diff --git a/app/build.gradle.kts b/app/build.gradle.kts
index 201015e..1d36efa 100644
--- a/app/build.gradle.kts
+++ b/app/build.gradle.kts
@@ -3,6 +3,7 @@ plugins {
     alias(libs.plugins.jetbrains.kotlin.android)
     alias(libs.plugins.hilt)
     alias(libs.plugins.ksp)
+    alias(libs.plugins.kotlin.serialization)
 }
 
 android {
@@ -82,6 +83,9 @@ dependencies {
     // WorkManager
     implementation(libs.work.runtime.ktx)
 
+    // Serialization
+    implementation(libs.kotlinx.serialization.json)
+
     // Tests
     testImplementation(libs.junit)
     androidTestImplementation(libs.androidx.junit)
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 8c6cf7a..a316bb8 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -26,6 +26,18 @@
             </intent-filter>
         </activity>
 
+        <receiver
+            android:name=".data.notification.ReminderReceiver"
+            android:exported="false" />
+
+        <receiver
+            android:name=".data.notification.BootReceiver"
+            android:exported="true">
+            <intent-filter>
+                <action android:name="android.intent.action.BOOT_COMPLETED" />
+            </intent-filter>
+        </receiver>
+
     </application>
 
 </manifest>
diff --git a/app/src/main/java/com/planify/mobile/data/local/AppDatabase.kt b/app/src/main/java/com/planify/mobile/data/local/AppDatabase.kt
index 0c86eaf..f872021 100644
--- a/app/src/main/java/com/planify/mobile/data/local/AppDatabase.kt
+++ b/app/src/main/java/com/planify/mobile/data/local/AppDatabase.kt
@@ -2,7 +2,9 @@ package com.planify.mobile.data.local
 
 import androidx.room.Database
 import androidx.room.RoomDatabase
+import com.planify.mobile.data.local.dao.LabelDao
 import com.planify.mobile.data.local.dao.ProjectDao
+import com.planify.mobile.data.local.dao.ReminderDao
 import com.planify.mobile.data.local.dao.SectionDao
 import com.planify.mobile.data.local.dao.TaskDao
 import com.planify.mobile.data.local.entity.LabelEntity
@@ -28,4 +30,6 @@ abstract class AppDatabase : RoomDatabase() {
     abstract fun taskDao(): TaskDao
     abstract fun projectDao(): ProjectDao
     abstract fun sectionDao(): SectionDao
+    abstract fun labelDao(): LabelDao
+    abstract fun reminderDao(): ReminderDao
 }
diff --git a/app/src/main/java/com/planify/mobile/data/local/dao/LabelDao.kt b/app/src/main/java/com/planify/mobile/data/local/dao/LabelDao.kt
new file mode 100644
index 0000000..e33d513
--- /dev/null
+++ b/app/src/main/java/com/planify/mobile/data/local/dao/LabelDao.kt
@@ -0,0 +1,27 @@
+package com.planify.mobile.data.local.dao
+
+import androidx.room.Dao
+import androidx.room.Insert
+import androidx.room.OnConflictStrategy
+import androidx.room.Query
+import androidx.room.Update
+import com.planify.mobile.data.local.entity.LabelEntity
+import kotlinx.coroutines.flow.Flow
+
+@Dao
+interface LabelDao {
+    @Query("SELECT * FROM labels WHERE is_deleted = 0 ORDER BY `order` ASC")
+    fun getAllLabels(): Flow<List<LabelEntity>>
+
+    @Query("SELECT * FROM labels WHERE id = :id")
+    suspend fun getById(id: String): LabelEntity?
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun insert(label: LabelEntity)
+
+    @Update
+    suspend fun update(label: LabelEntity)
+
+    @Query("UPDATE labels SET is_deleted = 1 WHERE id = :id")
+    suspend fun softDelete(id: String)
+}
diff --git a/app/src/main/java/com/planify/mobile/data/local/dao/ReminderDao.kt b/app/src/main/java/com/planify/mobile/data/local/dao/ReminderDao.kt
new file mode 100644
index 0000000..d0e1675
--- /dev/null
+++ b/app/src/main/java/com/planify/mobile/data/local/dao/ReminderDao.kt
@@ -0,0 +1,24 @@
+package com.planify.mobile.data.local.dao
+
+import androidx.room.Dao
+import androidx.room.Delete
+import androidx.room.Insert
+import androidx.room.OnConflictStrategy
+import androidx.room.Query
+import com.planify.mobile.data.local.entity.ReminderEntity
+import kotlinx.coroutines.flow.Flow
+
+@Dao
+interface ReminderDao {
+    @Query("SELECT * FROM reminders WHERE task_id = :taskId")
+    fun getRemindersByTask(taskId: String): Flow<List<ReminderEntity>>
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun insert(reminder: ReminderEntity)
+
+    @Delete
+    suspend fun delete(reminder: ReminderEntity)
+
+    @Query("DELETE FROM reminders WHERE task_id = :taskId")
+    suspend fun deleteByTask(taskId: String)
+}
diff --git a/app/src/main/java/com/planify/mobile/data/notification/BootReceiver.kt b/app/src/main/java/com/planify/mobile/data/notification/BootReceiver.kt
new file mode 100644
index 0000000..9f94458
--- /dev/null
+++ b/app/src/main/java/com/planify/mobile/data/notification/BootReceiver.kt
@@ -0,0 +1,16 @@
+package com.planify.mobile.data.notification
+
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+import dagger.hilt.android.AndroidEntryPoint
+
+@AndroidEntryPoint
+class BootReceiver : BroadcastReceiver() {
+
+    override fun onReceive(context: Context, intent: Intent) {
+        if (intent.action != Intent.ACTION_BOOT_COMPLETED) return
+        // TODO #14 : replanifier toutes les alarmes depuis la base de données
+        // Inject ReminderScheduler + ReminderRepository et rejouer tous les rappels actifs
+    }
+}
diff --git a/app/src/main/java/com/planify/mobile/data/notification/ReminderReceiver.kt b/app/src/main/java/com/planify/mobile/data/notification/ReminderReceiver.kt
new file mode 100644
index 0000000..afacb9c
--- /dev/null
+++ b/app/src/main/java/com/planify/mobile/data/notification/ReminderReceiver.kt
@@ -0,0 +1,56 @@
+package com.planify.mobile.data.notification
+
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.app.PendingIntent
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+import androidx.core.app.NotificationCompat
+import com.planify.mobile.ui.MainActivity
+import dagger.hilt.android.AndroidEntryPoint
+
+@AndroidEntryPoint
+class ReminderReceiver : BroadcastReceiver() {
+
+    override fun onReceive(context: Context, intent: Intent) {
+        val taskId = intent.getStringExtra(EXTRA_TASK_ID) ?: return
+        val title = intent.getStringExtra(EXTRA_TASK_TITLE) ?: "Rappel"
+
+        val notificationManager = context.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
+        ensureChannel(notificationManager)
+
+        val openIntent = Intent(context, MainActivity::class.java).apply {
+            flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TOP
+            putExtra("taskId", taskId)
+        }
+        val openPi = PendingIntent.getActivity(
+            context, taskId.hashCode(), openIntent,
+            PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE,
+        )
+
+        val notification = NotificationCompat.Builder(context, CHANNEL_ID)
+            .setSmallIcon(android.R.drawable.ic_lock_idle_alarm)
+            .setContentTitle("Rappel")
+            .setContentText(title)
+            .setContentIntent(openPi)
+            .setAutoCancel(true)
+            .setPriority(NotificationCompat.PRIORITY_HIGH)
+            .build()
+
+        notificationManager.notify(taskId.hashCode(), notification)
+    }
+
+    private fun ensureChannel(nm: NotificationManager) {
+        if (nm.getNotificationChannel(CHANNEL_ID) != null) return
+        val channel = NotificationChannel(CHANNEL_ID, "Rappels", NotificationManager.IMPORTANCE_HIGH)
+        nm.createNotificationChannel(channel)
+    }
+
+    companion object {
+        const val CHANNEL_ID = "planify_reminders"
+        const val EXTRA_REMINDER_ID = "reminder_id"
+        const val EXTRA_TASK_ID = "task_id"
+        const val EXTRA_TASK_TITLE = "task_title"
+    }
+}
diff --git a/app/src/main/java/com/planify/mobile/data/notification/ReminderScheduler.kt b/app/src/main/java/com/planify/mobile/data/notification/ReminderScheduler.kt
new file mode 100644
index 0000000..7a66f41
--- /dev/null
+++ b/app/src/main/java/com/planify/mobile/data/notification/ReminderScheduler.kt
@@ -0,0 +1,73 @@
+package com.planify.mobile.data.notification
+
+import android.app.AlarmManager
+import android.app.PendingIntent
+import android.content.Context
+import android.content.Intent
+import android.os.Build
+import com.planify.mobile.domain.model.Reminder
+import com.planify.mobile.domain.model.ReminderType
+import dagger.hilt.android.qualifiers.ApplicationContext
+import java.time.LocalDate
+import java.time.LocalDateTime
+import java.time.ZoneId
+import java.time.format.DateTimeFormatter
+import javax.inject.Inject
+import javax.inject.Singleton
+
+@Singleton
+class ReminderScheduler @Inject constructor(
+    @ApplicationContext private val context: Context,
+) {
+    private val alarmManager = context.getSystemService(Context.ALARM_SERVICE) as AlarmManager
+
+    fun schedule(reminder: Reminder, taskTitle: String, taskDueDateIso: String?) {
+        val triggerMillis = when (reminder.type) {
+            ReminderType.ABSOLUTE -> reminder.dueDate?.date?.let { parseToMillis(it) }
+            ReminderType.RELATIVE -> {
+                val offset = reminder.minutesOffset ?: return
+                taskDueDateIso?.let { parseToMillis(it) }?.minus(offset * 60_000L)
+            }
+        } ?: return
+
+        if (triggerMillis <= System.currentTimeMillis()) return
+
+        val intent = Intent(context, ReminderReceiver::class.java).apply {
+            putExtra(ReminderReceiver.EXTRA_REMINDER_ID, reminder.id)
+            putExtra(ReminderReceiver.EXTRA_TASK_ID, reminder.taskId)
+            putExtra(ReminderReceiver.EXTRA_TASK_TITLE, taskTitle)
+        }
+        val pi = PendingIntent.getBroadcast(
+            context,
+            reminder.id.hashCode(),
+            intent,
+            PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE,
+        )
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S && !alarmManager.canScheduleExactAlarms()) {
+            alarmManager.setAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, triggerMillis, pi)
+        } else {
+            alarmManager.setExactAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, triggerMillis, pi)
+        }
+    }
+
+    fun cancel(reminderId: String) {
+        val intent = Intent(context, ReminderReceiver::class.java)
+        val pi = PendingIntent.getBroadcast(
+            context,
+            reminderId.hashCode(),
+            intent,
+            PendingIntent.FLAG_NO_CREATE or PendingIntent.FLAG_IMMUTABLE,
+        ) ?: return
+        alarmManager.cancel(pi)
+        pi.cancel()
+    }
+
+    private fun parseToMillis(dateIso: String): Long? = runCatching {
+        val formatter = if (dateIso.contains("T")) DateTimeFormatter.ISO_LOCAL_DATE_TIME
+        else DateTimeFormatter.ISO_LOCAL_DATE
+        val ldt = if (dateIso.contains("T")) LocalDateTime.parse(dateIso, formatter)
+        else LocalDate.parse(dateIso, formatter).atStartOfDay()
+        ldt.atZone(ZoneId.systemDefault()).toInstant().toEpochMilli()
+    }.getOrNull()
+}
diff --git a/app/src/main/java/com/planify/mobile/data/repository/LabelRepositoryImpl.kt b/app/src/main/java/com/planify/mobile/data/repository/LabelRepositoryImpl.kt
new file mode 100644
index 0000000..0cc7d01
--- /dev/null
+++ b/app/src/main/java/com/planify/mobile/data/repository/LabelRepositoryImpl.kt
@@ -0,0 +1,34 @@
+package com.planify.mobile.data.repository
+
+import com.planify.mobile.data.local.dao.LabelDao
+import com.planify.mobile.data.local.entity.LabelEntity
+import com.planify.mobile.domain.model.BackendType
+import com.planify.mobile.domain.model.Label
+import com.planify.mobile.domain.repository.LabelRepository
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.map
+import javax.inject.Inject
+
+class LabelRepositoryImpl @Inject constructor(
+    private val dao: LabelDao,
+) : LabelRepository {
+
+    override fun getAllLabels(): Flow<List<Label>> =
+        dao.getAllLabels().map { it.map { e -> e.toDomain() } }
+
+    override suspend fun getLabelById(id: String): Label? = dao.getById(id)?.toDomain()
+    override suspend fun insertLabel(label: Label) = dao.insert(label.toEntity())
+    override suspend fun updateLabel(label: Label) = dao.update(label.toEntity())
+    override suspend fun deleteLabel(id: String) = dao.softDelete(id)
+
+    private fun LabelEntity.toDomain() = Label(
+        id = id, name = name, color = color, order = order, sourceId = sourceId,
+        backendType = runCatching { BackendType.valueOf(backendType) }.getOrDefault(BackendType.LOCAL),
+        isFavorite = isFavorite, isDeleted = isDeleted,
+    )
+
+    private fun Label.toEntity() = LabelEntity(
+        id = id, name = name, color = color, order = order, sourceId = sourceId,
+        backendType = backendType.name, isFavorite = isFavorite, isDeleted = isDeleted,
+    )
+}
diff --git a/app/src/main/java/com/planify/mobile/data/repository/ReminderRepositoryImpl.kt b/app/src/main/java/com/planify/mobile/data/repository/ReminderRepositoryImpl.kt
new file mode 100644
index 0000000..d126ea3
--- /dev/null
+++ b/app/src/main/java/com/planify/mobile/data/repository/ReminderRepositoryImpl.kt
@@ -0,0 +1,43 @@
+package com.planify.mobile.data.repository
+
+import com.planify.mobile.data.local.dao.ReminderDao
+import com.planify.mobile.data.local.entity.ReminderEntity
+import com.planify.mobile.domain.model.DueDate
+import com.planify.mobile.domain.model.Reminder
+import com.planify.mobile.domain.model.ReminderType
+import com.planify.mobile.domain.repository.ReminderRepository
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.map
+import kotlinx.serialization.encodeToString
+import kotlinx.serialization.json.Json
+import javax.inject.Inject
+
+class ReminderRepositoryImpl @Inject constructor(
+    private val dao: ReminderDao,
+) : ReminderRepository {
+
+    override fun getRemindersByTask(taskId: String): Flow<List<Reminder>> =
+        dao.getRemindersByTask(taskId).map { list -> list.map { it.toDomain() } }
+
+    override suspend fun insertReminder(reminder: Reminder) = dao.insert(reminder.toEntity())
+
+    override suspend fun deleteReminder(reminder: Reminder) = dao.delete(reminder.toEntity())
+
+    override suspend fun deleteRemindersByTask(taskId: String) = dao.deleteByTask(taskId)
+
+    private fun ReminderEntity.toDomain() = Reminder(
+        id = id,
+        taskId = taskId,
+        type = ReminderType.valueOf(type),
+        dueDate = dueDate?.let { runCatching { Json.decodeFromString<DueDate>(it) }.getOrNull() },
+        minutesOffset = minutesOffset,
+    )
+
+    private fun Reminder.toEntity() = ReminderEntity(
+        id = id,
+        taskId = taskId,
+        type = type.name,
+        dueDate = dueDate?.let { Json.encodeToString(it) },
+        minutesOffset = minutesOffset,
+    )
+}
diff --git a/app/src/main/java/com/planify/mobile/di/DatabaseModule.kt b/app/src/main/java/com/planify/mobile/di/DatabaseModule.kt
index e8d5238..bc9352e 100644
--- a/app/src/main/java/com/planify/mobile/di/DatabaseModule.kt
+++ b/app/src/main/java/com/planify/mobile/di/DatabaseModule.kt
@@ -24,4 +24,6 @@ object DatabaseModule {
     @Provides fun provideTaskDao(db: AppDatabase) = db.taskDao()
     @Provides fun provideProjectDao(db: AppDatabase) = db.projectDao()
     @Provides fun provideSectionDao(db: AppDatabase) = db.sectionDao()
+    @Provides fun provideLabelDao(db: AppDatabase) = db.labelDao()
+    @Provides fun provideReminderDao(db: AppDatabase) = db.reminderDao()
 }
diff --git a/app/src/main/java/com/planify/mobile/di/RepositoryModule.kt b/app/src/main/java/com/planify/mobile/di/RepositoryModule.kt
index 0eb6edd..8c0977b 100644
--- a/app/src/main/java/com/planify/mobile/di/RepositoryModule.kt
+++ b/app/src/main/java/com/planify/mobile/di/RepositoryModule.kt
@@ -1,9 +1,13 @@
 package com.planify.mobile.di
 
+import com.planify.mobile.data.repository.LabelRepositoryImpl
 import com.planify.mobile.data.repository.ProjectRepositoryImpl
+import com.planify.mobile.data.repository.ReminderRepositoryImpl
 import com.planify.mobile.data.repository.SectionRepositoryImpl
 import com.planify.mobile.data.repository.TaskRepositoryImpl
+import com.planify.mobile.domain.repository.LabelRepository
 import com.planify.mobile.domain.repository.ProjectRepository
+import com.planify.mobile.domain.repository.ReminderRepository
 import com.planify.mobile.domain.repository.SectionRepository
 import com.planify.mobile.domain.repository.TaskRepository
 import dagger.Binds
@@ -24,4 +28,10 @@ abstract class RepositoryModule {
 
     @Binds @Singleton
     abstract fun bindSectionRepository(impl: SectionRepositoryImpl): SectionRepository
+
+    @Binds @Singleton
+    abstract fun bindLabelRepository(impl: LabelRepositoryImpl): LabelRepository
+
+    @Binds @Singleton
+    abstract fun bindReminderRepository(impl: ReminderRepositoryImpl): ReminderRepository
 }
diff --git a/app/src/main/java/com/planify/mobile/domain/model/DueDate.kt b/app/src/main/java/com/planify/mobile/domain/model/DueDate.kt
index 72e7508..9d85c3f 100644
--- a/app/src/main/java/com/planify/mobile/domain/model/DueDate.kt
+++ b/app/src/main/java/com/planify/mobile/domain/model/DueDate.kt
@@ -1,5 +1,8 @@
 package com.planify.mobile.domain.model
 
+import kotlinx.serialization.Serializable
+
+@Serializable
 data class DueDate(
     val date: String,
     val timezone: String? = null,
@@ -11,6 +14,7 @@ data class DueDate(
     val recurrencyEnd: String? = null,
 )
 
+@Serializable
 enum class RecurrencyType {
     NONE, MINUTELY, HOURLY, EVERY_DAY, EVERY_WEEK, EVERY_MONTH, EVERY_YEAR
 }
diff --git a/app/src/main/java/com/planify/mobile/domain/repository/LabelRepository.kt b/app/src/main/java/com/planify/mobile/domain/repository/LabelRepository.kt
new file mode 100644
index 0000000..f353d16
--- /dev/null
+++ b/app/src/main/java/com/planify/mobile/domain/repository/LabelRepository.kt
@@ -0,0 +1,12 @@
+package com.planify.mobile.domain.repository
+
+import com.planify.mobile.domain.model.Label
+import kotlinx.coroutines.flow.Flow
+
+interface LabelRepository {
+    fun getAllLabels(): Flow<List<Label>>
+    suspend fun getLabelById(id: String): Label?
+    suspend fun insertLabel(label: Label)
+    suspend fun updateLabel(label: Label)
+    suspend fun deleteLabel(id: String)
+}
diff --git a/app/src/main/java/com/planify/mobile/domain/repository/ReminderRepository.kt b/app/src/main/java/com/planify/mobile/domain/repository/ReminderRepository.kt
new file mode 100644
index 0000000..50d8d4e
--- /dev/null
+++ b/app/src/main/java/com/planify/mobile/domain/repository/ReminderRepository.kt
@@ -0,0 +1,11 @@
+package com.planify.mobile.domain.repository
+
+import com.planify.mobile.domain.model.Reminder
+import kotlinx.coroutines.flow.Flow
+
+interface ReminderRepository {
+    fun getRemindersByTask(taskId: String): Flow<List<Reminder>>
+    suspend fun insertReminder(reminder: Reminder)
+    suspend fun deleteReminder(reminder: Reminder)
+    suspend fun deleteRemindersByTask(taskId: String)
+}
diff --git a/app/src/main/java/com/planify/mobile/domain/util/RRuleBuilder.kt b/app/src/main/java/com/planify/mobile/domain/util/RRuleBuilder.kt
new file mode 100644
index 0000000..971d7af
--- /dev/null
+++ b/app/src/main/java/com/planify/mobile/domain/util/RRuleBuilder.kt
@@ -0,0 +1,75 @@
+package com.planify.mobile.domain.util
+
+import com.planify.mobile.domain.model.DueDate
+import com.planify.mobile.domain.model.RecurrencyType
+
+object RRuleBuilder {
+
+    private val weekDayNames = listOf("MO", "TU", "WE", "TH", "FR", "SA", "SU")
+
+    fun build(dueDate: DueDate): String? {
+        if (!dueDate.isRecurring || dueDate.recurrencyType == RecurrencyType.NONE) return null
+
+        val freq = when (dueDate.recurrencyType) {
+            RecurrencyType.MINUTELY -> "MINUTELY"
+            RecurrencyType.HOURLY -> "HOURLY"
+            RecurrencyType.EVERY_DAY -> "DAILY"
+            RecurrencyType.EVERY_WEEK -> "WEEKLY"
+            RecurrencyType.EVERY_MONTH -> "MONTHLY"
+            RecurrencyType.EVERY_YEAR -> "YEARLY"
+            RecurrencyType.NONE -> return null
+        }
+
+        val parts = mutableListOf("FREQ=$freq")
+
+        if (dueDate.recurrencyInterval > 1) {
+            parts.add("INTERVAL=${dueDate.recurrencyInterval}")
+        }
+
+        if (dueDate.recurrencyType == RecurrencyType.EVERY_WEEK && dueDate.recurrencyWeekDays.isNotEmpty()) {
+            val days = dueDate.recurrencyWeekDays
+                .filter { it in 0..6 }
+                .joinToString(",") { weekDayNames[it] }
+            parts.add("BYDAY=$days")
+        }
+
+        dueDate.recurrencyCount?.let { parts.add("COUNT=$it") }
+        dueDate.recurrencyEnd?.let { parts.add("UNTIL=${it.replace("-", "").take(8)}T000000Z") }
+
+        return "RRULE:${parts.joinToString(";")}"
+    }
+
+    fun parse(rrule: String): DueDate? {
+        val line = rrule.removePrefix("RRULE:")
+        val props = line.split(";").associate {
+            val (k, v) = it.split("=", limit = 2)
+            k to v
+        }
+
+        val type = when (props["FREQ"]) {
+            "MINUTELY" -> RecurrencyType.MINUTELY
+            "HOURLY" -> RecurrencyType.HOURLY
+            "DAILY" -> RecurrencyType.EVERY_DAY
+            "WEEKLY" -> RecurrencyType.EVERY_WEEK
+            "MONTHLY" -> RecurrencyType.EVERY_MONTH
+            "YEARLY" -> RecurrencyType.EVERY_YEAR
+            else -> return null
+        }
+
+        val weekDays = props["BYDAY"]?.split(",")?.mapNotNull { weekDayNames.indexOf(it).takeIf { i -> i >= 0 } } ?: emptyList()
+        val count = props["COUNT"]?.toIntOrNull()
+        val until = props["UNTIL"]?.let { raw ->
+            if (raw.length >= 8) "${raw.take(4)}-${raw.substring(4, 6)}-${raw.substring(6, 8)}" else null
+        }
+
+        return DueDate(
+            date = "",
+            isRecurring = true,
+            recurrencyType = type,
+            recurrencyInterval = props["INTERVAL"]?.toIntOrNull() ?: 1,
+            recurrencyWeekDays = weekDays,
+            recurrencyCount = count,
+            recurrencyEnd = until,
+        )
+    }
+}
diff --git a/app/src/main/java/com/planify/mobile/ui/project/ProjectEditSheet.kt b/app/src/main/java/com/planify/mobile/ui/project/ProjectEditSheet.kt
new file mode 100644
index 0000000..86f8f57
--- /dev/null
+++ b/app/src/main/java/com/planify/mobile/ui/project/ProjectEditSheet.kt
@@ -0,0 +1,167 @@
+package com.planify.mobile.ui.project
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.border
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.lazy.grid.GridCells
+import androidx.compose.foundation.lazy.grid.LazyVerticalGrid
+import androidx.compose.foundation.lazy.grid.items
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.outlined.Delete
+import androidx.compose.material.icons.outlined.Star
+import androidx.compose.material.icons.outlined.StarBorder
+import androidx.compose.material3.Button
+import androidx.compose.material3.ButtonDefaults
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.HorizontalDivider
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.ModalBottomSheet
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.SegmentedButton
+import androidx.compose.material3.SegmentedButtonDefaults
+import androidx.compose.material3.SingleChoiceSegmentedButtonRow
+import androidx.compose.material3.Text
+import androidx.compose.material3.rememberModalBottomSheetState
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+import com.planify.mobile.domain.model.ViewStyle
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun ProjectEditSheet(
+    projectId: String? = null,
+    onDismiss: () -> Unit,
+    onSaved: (projectId: String) -> Unit = {},
+    onDeleted: () -> Unit = {},
+    viewModel: ProjectEditViewModel = hiltViewModel(),
+) {
+    LaunchedEffect(projectId) { viewModel.init(projectId) }
+
+    val state by viewModel.state.collectAsState()
+    val sheetState = rememberModalBottomSheetState(skipPartiallyExpanded = true)
+
+    ModalBottomSheet(onDismissRequest = onDismiss, sheetState = sheetState) {
+        Column(Modifier.padding(horizontal = 16.dp)) {
+            Row(
+                modifier = Modifier.fillMaxWidth(),
+                verticalAlignment = Alignment.CenterVertically,
+            ) {
+                Text(
+                    text = if (projectId == null) "Nouveau projet" else "Modifier le projet",
+                    style = MaterialTheme.typography.titleMedium,
+                    modifier = Modifier.weight(1f),
+                )
+                IconButton(onClick = { viewModel.toggleFavorite() }) {
+                    Icon(
+                        imageVector = if (state.isFavorite) Icons.Outlined.Star else Icons.Outlined.StarBorder,
+                        contentDescription = "Favori",
+                        tint = if (state.isFavorite) Color(0xFFFFC107) else MaterialTheme.colorScheme.onSurfaceVariant,
+                    )
+                }
+                if (projectId != null) {
+                    IconButton(onClick = { viewModel.delete { onDeleted(); onDismiss() } }) {
+                        Icon(Icons.Outlined.Delete, contentDescription = "Supprimer", tint = MaterialTheme.colorScheme.error)
+                    }
+                }
+            }
+
+            Spacer(Modifier.height(12.dp))
+
+            OutlinedTextField(
+                value = state.name,
+                onValueChange = viewModel::setName,
+                placeholder = { Text("Nom du projet") },
+                modifier = Modifier.fillMaxWidth(),
+                singleLine = true,
+                leadingIcon = {
+                    Box(
+                        modifier = Modifier
+                            .size(20.dp)
+                            .clip(CircleShape)
+                            .background(parseColor(state.color)),
+                    )
+                },
+            )
+
+            Spacer(Modifier.height(16.dp))
+            Text("Couleur", style = MaterialTheme.typography.labelMedium, color = MaterialTheme.colorScheme.onSurfaceVariant)
+            Spacer(Modifier.height(8.dp))
+
+            LazyVerticalGrid(
+                columns = GridCells.Fixed(6),
+                modifier = Modifier.height(80.dp),
+                horizontalArrangement = Arrangement.spacedBy(8.dp),
+                verticalArrangement = Arrangement.spacedBy(8.dp),
+            ) {
+                items(viewModel.colors) { color ->
+                    Box(
+                        modifier = Modifier
+                            .size(36.dp)
+                            .clip(CircleShape)
+                            .background(parseColor(color))
+                            .then(
+                                if (color == state.color) Modifier.border(2.dp, MaterialTheme.colorScheme.onSurface, CircleShape)
+                                else Modifier
+                            )
+                            .clickable { viewModel.setColor(color) },
+                    )
+                }
+            }
+
+            Spacer(Modifier.height(16.dp))
+            HorizontalDivider()
+            Spacer(Modifier.height(12.dp))
+
+            Text("Vue par défaut", style = MaterialTheme.typography.labelMedium, color = MaterialTheme.colorScheme.onSurfaceVariant)
+            Spacer(Modifier.height(8.dp))
+
+            SingleChoiceSegmentedButtonRow(modifier = Modifier.fillMaxWidth()) {
+                ViewStyle.entries.forEachIndexed { index, style ->
+                    SegmentedButton(
+                        selected = state.viewStyle == style,
+                        onClick = { viewModel.setViewStyle(style) },
+                        shape = SegmentedButtonDefaults.itemShape(index = index, count = ViewStyle.entries.size),
+                        label = { Text(if (style == ViewStyle.LIST) "Liste" else "Tableau") },
+                    )
+                }
+            }
+
+            Spacer(Modifier.height(16.dp))
+
+            Row(modifier = Modifier.fillMaxWidth(), horizontalArrangement = Arrangement.End) {
+                Button(
+                    onClick = { viewModel.save(onDone = { id -> onSaved(id); onDismiss() }) },
+                    enabled = state.name.isNotBlank() && !state.isSaving,
+                ) {
+                    Text(if (projectId == null) "Créer" else "Enregistrer")
+                }
+            }
+
+            Spacer(Modifier.height(16.dp))
+        }
+    }
+}
+
+private fun parseColor(hex: String): Color = runCatching {
+    Color(android.graphics.Color.parseColor(hex))
+}.getOrDefault(Color.Gray)
diff --git a/app/src/main/java/com/planify/mobile/ui/project/ProjectEditViewModel.kt b/app/src/main/java/com/planify/mobile/ui/project/ProjectEditViewModel.kt
new file mode 100644
index 0000000..593648c
--- /dev/null
+++ b/app/src/main/java/com/planify/mobile/ui/project/ProjectEditViewModel.kt
@@ -0,0 +1,113 @@
+package com.planify.mobile.ui.project
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.planify.mobile.domain.model.BackendType
+import com.planify.mobile.domain.model.Project
+import com.planify.mobile.domain.model.SortBy
+import com.planify.mobile.domain.model.ViewStyle
+import com.planify.mobile.domain.repository.ProjectRepository
+import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.update
+import kotlinx.coroutines.launch
+import java.util.UUID
+import javax.inject.Inject
+
+data class ProjectEditState(
+    val projectId: String? = null,
+    val name: String = "",
+    val color: String = "#4CAF50",
+    val emoji: String? = null,
+    val isFavorite: Boolean = false,
+    val viewStyle: ViewStyle = ViewStyle.LIST,
+    val isSaving: Boolean = false,
+)
+
+private val defaultColors = listOf(
+    "#F44336", "#E91E63", "#9C27B0", "#3F51B5",
+    "#2196F3", "#00BCD4", "#4CAF50", "#8BC34A",
+    "#FFEB3B", "#FF9800", "#795548", "#607D8B",
+)
+
+@HiltViewModel
+class ProjectEditViewModel @Inject constructor(
+    private val projectRepository: ProjectRepository,
+) : ViewModel() {
+
+    val colors = defaultColors
+
+    private val _state = MutableStateFlow(ProjectEditState())
+    val state = _state.asStateFlow()
+
+    fun init(projectId: String?) {
+        if (projectId != null) {
+            viewModelScope.launch {
+                val project = projectRepository.getProjectById(projectId) ?: return@launch
+                _state.update {
+                    it.copy(
+                        projectId = projectId,
+                        name = project.name,
+                        color = project.color,
+                        emoji = project.emoji,
+                        isFavorite = project.isFavorite,
+                        viewStyle = project.viewStyle,
+                    )
+                }
+            }
+        }
+    }
+
+    fun setName(name: String) = _state.update { it.copy(name = name) }
+    fun setColor(color: String) = _state.update { it.copy(color = color) }
+    fun setEmoji(emoji: String?) = _state.update { it.copy(emoji = emoji) }
+    fun toggleFavorite() = _state.update { it.copy(isFavorite = !it.isFavorite) }
+    fun setViewStyle(style: ViewStyle) = _state.update { it.copy(viewStyle = style) }
+
+    fun save(onDone: (projectId: String) -> Unit) {
+        val st = _state.value
+        if (st.name.isBlank()) return
+        _state.update { it.copy(isSaving = true) }
+        viewModelScope.launch {
+            val id = st.projectId ?: UUID.randomUUID().toString()
+            if (st.projectId != null) {
+                val existing = projectRepository.getProjectById(id)
+                if (existing != null) {
+                    projectRepository.updateProject(
+                        existing.copy(
+                            name = st.name,
+                            color = st.color,
+                            emoji = st.emoji,
+                            isFavorite = st.isFavorite,
+                            viewStyle = st.viewStyle,
+                        )
+                    )
+                }
+            } else {
+                projectRepository.insertProject(
+                    Project(
+                        id = id,
+                        name = st.name,
+                        color = st.color,
+                        emoji = st.emoji,
+                        isFavorite = st.isFavorite,
+                        viewStyle = st.viewStyle,
+                        backendType = BackendType.LOCAL,
+                        sortedBy = SortBy.MANUAL,
+                    )
+                )
+            }
+            _state.update { it.copy(isSaving = false) }
+            onDone(id)
+        }
+    }
+
+    fun delete(onDone: () -> Unit) {
+        val id = _state.value.projectId ?: return
+        viewModelScope.launch {
+            projectRepository.deleteProject(id)
+            onDone()
+        }
+    }
+}
diff --git a/app/src/main/java/com/planify/mobile/ui/task/DueDatePickerSheet.kt b/app/src/main/java/com/planify/mobile/ui/task/DueDatePickerSheet.kt
new file mode 100644
index 0000000..427958e
--- /dev/null
+++ b/app/src/main/java/com/planify/mobile/ui/task/DueDatePickerSheet.kt
@@ -0,0 +1,129 @@
+package com.planify.mobile.ui.task
+
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.width
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.outlined.Clear
+import androidx.compose.material.icons.outlined.Repeat
+import androidx.compose.material3.DatePicker
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.HorizontalDivider
+import androidx.compose.material3.Icon
+import androidx.compose.material3.ModalBottomSheet
+import androidx.compose.material3.SuggestionChip
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.material3.rememberDatePickerState
+import androidx.compose.material3.rememberModalBottomSheetState
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import com.planify.mobile.domain.model.DueDate
+import java.time.Instant
+import java.time.LocalDate
+import java.time.ZoneId
+import java.time.format.DateTimeFormatter
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun DueDatePickerSheet(
+    currentDueDate: DueDate?,
+    onConfirm: (DueDate?) -> Unit,
+    onDismiss: () -> Unit,
+) {
+    val sheetState = rememberModalBottomSheetState(skipPartiallyExpanded = true)
+    val datePickerState = rememberDatePickerState(
+        initialSelectedDateMillis = currentDueDate?.date
+            ?.let { runCatching { LocalDate.parse(it).atStartOfDay(ZoneId.UTC).toInstant().toEpochMilli() }.getOrNull() }
+    )
+    var showRecurrence by remember { mutableStateOf(false) }
+
+    ModalBottomSheet(onDismissRequest = onDismiss, sheetState = sheetState) {
+        Column(Modifier.padding(horizontal = 16.dp)) {
+            Text("Date d'échéance", style = androidx.compose.material3.MaterialTheme.typography.titleMedium)
+            Spacer(Modifier.height(12.dp))
+
+            Row(horizontalArrangement = Arrangement.spacedBy(8.dp)) {
+                val today = LocalDate.now()
+                listOf(
+                    "Aujourd'hui" to today,
+                    "Demain" to today.plusDays(1),
+                    "Semaine prochaine" to today.plusWeeks(1),
+                ).forEach { (label, date) ->
+                    SuggestionChip(
+                        onClick = {
+                            onConfirm(DueDate(date = date.toString(), isRecurring = currentDueDate?.isRecurring ?: false))
+                        },
+                        label = { Text(label) },
+                    )
+                }
+            }
+
+            DatePicker(state = datePickerState, showModeToggle = false)
+
+            HorizontalDivider()
+            Row(
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .clickable { showRecurrence = true }
+                    .padding(vertical = 12.dp),
+                verticalAlignment = Alignment.CenterVertically,
+            ) {
+                Icon(Icons.Outlined.Repeat, contentDescription = null)
+                Spacer(Modifier.width(12.dp))
+                Text("Récurrence")
+                if (currentDueDate?.isRecurring == true) {
+                    Spacer(Modifier.weight(1f))
+                    Text(currentDueDate.recurrencyType.name.lowercase().replace("_", " "))
+                }
+            }
+            HorizontalDivider()
+            Spacer(Modifier.height(8.dp))
+
+            Row(modifier = Modifier.fillMaxWidth(), horizontalArrangement = Arrangement.End) {
+                TextButton(onClick = { onConfirm(null) }) {
+                    Icon(Icons.Outlined.Clear, contentDescription = null)
+                    Spacer(Modifier.width(4.dp))
+                    Text("Supprimer")
+                }
+                Spacer(Modifier.weight(1f))
+                TextButton(onClick = onDismiss) { Text("Annuler") }
+                TextButton(onClick = {
+                    val millis = datePickerState.selectedDateMillis
+                    val date = millis?.let {
+                        Instant.ofEpochMilli(it).atZone(ZoneId.UTC).toLocalDate().toString()
+                    } ?: return@TextButton
+                    onConfirm(DueDate(date = date, isRecurring = currentDueDate?.isRecurring ?: false,
+                        recurrencyType = currentDueDate?.recurrencyType ?: com.planify.mobile.domain.model.RecurrencyType.NONE))
+                }) { Text("OK") }
+            }
+        }
+    }
+
+    if (showRecurrence) {
+        RecurrencePickerSheet(
+            current = currentDueDate,
+            onConfirm = { recDueDate ->
+                showRecurrence = false
+                val millis = datePickerState.selectedDateMillis
+                val date = millis?.let {
+                    Instant.ofEpochMilli(it).atZone(ZoneId.UTC).toLocalDate().toString()
+                } ?: currentDueDate?.date ?: LocalDate.now().toString()
+                onConfirm(recDueDate?.copy(date = date))
+            },
+            onDismiss = { showRecurrence = false },
+        )
+    }
+}
diff --git a/app/src/main/java/com/planify/mobile/ui/task/LabelPickerSheet.kt b/app/src/main/java/com/planify/mobile/ui/task/LabelPickerSheet.kt
new file mode 100644
index 0000000..c667638
--- /dev/null
+++ b/app/src/main/java/com/planify/mobile/ui/task/LabelPickerSheet.kt
@@ -0,0 +1,116 @@
+package com.planify.mobile.ui.task
+
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.outlined.Label
+import androidx.compose.material3.Checkbox
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Icon
+import androidx.compose.material3.ModalBottomSheet
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.material3.rememberModalBottomSheetState
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.planify.mobile.domain.model.Label
+import com.planify.mobile.domain.repository.LabelRepository
+import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.stateIn
+import javax.inject.Inject
+
+@HiltViewModel
+class LabelPickerViewModel @Inject constructor(
+    labelRepository: LabelRepository,
+) : ViewModel() {
+    val labels = labelRepository.getAllLabels()
+        .stateIn(viewModelScope, SharingStarted.WhileSubscribed(5_000), emptyList())
+}
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun LabelPickerSheet(
+    selectedLabels: List<String>,
+    onConfirm: (List<String>) -> Unit,
+    onDismiss: () -> Unit,
+    viewModel: LabelPickerViewModel = hiltViewModel(),
+) {
+    val sheetState = rememberModalBottomSheetState(skipPartiallyExpanded = true)
+    val labels by viewModel.labels.collectAsState()
+    var selected by remember { mutableStateOf(selectedLabels.toSet()) }
+
+    ModalBottomSheet(onDismissRequest = onDismiss, sheetState = sheetState) {
+        Column {
+            Row(
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .padding(horizontal = 16.dp, vertical = 12.dp),
+                verticalAlignment = Alignment.CenterVertically,
+            ) {
+                Text(
+                    text = "Labels",
+                    style = androidx.compose.material3.MaterialTheme.typography.titleMedium,
+                    modifier = Modifier.weight(1f),
+                )
+                TextButton(onClick = { onConfirm(selected.toList()) }) { Text("OK") }
+            }
+            LazyColumn {
+                items(labels, key = { it.id }) { label ->
+                    LabelRow(
+                        label = label,
+                        checked = label.name in selected,
+                        onToggle = {
+                            selected = if (label.name in selected) selected - label.name else selected + label.name
+                        },
+                    )
+                }
+                if (labels.isEmpty()) {
+                    item {
+                        Text(
+                            "Aucun label. Créez-en un dans les paramètres.",
+                            modifier = Modifier.padding(16.dp),
+                            color = androidx.compose.material3.MaterialTheme.colorScheme.onSurfaceVariant,
+                        )
+                    }
+                }
+            }
+        }
+    }
+}
+
+@Composable
+private fun LabelRow(label: Label, checked: Boolean, onToggle: () -> Unit) {
+    Row(
+        modifier = Modifier
+            .fillMaxWidth()
+            .padding(horizontal = 16.dp, vertical = 8.dp),
+        verticalAlignment = Alignment.CenterVertically,
+    ) {
+        Icon(
+            Icons.Outlined.Label,
+            contentDescription = null,
+            tint = runCatching { Color(android.graphics.Color.parseColor(label.color)) }.getOrDefault(Color.Gray),
+        )
+        Spacer(Modifier.width(12.dp))
+        Text(text = label.name, modifier = Modifier.weight(1f))
+        Checkbox(checked = checked, onCheckedChange = { onToggle() })
+    }
+}
diff --git a/app/src/main/java/com/planify/mobile/ui/task/PriorityPickerSheet.kt b/app/src/main/java/com/planify/mobile/ui/task/PriorityPickerSheet.kt
new file mode 100644
index 0000000..f6baf73
--- /dev/null
+++ b/app/src/main/java/com/planify/mobile/ui/task/PriorityPickerSheet.kt
@@ -0,0 +1,65 @@
+package com.planify.mobile.ui.task
+
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.width
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.ModalBottomSheet
+import androidx.compose.material3.RadioButton
+import androidx.compose.material3.Text
+import androidx.compose.material3.rememberModalBottomSheetState
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import com.planify.mobile.ui.components.PriorityBadge
+import com.planify.mobile.ui.components.priorityColor
+
+private val priorityLabels = mapOf(
+    1 to "Urgente",
+    2 to "Haute",
+    3 to "Moyenne",
+    4 to "Aucune",
+)
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun PriorityPickerSheet(
+    current: Int,
+    onSelect: (Int) -> Unit,
+    onDismiss: () -> Unit,
+) {
+    val sheetState = rememberModalBottomSheetState()
+
+    ModalBottomSheet(onDismissRequest = onDismiss, sheetState = sheetState) {
+        Column(Modifier.padding(bottom = 16.dp)) {
+            Text(
+                text = "Priorité",
+                style = androidx.compose.material3.MaterialTheme.typography.titleMedium,
+                modifier = Modifier.padding(horizontal = 16.dp, vertical = 12.dp),
+            )
+            listOf(1, 2, 3, 4).forEach { priority ->
+                Row(
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .clickable { onSelect(priority); onDismiss() }
+                        .padding(horizontal = 16.dp, vertical = 12.dp),
+                    verticalAlignment = Alignment.CenterVertically,
+                ) {
+                    PriorityBadge(priority = priority)
+                    Spacer(Modifier.width(12.dp))
+                    Text(
+                        text = priorityLabels[priority] ?: "",
+                        color = priorityColor[priority] ?: androidx.compose.ui.graphics.Color.Gray,
+                        modifier = Modifier.weight(1f),
+                    )
+                    RadioButton(selected = current == priority, onClick = null)
+                }
+            }
+        }
+    }
+}
diff --git a/app/src/main/java/com/planify/mobile/ui/task/RecurrencePickerSheet.kt b/app/src/main/java/com/planify/mobile/ui/task/RecurrencePickerSheet.kt
new file mode 100644
index 0000000..8bab636
--- /dev/null
+++ b/app/src/main/java/com/planify/mobile/ui/task/RecurrencePickerSheet.kt
@@ -0,0 +1,113 @@
+package com.planify.mobile.ui.task
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.selection.selectable
+import androidx.compose.foundation.selection.selectableGroup
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.FilterChip
+import androidx.compose.material3.HorizontalDivider
+import androidx.compose.material3.ModalBottomSheet
+import androidx.compose.material3.RadioButton
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.material3.rememberModalBottomSheetState
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.semantics.Role
+import androidx.compose.ui.unit.dp
+import com.planify.mobile.domain.model.DueDate
+import com.planify.mobile.domain.model.RecurrencyType
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun RecurrencePickerSheet(
+    current: DueDate?,
+    onConfirm: (DueDate?) -> Unit,
+    onDismiss: () -> Unit,
+) {
+    val sheetState = rememberModalBottomSheetState(skipPartiallyExpanded = true)
+    var selectedType by remember { mutableStateOf(current?.recurrencyType ?: RecurrencyType.EVERY_DAY) }
+    var interval by remember { mutableStateOf(current?.recurrencyInterval ?: 1) }
+    var weekDays by remember { mutableStateOf(current?.recurrencyWeekDays ?: emptyList()) }
+
+    val options = listOf(
+        RecurrencyType.EVERY_DAY to "Chaque jour",
+        RecurrencyType.EVERY_WEEK to "Chaque semaine",
+        RecurrencyType.EVERY_MONTH to "Chaque mois",
+        RecurrencyType.EVERY_YEAR to "Chaque année",
+    )
+    val dayLabels = listOf("L", "M", "M", "J", "V", "S", "D")
+
+    ModalBottomSheet(onDismissRequest = onDismiss, sheetState = sheetState) {
+        Column(
+            Modifier
+                .padding(horizontal = 16.dp)
+                .selectableGroup()
+        ) {
+            Text("Récurrence", style = androidx.compose.material3.MaterialTheme.typography.titleMedium)
+            Spacer(Modifier.height(12.dp))
+
+            options.forEach { (type, label) ->
+                Row(
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .selectable(selected = selectedType == type, onClick = { selectedType = type }, role = Role.RadioButton)
+                        .padding(vertical = 8.dp),
+                    verticalAlignment = Alignment.CenterVertically,
+                ) {
+                    RadioButton(selected = selectedType == type, onClick = null)
+                    Text(label, modifier = Modifier.padding(start = 12.dp))
+                }
+            }
+
+            if (selectedType == RecurrencyType.EVERY_WEEK) {
+                Spacer(Modifier.height(8.dp))
+                HorizontalDivider()
+                Spacer(Modifier.height(8.dp))
+                Text("Jours de la semaine", style = androidx.compose.material3.MaterialTheme.typography.labelMedium)
+                Spacer(Modifier.height(8.dp))
+                Row(horizontalArrangement = Arrangement.spacedBy(6.dp)) {
+                    dayLabels.forEachIndexed { index, label ->
+                        FilterChip(
+                            selected = index in weekDays,
+                            onClick = {
+                                weekDays = if (index in weekDays) weekDays - index else weekDays + index
+                            },
+                            label = { Text(label) },
+                        )
+                    }
+                }
+            }
+
+            Spacer(Modifier.height(16.dp))
+            Row(modifier = Modifier.fillMaxWidth(), horizontalArrangement = Arrangement.End) {
+                TextButton(onClick = { onConfirm(null) }) { Text("Pas de récurrence") }
+                Spacer(Modifier.weight(1f))
+                TextButton(onClick = onDismiss) { Text("Annuler") }
+                TextButton(onClick = {
+                    onConfirm(
+                        DueDate(
+                            date = current?.date ?: "",
+                            isRecurring = true,
+                            recurrencyType = selectedType,
+                            recurrencyInterval = interval,
+                            recurrencyWeekDays = if (selectedType == RecurrencyType.EVERY_WEEK) weekDays else emptyList(),
+                        )
+                    )
+                }) { Text("OK") }
+            }
+            Spacer(Modifier.height(8.dp))
+        }
+    }
+}
diff --git a/app/src/main/java/com/planify/mobile/ui/task/ReminderPickerSheet.kt b/app/src/main/java/com/planify/mobile/ui/task/ReminderPickerSheet.kt
new file mode 100644
index 0000000..6ed83c6
--- /dev/null
+++ b/app/src/main/java/com/planify/mobile/ui/task/ReminderPickerSheet.kt
@@ -0,0 +1,82 @@
+package com.planify.mobile.ui.task
+
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.outlined.Add
+import androidx.compose.material.icons.outlined.Notifications
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Icon
+import androidx.compose.material3.ModalBottomSheet
+import androidx.compose.material3.RadioButton
+import androidx.compose.material3.Text
+import androidx.compose.material3.rememberModalBottomSheetState
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import com.planify.mobile.domain.model.DueDate
+import com.planify.mobile.domain.model.Reminder
+import com.planify.mobile.domain.model.ReminderType
+import java.util.UUID
+
+private val relativeOptions = listOf(
+    5 to "5 minutes avant",
+    15 to "15 minutes avant",
+    30 to "30 minutes avant",
+    60 to "1 heure avant",
+    1440 to "1 jour avant",
+)
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun ReminderPickerSheet(
+    taskId: String,
+    currentReminders: List<Reminder>,
+    onUpdate: (List<Reminder>) -> Unit,
+    onDismiss: () -> Unit,
+) {
+    val sheetState = rememberModalBottomSheetState(skipPartiallyExpanded = true)
+
+    ModalBottomSheet(onDismissRequest = onDismiss, sheetState = sheetState) {
+        Column(Modifier.padding(bottom = 16.dp)) {
+            Text(
+                text = "Rappels",
+                style = androidx.compose.material3.MaterialTheme.typography.titleMedium,
+                modifier = Modifier.padding(16.dp),
+            )
+
+            relativeOptions.forEach { (minutes, label) ->
+                val existing = currentReminders.find { it.type == ReminderType.RELATIVE && it.minutesOffset == minutes }
+                Row(
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .clickable {
+                            val updated = if (existing != null) {
+                                currentReminders - existing
+                            } else {
+                                currentReminders + Reminder(
+                                    id = UUID.randomUUID().toString(),
+                                    taskId = taskId,
+                                    type = ReminderType.RELATIVE,
+                                    minutesOffset = minutes,
+                                )
+                            }
+                            onUpdate(updated)
+                        }
+                        .padding(horizontal = 16.dp, vertical = 12.dp),
+                    verticalAlignment = Alignment.CenterVertically,
+                ) {
+                    Icon(Icons.Outlined.Notifications, contentDescription = null)
+                    Text(label, modifier = Modifier
+                        .weight(1f)
+                        .padding(start = 12.dp))
+                    RadioButton(selected = existing != null, onClick = null)
+                }
+            }
+        }
+    }
+}
diff --git a/app/src/main/java/com/planify/mobile/ui/task/SubTaskSection.kt b/app/src/main/java/com/planify/mobile/ui/task/SubTaskSection.kt
new file mode 100644
index 0000000..d56101d
--- /dev/null
+++ b/app/src/main/java/com/planify/mobile/ui/task/SubTaskSection.kt
@@ -0,0 +1,113 @@
+package com.planify.mobile.ui.task
+
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.text.KeyboardActions
+import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.outlined.Add
+import androidx.compose.material.icons.outlined.Close
+import androidx.compose.material3.Checkbox
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.input.ImeAction
+import androidx.compose.ui.text.style.TextDecoration
+import androidx.compose.ui.unit.dp
+import com.planify.mobile.domain.model.Task
+
+@Composable
+fun SubTaskSection(
+    subTasks: List<Task>,
+    onAddSubTask: (String) -> Unit,
+    onToggleSubTask: (Task) -> Unit,
+    onDeleteSubTask: (Task) -> Unit,
+    modifier: Modifier = Modifier,
+) {
+    var newSubTaskContent by remember { mutableStateOf("") }
+    var showInput by remember { mutableStateOf(false) }
+
+    Column(modifier = modifier) {
+        Row(
+            modifier = Modifier.padding(horizontal = 16.dp, vertical = 4.dp),
+            verticalAlignment = Alignment.CenterVertically,
+        ) {
+            Text(
+                text = "Sous-tâches (${subTasks.count { it.checked }}/${subTasks.size})",
+                style = MaterialTheme.typography.labelMedium,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                modifier = Modifier.weight(1f),
+            )
+        }
+
+        subTasks.forEach { subTask ->
+            Row(
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .padding(start = 8.dp, end = 8.dp),
+                verticalAlignment = Alignment.CenterVertically,
+            ) {
+                Checkbox(
+                    checked = subTask.checked,
+                    onCheckedChange = { onToggleSubTask(subTask) },
+                )
+                Text(
+                    text = subTask.content,
+                    style = MaterialTheme.typography.bodyMedium,
+                    textDecoration = if (subTask.checked) TextDecoration.LineThrough else null,
+                    modifier = Modifier.weight(1f),
+                )
+                IconButton(onClick = { onDeleteSubTask(subTask) }) {
+                    Icon(Icons.Outlined.Close, contentDescription = "Supprimer")
+                }
+            }
+        }
+
+        if (showInput) {
+            Row(
+                modifier = Modifier.padding(horizontal = 8.dp),
+                verticalAlignment = Alignment.CenterVertically,
+            ) {
+                Spacer(Modifier.width(40.dp))
+                OutlinedTextField(
+                    value = newSubTaskContent,
+                    onValueChange = { newSubTaskContent = it },
+                    placeholder = { Text("Nouvelle sous-tâche") },
+                    modifier = Modifier.weight(1f),
+                    singleLine = true,
+                    keyboardOptions = KeyboardOptions(imeAction = ImeAction.Done),
+                    keyboardActions = KeyboardActions(onDone = {
+                        if (newSubTaskContent.isNotBlank()) {
+                            onAddSubTask(newSubTaskContent.trim())
+                            newSubTaskContent = ""
+                        }
+                        showInput = false
+                    }),
+                )
+            }
+        }
+
+        TextButton(
+            onClick = { showInput = true },
+            modifier = Modifier.padding(start = 8.dp),
+        ) {
+            Icon(Icons.Outlined.Add, contentDescription = null)
+            Spacer(Modifier.width(4.dp))
+            Text("Ajouter une sous-tâche")
+        }
+    }
+}
diff --git a/app/src/main/java/com/planify/mobile/ui/task/TaskEditSheet.kt b/app/src/main/java/com/planify/mobile/ui/task/TaskEditSheet.kt
new file mode 100644
index 0000000..f0e731e
--- /dev/null
+++ b/app/src/main/java/com/planify/mobile/ui/task/TaskEditSheet.kt
@@ -0,0 +1,210 @@
+package com.planify.mobile.ui.task
+
+import androidx.compose.foundation.horizontalScroll
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.outlined.CalendarToday
+import androidx.compose.material.icons.outlined.Flag
+import androidx.compose.material.icons.outlined.Label
+import androidx.compose.material.icons.outlined.List
+import androidx.compose.material.icons.outlined.Notifications
+import androidx.compose.material3.Button
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.FilterChip
+import androidx.compose.material3.HorizontalDivider
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.ModalBottomSheet
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.Text
+import androidx.compose.material3.rememberModalBottomSheetState
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+import com.planify.mobile.ui.components.PriorityBadge
+import java.time.LocalDate
+import java.time.format.DateTimeFormatter
+import java.util.Locale
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun TaskEditSheet(
+    projectId: String,
+    taskId: String? = null,
+    sectionId: String? = null,
+    parentId: String? = null,
+    onDismiss: () -> Unit,
+    viewModel: TaskEditViewModel = hiltViewModel(),
+) {
+    LaunchedEffect(taskId, projectId) {
+        viewModel.init(taskId, projectId, sectionId, parentId)
+    }
+
+    val state by viewModel.state.collectAsState()
+    val sheetState = rememberModalBottomSheetState(skipPartiallyExpanded = true)
+
+    var showDueDatePicker by remember { mutableStateOf(false) }
+    var showPriorityPicker by remember { mutableStateOf(false) }
+    var showLabelPicker by remember { mutableStateOf(false) }
+    var showReminderPicker by remember { mutableStateOf(false) }
+    var showSubTasks by remember { mutableStateOf(false) }
+
+    ModalBottomSheet(onDismissRequest = onDismiss, sheetState = sheetState) {
+        Column(Modifier.padding(horizontal = 16.dp)) {
+            Text(
+                text = if (taskId == null) "Nouvelle tâche" else "Modifier la tâche",
+                style = MaterialTheme.typography.titleMedium,
+                modifier = Modifier.padding(bottom = 12.dp),
+            )
+
+            OutlinedTextField(
+                value = state.content,
+                onValueChange = viewModel::setContent,
+                placeholder = { Text("Nom de la tâche") },
+                modifier = Modifier.fillMaxWidth(),
+                singleLine = true,
+            )
+
+            Spacer(Modifier.height(8.dp))
+
+            OutlinedTextField(
+                value = state.description,
+                onValueChange = viewModel::setDescription,
+                placeholder = { Text("Description (optionnelle)") },
+                modifier = Modifier.fillMaxWidth(),
+                minLines = 2,
+                maxLines = 4,
+            )
+
+            Spacer(Modifier.height(12.dp))
+            HorizontalDivider()
+            Spacer(Modifier.height(8.dp))
+
+            Row(
+                modifier = Modifier.horizontalScroll(rememberScrollState()),
+                horizontalArrangement = Arrangement.spacedBy(8.dp),
+            ) {
+                FilterChip(
+                    selected = state.dueDate != null,
+                    onClick = { showDueDatePicker = true },
+                    label = { Text(state.dueDate?.date?.let { formatDateShort(it) } ?: "Date") },
+                    leadingIcon = { Icon(Icons.Outlined.CalendarToday, contentDescription = null) },
+                )
+                FilterChip(
+                    selected = state.priority != 4,
+                    onClick = { showPriorityPicker = true },
+                    label = { Text("P${state.priority}") },
+                    leadingIcon = { PriorityBadge(priority = state.priority) },
+                )
+                FilterChip(
+                    selected = state.labels.isNotEmpty(),
+                    onClick = { showLabelPicker = true },
+                    label = {
+                        Text(if (state.labels.isNotEmpty()) "${state.labels.size} label(s)" else "Labels")
+                    },
+                    leadingIcon = { Icon(Icons.Outlined.Label, contentDescription = null) },
+                )
+                FilterChip(
+                    selected = state.reminders.isNotEmpty(),
+                    onClick = { showReminderPicker = true },
+                    label = {
+                        Text(if (state.reminders.isNotEmpty()) "${state.reminders.size} rappel(s)" else "Rappels")
+                    },
+                    leadingIcon = { Icon(Icons.Outlined.Notifications, contentDescription = null) },
+                )
+                FilterChip(
+                    selected = state.subTasks.isNotEmpty() || showSubTasks,
+                    onClick = { showSubTasks = !showSubTasks },
+                    label = {
+                        Text(if (state.subTasks.isNotEmpty()) "${state.subTasks.size} sous-tâche(s)" else "Sous-tâches")
+                    },
+                    leadingIcon = { Icon(Icons.Outlined.List, contentDescription = null) },
+                )
+            }
+
+            if (showSubTasks) {
+                Spacer(Modifier.height(8.dp))
+                SubTaskSection(
+                    subTasks = state.subTasks,
+                    onAddSubTask = viewModel::addSubTask,
+                    onToggleSubTask = viewModel::toggleSubTask,
+                    onDeleteSubTask = viewModel::deleteSubTask,
+                )
+            }
+
+            Spacer(Modifier.height(12.dp))
+
+            Row(
+                modifier = Modifier.fillMaxWidth(),
+                horizontalArrangement = Arrangement.End,
+                verticalAlignment = Alignment.CenterVertically,
+            ) {
+                Spacer(Modifier.width(8.dp))
+                Button(
+                    onClick = { viewModel.save(onDone = onDismiss) },
+                    enabled = state.content.isNotBlank() && !state.isSaving,
+                ) {
+                    Text(if (taskId == null) "Créer" else "Enregistrer")
+                }
+            }
+
+            Spacer(Modifier.height(16.dp))
+        }
+    }
+
+    if (showDueDatePicker) {
+        DueDatePickerSheet(
+            currentDueDate = state.dueDate,
+            onConfirm = { viewModel.setDueDate(it); showDueDatePicker = false },
+            onDismiss = { showDueDatePicker = false },
+        )
+    }
+    if (showPriorityPicker) {
+        PriorityPickerSheet(
+            current = state.priority,
+            onSelect = viewModel::setPriority,
+            onDismiss = { showPriorityPicker = false },
+        )
+    }
+    if (showLabelPicker) {
+        LabelPickerSheet(
+            selectedLabels = state.labels,
+            onConfirm = { viewModel.setLabels(it); showLabelPicker = false },
+            onDismiss = { showLabelPicker = false },
+        )
+    }
+    if (showReminderPicker) {
+        ReminderPickerSheet(
+            taskId = state.taskId ?: "",
+            currentReminders = state.reminders,
+            onUpdate = viewModel::setReminders,
+            onDismiss = { showReminderPicker = false },
+        )
+    }
+}
+
+private fun formatDateShort(dateIso: String): String = runCatching {
+    val date = LocalDate.parse(dateIso)
+    val today = LocalDate.now()
+    when (date) {
+        today -> "Aujourd'hui"
+        today.plusDays(1) -> "Demain"
+        else -> date.format(DateTimeFormatter.ofPattern("d MMM", Locale.FRENCH))
+    }
+}.getOrDefault(dateIso)
diff --git a/app/src/main/java/com/planify/mobile/ui/task/TaskEditViewModel.kt b/app/src/main/java/com/planify/mobile/ui/task/TaskEditViewModel.kt
new file mode 100644
index 0000000..c4ba5b1
--- /dev/null
+++ b/app/src/main/java/com/planify/mobile/ui/task/TaskEditViewModel.kt
@@ -0,0 +1,157 @@
+package com.planify.mobile.ui.task
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.planify.mobile.data.notification.ReminderScheduler
+import com.planify.mobile.domain.model.DueDate
+import com.planify.mobile.domain.model.Reminder
+import com.planify.mobile.domain.model.Task
+import com.planify.mobile.domain.repository.ReminderRepository
+import com.planify.mobile.domain.repository.TaskRepository
+import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.update
+import kotlinx.coroutines.launch
+import java.time.LocalDateTime
+import java.time.format.DateTimeFormatter
+import java.util.UUID
+import javax.inject.Inject
+
+data class TaskEditState(
+    val taskId: String? = null,
+    val projectId: String = "",
+    val sectionId: String? = null,
+    val parentId: String? = null,
+    val content: String = "",
+    val description: String = "",
+    val priority: Int = 4,
+    val dueDate: DueDate? = null,
+    val labels: List<String> = emptyList(),
+    val reminders: List<Reminder> = emptyList(),
+    val subTasks: List<Task> = emptyList(),
+    val isSaving: Boolean = false,
+)
+
+@HiltViewModel
+class TaskEditViewModel @Inject constructor(
+    private val taskRepository: TaskRepository,
+    private val reminderRepository: ReminderRepository,
+    private val reminderScheduler: ReminderScheduler,
+) : ViewModel() {
+
+    private val _state = MutableStateFlow(TaskEditState())
+    val state = _state.asStateFlow()
+
+    fun init(taskId: String?, projectId: String, sectionId: String? = null, parentId: String? = null) {
+        if (taskId != null) {
+            viewModelScope.launch {
+                val task = taskRepository.getTaskById(taskId) ?: return@launch
+                val subTasks = taskRepository.getSubTasks(taskId).first()
+                val reminders = reminderRepository.getRemindersByTask(taskId).first()
+                _state.update {
+                    it.copy(
+                        taskId = taskId,
+                        projectId = task.projectId,
+                        sectionId = task.sectionId,
+                        parentId = task.parentId,
+                        content = task.content,
+                        description = task.description,
+                        priority = task.priority,
+                        dueDate = task.dueDate,
+                        labels = task.labels,
+                        reminders = reminders,
+                        subTasks = subTasks,
+                    )
+                }
+            }
+        } else {
+            _state.update { it.copy(projectId = projectId, sectionId = sectionId, parentId = parentId) }
+        }
+    }
+
+    fun setContent(content: String) = _state.update { it.copy(content = content) }
+    fun setDescription(desc: String) = _state.update { it.copy(description = desc) }
+    fun setPriority(priority: Int) = _state.update { it.copy(priority = priority) }
+    fun setDueDate(dueDate: DueDate?) = _state.update { it.copy(dueDate = dueDate) }
+    fun setLabels(labels: List<String>) = _state.update { it.copy(labels = labels) }
+    fun setReminders(reminders: List<Reminder>) = _state.update { it.copy(reminders = reminders) }
+
+    fun addSubTask(content: String) {
+        val sub = Task(
+            id = UUID.randomUUID().toString(),
+            content = content,
+            projectId = _state.value.projectId,
+            parentId = _state.value.taskId ?: "pending",
+        )
+        _state.update { it.copy(subTasks = it.subTasks + sub) }
+    }
+
+    fun toggleSubTask(subTask: Task) {
+        _state.update {
+            it.copy(subTasks = it.subTasks.map { t ->
+                if (t.id == subTask.id) t.copy(checked = !t.checked) else t
+            })
+        }
+    }
+
+    fun deleteSubTask(subTask: Task) {
+        _state.update { it.copy(subTasks = it.subTasks.filter { t -> t.id != subTask.id }) }
+    }
+
+    fun save(onDone: () -> Unit) {
+        val st = _state.value
+        if (st.content.isBlank()) return
+        _state.update { it.copy(isSaving = true) }
+        viewModelScope.launch {
+            val now = LocalDateTime.now().format(DateTimeFormatter.ISO_LOCAL_DATE_TIME)
+            val id = st.taskId ?: UUID.randomUUID().toString()
+
+            val task = Task(
+                id = id,
+                content = st.content,
+                description = st.description,
+                projectId = st.projectId,
+                sectionId = st.sectionId,
+                parentId = st.parentId,
+                priority = st.priority,
+                dueDate = st.dueDate,
+                labels = st.labels,
+                addedAt = if (st.taskId == null) now else "",
+                updatedAt = now,
+            )
+
+            if (st.taskId == null) taskRepository.insertTask(task)
+            else taskRepository.updateTask(task)
+
+            // Sub-tasks: delete removed ones, then upsert remaining
+            if (st.taskId != null) {
+                val existingIds = taskRepository.getSubTasks(id).first().map { it.id }.toSet()
+                val currentIds = st.subTasks.map { it.id }.toSet()
+                (existingIds - currentIds).forEach { taskRepository.deleteTask(it) }
+            }
+            st.subTasks.forEach { sub ->
+                val actualSub = sub.copy(
+                    parentId = id,
+                    projectId = st.projectId,
+                    addedAt = if (sub.addedAt.isBlank()) now else sub.addedAt,
+                    updatedAt = now,
+                )
+                if (taskRepository.getTaskById(sub.id) != null) taskRepository.updateTask(actualSub)
+                else taskRepository.insertTask(actualSub)
+            }
+
+            // Reminders: replace all, reschedule
+            reminderRepository.deleteRemindersByTask(id)
+            st.reminders.forEach { reminder ->
+                val actual = reminder.copy(taskId = id)
+                reminderRepository.insertReminder(actual)
+                reminderScheduler.schedule(actual, task.content, task.dueDate?.date)
+            }
+
+            _state.update { it.copy(isSaving = false) }
+            onDone()
+        }
+    }
+}
diff --git a/build.gradle.kts b/build.gradle.kts
index 0adef57..c848b72 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -3,4 +3,5 @@ plugins {
     alias(libs.plugins.jetbrains.kotlin.android) apply false
     alias(libs.plugins.hilt) apply false
     alias(libs.plugins.ksp) apply false
+    alias(libs.plugins.kotlin.serialization) apply false
 }
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index d308142..23fc40d 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -14,6 +14,7 @@ okhttp = "4.12.0"
 datastore = "1.1.1"
 securityCrypto = "1.1.0-alpha06"
 workManager = "2.9.0"
+serialization = "1.6.3"
 junit = "4.13.2"
 junitExt = "1.2.1"
 espressoCore = "3.6.1"
@@ -47,6 +48,7 @@ okhttp-logging = { group = "com.squareup.okhttp3", name = "logging-interceptor",
 datastore-preferences = { group = "androidx.datastore", name = "datastore-preferences", version.ref = "datastore" }
 security-crypto = { group = "androidx.security", name = "security-crypto", version.ref = "securityCrypto" }
 work-runtime-ktx = { group = "androidx.work", name = "work-runtime-ktx", version.ref = "workManager" }
+kotlinx-serialization-json = { group = "org.jetbrains.kotlinx", name = "kotlinx-serialization-json", version.ref = "serialization" }
 junit = { group = "junit", name = "junit", version.ref = "junit" }
 androidx-junit = { group = "androidx.test.ext", name = "junit", version.ref = "junitExt" }
 androidx-espresso-core = { group = "androidx.test.espresso", name = "espresso-core", version.ref = "espressoCore" }
@@ -56,3 +58,4 @@ android-application = { id = "com.android.application", version.ref = "agp" }
 jetbrains-kotlin-android = { id = "org.jetbrains.kotlin.android", version.ref = "kotlin" }
 hilt = { id = "com.google.dagger.hilt.android", version.ref = "hilt" }
 ksp = { id = "com.google.devtools.ksp", version = "1.9.24-1.0.20" }
+kotlin-serialization = { id = "org.jetbrains.kotlin.plugin.serialization", version.ref = "kotlin" }