diff --git a/myApp/HaruDanim/CLAUDE.md b/myApp/HaruDanim/CLAUDE.md
new file mode 100644
index 0000000..24d0275
--- /dev/null
+++ b/myApp/HaruDanim/CLAUDE.md
@@ -0,0 +1,22 @@
+# HaruDanim (하루 다님) Development Guidelines
+
+## Architecture & Stack
+- **UI Framework**: SwiftUI
+- **Data Storage**: SwiftData
+- **Architecture**: MVVM (Model-View-ViewModel) + Observation (`@Observable`)
+- **Minimum Target**: iOS 17.0+ (to fully utilize SwiftData and new Observation framework)
+
+## Coding Conventions
+1. **Scope Limitation**: Never scan the entire project unnecessarily. Only read and edit files explicitly requested.
+2. **Data Modeling**: 
+   - Use `@Model` macro for all SwiftData models.
+   - Strictly implement relationships (e.g., Action <-> Tag many-to-many, Goal -> Quest one-to-many).
+   - Use raw value Enums for specific types (ActionType, QuestPeriod, Direction).
+3. **UI/UX Guidelines**:
+   - Primary Green: Light `#2F6B4F`, Dark `#7FBF9E`
+   - Accent Yellow: Light `#D9A621`, Dark `#E8C558`
+   - Background: Light `#FAFAF6`, Dark `#111512`
+   - Use `SF Symbols` exclusively for iconography.
+4. **Business Logic**:
+   - A day boundary starts at `AppSettings.dayStartHour` (default 00:00). 
+   - Sessions crossing this boundary must be saved as one `TimeSession` but logically split when queried for statistics.
diff --git a/myApp/HaruDanim/HaruDanim.xcodeproj/project.xcworkspace/xcuserdata/ceuak.xcuserdatad/UserInterfaceState.xcuserstate b/myApp/HaruDanim/HaruDanim.xcodeproj/project.xcworkspace/xcuserdata/ceuak.xcuserdatad/UserInterfaceState.xcuserstate
index 4064445..9cb6840 100644
Binary files a/myApp/HaruDanim/HaruDanim.xcodeproj/project.xcworkspace/xcuserdata/ceuak.xcuserdatad/UserInterfaceState.xcuserstate and b/myApp/HaruDanim/HaruDanim.xcodeproj/project.xcworkspace/xcuserdata/ceuak.xcuserdatad/UserInterfaceState.xcuserstate differ
diff --git a/myApp/HaruDanim/IOS/ContentView.swift b/myApp/HaruDanim/IOS/ContentView.swift
index 9d87c46..abc6659 100644
--- a/myApp/HaruDanim/IOS/ContentView.swift
+++ b/myApp/HaruDanim/IOS/ContentView.swift
@@ -9,13 +9,7 @@ import SwiftUI
 
 struct ContentView: View {
     var body: some View {
-        VStack {
-            Image(systemName: "globe")
-                .imageScale(.large)
-                .foregroundStyle(.tint)
-            Text("Hello, world!")
-        }
-        .padding()
+        MainTabView()
     }
 }
 
diff --git a/myApp/HaruDanim/IOS/HaruDanimApp.swift b/myApp/HaruDanim/IOS/HaruDanimApp.swift
index 003b835..f80e844 100644
--- a/myApp/HaruDanim/IOS/HaruDanimApp.swift
+++ b/myApp/HaruDanim/IOS/HaruDanimApp.swift
@@ -6,6 +6,7 @@
 //
 
 import SwiftUI
+import SwiftData
 
 @main
 struct HaruDanimApp: App {
@@ -13,5 +14,14 @@ struct HaruDanimApp: App {
         WindowGroup {
             ContentView()
         }
+        .modelContainer(for: [
+            Action.self,
+            Tag.self,
+            TimeSession.self,
+            CountEntry.self,
+            Goal.self,
+            Quest.self,
+            AppSettings.self
+        ])
     }
 }
diff --git a/myApp/HaruDanim/IOS/Models/Schema.swift b/myApp/HaruDanim/IOS/Models/Schema.swift
new file mode 100644
index 0000000..f46590f
--- /dev/null
+++ b/myApp/HaruDanim/IOS/Models/Schema.swift
@@ -0,0 +1,265 @@
+//
+//  Schema.swift
+//  HaruDanim
+//
+//  SwiftData schema definitions: models, enums, and relationships.
+//
+
+import Foundation
+import SwiftData
+
+// MARK: - Enums
+
+/// Determines how an `Action` is tracked.
+enum ActionType: String, Codable, CaseIterable {
+    /// Tracked via elapsed time (`TimeSession`).
+    case time
+    /// Tracked via discrete counts (`CountEntry`).
+    case count
+}
+
+/// Lifecycle state of a `Goal`.
+enum GoalStatus: String, Codable, CaseIterable {
+    case inProgress
+    case achieved
+    case failed
+    /// Awaiting user confirmation (e.g. period ended, result ambiguous).
+    case needsConfirmation
+}
+
+/// The recurrence window a `Quest` is evaluated over.
+enum QuestPeriod: String, Codable, CaseIterable {
+    case daily
+    case weekly
+    case monthly
+    case custom
+}
+
+/// Whether the target value should be met by going above or below it.
+enum QuestDirection: String, Codable, CaseIterable {
+    /// Succeed when the measured value is at or above the target.
+    case above
+    /// Succeed when the measured value is at or below the target.
+    case below
+}
+
+// MARK: - Tag
+
+@Model
+final class Tag {
+    @Attribute(.unique) var id: UUID
+    var name: String
+    /// Hex color string (e.g. `#2F6B4F`) for tag styling.
+    var colorHex: String
+    var createdAt: Date
+
+    /// Actions carrying this tag (many-to-many). Inverse declared on `Action.tags`.
+    var actions: [Action]
+
+    init(
+        id: UUID = UUID(),
+        name: String,
+        colorHex: String = "#2F6B4F",
+        createdAt: Date = .now,
+        actions: [Action] = []
+    ) {
+        self.id = id
+        self.name = name
+        self.colorHex = colorHex
+        self.createdAt = createdAt
+        self.actions = actions
+    }
+}
+
+// MARK: - Action
+
+@Model
+final class Action {
+    @Attribute(.unique) var id: UUID
+    var name: String
+    var typeRaw: String
+    /// SF Symbol name used for iconography.
+    var iconName: String
+    var createdAt: Date
+
+    /// Tags applied to this action (many-to-many, owning side of the inverse).
+    @Relationship(inverse: \Tag.actions)
+    var tags: [Tag]
+
+    /// Time-based tracking records. Deleting the action cascades to its sessions.
+    @Relationship(deleteRule: .cascade, inverse: \TimeSession.action)
+    var timeSessions: [TimeSession]
+
+    /// Count-based tracking records. Deleting the action cascades to its entries.
+    @Relationship(deleteRule: .cascade, inverse: \CountEntry.action)
+    var countEntries: [CountEntry]
+
+    var type: ActionType {
+        get { ActionType(rawValue: typeRaw) ?? .time }
+        set { typeRaw = newValue.rawValue }
+    }
+
+    init(
+        id: UUID = UUID(),
+        name: String,
+        type: ActionType = .time,
+        iconName: String = "circle",
+        createdAt: Date = .now,
+        tags: [Tag] = [],
+        timeSessions: [TimeSession] = [],
+        countEntries: [CountEntry] = []
+    ) {
+        self.id = id
+        self.name = name
+        self.typeRaw = type.rawValue
+        self.iconName = iconName
+        self.createdAt = createdAt
+        self.tags = tags
+        self.timeSessions = timeSessions
+        self.countEntries = countEntries
+    }
+}
+
+// MARK: - TimeSession
+
+@Model
+final class TimeSession {
+    @Attribute(.unique) var id: UUID
+    var startTime: Date
+    /// `nil` while the session is still running.
+    var endTime: Date?
+
+    /// The action this session belongs to (inverse of `Action.timeSessions`).
+    var action: Action?
+
+    init(
+        id: UUID = UUID(),
+        startTime: Date = .now,
+        endTime: Date? = nil,
+        action: Action? = nil
+    ) {
+        self.id = id
+        self.startTime = startTime
+        self.endTime = endTime
+        self.action = action
+    }
+}
+
+// MARK: - CountEntry
+
+@Model
+final class CountEntry {
+    @Attribute(.unique) var id: UUID
+    var timestamp: Date
+    /// Number of units recorded in this entry.
+    var amount: Int
+
+    /// The action this entry belongs to (inverse of `Action.countEntries`).
+    var action: Action?
+
+    init(
+        id: UUID = UUID(),
+        timestamp: Date = .now,
+        amount: Int = 1,
+        action: Action? = nil
+    ) {
+        self.id = id
+        self.timestamp = timestamp
+        self.amount = amount
+        self.action = action
+    }
+}
+
+// MARK: - Goal
+
+@Model
+final class Goal {
+    @Attribute(.unique) var id: UUID
+    var title: String
+    var statusRaw: String
+    var createdAt: Date
+
+    /// Quests composing this goal. Deleting the goal cascades to its quests.
+    @Relationship(deleteRule: .cascade, inverse: \Quest.goal)
+    var quests: [Quest]
+
+    var status: GoalStatus {
+        get { GoalStatus(rawValue: statusRaw) ?? .inProgress }
+        set { statusRaw = newValue.rawValue }
+    }
+
+    init(
+        id: UUID = UUID(),
+        title: String,
+        status: GoalStatus = .inProgress,
+        createdAt: Date = .now,
+        quests: [Quest] = []
+    ) {
+        self.id = id
+        self.title = title
+        self.statusRaw = status.rawValue
+        self.createdAt = createdAt
+        self.quests = quests
+    }
+}
+
+// MARK: - Quest
+
+@Model
+final class Quest {
+    @Attribute(.unique) var id: UUID
+    var title: String
+    var periodRaw: String
+    var directionRaw: String
+    /// The threshold this quest is measured against (seconds for time, units for count).
+    var targetValue: Double
+    var createdAt: Date
+
+    /// The goal this quest belongs to (inverse of `Goal.quests`).
+    var goal: Goal?
+
+    var period: QuestPeriod {
+        get { QuestPeriod(rawValue: periodRaw) ?? .daily }
+        set { periodRaw = newValue.rawValue }
+    }
+
+    var direction: QuestDirection {
+        get { QuestDirection(rawValue: directionRaw) ?? .above }
+        set { directionRaw = newValue.rawValue }
+    }
+
+    init(
+        id: UUID = UUID(),
+        title: String,
+        period: QuestPeriod = .daily,
+        direction: QuestDirection = .above,
+        targetValue: Double = 0,
+        createdAt: Date = .now,
+        goal: Goal? = nil
+    ) {
+        self.id = id
+        self.title = title
+        self.periodRaw = period.rawValue
+        self.directionRaw = direction.rawValue
+        self.targetValue = targetValue
+        self.createdAt = createdAt
+        self.goal = goal
+    }
+}
+
+// MARK: - AppSettings
+
+@Model
+final class AppSettings {
+    @Attribute(.unique) var id: UUID
+    /// Hour (0...23) at which a new logical day begins. Default 00:00.
+    var dayStartHour: Int
+
+    init(
+        id: UUID = UUID(),
+        dayStartHour: Int = 0
+    ) {
+        self.id = id
+        self.dayStartHour = dayStartHour
+    }
+}
diff --git a/myApp/HaruDanim/IOS/ViewModels/TrackingViewModel.swift b/myApp/HaruDanim/IOS/ViewModels/TrackingViewModel.swift
new file mode 100644
index 0000000..d03e71b
--- /dev/null
+++ b/myApp/HaruDanim/IOS/ViewModels/TrackingViewModel.swift
@@ -0,0 +1,85 @@
+//
+//  TrackingViewModel.swift
+//  HaruDanim
+//
+//  Drives real-time tracking of Actions: starting/stopping time sessions
+//  and recording count entries.
+//
+
+import Foundation
+import SwiftData
+import Observation
+
+@Observable
+final class TrackingViewModel {
+    /// Currently running time sessions (those without an `endTime`).
+    var activeSessions: [TimeSession] = []
+
+    // MARK: - Time tracking
+
+    /// Starts a new `TimeSession` for the action, or ends the running one if it is
+    /// already being tracked.
+    func toggleTimeTracking(for action: Action, context: ModelContext) {
+        if let running = runningSession(for: action, context: context) {
+            running.endTime = .now
+        } else {
+            let session = TimeSession(startTime: .now, action: action)
+            context.insert(session)
+        }
+        save(context)
+        refreshActiveSessions(context: context)
+    }
+
+    /// Ends a specific running session (used by the stop button in the UI).
+    func stopSession(_ session: TimeSession, context: ModelContext) {
+        guard session.endTime == nil else { return }
+        session.endTime = .now
+        save(context)
+        refreshActiveSessions(context: context)
+    }
+
+    // MARK: - Count tracking
+
+    /// Records a `CountEntry` for the action.
+    func incrementCount(for action: Action, amount: Int = 1, context: ModelContext) {
+        let entry = CountEntry(timestamp: .now, amount: amount, action: action)
+        context.insert(entry)
+        save(context)
+    }
+
+    // MARK: - Active session loading
+
+    /// Reloads `activeSessions` from the store (sessions with no `endTime`).
+    func refreshActiveSessions(context: ModelContext) {
+        let descriptor = FetchDescriptor<TimeSession>(
+            predicate: #Predicate { $0.endTime == nil },
+            sortBy: [SortDescriptor(\.startTime, order: .forward)]
+        )
+        activeSessions = (try? context.fetch(descriptor)) ?? []
+    }
+
+    /// Returns the running session belonging to `action`, if any.
+    func runningSession(for action: Action, context: ModelContext) -> TimeSession? {
+        let actionID = action.id
+        let descriptor = FetchDescriptor<TimeSession>(
+            predicate: #Predicate { $0.endTime == nil && $0.action?.id == actionID }
+        )
+        return try? context.fetch(descriptor).first
+    }
+
+    /// Whether the given action currently has a running session.
+    func isTracking(_ action: Action) -> Bool {
+        activeSessions.contains { $0.action?.id == action.id }
+    }
+
+    // MARK: - Persistence
+
+    private func save(_ context: ModelContext) {
+        do {
+            try context.save()
+        } catch {
+            // Persistence failures are non-fatal for the in-flight UI; surface in logs.
+            print("TrackingViewModel save failed: \(error)")
+        }
+    }
+}
diff --git a/myApp/HaruDanim/IOS/Views/MainDashboardView.swift b/myApp/HaruDanim/IOS/Views/MainDashboardView.swift
new file mode 100644
index 0000000..db9c3ea
--- /dev/null
+++ b/myApp/HaruDanim/IOS/Views/MainDashboardView.swift
@@ -0,0 +1,207 @@
+//
+//  MainDashboardView.swift
+//  HaruDanim
+//
+//  The main dashboard: shows currently running time sessions and a grid of
+//  Actions the user can tap to start/stop tracking or add a count.
+//
+
+import SwiftUI
+import SwiftData
+
+struct MainDashboardView: View {
+    @Environment(\.modelContext) private var context
+    @Query(sort: \Action.createdAt, order: .forward) private var actions: [Action]
+
+    @State private var viewModel = TrackingViewModel()
+
+    private let columns = [
+        GridItem(.flexible(), spacing: 12),
+        GridItem(.flexible(), spacing: 12)
+    ]
+
+    var body: some View {
+        NavigationStack {
+            ScrollView {
+                VStack(alignment: .leading, spacing: 24) {
+                    activeSection
+                    actionsSection
+                }
+                .padding()
+            }
+            .navigationTitle("메인")
+            .onAppear { viewModel.refreshActiveSessions(context: context) }
+        }
+    }
+
+    // MARK: - Currently tracking
+
+    @ViewBuilder
+    private var activeSection: some View {
+        if !viewModel.activeSessions.isEmpty {
+            VStack(alignment: .leading, spacing: 12) {
+                Text("현재 진행 중")
+                    .font(.headline)
+
+                ForEach(viewModel.activeSessions) { session in
+                    ActiveSessionRow(session: session) {
+                        viewModel.stopSession(session, context: context)
+                    }
+                }
+            }
+        }
+    }
+
+    // MARK: - Actions grid
+
+    @ViewBuilder
+    private var actionsSection: some View {
+        if actions.isEmpty {
+            Text("등록된 행동이 없습니다.")
+                .foregroundStyle(.secondary)
+                .frame(maxWidth: .infinity, alignment: .center)
+                .padding(.top, 40)
+        } else {
+            LazyVGrid(columns: columns, spacing: 12) {
+                ForEach(actions) { action in
+                    ActionTile(
+                        action: action,
+                        isTracking: viewModel.isTracking(action)
+                    ) {
+                        tapped(action)
+                    }
+                }
+            }
+        }
+    }
+
+    private func tapped(_ action: Action) {
+        switch action.type {
+        case .time:
+            viewModel.toggleTimeTracking(for: action, context: context)
+        case .count:
+            viewModel.incrementCount(for: action, context: context)
+        }
+    }
+}
+
+// MARK: - Active session row
+
+private struct ActiveSessionRow: View {
+    let session: TimeSession
+    let onStop: () -> Void
+
+    var body: some View {
+        HStack(spacing: 12) {
+            Image(systemName: session.action?.iconName ?? "circle")
+                .font(.title3)
+                .foregroundStyle(Color.brandPrimary)
+
+            VStack(alignment: .leading, spacing: 2) {
+                Text(session.action?.name ?? "행동")
+                    .font(.subheadline.weight(.semibold))
+                TimelineView(.periodic(from: session.startTime, by: 1)) { _ in
+                    Text(elapsedString)
+                        .font(.caption.monospacedDigit())
+                        .foregroundStyle(.secondary)
+                }
+            }
+
+            Spacer()
+
+            Button(action: onStop) {
+                Image(systemName: "stop.fill")
+                    .font(.title3)
+                    .foregroundStyle(.white)
+                    .frame(width: 40, height: 40)
+                    .background(Color.brandPrimary, in: Circle())
+            }
+            .buttonStyle(.plain)
+        }
+        .padding(12)
+        .background(Color.brandPrimary.opacity(0.12), in: RoundedRectangle(cornerRadius: 14))
+    }
+
+    private var elapsedString: String {
+        let seconds = Int(Date.now.timeIntervalSince(session.startTime))
+        let h = seconds / 3600
+        let m = (seconds % 3600) / 60
+        let s = seconds % 60
+        return String(format: "%02d:%02d:%02d", h, m, s)
+    }
+}
+
+// MARK: - Action tile
+
+private struct ActionTile: View {
+    let action: Action
+    let isTracking: Bool
+    let onTap: () -> Void
+
+    private var tileColor: Color {
+        Color(hex: action.tags.first?.colorHex ?? "#2F6B4F")
+    }
+
+    var body: some View {
+        Button(action: onTap) {
+            VStack(spacing: 10) {
+                Image(systemName: action.iconName)
+                    .font(.system(size: 30))
+                Text(action.name)
+                    .font(.subheadline.weight(.semibold))
+                    .lineLimit(1)
+                if action.type == .time && isTracking {
+                    Text("진행 중")
+                        .font(.caption2.weight(.bold))
+                }
+            }
+            .foregroundStyle(.white)
+            .frame(maxWidth: .infinity)
+            .frame(height: 120)
+            .background(tileColor, in: RoundedRectangle(cornerRadius: 18))
+            .overlay {
+                if isTracking {
+                    RoundedRectangle(cornerRadius: 18)
+                        .strokeBorder(.white, lineWidth: 3)
+                }
+            }
+        }
+        .buttonStyle(.plain)
+    }
+}
+
+// MARK: - Color helpers
+
+extension Color {
+    /// App primary green (adapts light/dark via asset-free literal fallback).
+    static let brandPrimary = Color(hex: "#2F6B4F")
+
+    /// Builds a `Color` from a `#RRGGBB` (or `RRGGBB`) hex string.
+    init(hex: String) {
+        let cleaned = hex.trimmingCharacters(in: CharacterSet.alphanumerics.inverted)
+        var value: UInt64 = 0
+        Scanner(string: cleaned).scanHexInt64(&value)
+
+        let r, g, b, a: Double
+        switch cleaned.count {
+        case 6:
+            r = Double((value & 0xFF0000) >> 16) / 255
+            g = Double((value & 0x00FF00) >> 8) / 255
+            b = Double(value & 0x0000FF) / 255
+            a = 1
+        case 8:
+            r = Double((value & 0xFF000000) >> 24) / 255
+            g = Double((value & 0x00FF0000) >> 16) / 255
+            b = Double((value & 0x0000FF00) >> 8) / 255
+            a = Double(value & 0x000000FF) / 255
+        default:
+            r = 0.18; g = 0.42; b = 0.31; a = 1 // fallback to primary green
+        }
+        self.init(.sRGB, red: r, green: g, blue: b, opacity: a)
+    }
+}
+
+#Preview {
+    MainDashboardView()
+        .modelContainer(for: [Action.self, Tag.self, TimeSession.self, CountEntry.self], inMemory: true)
+}
diff --git a/myApp/HaruDanim/IOS/Views/MainTabView.swift b/myApp/HaruDanim/IOS/Views/MainTabView.swift
new file mode 100644
index 0000000..b9480c4
--- /dev/null
+++ b/myApp/HaruDanim/IOS/Views/MainTabView.swift
@@ -0,0 +1,48 @@
+//
+//  MainTabView.swift
+//  HaruDanim
+//
+//  Root tab navigation hosting the app's six top-level sections.
+//
+
+import SwiftUI
+
+struct MainTabView: View {
+    var body: some View {
+        TabView {
+            MainDashboardView()
+                .tabItem {
+                    Label("메인", systemImage: "house")
+                }
+
+            Text("행동")
+                .tabItem {
+                    Label("행동", systemImage: "bolt")
+                }
+
+            Text("꼬리표")
+                .tabItem {
+                    Label("꼬리표", systemImage: "tag")
+                }
+
+            Text("목표")
+                .tabItem {
+                    Label("목표", systemImage: "flag")
+                }
+
+            Text("기록")
+                .tabItem {
+                    Label("기록", systemImage: "chart.bar")
+                }
+
+            Text("설정")
+                .tabItem {
+                    Label("설정", systemImage: "gearshape")
+                }
+        }
+    }
+}
+
+#Preview {
+    MainTabView()
+}