diff --git a/dao/build.gradle.kts b/dao/build.gradle.kts
index 92bc8c5..efff270 100644
--- a/dao/build.gradle.kts
+++ b/dao/build.gradle.kts
@@ -35,6 +35,10 @@ kotlin {
             implementation(kotlin("test"))
         }
 
+        jvmTest.dependencies {
+            implementation(libs.sqlDelight.driver.sqlite)
+        }
+
         androidMain.dependencies {
             implementation(libs.kotlinx.coroutines.android)
             implementation(libs.sqlDelight.driver.android)
diff --git a/dao/src/jvmTest/kotlin/io/github/kdroidfilter/seforimlibrary/dao/repository/SeforimRepositoryIntegrationTest.kt b/dao/src/jvmTest/kotlin/io/github/kdroidfilter/seforimlibrary/dao/repository/SeforimRepositoryIntegrationTest.kt
new file mode 100644
index 0000000..565fdd5
--- /dev/null
+++ b/dao/src/jvmTest/kotlin/io/github/kdroidfilter/seforimlibrary/dao/repository/SeforimRepositoryIntegrationTest.kt
@@ -0,0 +1,467 @@
+package io.github.kdroidfilter.seforimlibrary.dao.repository
+
+import app.cash.sqldelight.driver.jdbc.sqlite.JdbcSqliteDriver
+import io.github.kdroidfilter.seforimlibrary.core.models.Book
+import io.github.kdroidfilter.seforimlibrary.core.models.Category
+import io.github.kdroidfilter.seforimlibrary.core.models.Line
+import io.github.kdroidfilter.seforimlibrary.core.models.TocEntry
+import kotlinx.coroutines.runBlocking
+import kotlin.test.AfterTest
+import kotlin.test.BeforeTest
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertNotEquals
+import kotlin.test.assertNotNull
+import kotlin.test.assertNull
+import kotlin.test.assertTrue
+
+/**
+ * Integration tests for [SeforimRepository].
+ * Uses an in-memory SQLite database for isolation and speed.
+ */
+class SeforimRepositoryIntegrationTest {
+    private lateinit var driver: JdbcSqliteDriver
+    private lateinit var repository: SeforimRepository
+
+    @BeforeTest
+    fun setup() {
+        driver = JdbcSqliteDriver(JdbcSqliteDriver.IN_MEMORY)
+        repository = SeforimRepository(":memory:", driver)
+    }
+
+    @AfterTest
+    fun tearDown() {
+        driver.close()
+    }
+
+    // ==================== Source Tests ====================
+
+    @Test
+    fun `insertSource creates new source and returns id`() = runBlocking {
+        val sourceId = repository.insertSource("Sefaria")
+        assertTrue(sourceId > 0)
+    }
+
+    @Test
+    fun `insertSource returns existing id for duplicate source`() = runBlocking {
+        val firstId = repository.insertSource("Sefaria")
+        val secondId = repository.insertSource("Sefaria")
+        assertEquals(firstId, secondId)
+    }
+
+    @Test
+    fun `getSourceByName returns source when exists`() = runBlocking {
+        val sourceName = "Otzaria"
+        repository.insertSource(sourceName)
+
+        val source = repository.getSourceByName(sourceName)
+
+        assertNotNull(source)
+        assertEquals(sourceName, source.name)
+    }
+
+    @Test
+    fun `getSourceByName returns null when not exists`() = runBlocking {
+        val source = repository.getSourceByName("NonExistent")
+        assertNull(source)
+    }
+
+    // ==================== Category Tests ====================
+
+    @Test
+    fun `insertCategory creates root category`() = runBlocking {
+        val category = Category(
+            parentId = null,
+            title = "Torah",
+            level = 0,
+            order = 1
+        )
+
+        val categoryId = repository.insertCategory(category)
+
+        assertTrue(categoryId > 0)
+    }
+
+    @Test
+    fun `insertCategory creates child category with parent`() = runBlocking {
+        val parentCategory = Category(parentId = null, title = "Torah", level = 0, order = 1)
+        val parentId = repository.insertCategory(parentCategory)
+
+        val childCategory = Category(parentId = parentId, title = "Bereshit", level = 1, order = 1)
+        val childId = repository.insertCategory(childCategory)
+
+        assertTrue(childId > 0)
+        assertNotEquals(parentId, childId)
+    }
+
+    @Test
+    fun `insertCategory returns existing id for duplicate in same parent`() = runBlocking {
+        val category = Category(parentId = null, title = "Torah", level = 0, order = 1)
+        val firstId = repository.insertCategory(category)
+        val secondId = repository.insertCategory(category)
+
+        assertEquals(firstId, secondId)
+    }
+
+    @Test
+    fun `getRootCategories returns only root categories`() = runBlocking {
+        // Insert root categories
+        repository.insertCategory(Category(parentId = null, title = "Torah", level = 0, order = 1))
+        repository.insertCategory(Category(parentId = null, title = "Neviim", level = 0, order = 2))
+
+        // Insert a child category
+        val parentId = repository.insertCategory(Category(parentId = null, title = "Ketuvim", level = 0, order = 3))
+        repository.insertCategory(Category(parentId = parentId, title = "Tehillim", level = 1, order = 1))
+
+        val rootCategories = repository.getRootCategories()
+
+        assertEquals(3, rootCategories.size)
+        assertTrue(rootCategories.all { it.parentId == null })
+    }
+
+    @Test
+    fun `getSubcategories returns children of parent`() = runBlocking {
+        val parentId = repository.insertCategory(Category(parentId = null, title = "Torah", level = 0, order = 1))
+        repository.insertCategory(Category(parentId = parentId, title = "Bereshit", level = 1, order = 1))
+        repository.insertCategory(Category(parentId = parentId, title = "Shemot", level = 1, order = 2))
+        repository.insertCategory(Category(parentId = parentId, title = "Vayikra", level = 1, order = 3))
+
+        val subcategories = repository.getCategoryChildren(parentId)
+
+        assertEquals(3, subcategories.size)
+        assertTrue(subcategories.all { cat -> cat.parentId == parentId })
+    }
+
+    @Test
+    fun `getCategory returns category by id`() = runBlocking {
+        val title = "Torah"
+        val categoryId = repository.insertCategory(Category(parentId = null, title = title, level = 0, order = 1))
+
+        val category = repository.getCategory(categoryId)
+
+        assertNotNull(category)
+        assertEquals(title, category.title)
+        assertEquals(categoryId, category.id)
+    }
+
+    @Test
+    fun `getCategory returns null for non-existent id`() = runBlocking {
+        val category = repository.getCategory(99999L)
+        assertNull(category)
+    }
+
+    // ==================== Book Tests ====================
+
+    @Test
+    fun `insertBook creates new book`() = runBlocking {
+        val sourceId = repository.insertSource("Sefaria")
+        val categoryId = repository.insertCategory(Category(parentId = null, title = "Torah", level = 0, order = 1))
+
+        val book = Book(
+            categoryId = categoryId,
+            sourceId = sourceId,
+            title = "Bereshit",
+            order = 1f
+        )
+        val bookId = repository.insertBook(book)
+
+        assertTrue(bookId > 0)
+    }
+
+    @Test
+    fun `getBook returns book with all metadata`() = runBlocking {
+        val sourceId = repository.insertSource("Sefaria")
+        val categoryId = repository.insertCategory(Category(parentId = null, title = "Torah", level = 0, order = 1))
+        val book = Book(
+            categoryId = categoryId,
+            sourceId = sourceId,
+            title = "Bereshit",
+            order = 1f,
+            heShortDesc = "בראשית"
+        )
+        val bookId = repository.insertBook(book)
+
+        val retrievedBook = repository.getBook(bookId)
+
+        assertNotNull(retrievedBook)
+        assertEquals("Bereshit", retrievedBook.title)
+        assertEquals("בראשית", retrievedBook.heShortDesc)
+        assertEquals(categoryId, retrievedBook.categoryId)
+    }
+
+    @Test
+    fun `getBook returns null for non-existent id`() = runBlocking {
+        val book = repository.getBook(99999L)
+        assertNull(book)
+    }
+
+    @Test
+    fun `getBookCore returns lightweight book data`() = runBlocking {
+        val sourceId = repository.insertSource("Sefaria")
+        val categoryId = repository.insertCategory(Category(parentId = null, title = "Torah", level = 0, order = 1))
+        val bookId = repository.insertBook(
+            Book(categoryId = categoryId, sourceId = sourceId, title = "Shemot", order = 2f)
+        )
+
+        val book = repository.getBookCore(bookId)
+
+        assertNotNull(book)
+        assertEquals("Shemot", book.title)
+    }
+
+    @Test
+    fun `getBooksByCategory returns books in category`() = runBlocking {
+        val sourceId = repository.insertSource("Sefaria")
+        val categoryId = repository.insertCategory(Category(parentId = null, title = "Torah", level = 0, order = 1))
+
+        repository.insertBook(Book(categoryId = categoryId, sourceId = sourceId, title = "Bereshit", order = 1f))
+        repository.insertBook(Book(categoryId = categoryId, sourceId = sourceId, title = "Shemot", order = 2f))
+        repository.insertBook(Book(categoryId = categoryId, sourceId = sourceId, title = "Vayikra", order = 3f))
+
+        val books = repository.getBooksByCategory(categoryId)
+
+        assertEquals(3, books.size)
+        assertTrue(books.all { it.categoryId == categoryId })
+    }
+
+    @Test
+    fun `updateBookTotalLines updates line count`() = runBlocking {
+        val sourceId = repository.insertSource("Sefaria")
+        val categoryId = repository.insertCategory(Category(parentId = null, title = "Torah", level = 0, order = 1))
+        val bookId = repository.insertBook(
+            Book(categoryId = categoryId, sourceId = sourceId, title = "Bereshit", order = 1f)
+        )
+
+        repository.updateBookTotalLines(bookId, 1533)
+
+        val book = repository.getBook(bookId)
+        assertNotNull(book)
+        assertEquals(1533, book.totalLines)
+    }
+
+    // ==================== Line Tests ====================
+
+    @Test
+    fun `insertLine creates new line`() = runBlocking {
+        val sourceId = repository.insertSource("Sefaria")
+        val categoryId = repository.insertCategory(Category(parentId = null, title = "Torah", level = 0, order = 1))
+        val bookId = repository.insertBook(
+            Book(categoryId = categoryId, sourceId = sourceId, title = "Bereshit", order = 1f)
+        )
+
+        val line = Line(
+            bookId = bookId,
+            lineIndex = 0,
+            content = "<p>בראשית ברא אלהים את השמים ואת הארץ</p>"
+        )
+        val lineId = repository.insertLine(line)
+
+        assertTrue(lineId > 0)
+    }
+
+    @Test
+    fun `getLine returns line by id`() = runBlocking {
+        val sourceId = repository.insertSource("Sefaria")
+        val categoryId = repository.insertCategory(Category(parentId = null, title = "Torah", level = 0, order = 1))
+        val bookId = repository.insertBook(
+            Book(categoryId = categoryId, sourceId = sourceId, title = "Bereshit", order = 1f)
+        )
+        val content = "<p>בראשית ברא אלהים</p>"
+        val lineId = repository.insertLine(Line(bookId = bookId, lineIndex = 0, content = content))
+
+        val line = repository.getLine(lineId)
+
+        assertNotNull(line)
+        assertEquals(content, line.content)
+        assertEquals(bookId, line.bookId)
+    }
+
+    @Test
+    fun `getLine returns null for non-existent id`() = runBlocking {
+        val line = repository.getLine(99999L)
+        assertNull(line)
+    }
+
+    @Test
+    fun `getLines returns lines for book within range`() = runBlocking {
+        val sourceId = repository.insertSource("Sefaria")
+        val categoryId = repository.insertCategory(Category(parentId = null, title = "Torah", level = 0, order = 1))
+        val bookId = repository.insertBook(
+            Book(categoryId = categoryId, sourceId = sourceId, title = "Bereshit", order = 1f)
+        )
+
+        repository.insertLine(Line(bookId = bookId, lineIndex = 0, content = "Line 0"))
+        repository.insertLine(Line(bookId = bookId, lineIndex = 1, content = "Line 1"))
+        repository.insertLine(Line(bookId = bookId, lineIndex = 2, content = "Line 2"))
+
+        val lines = repository.getLines(bookId, startIndex = 0, endIndex = 3)
+
+        assertEquals(3, lines.size)
+        assertTrue(lines.all { it.bookId == bookId })
+    }
+
+    @Test
+    fun `getLines returns paginated lines`() = runBlocking {
+        val sourceId = repository.insertSource("Sefaria")
+        val categoryId = repository.insertCategory(Category(parentId = null, title = "Torah", level = 0, order = 1))
+        val bookId = repository.insertBook(
+            Book(categoryId = categoryId, sourceId = sourceId, title = "Bereshit", order = 1f)
+        )
+
+        // Insert 10 lines
+        repeat(10) { i ->
+            repository.insertLine(Line(bookId = bookId, lineIndex = i, content = "Line $i"))
+        }
+
+        // Get first range (lineIndex 0-4)
+        val firstRange = repository.getLines(bookId, startIndex = 0, endIndex = 4)
+        assertTrue(firstRange.isNotEmpty())
+        assertTrue(firstRange.all { it.lineIndex < 5 })
+
+        // Get second range (lineIndex 5-9)
+        val secondRange = repository.getLines(bookId, startIndex = 5, endIndex = 9)
+        assertTrue(secondRange.isNotEmpty())
+        assertTrue(secondRange.all { it.lineIndex >= 5 })
+
+        // Verify no overlap by line index
+        val firstRangeIndices = firstRange.map { it.lineIndex }.toSet()
+        val secondRangeIndices = secondRange.map { it.lineIndex }.toSet()
+        assertTrue(firstRangeIndices.intersect(secondRangeIndices).isEmpty())
+    }
+
+    // ==================== TOC Tests ====================
+
+    @Test
+    fun `insertTocEntry creates new toc entry`() = runBlocking {
+        val sourceId = repository.insertSource("Sefaria")
+        val categoryId = repository.insertCategory(Category(parentId = null, title = "Torah", level = 0, order = 1))
+        val bookId = repository.insertBook(
+            Book(categoryId = categoryId, sourceId = sourceId, title = "Bereshit", order = 1f)
+        )
+
+        val tocEntry = TocEntry(
+            bookId = bookId,
+            parentId = null,
+            text = "Chapter 1",
+            level = 0,
+            hasChildren = false
+        )
+        val tocId = repository.insertTocEntry(tocEntry)
+
+        assertTrue(tocId > 0)
+    }
+
+    @Test
+    fun `getTocEntriesForBook returns entries for book`() = runBlocking {
+        val sourceId = repository.insertSource("Sefaria")
+        val categoryId = repository.insertCategory(Category(parentId = null, title = "Torah", level = 0, order = 1))
+        val bookId = repository.insertBook(
+            Book(categoryId = categoryId, sourceId = sourceId, title = "Bereshit", order = 1f)
+        )
+
+        // Insert entries
+        repository.insertTocEntry(TocEntry(bookId = bookId, parentId = null, text = "Chapter 1", level = 0, hasChildren = true))
+        repository.insertTocEntry(TocEntry(bookId = bookId, parentId = null, text = "Chapter 2", level = 0, hasChildren = true))
+
+        val entries = repository.getTocEntriesForBook(bookId)
+
+        assertEquals(2, entries.size)
+        assertTrue(entries.all { it.bookId == bookId })
+    }
+
+    @Test
+    fun `getTocChildren returns children of parent entry`() = runBlocking {
+        val sourceId = repository.insertSource("Sefaria")
+        val categoryId = repository.insertCategory(Category(parentId = null, title = "Torah", level = 0, order = 1))
+        val bookId = repository.insertBook(
+            Book(categoryId = categoryId, sourceId = sourceId, title = "Bereshit", order = 1f)
+        )
+
+        val parentId = repository.insertTocEntry(
+            TocEntry(bookId = bookId, parentId = null, text = "Chapter 1", level = 0, hasChildren = true)
+        )
+        repository.insertTocEntry(TocEntry(bookId = bookId, parentId = parentId, text = "Verse 1", level = 1, hasChildren = false))
+        repository.insertTocEntry(TocEntry(bookId = bookId, parentId = parentId, text = "Verse 2", level = 1, hasChildren = false))
+        repository.insertTocEntry(TocEntry(bookId = bookId, parentId = parentId, text = "Verse 3", level = 1, hasChildren = false))
+
+        val children = repository.getTocChildren(parentId)
+
+        assertEquals(3, children.size)
+        assertTrue(children.all { it.parentId == parentId })
+    }
+
+    // ==================== Category Closure Tests ====================
+
+    @Test
+    fun `rebuildCategoryClosure creates self and ancestor pairs`() = runBlocking {
+        // Create a hierarchy: Torah -> Bereshit -> Chapters
+        val torahId = repository.insertCategory(Category(parentId = null, title = "Torah", level = 0, order = 1))
+        val bereshitId = repository.insertCategory(Category(parentId = torahId, title = "Bereshit", level = 1, order = 1))
+        val chaptersId = repository.insertCategory(Category(parentId = bereshitId, title = "Chapters", level = 2, order = 1))
+
+        repository.rebuildCategoryClosure()
+
+        // Verify hierarchy works by getting books under ancestor category
+        val sourceId = repository.insertSource("Test")
+        repository.insertBook(Book(categoryId = chaptersId, sourceId = sourceId, title = "Test Book", order = 1f))
+
+        val booksUnderTorah = repository.getBooksUnderCategoryTree(torahId)
+        assertEquals(1, booksUnderTorah.size)
+    }
+
+    // ==================== Transaction Tests ====================
+
+    @Test
+    fun `runInTransaction executes block and returns result`() = runBlocking {
+        val result = repository.runInTransaction {
+            val sourceId = repository.insertSource("Test")
+            val categoryId = repository.insertCategory(Category(parentId = null, title = "Test", level = 0, order = 1))
+            repository.insertBook(Book(categoryId = categoryId, sourceId = sourceId, title = "Test Book", order = 1f))
+        }
+
+        assertTrue(result > 0)
+    }
+
+    // ==================== Max ID Tests ====================
+
+    @Test
+    fun `getMaxBookId returns 0 when no books exist`() = runBlocking {
+        val maxId = repository.getMaxBookId()
+        assertEquals(0L, maxId)
+    }
+
+    @Test
+    fun `getMaxBookId returns highest book id`() = runBlocking {
+        val sourceId = repository.insertSource("Test")
+        val categoryId = repository.insertCategory(Category(parentId = null, title = "Test", level = 0, order = 1))
+
+        repository.insertBook(Book(categoryId = categoryId, sourceId = sourceId, title = "Book 1", order = 1f))
+        repository.insertBook(Book(categoryId = categoryId, sourceId = sourceId, title = "Book 2", order = 2f))
+        val lastBookId = repository.insertBook(Book(categoryId = categoryId, sourceId = sourceId, title = "Book 3", order = 3f))
+
+        val maxId = repository.getMaxBookId()
+
+        assertEquals(lastBookId, maxId)
+    }
+
+    @Test
+    fun `getMaxLineId returns 0 when no lines exist`() = runBlocking {
+        val maxId = repository.getMaxLineId()
+        assertEquals(0L, maxId)
+    }
+
+    @Test
+    fun `getMaxLineId returns highest line id`() = runBlocking {
+        val sourceId = repository.insertSource("Test")
+        val categoryId = repository.insertCategory(Category(parentId = null, title = "Test", level = 0, order = 1))
+        val bookId = repository.insertBook(Book(categoryId = categoryId, sourceId = sourceId, title = "Book", order = 1f))
+
+        repository.insertLine(Line(bookId = bookId, lineIndex = 0, content = "Line 1"))
+        repository.insertLine(Line(bookId = bookId, lineIndex = 1, content = "Line 2"))
+        val lastLineId = repository.insertLine(Line(bookId = bookId, lineIndex = 2, content = "Line 3"))
+
+        val maxId = repository.getMaxLineId()
+
+        assertEquals(lastLineId, maxId)
+    }
+}