode // flattened view of nodes for easy line access, map so that I can handle blank padding
-	selectedNode *FsNode
+	SelectedNode *FsNode
 	hoveredNode  *FsNode
-	errMsg       string
+	ErrMsg       string
 	height       int
 	width        int
 	viewStart    int
@@ -97,13 +97,13 @@ func (t *FsTree) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 	case PerformActionMsg:
 		err := t.PerformAction(m.Action, m.Name)
 		if err != nil {
-			t.errMsg = err.Error()
+			t.ErrMsg = err.Error()
 		}
 	case tea.WindowSizeMsg:
 		t.width = m.Width
 		t.height = m.Height
 	case tea.KeyMsg:
-		t.errMsg = ""
+		t.ErrMsg = ""
 		switch m.String() {
 		case "w", "up":
 			_ = t.MoveUp()
@@ -118,9 +118,9 @@ func (t *FsTree) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		case "C": // new root node
 			return t, func() tea.Msg { return RequestInputMsg{Action: ActionNewRoot} }
 		case "delete": // delete node
-			err := t.DeleteNode(t.selectedNode)
+			err := t.DeleteNode(t.SelectedNode)
 			if err != nil {
-				t.errMsg = err.Error()
+				t.ErrMsg = err.Error()
 			}
 		}
 
@@ -138,15 +138,15 @@ func (t *FsTree) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		if m.X >= t.width {
 			break
 		}
-		t.errMsg = ""
+		t.ErrMsg = ""
 		t.hoveredNode = t.lines[m.Y] // hover
 
 		// click
 		if m.Button == tea.MouseButtonLeft && m.Action == tea.MouseActionPress {
 			nodeAtLine := t.lines[m.Y]
 			if nodeAtLine != nil {
-				t.selectedNode = nodeAtLine
-				if nodeAtLine.nodeType == FolderNode {
+				t.SelectedNode = nodeAtLine
+				if nodeAtLine.Type == FolderNode {
 					_ = t.ToggleExpand(nodeAtLine)
 				}
 			}
@@ -155,10 +155,10 @@ func (t *FsTree) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 
 	t.viewStart, t.viewEnd = t.getViewportBounds()
 
-	if t.oldSelected != t.selectedNode && t.selectedNode.nodeType == FileNode {
-		t.oldSelected = t.selectedNode
+	if t.oldSelected != t.SelectedNode && t.SelectedNode.Type == FileNode {
+		t.oldSelected = t.SelectedNode
 		return t, func() tea.Msg {
-			return nodeSelected{path: t.selectedNode.path}
+			return NodeSelectedMsg{Path: t.SelectedNode.Path}
 		}
 	}
 	return t, nil
@@ -167,20 +167,20 @@ func (t *FsTree) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 func (t *FsTree) PerformAction(action FsActionType, name string) error {
 	switch action {
 	case ActionNewFile:
-		return t.CreateNode(t.selectedNode, name, FileNode)
+		return t.CreateNode(t.SelectedNode, name, FileNode)
 	case ActionNewFolder:
-		return t.CreateNode(t.selectedNode, name, FolderNode)
+		return t.CreateNode(t.SelectedNode, name, FolderNode)
 	case ActionNewRoot:
-		return t.CreateNode(t.root, name, FolderNode)
+		return t.CreateNode(t.Root, name, FolderNode)
 	}
 	return nil
 }
 
 func (t *FsTree) getViewportBounds() (startLine, endLine int) {
-	if t.selectedNode == nil {
+	if t.SelectedNode == nil {
 		return 0, 0 // doesn't amtter in this case
 	}
-	selectedLine := t.selectedNode.line
+	selectedLine := t.SelectedNode.line
 	halfHeight := t.height / 2
 
 	startLine = max(0, selectedLine-halfHeight)
@@ -198,16 +198,16 @@ func (t *FsTree) getViewportBounds() (startLine, endLine int) {
 }
 
 func (t *FsTree) View() string {
-	if t.errMsg != "" {
-		return t.errMsg
+	if t.ErrMsg != "" {
+		return t.ErrMsg
 	}
 
-	if len(t.root.children) == 0 {
+	if len(t.Root.Children) == 0 {
 		return "no files/folders\nPress C to create"
 	}
 
 	builder := &strings.Builder{}
-	t.renderNode(t.root, 0, builder)
+	t.renderNode(t.Root, 0, builder)
 	rendered := builder.String()
 
 	lines := strings.Split(rendered, "\n")
@@ -226,21 +226,21 @@ func (t *FsTree) View() string {
 
 func NewFsTree(rootPath string, startOffset int) *FsTree {
 	root := &FsNode{
-		nodeType: FolderNode,
-		path:     rootPath,
-		children: make([]*FsNode, 0),
-		expanded: true,
+		Type:     FolderNode,
+		Path:     rootPath,
+		Children: make([]*FsNode, 0),
+		Expanded: true,
 	}
-	walkFileSystemAndBuildTree(rootPath, root)
+	WalkFileSystemAndBuildTree(rootPath, root)
 
 	tree := &FsTree{
-		root:        root,
+		Root:        root,
 		startOffset: startOffset,
 	}
-	if len(root.children) > 0 {
-		tree.selectedNode = root.children[0]
+	if len(root.Children) > 0 {
+		tree.SelectedNode = root.Children[0]
 	}
-	tree.buildLines()
+	tree.BuildLines()
 	return tree
 }
 
@@ -248,27 +248,27 @@ func (t *FsTree) DeleteNode(node *FsNode) error {
 	if node == nil {
 		return errors.New("node to delete cannot be nil")
 	}
-	parent := node.parent
+	parent := node.Parent
 	if parent == nil {
 		return errors.New("node to delete must have a parent")
 	}
 
 	// materialise
-	if err := deletePath(node.path); err != nil {
+	if err := filesystem.DeletePath(node.Path); err != nil {
 		return err
 	}
 
-	t.selectedNode = node.prev // cannot be next as subfolder/file deletion
-	parent.children = utils.RemoveFromSlice(parent.children, node)
+	t.SelectedNode = node.prev // cannot be next as subfolder/file deletion
+	parent.Children = utils.RemoveFromSlice(parent.Children, node)
 
-	if t.selectedNode == nil {
+	if t.SelectedNode == nil {
 		// can only happen if first root level node is deleted
-		if len(t.root.children) > 0 {
-			t.selectedNode = t.root.children[0]
+		if len(t.Root.Children) > 0 {
+			t.SelectedNode = t.Root.Children[0]
 		}
 	}
 
-	t.buildLines()
+	t.BuildLines()
 	return nil
 }
 
@@ -276,17 +276,17 @@ func (t *FsTree) ToggleExpand(node *FsNode) error {
 	if node == nil {
 		return errors.New("node cannot be nil")
 	}
-	if node.nodeType != FolderNode {
+	if node.Type != FolderNode {
 		return errors.New("only folder nodes can be expanded or collapsed")
 	}
 
-	node.expanded = !node.expanded
-	t.buildLines()
+	node.Expanded = !node.Expanded
+	t.BuildLines()
 	return nil
 }
 
 func (t *FsTree) move(delta int) error {
-	selected := t.selectedNode
+	selected := t.SelectedNode
 	if selected == nil {
 		return errors.New("no node is currently selected")
 	}
@@ -301,7 +301,7 @@ func (t *FsTree) move(delta int) error {
 		next = selected.prev
 	}
 	if next != nil {
-		t.selectedNode = next
+		t.SelectedNode = next
 	}
 	return nil
 }
@@ -310,14 +310,14 @@ func (t *FsTree) MoveUp() error   { return t.move(-1) }
 func (t *FsTree) MoveDown() error { return t.move(1) }
 
 func (t *FsTree) ToggleSelectedExpand() error {
-	if t.selectedNode == nil {
+	if t.SelectedNode == nil {
 		return errors.New("no node is currently selected")
 	}
-	if t.selectedNode.nodeType != FolderNode {
+	if t.SelectedNode.Type != FolderNode {
 		return errors.New("only folder nodes can be expanded or collapsed")
 	}
 
-	t.ToggleExpand(t.selectedNode)
+	t.ToggleExpand(t.SelectedNode)
 	return nil
 }
 
@@ -327,7 +327,7 @@ func (t *FsTree) renderNode(node *FsNode, depth int, builder *strings.Builder) {
 	}
 
 	folderInRoot := false
-	if node.nodeType == FolderNode && depth == 1 && node.prev != nil {
+	if node.Type == FolderNode && depth == 1 && node.prev != nil {
 		folderInRoot = true
 	}
 
@@ -335,9 +335,9 @@ func (t *FsTree) renderNode(node *FsNode, depth int, builder *strings.Builder) {
 	prevIndent := strings.Repeat(" ", max(depth-1, 0))
 
 	var icon string
-	switch node.nodeType {
+	switch node.Type {
 	case FolderNode:
-		if node.expanded {
+		if node.Expanded {
 			icon = indent + styles.ArrowDownIcon
 		} else {
 			icon = indent + styles.ArrowRightIcon
@@ -350,7 +350,7 @@ func (t *FsTree) renderNode(node *FsNode, depth int, builder *strings.Builder) {
 	// highlight if selected or hovered
 	// note: the logic of lines cache needs to match render
 	fileName := node.FileName()
-	isSelected := node == t.selectedNode
+	isSelected := node == t.SelectedNode
 	isHovered := node == t.hoveredNode
 
 	if isSelected {
@@ -368,19 +368,19 @@ func (t *FsTree) renderNode(node *FsNode, depth int, builder *strings.Builder) {
 		builder.WriteString(line)
 	}
 
-	if node.expanded {
-		for _, child := range node.children {
+	if node.Expanded {
+		for _, child := range node.Children {
 			t.renderNode(child, depth+1, builder)
 		}
 	}
 }
 
 // builds a cache of line num to rendered node in view
-func (t *FsTree) buildLines() {
+func (t *FsTree) BuildLines() {
 	t.lines = make(map[int]*FsNode)
 	line := -1
 	flatTree := make([]*FsNode, 0)
-	t.buildLinesRec(t.root, 0, &line, &flatTree) // root has -1 depth and -1 index, as it's not meant to be rendered
+	t.buildLinesRec(t.Root, 0, &line, &flatTree) // root has -1 depth and -1 index, as it's not meant to be rendered
 	// everything is a child of root
 	flatTree[0] = nil // basically a merge of skip root and padding ends with nil
 	flatTree = append(flatTree, nil)
@@ -398,7 +398,7 @@ func (t *FsTree) buildLinesRec(node *FsNode, depth int, currentLine *int, flatTr
 		return
 	}
 
-	if node.nodeType == FolderNode && depth == 1 && *currentLine != 0 {
+	if node.Type == FolderNode && depth == 1 && *currentLine != 0 {
 		(*currentLine)++
 	}
 	t.lines[*currentLine] = node
@@ -406,8 +406,8 @@ func (t *FsTree) buildLinesRec(node *FsNode, depth int, currentLine *int, flatTr
 	*flatTree = append(*flatTree, node)
 	(*currentLine)++
 
-	if node.expanded {
-		for _, child := range node.children {
+	if node.Expanded {
+		for _, child := range node.Children {
 			t.buildLinesRec(child, depth+1, currentLine, flatTree)
 		}
 	}
@@ -418,14 +418,14 @@ func (t *FsTree) CreateNode(folder *FsNode, name string, nodeType FsNodeType) er
 		return errors.New("folder node cannot be nil")
 	}
 
-	if folder.nodeType == FileNode {
-		folder = folder.parent
+	if folder.Type == FileNode {
+		folder = folder.Parent
 	}
 
-	if folder.nodeType != FolderNode {
+	if folder.Type != FolderNode {
 		return errors.New("parent node must be a folder. this should not be allowed by ui")
-	} else if folder.nodeType == FolderNode && !folder.expanded {
-		folder.expanded = true
+	} else if folder.Type == FolderNode && !folder.Expanded {
+		folder.Expanded = true
 	}
 
 	if name == "" {
@@ -436,16 +436,16 @@ func (t *FsTree) CreateNode(folder *FsNode, name string, nodeType FsNodeType) er
 		name += ".md"
 	}
 
-	path := filepath.Join(folder.path, name)
+	path := filepath.Join(folder.Path, name)
 	// materialise it first
 	switch nodeType {
 	case FileNode:
-		err := createFile(path, []byte{})
+		err := filesystem.CreateFile(path, []byte{})
 		if err != nil {
 			return err
 		}
 	case FolderNode:
-		err := createFolder(path)
+		err := filesystem.CreateFolder(path)
 		if err != nil {
 			return err
 		}
@@ -456,19 +456,74 @@ func (t *FsTree) CreateNode(folder *FsNode, name string, nodeType FsNodeType) er
 		expanded = true
 	}
 	newNode := &FsNode{
-		nodeType: nodeType,
-		path:     path,
-		children: make([]*FsNode, 0),
-		parent:   folder,
-		expanded: expanded,
+		Type:     nodeType,
+		Path:     path,
+		Children: make([]*FsNode, 0),
+		Parent:   folder,
+		Expanded: expanded,
 	}
 	// files are first of children, folder last of children
 	if nodeType == FileNode {
-		folder.children = append([]*FsNode{newNode}, folder.children...)
+		folder.Children = append([]*FsNode{newNode}, folder.Children...)
 	} else {
-		folder.children = append(folder.children, newNode)
+		folder.Children = append(folder.Children, newNode)
 	}
-	t.selectedNode = newNode
-	t.buildLines()
+	t.SelectedNode = newNode
+	t.BuildLines()
+	return nil
+}
+
+func WalkFileSystemAndBuildTree(rootPath string, node *FsNode) error {
+	if node == nil {
+		return errors.New("node cannot be nil")
+	}
+	if len(node.Children) > 0 {
+		return errors.New("node already has children")
+	}
+
+	entries, err := os.ReadDir(rootPath)
+	if err != nil {
+		return err
+	}
+
+	files := make([]os.DirEntry, 0)
+	folders := make([]os.DirEntry, 0)
+
+	for _, entry := range entries {
+		// dot folders and files skipped
+		if len(entry.Name()) > 0 && entry.Name()[0] == '.' {
+			continue
+		}
+
+		if entry.IsDir() {
+			folders = append(folders, entry)
+		} else {
+			files = append(files, entry)
+		}
+	}
+
+	for _, file := range files {
+		newNode := &FsNode{
+			Type:     FileNode,
+			Path:     filepath.Join(rootPath, file.Name()),
+			Children: make([]*FsNode, 0),
+			Parent:   node,
+			Expanded: false,
+		}
+		node.Children = append(node.Children, newNode)
+	}
+
+	for _, folder := range folders {
+		newNode := &FsNode{
+			Type:     FolderNode,
+			Path:     filepath.Join(rootPath, folder.Name()),
+			Children: make([]*FsNode, 0),
+			Parent:   node,
+			Expanded: true, // all expanded by default
+		}
+		node.Children = append(node.Children, newNode)
+		WalkFileSystemAndBuildTree(newNode.Path, newNode)
+	}
+
 	return nil
 }
diff --git a/fstree_test.go b/internal/ui/fstree/model_test.go
similarity index 76%
rename from fstree_test.go
rename to internal/ui/fstree/model_test.go
index f4d33a9..02fd886 100644
--- a/fstree_test.go
+++ b/internal/ui/fstree/model_test.go
@@ -1,4 +1,4 @@
-package main
+package fstree
 
 import (
 	"os"
@@ -29,12 +29,12 @@ func TestNewFsTree(t *testing.T) {
 	if tree == nil {
 		t.Fatal("expected tree to be created, got nil")
 	}
-	if tree.root.path != tmpDir {
-		t.Errorf("expected root path %s, got %s", tmpDir, tree.root.path)
+	if tree.Root.Path != tmpDir {
+		t.Errorf("expected root path %s, got %s", tmpDir, tree.Root.Path)
 	}
 	// root children: folder1, file2.md
-	if len(tree.root.children) != 2 {
-		t.Errorf("expected 2 children, got %d", len(tree.root.children))
+	if len(tree.Root.Children) != 2 {
+		t.Errorf("expected 2 children, got %d", len(tree.Root.Children))
 	}
 }
 
@@ -48,7 +48,7 @@ func TestTreeCreateNode(t *testing.T) {
 
 	tree := NewFsTree(tmpDir, 0)
 	// create folder
-	err = tree.CreateNode(tree.root, "new_folder", FolderNode)
+	err = tree.CreateNode(tree.Root, "new_folder", FolderNode)
 	if err != nil {
 		t.Errorf("expected no error creating folder, got %v", err)
 	}
@@ -57,12 +57,12 @@ func TestTreeCreateNode(t *testing.T) {
 		t.Error("folder not created on fs")
 	}
 	// check tree
-	if len(tree.root.children) != 1 || tree.root.children[0].nodeType != FolderNode {
+	if len(tree.Root.Children) != 1 || tree.Root.Children[0].Type != FolderNode {
 		t.Error("tree block not updated with new folder")
 	}
 
 	// create file in new folder
-	newFolder := tree.root.children[0]
+	newFolder := tree.Root.Children[0]
 	err = tree.CreateNode(newFolder, "new_file", FileNode)
 	if err != nil {
 		t.Errorf("expected no error creating file, got %v", err)
@@ -73,7 +73,7 @@ func TestTreeCreateNode(t *testing.T) {
 		t.Error("file not created on fs")
 	}
 	// check tree
-	if len(newFolder.children) != 1 || newFolder.children[0].nodeType != FileNode {
+	if len(newFolder.Children) != 1 || newFolder.Children[0].Type != FileNode {
 		t.Error("tree node not updated with new file")
 	}
 }
@@ -90,7 +90,7 @@ func TestTreeDeleteNode(t *testing.T) {
 	os.WriteFile(filepath.Join(tmpDir, "file.md"), []byte(""), 0644)
 
 	tree := NewFsTree(tmpDir, 0)
-	targetNode := tree.root.children[0]
+	targetNode := tree.Root.Children[0]
 
 	err = tree.DeleteNode(targetNode)
 	if err != nil {
@@ -102,7 +102,7 @@ func TestTreeDeleteNode(t *testing.T) {
 		t.Error("file not deleted from fs")
 	}
 	// check tree
-	if len(tree.root.children) != 0 {
+	if len(tree.Root.Children) != 0 {
 		t.Error("tree node not updated after deletion")
 	}
 }
@@ -110,30 +110,30 @@ func TestTreeDeleteNode(t *testing.T) {
 // tests toggling expand
 func TestTreeToggleExpand(t *testing.T) {
 	root := &FsNode{
-		nodeType: FolderNode,
-		expanded: true,
-		children: []*FsNode{}, // Initialize children
+		Type:     FolderNode,
+		Expanded: true,
+		Children: []*FsNode{}, // Initialize children
 	}
 
 	node := &FsNode{
-		nodeType: FolderNode,
-		expanded: true,
-		parent:   root,
+		Type:     FolderNode,
+		Expanded: true,
+		Parent:   root,
 	}
-	root.children = append(root.children, node)
+	root.Children = append(root.Children, node)
 
 	// mocked tree for this test
 	tree := &FsTree{
-		root: root,
+		Root: root,
 	}
 	// Initial buildLines to setup state
-	tree.buildLines()
+	tree.BuildLines()
 
 	err := tree.ToggleExpand(node)
 	if err != nil {
 		t.Error(err)
 	}
-	if node.expanded {
+	if node.Expanded {
 		t.Error("expected node to be collapsed")
 	}
 
@@ -141,7 +141,7 @@ func TestTreeToggleExpand(t *testing.T) {
 	if err != nil {
 		t.Error(err)
 	}
-	if !node.expanded {
+	if !node.Expanded {
 		t.Error("expected node to be expanded")
 	}
 }
diff --git a/notes.go b/internal/ui/note/model.go
similarity index 89%
rename from notes.go
rename to internal/ui/note/model.go
index 3170fa5..687427d 100644
--- a/notes.go
+++ b/internal/ui/note/model.go
@@ -1,10 +1,9 @@
 /*
 this pakckage basically handles notes which are the individual files for spaced
 repetition in mend
-- ruinivist, 3Jan26
 */
 
-package main
+package note
 
 import (
 	"fmt"
@@ -39,7 +38,7 @@ const (
 
 type NoteView struct {
 	// the actual content
-	path                string
+	Path                string
 	rawContent          string // full content for editing
 	sections            []Section
 	currentSectionIndex int
@@ -55,15 +54,15 @@ type NoteView struct {
 }
 
 // ================== messages ===================
-type loadNote struct {
-	path  string
-	force bool
+type LoadNoteMsg struct {
+	Path  string
+	Force bool
 }
 
-type loadedNote struct {
-	rawContent string
-	sections   []Section
-	err        error
+type LoadedNote struct {
+	RawContent string
+	Sections   []Section
+	Err        error
 }
 
 func NewNoteView() *NoteView {
@@ -107,7 +106,7 @@ func (m *NoteView) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 			switch msg.String() {
 			case "esc", "ctrl+q":
 				m.isEditing = false
-				return m, saveContent(m.path, m.textarea.Value())
+				return m, saveContent(m.Path, m.textarea.Value())
 			}
 			var cmd tea.Cmd
 			m.textarea, cmd = m.textarea.Update(msg)
@@ -116,7 +115,7 @@ func (m *NoteView) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 
 		switch msg.String() {
 		case "enter":
-			if m.path != "" && !m.loading {
+			if m.Path != "" && !m.loading {
 				m.isEditing = true
 				m.textarea.SetValue(m.rawContent)
 				m.textarea.Focus()
@@ -157,21 +156,21 @@ func (m *NoteView) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		m.vp, cmd = m.vp.Update(msg)
 		return m, cmd
 
-	case loadNote:
-		if m.path == msg.path && !msg.force {
+	case LoadNoteMsg:
+		if m.Path == msg.Path && !msg.Force {
 			return m, nil //noop
 		}
-		m.path = msg.path
+		m.Path = msg.Path
 		m.isEditing = false
 		m.loading = true
 		m.currentSectionIndex = 0
-		return m, fetchContent(msg.path)
+		return m, fetchContent(msg.Path)
 
-	case loadedNote:
+	case LoadedNote:
 		m.loading = false
-		m.rawContent = msg.rawContent
-		m.sections = msg.sections
-		m.err = msg.err
+		m.rawContent = msg.RawContent
+		m.sections = msg.Sections
+		m.err = msg.Err
 		m.currentSectionIndex = 0
 		m.viewState = StateTitleOnly
 		m.vp.SetContent(m.renderNote())
@@ -193,7 +192,7 @@ func (m NoteView) View() string {
 	if m.loading {
 		return "loading..."
 	}
-	if m.path == "" {
+	if m.Path == "" {
 		return ""
 	}
 
@@ -222,20 +221,20 @@ func fetchContent(path string) tea.Cmd {
 	return func() tea.Msg {
 		data, err := os.ReadFile(path)
 		if err != nil {
-			return loadedNote{err: err}
+			return LoadedNote{Err: err}
 		}
 
 		rawContent := string(data)
-		sections := parseSections(data)
+		sections := ParseSections(data)
 
-		return loadedNote{
-			rawContent: rawContent,
-			sections:   sections,
+		return LoadedNote{
+			RawContent: rawContent,
+			Sections:   sections,
 		}
 	}
 }
 
-func parseSections(source []byte) []Section {
+func ParseSections(source []byte) []Section {
 	md := goldmark.New()
 	reader := text.NewReader(source)
 	doc := md.Parser().Parse(reader)
@@ -259,7 +258,7 @@ func parseSections(source []byte) []Section {
 				// you have a heading and a content to accumulte over
 				contentsRaw := source[lastPos:contentEnd]
 				contents := strings.TrimSpace(string(contentsRaw))
-				hints := extractHints(contents)
+				hints := ExtractHints(contents)
 				sections = append(sections, Section{
 					Title:   title,
 					Content: contents,
@@ -276,7 +275,7 @@ func parseSections(source []byte) []Section {
 	if lastPos < len(source) {
 		contentsRaw := source[lastPos:]
 		contents := strings.TrimSpace(string(contentsRaw))
-		hints := extractHints(contents)
+		hints := ExtractHints(contents)
 		sections = append(sections, Section{
 			Title:   title,
 			Content: contents,
@@ -291,13 +290,13 @@ func saveContent(path, content string) tea.Cmd {
 	return func() tea.Msg {
 		err := os.WriteFile(path, []byte(content), 0644)
 		if err != nil {
-			return loadedNote{err: err}
+			return LoadedNote{Err: err}
 		}
 		return fetchContent(path)()
 	}
 }
 
-func extractHints(content string) []string {
+func ExtractHints(content string) []string {
 	re := regexp.MustCompile(`(?s)\*\*(.*?)\*\*|__(.*?)__`)
 	matches := re.FindAllStringSubmatch(content, -1)
 	hints := make([]string, 0)
@@ -312,7 +311,7 @@ func extractHints(content string) []string {
 }
 
 func (m NoteView) renderNote() string {
-	if m.path == "" {
+	if m.Path == "" {
 		return "" // no note is loaded, don't need to bother with anything
 	}
 	var titleText, contentText string
diff --git a/notes_test.go b/internal/ui/note/model_test.go
similarity index 92%
rename from notes_test.go
rename to internal/ui/note/model_test.go
index 219fa80..77848c7 100644
--- a/notes_test.go
+++ b/internal/ui/note/model_test.go
@@ -1,4 +1,4 @@
-package main
+package note
 
 import (
 	"reflect"
@@ -41,9 +41,9 @@ func TestExtractHints(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			got := extractHints(tt.content)
+			got := ExtractHints(tt.content)
 			if !reflect.DeepEqual(got, tt.expected) {
-				t.Errorf("extractHints() = %v, want %v", got, tt.expected)
+				t.Errorf("ExtractHints() = %v, want %v", got, tt.expected)
 			}
 		})
 	}
@@ -58,7 +58,7 @@ Content 1 with **hint1**.
 Content 2 with __hint2__.
 `)
 
-	sections := parseSections(content)
+	sections := ParseSections(content)
 
 	if len(sections) != 2 {
 		t.Fatalf("expected 2 sections, got %d", len(sections))
@@ -92,7 +92,7 @@ func TestParseSectionsNoHeaders(t *testing.T) {
 	content := []byte(`Just some content without any headers.
 It has **one hint**.`)
 
-	sections := parseSections(content)
+	sections := ParseSections(content)
 
 	if len(sections) != 1 {
 		t.Fatalf("expected 1 section, got %d", len(sections))
diff --git a/main.go b/main.go
index 037ab82..e2d58f4 100644
--- a/main.go
+++ b/main.go
@@ -5,6 +5,9 @@ import (
 	"os"
 	"os/exec"
 
+	"mend/internal/ui/fstree"
+	"mend/internal/ui/note"
+
 	"github.com/charmbracelet/bubbles/textinput"
 	tea "github.com/charmbracelet/bubbletea"
 	"github.com/charmbracelet/lipgloss"
@@ -12,25 +15,7 @@ import (
 
 /*
 Quick notes to self:
-
-# How bubbletea works?
-Bubbletea is a
-Init ( once for sync/async opts both )
--> Update ( model ) ( againc an be sync/async )
--> View loop
-init creates initial model ( model is the global ui state and just a struct )
-update modifies model based on an immediate or deferred compute
-view is purely for rendering based on model
-
-notes:
-- model struct next -> global ui model
-- createModel is the initial sync model state population
-I anyways need to create the model struct even if blank
-- Init func is for bubbletea to call once at start so both are needed
-- all widths and heights are character count based
-- async updates are via cmds (tea.Cmd ) that are no arg funcs that return
-a tea.Msg ( that is basically a struct and hence has the data needed )
-this data in msg when returned to the update func is used to update the model
+... (comments preserved)
 */
 
 type model struct {
@@ -39,10 +24,10 @@ type model struct {
 	terminalHeight    int
 	fsTreeWidth       int
 	noteViewWidth     int
-	tree              *FsTree
+	tree              *fstree.FsTree
 	rootPath          string // path to load the tree from
 	loading           bool
-	noteView          *NoteView
+	noteView          *note.NoteView
 	isDragging        bool
 	isHoveringDivider bool
 	contentHeight     int
@@ -50,7 +35,7 @@ type model struct {
 	// input handling
 	textInput     textinput.Model
 	inputMode     bool
-	pendingAction FsActionType
+	pendingAction fstree.FsActionType
 }
 
 func NewModel(rootPath string) *model {
@@ -61,7 +46,7 @@ func NewModel(rootPath string) *model {
 	return &model{
 		rootPath:      rootPath,
 		loading:       true,
-		noteView:      NewNoteView(),
+		noteView:      note.NewNoteView(),
 		showStatusBar: false,
 		textInput:     ti,
 	}
@@ -71,7 +56,7 @@ func NewModel(rootPath string) *model {
 // these need to be on the "model" ( duck typing "implements" interface )
 
 type treeLoadedMsg struct {
-	tree *FsTree
+	tree *fstree.FsTree
 }
 
 func (m *model) loadTreeCmd(path string) tea.Cmd {
@@ -87,7 +72,7 @@ func (m *model) loadTreeCmd(path string) tea.Cmd {
 		} else {
 			targetPath = path
 		}
-		return treeLoadedMsg{tree: NewFsTree(targetPath, fsTreeStartOffset)}
+		return treeLoadedMsg{tree: fstree.NewFsTree(targetPath, fsTreeStartOffset)}
 	}
 }
 
@@ -141,40 +126,40 @@ func (m *model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		})
 		return m, cmd
 
-	case nodeSelected:
+	case fstree.NodeSelectedMsg:
 		// Forward node selection to noteView
-		_, cmd := m.noteView.Update(loadNote{path: msg.path})
+		_, cmd := m.noteView.Update(note.LoadNoteMsg{Path: msg.Path})
 		return m, cmd
 
-	case loadNote:
+	case note.LoadNoteMsg:
 		_, cmd := m.noteView.Update(msg)
-		if msg.force {
+		if msg.Force {
 			return m, tea.Batch(cmd, tea.EnableMouseAllMotion)
 		}
 		return m, cmd
 
-	case loadedNote:
+	case note.LoadedNote:
 		// Forward loaded note to noteView
 		_, cmd := m.noteView.Update(msg)
 		return m, cmd
 
-	case PerformActionMsg:
+	case fstree.PerformActionMsg:
 		if m.tree != nil {
 			_, cmd := m.tree.Update(msg)
 			return m, cmd
 		}
 
-	case RequestInputMsg:
+	case fstree.RequestInputMsg:
 		m.inputMode = true
 		m.pendingAction = msg.Action
 		m.textInput.Focus()
 		m.textInput.SetValue("")
 		switch msg.Action {
-		case ActionNewFile:
+		case fstree.ActionNewFile:
 			m.textInput.Placeholder = "New File Name"
-		case ActionNewFolder:
+		case fstree.ActionNewFolder:
 			m.textInput.Placeholder = "New Folder Name"
-		case ActionNewRoot:
+		case fstree.ActionNewRoot:
 			m.textInput.Placeholder = "New Root Folder Name"
 		}
 		m.layout(m.terminalWidth, m.terminalHeight) // recalc layout for status bar area
@@ -192,7 +177,7 @@ func (m *model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 				cmds := []tea.Cmd{m.resizeChildren()}
 				if val != "" {
 					cmds = append(cmds, func() tea.Msg {
-						return PerformActionMsg{
+						return fstree.PerformActionMsg{
 							Action: m.pendingAction,
 							Name:   val,
 						}
@@ -224,16 +209,22 @@ func (m *model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 			m.layout(m.terminalWidth, m.terminalHeight)
 			return m, m.resizeChildren()
 		case "o":
-			if m.tree != nil && m.tree.selectedNode != nil && m.tree.selectedNode.nodeType == FileNode {
-				c := exec.Command("micro", m.tree.selectedNode.path)
+			if m.tree != nil && m.tree.SelectedNode != nil && m.tree.SelectedNode.Type == fstree.FileNode {
+				c := exec.Command("micro", m.tree.SelectedNode.Path)
 				c.Stdin = os.Stdin
 				c.Stdout = os.Stdout
 				c.Stderr = os.Stderr
 				return m, tea.ExecProcess(c, func(err error) tea.Msg {
 					// mouse loses focus so this is neededd
-					return loadNote{path: m.tree.selectedNode.path, force: true}
+					return note.LoadNoteMsg{Path: m.tree.SelectedNode.Path, Force: true}
 				})
 			}
+		case "delete":
+			// Forward delete to fstree if focused (implied focus on tree for now when not editing)
+			if m.tree != nil {
+				_, cmd := m.tree.Update(msg)
+				return m, cmd
+			}
 		}
 
 		var cmds []tea.Cmd
@@ -340,8 +331,8 @@ func (m model) View() string {
 	statusContent := ""
 	if m.inputMode {
 		statusContent = m.textInput.View()
-	} else if m.tree != nil && m.tree.errMsg != "" {
-		statusContent = lipgloss.NewStyle().Foreground(lipgloss.Color("9")).Render(m.tree.errMsg)
+	} else if m.tree != nil && m.tree.ErrMsg != "" {
+		statusContent = lipgloss.NewStyle().Foreground(lipgloss.Color("9")).Render(m.tree.ErrMsg)
 	}
 
 	statusBar := lipgloss.NewStyle().