Streamline GameTests and writing workstation logic

Complete Milestone 4 writing acceptance and migration coverage (#26 , #27 )
Use Legacy Linking Book recipe and add page-turn audio
2026-09-29 23:12:35 -04:00 · 2026-09-29 22:51:49 -04:00 · 2026-09-29 22:37:45 -04:00 · 2026-09-29 10:35:29 -04:00
52 changed files with 1379 additions and 113 deletions
@@ -16,6 +16,9 @@ The Writing Desk block texture is copied from Legacy's
 assets/mystcraft/textures/entity/desk.png under the same license.
 The Writing Desk GUI atlas is copied from Legacy's assets/mystcraft/gui/writingdesk.png
 under the same license; desk wood and inlay textures are cropped from desk.png.
+The Ink Mixer GUI atlas and block textures are copied from Legacy's
+assets/mystcraft/gui/inkmixer.png and textures/blocks/inkmixer_*.png under
+the same license. Rivencraft's block model is original and uses those textures.

 The initial build layout is derived from the official NeoForge 1.21.1
 ModDevGradle MDK: https://github.com/NeoForgeMDKs/MDK-1.21.1-ModDevGradle
@@ -4,8 +4,8 @@ Rivencraft is a clean, incremental port of the ideas and gameplay of
 [Mystcraft Legacy](https://github.com/Mystcraft/Mystcraft-Legacy) to Minecraft
 1.21.1 on NeoForge.

-The bootstrap, books/linking, and Ages milestones are complete. Milestone 4 is
-building the writing system on a data-pack symbol catalog and persistent
+The bootstrap, books/linking, Ages, and writing-system milestones are complete.
+The writing system uses a data-pack symbol catalog and persistent
 ordered-writing model. The project currently provides functional Linking Books
 and randomly seeded, persistent vanilla-like Ages created from page-free
 Descriptive Books. Instability and full symbol-to-world grammar interpretation
@@ -19,6 +19,11 @@ hand and use the Ink Vial in the other to prepare a baseline Link Panel Page.
 Each vial holds 16 ink units, and the default link-panel cost is two units.
 The spent vial returns a glass bottle. Server owners can adjust the symbol-copy
 and link-panel costs in the `writing` section of `rivencraft-server.toml`.
+The Ink Mixer now offers a Legacy-style station for producing Link Panels:
+insert paper and Ink Vials, then take a Link Panel from the result slot. Each
+vial fills its 16-unit basin and returns a glass bottle; no server tick is
+needed. The earlier paper-in-one-hand method remains available. Ink modifier
+ingredients and link properties are planned for Milestone 5.
 The Writing Desk can copy a selected written page from its collection tabs.
 The Writing Desk is now craftable from planks, a glass bottle, and a feather.
 It occupies two adjacent blocks, with one shared inventory; loaded paper and
@@ -61,6 +66,21 @@ portrait preview and name above the player inventory.

 ## Book Binder

+For a new survival Age: craft an Ink Vial, an Ink Mixer, a Writing Desk, and a Book Binder.
+Put vanilla paper and an Ink Vial in the Ink Mixer to make a Link Panel
+Page. Place leather (or an empty Notebook) and the Link Panel in the Book Binder,
+enter an Age name, and take the finished Descriptive Book. Written symbol Pages
+are optional; without them, the book creates a random Age. To duplicate a Page
+you already own, store it in a Writing Desk tab, select it, supply paper and ink,
+and take the copied Page from the output. A Notebook can hold and transfer a
+larger ordered collection of Pages between desks and the binder.
+
+With JEI installed, Rivencraft displays the Ink Mixer operation in its own
+category and the hand-use, copying, binding, and Linking Book crafting flows in a Writing category.
+JEI is optional; vanilla crafting
+recipes and all writing interactions work without it. For a development client
+with JEI, run `./gradlew runClient -PwithJei=true`.
+
 Craft a Book Binder from three iron ingots and five planks. Put leather or an
 empty Notebook in the left cover slot. Enter a title, then place a Link Panel
 Page first in the horizontal page strip. Click a page in the strip with a
@@ -84,8 +104,8 @@ font.

 ## Linking Book

-Craft a Linking Book from a vanilla book and an ender pearl, then use it in the
-air. An unbound book opens a screen where it can be named and bound to the
+Craft an unwritten Linking Book from one Link Panel Page and one leather in any
+two crafting-grid positions. An unbound book opens a screen where it can be named and bound to the
 current location. A bound book opens its destination screen and travels when
 its preview panel is clicked. The destination is stored on the item and
 survives inventory and world saves. Travel only succeeds if the target
@@ -93,6 +113,7 @@ dimension is loaded and a non-fluid, passable landing position can be found
 nearby.
 The Linking Book uses the same Legacy page layout and bottom-corner page turns
 as the Descriptive Book, but without the Descriptive Book's gold cover edges.
+Both screens play Minecraft's book-page-turn sound when a page is turned.

 Successful book travel plays Mystcraft Legacy's original linking sound at both
 the departure and arrival locations.
@@ -168,6 +189,10 @@ known upstream limits are documented in
 ```

 The built mod is written to `build/libs/`.
+The default dedicated-server GameTest run is deliberately small. Use
+`./gradlew runGameTestServer -PwithArchivedGameTests=true` for the complete
+regression suite before a release or when investigating a related issue. See
+[docs/GAMETESTS.md](docs/GAMETESTS.md).

 ## Versioning

@@ -17,6 +17,18 @@ tasks.named('wrapper', Wrapper).configure {
 version = mod_version
 group = mod_group_id

+List<String> archivedGameTestSuites = ['linking', 'writing', 'desk', 'binder', 'mixer', 'recipe']
+List<String> selectedArchivedGameTestSuites = providers.gradleProperty('withArchivedGameTests')
+        .map { it.toBoolean() }.orElse(false).get() ? archivedGameTestSuites
+        : providers.gradleProperty('archivedGameTestSuites').orElse('').get()
+                .split(',').collect { it.trim() }.findAll { !it.isEmpty() }
+if (!archivedGameTestSuites.containsAll(selectedArchivedGameTestSuites)) {
+    throw new GradleException("Unknown archived GameTest suite. Choose from: ${archivedGameTestSuites.join(', ')}")
+}
+String enabledGameTestNamespaces = ([mod_id] + selectedArchivedGameTestSuites.collect {
+    "rivencraft_archive_${it}"
+}).join(',')
+
 sourceSets.main.resources {
    // Include resources generated by data generators.
    srcDir('src/generated/resources')
@@ -26,7 +38,24 @@ sourceSets.main.resources {
    exclude("src/generated/**/.cache") // datagen cache files
 }

+// Archived suites use separate namespaces but share the same empty structure.
+tasks.named('processResources', ProcessResources).configure {
+    archivedGameTestSuites.each { suite ->
+        from('src/main/resources/data/rivencraft/structure/empty.nbt') {
+            into "data/rivencraft_archive_${suite}/structure"
+        }
+    }
+}
+
 repositories {
+    maven {
+        name = 'JaredsMaven'
+        url = 'https://maven.blamejared.com'
+        content {
+            includeGroup 'mezz.jei'
+            includeGroup 'net.mezzdev.config'
+        }
+    }
    maven { url = 'https://maven.createmod.net' }
    maven {
        url = 'https://www.cursemaven.com'
@@ -81,7 +110,7 @@ neoForge {
            // Keep generated test Ages separate from worlds used by the dev client/server.
            gameDirectory = project.file(project.findProperty('gameTestRunDir')
                    ?: layout.buildDirectory.dir('gametest-run').get().asFile)
-            systemProperty 'neoforge.enabledGameTestNamespaces', project.mod_id
+            systemProperty 'neoforge.enabledGameTestNamespaces', enabledGameTestNamespaces
        }

        data {
@@ -172,12 +201,12 @@ dependencies {
    compileOnly "maven.modrinth:immersive-portals-neoforge:${immersive_portals_version}"
    implementation "curse.maven:dynamicdimension-ar-edition-1469680:${dynamic_dimensions_file_id}"
    implementation "lol.bai:badpackets:neo-${badpackets_version}"
-    // Example optional mod dependency with JEI
-    // The JEI API is declared for compile time use, while the full JEI artifact is used at runtime
-    // compileOnly "mezz.jei:jei-${mc_version}-common-api:${jei_version}"
-    // compileOnly "mezz.jei:jei-${mc_version}-neoforge-api:${jei_version}"
-    // We add the full version to localRuntime, not runtimeOnly, so that we do not publish a dependency on it
-    // localRuntime "mezz.jei:jei-${mc_version}-neoforge:${jei_version}"
+    // JEI integration is isolated in its plugin and absent from the published runtime dependencies.
+    compileOnly "mezz.jei:jei-${minecraft_version}-neoforge-api:${jei_version}"
+    // Opt in to JEI for a dev client with -PwithJei=true.
+    if (providers.gradleProperty('withJei').map { it.toBoolean() }.orElse(false).get()) {
+        localRuntime "mezz.jei:jei-${minecraft_version}-neoforge:${jei_version}"
+    }

    // Example mod dependency using a mod jar from ./libs with a flat dir repository
    // This maps to ./libs/coolmod-${mc_version}-${coolmod_version}.jar
@@ -19,6 +19,8 @@ project's GNU LGPL v3 license. Rivencraft itself uses the same license.
 | `assets/rivencraft/textures/block/book_binder.png` | `assets/mystcraft/textures/entity/bookbinder/bookbinder.png` | `9bc8ddc061845df0cd5ea47f4fdef773cff786ae` | Namespace/path rename only; Book Binder model uses this body texture |
 | `assets/rivencraft/textures/block/book_binder_press.png` | `assets/mystcraft/textures/entity/bookbinder/press_part.png` | `9bc8ddc061845df0cd5ea47f4fdef773cff786ae` | Namespace/path rename only; Book Binder model uses this press texture |
 | `assets/rivencraft/textures/gui/book_binder_legacy.png` | `assets/mystcraft/gui/pagebinder.png` | `9bc8ddc061845df0cd5ea47f4fdef773cff786ae` | Namespace/path rename only; Book Binder GUI uses the original 176×181 panel |
+| `assets/rivencraft/textures/gui/ink_mixer_legacy.png` | `assets/mystcraft/gui/inkmixer.png` | `9bc8ddc061845df0cd5ea47f4fdef773cff786ae` | Namespace/path rename only; Ink Mixer GUI uses the original 176×181 panel |
+| `assets/rivencraft/textures/block/ink_mixer_top.png`, `ink_mixer_side.png`, `ink_mixer_bottom.png` | `assets/mystcraft/textures/blocks/inkmixer_top.png`, `inkmixer_side.png`, `inkmixer_bottom.png` | `9bc8ddc061845df0cd5ea47f4fdef773cff786ae` | Namespace/path rename only; Rivencraft supplies its own block model |
 | `assets/rivencraft/textures/item/linking_book_unwritten.png` | `assets/mystcraft/textures/items/unlinked.png` | `9bc8ddc061845df0cd5ea47f4fdef773cff786ae` | Namespace/path rename only |
 | `assets/rivencraft/textures/item/page_link_panel.png` | `page_background.png` and `PageBuilder.BasicPageSprite` | `9bc8ddc061845df0cd5ea47f4fdef773cff786ae` | Reproduces the legacy 160 px scale, black panel at `(25,30)`–`(135,75)`, and 128 px resample |
 | `assets/rivencraft/textures/item/page_symbol*.png` and `page_unresolved.png` | `page_background.png`, `textures/symbolcomponents.png`, `WordData`, `ModSymbols`, and `PageBuilder.PageSprite` | `9bc8ddc061845df0cd5ea47f4fdef773cff786ae` | Static 1.21.1 renditions of the legacy runtime-composed four-word symbol pages; `normal_time` uses the legacy Full Length poem |
@@ -0,0 +1,42 @@
+# GameTest suites
+
+The default dedicated-server run is a small smoke suite: 16 Rivencraft tests
+cover core linking, deterministic Age definition, writing persistence, legacy
+data migration, workstation transactions, and forged/replayed menu actions.
+NeoForge currently adds two of its own tests, so the runner reports 18.
+
+```shell
+./gradlew runGameTestServer
+```
+
+The remaining 46 Rivencraft tests are archived, not deleted. They cover
+completed milestone details such as every Age terrain profile, Notebook and
+Desk surface interactions, refill edge cases, book assembly controls, and
+workstation break/drop behavior. Run only the relevant archive alongside the
+core tests when investigating an issue:
+
+```shell
+./gradlew runGameTestServer -ParchivedGameTestSuites=desk
+./gradlew runGameTestServer -ParchivedGameTestSuites=linking,binder
+```
+
+Available suite names are `linking`, `writing`, `desk`, `binder`, `mixer`, and
+`recipe`. Run all 62 Rivencraft tests (64 including NeoForge's two) before a
+release or after broad cross-system changes:
+
+```shell
+./gradlew runGameTestServer -PwithArchivedGameTests=true
+```
+
+Each archive is selected by its `rivencraft_archive_<suite>` GameTest namespace.
+The suites share the normal empty test structure and do not need Create, Ponder, or
+Immersive Portals. The core suite delegates to the original regression methods
+for its selected cases, so the two suites do not maintain duplicate test logic.
+
+GameTest Ages are created in `build/gametest-run/world`, not in a development
+client save. The Gradle task removes that **dedicated** world automatically if
+it exceeds 512 MiB; override the threshold with `-PgameTestMaxWorldMiB=128`,
+for example. Cleanup never targets a custom `-PgameTestRunDir` or a player
+world. A fresh test world can also help diagnose a slow or stalled worldgen
+run. The full suite should still be run before shipping changes in the
+archived systems.
@@ -33,8 +33,10 @@ acceptance issue and all required implementation issues are complete.
   lifecycle management, data-pack integration, and optional destination
   renderer compatibility. **Complete.** See
   [Milestone 3](https://gitea.tail180fb1.ts.net/dnorberg/rivencraft/milestone/8).
-4. **Writing system** — pages, symbols, notebooks, desks, and book assembly.
-   **In progress.**
+4. **Writing system** — pages, notebooks, desks, book assembly, and the baseline
+   Ink Mixer for Link Panels. Symbol effects are deferred until Milestone 5.
+   **Complete.** See [Milestone 4](https://gitea.tail180fb1.ts.net/dnorberg/rivencraft/milestone/9)
+   and [writing-system data and migration](WRITING_DATA.md).
 5. **Age grammar** — translate symbol combinations into modern biome, noise,
   dimension-type, and world-generation configuration. Optional integrations
   may add composable biome regions and seasonal behavior.
@@ -62,10 +64,13 @@ The writing system and Age grammar will build on the existing page-free Age
 path. Page-free books remain a useful deterministic fallback and test fixture
 after written symbol combinations become available.

-Milestone 4 begins with a versioned, data-pack-defined symbol catalog and an
+Milestone 4 delivered a versioned, data-pack-defined symbol catalog and an
 immutable ordered-writing model. See [WRITING_DATA.md](WRITING_DATA.md). These
 contracts preserve unknown symbol identifiers and store author intent; they do
 not interpret symbols into Age generation, which remains Milestone 5 work.
+The Ink Mixer is included in Milestone 4 after book assembly; it
+uses paper and Ink Vials to make baseline Link Panels. Adding modifier
+ingredients and symbol-driven link properties belongs to Milestone 5.

 ## Provenance rules

@@ -66,7 +66,7 @@ unstable in a particular graphics or mod configuration.

 For preview-related releases:

-1. Run `./gradlew runGameTestServer` to verify the complete selection matrix,
+1. Run `./gradlew runGameTestServer -PwithArchivedGameTests=true` to verify the complete selection matrix,
   core Age creation, persistence, and travel without optional renderers.
 2. Open held Linking and Descriptive Books once with each available backend.
 3. Open both book types from a Book Stand and confirm Explore is disabled.
@@ -75,4 +75,3 @@ For preview-related releases:
   preview loader remains active.
 5. With Ponder, reopen different destinations and confirm the previous
   snapshot does not bleed into the next one.
-
@@ -65,11 +65,11 @@ unresolved symbol, and baseline link panel. Symbol and unresolved-symbol pages
 retain their namespaced symbol reference; unresolved pages can be inspected and
 removed but are rejected as usable writing until their data pack returns.

-Only server-side writing operations may create a known symbol
-page or link panel from vanilla paper. The shared `PageItem` creation and validation gates reject
-new pages for identifiers absent from the server catalog. Later Writing Desk
-and Book Binder packets must call these gates rather than accepting page
-contents supplied by a client.
+Only server-side writing operations may create a known symbol page or link
+panel from vanilla paper. The shared `PageItem` creation and validation gates
+reject new pages for identifiers absent from the server catalog. The Writing
+Desk refuses to copy an unresolved page, and the Book Binder keeps such a page
+removable but will not assemble a book from it until its symbol resolves again.

 The item model uses server-assigned custom-model data derived from the symbol
 identifier. Built-in pages reproduce Mystcraft Legacy's four-word poem
@@ -84,6 +84,29 @@ placement. The surface draws the native 30×40 portrait page region from
 Legacy's book UI atlas; symbols are layered at a uniform scale, while the
 square item models remain unchanged in inventories.

+A Notebook holds 27 ordered positions. Its pages, names, gaps, and unresolved
+IDs are saved on the item, so moving the Notebook between an inventory, Desk,
+and Binder does not rearrange them. A loose Page in a Desk tab exposes just one
+position; a Notebook exposes all 27. The Desk has 88 persistent collection
+tabs, shown four at a time. Use the up/down tab controls to move by four, put
+paper and Ink Vials in their input slots, select a stored page, and take the
+copy from the virtual output. Taking it spends one paper and the configured
+symbol-copy ink cost. The `AZ`, `ALL`, search, and category controls only change
+which stored pages are displayed; the server rechecks the actual source before
+copying. Moving a page within the Desk or dragging it into the inventory removes
+the original only when the destination accepts it.
+
+The Book Binder takes a leather or empty-Notebook cover, an Age title, one Link
+Panel, and optionally up to 27 ordered written Pages. A filled Notebook can be
+imported at a chosen strip position; the empty Notebook remains recoverable.
+The preview result is virtual. Taking the completed Descriptive Book commits the
+inputs once, creates its Age identity, and saves schema-versioned
+`OrderedWriting` plus the Age reference on the book. Link-Panel-only books
+create random Ages. A written symbol does **not** yet change that generation.
+Inputs, title, and pending Age identity survive Binder save/load; breaking the
+Binder returns stored inputs. The completed book retains both its writing and
+Age identity through item save/load and copying.
+
 ## Ink and baseline link panels

 An Ink Vial is crafted from two black dye, a glass bottle, and a water bucket.
@@ -103,3 +126,32 @@ resolved page, then spends paper and ink only when that copy is taken. The
 desk's 16-unit ink meter refills from an Ink Vial when needed and returns a
 vanilla glass bottle. Link-property modifiers are
 deferred beyond this baseline flow.
+
+The Ink Mixer is the station version of Link Panel preparation. Put paper and
+Ink Vials in its inputs and take the Link Panel from its virtual output. Its
+16-unit basin refills only when needed and only if the glass-bottle output has
+space. The basin and inputs persist through save/load; breaking the Mixer
+returns stored items. A Link Panel plus leather also crafts an unwritten
+Linking Book. JEI, when installed, displays the Mixer operation and the
+writing, binding, and Linking Book crafting flows; it is not required to play.
+
+## Migration and validation
+
+The 0.3.7.2 bare-list `OrderedWriting` form reads as schema version 1 without
+changing entry order. Descriptive Books with no writing component keep their
+existing Age behavior. Old eight-slot Desks migrate their four collections,
+ink supply, paper, bottle return, and legacy output into the 88-tab layout;
+saved inputs are never silently discarded. Missing symbol IDs survive page,
+Notebook, Binder, and assembled-book persistence instead of being substituted
+or erased.
+
+The core and archived dedicated-server [GameTests](GAMETESTS.md) together
+exercise codec and item round-trips, legacy data,
+workstation NBT reload, break drops, full-inventory refusal, forged menu IDs,
+and replayed output requests. World saves and chunk unloads use the same block
+entity NBT persistence path as those reload tests. This does not replace a
+manual smoke test of loading an older world before updating a production save.
+
+Milestone 4 stops at preserving author intent and offering a playable random
+Age fallback. Milestone 5 will define symbol grammar and validation, translate
+valid writing into actual Age generation, and introduce symbol and ink modifiers.
@@ -22,6 +22,7 @@ neo_version=21.1.251
 ponder_version=1.0.82
 dynamic_dimensions_file_id=7707789
 badpackets_version=0.8.2
+jei_version=19.57.0.449
 # The loader version range can only use the major version of FML as bounds
 loader_version_range=[1,)

@@ -35,7 +36,7 @@ mod_name=Rivencraft
 # The license of the mod. Review your options at https://choosealicense.com/. All Rights Reserved is the default.
 mod_license=LGPL-3.0-or-later
 # The mod version. Rivencraft uses the x.y.z.b policy documented in README.md.
-mod_version=0.3.8.2
+mod_version=0.4.0.2
 immersive_portals_version=6.0.7
 # The group ID for the mod. It is only important when publishing as an artifact to a Maven repository.
 # This should match the base package used for the mod sources.
@@ -5,6 +5,7 @@ import net.dnorberg.rivencraft.registry.ModCreativeTabs;
 import net.dnorberg.rivencraft.registry.ModDataComponents;
 import net.dnorberg.rivencraft.registry.ModItems;
 import net.dnorberg.rivencraft.registry.ModMenus;
+import net.dnorberg.rivencraft.registry.ModRecipeSerializers;
 import net.dnorberg.rivencraft.registry.ModSounds;
 import net.dnorberg.rivencraft.registry.ModBlocks;
 import net.dnorberg.rivencraft.registry.ModBlockEntities;
@@ -43,6 +44,7 @@ public final class Rivencraft {
        ModBlockEntities.register(modEventBus);
        ModItems.register(modEventBus);
        ModMenus.register(modEventBus);
+        ModRecipeSerializers.register(modEventBus);
        ModSounds.register(modEventBus);
        ModCreativeTabs.register(modEventBus);
        NeoForge.EVENT_BUS.addListener(BookStandConversionHandler::onRightClickBlock);
@@ -0,0 +1,52 @@
+package net.dnorberg.rivencraft.block;
+
+import com.mojang.serialization.MapCodec;
+import net.dnorberg.rivencraft.block.entity.InkMixerBlockEntity;
+import net.dnorberg.rivencraft.menu.InkMixerMenu;
+import net.minecraft.core.BlockPos;
+import net.minecraft.network.chat.Component;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.Containers;
+import net.minecraft.world.InteractionResult;
+import net.minecraft.world.SimpleMenuProvider;
+import net.minecraft.world.entity.player.Player;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.block.BaseEntityBlock;
+import net.minecraft.world.level.block.RenderShape;
+import net.minecraft.world.level.block.entity.BlockEntity;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.phys.BlockHitResult;
+
+public final class InkMixerBlock extends BaseEntityBlock {
+    public static final MapCodec<InkMixerBlock> CODEC = simpleCodec(InkMixerBlock::new);
+
+    public InkMixerBlock(Properties properties) { super(properties); }
+
+    @Override protected MapCodec<? extends BaseEntityBlock> codec() { return CODEC; }
+    @Override protected RenderShape getRenderShape(BlockState state) { return RenderShape.MODEL; }
+    @Override public BlockEntity newBlockEntity(BlockPos pos, BlockState state) {
+        return new InkMixerBlockEntity(pos, state);
+    }
+
+    @Override protected InteractionResult useWithoutItem(BlockState state, Level level, BlockPos pos,
+                                                          Player player, BlockHitResult hit) {
+        if (!level.isClientSide && player instanceof ServerPlayer serverPlayer
+                && level.getBlockEntity(pos) instanceof InkMixerBlockEntity mixer) {
+            serverPlayer.openMenu(new SimpleMenuProvider(
+                    (id, inventory, ignored) -> new InkMixerMenu(id, inventory, mixer),
+                    Component.translatable("container.rivencraft.ink_mixer")),
+                    buffer -> buffer.writeBlockPos(pos));
+        }
+        return InteractionResult.sidedSuccess(level.isClientSide);
+    }
+
+    @Override protected void onRemove(BlockState state, Level level, BlockPos pos,
+                                      BlockState replacement, boolean moving) {
+        if (!state.is(replacement.getBlock()) && !level.isClientSide
+                && level.getBlockEntity(pos) instanceof InkMixerBlockEntity mixer) {
+            Containers.dropContents(level, pos, mixer);
+            level.updateNeighbourForOutputSignal(pos, this);
+        }
+        super.onRemove(state, level, pos, replacement, moving);
+    }
+}
@@ -105,7 +105,7 @@ public final class BookBinderBlockEntity extends BlockEntity implements Containe
                || items.get(LINK_PANEL).getCount() != 1) return false;
        for (int slot = FIRST_PAGE; slot < SIZE; slot++) {
            ItemStack page = items.get(slot);
-            if (!page.isEmpty() && (!validPage(page) || page.getCount() != 1
+            if (!page.isEmpty() && (!validPage(page) || !PageItem.isUsableWriting(page) || page.getCount() != 1
                    || PageItem.content(page).kind() == PageContent.Kind.BLANK)) return false;
        }
        return true;
@@ -195,26 +195,19 @@ public final class BookBinderBlockEntity extends BlockEntity implements Containe
        if (pages.isEmpty()) return ItemStack.EMPTY;
        int end = nextPageIndex();
        if (index < 0 || index > end) return ItemStack.EMPTY;
-        boolean link = false;
+        ItemStack linkPanel = ItemStack.EMPTY;
        List<ItemStack> writing = new ArrayList<>();
        for (ItemStack page : pages) {
            if (page.isEmpty()) continue;
            if (!page.is(ModItems.PAGE.get()) || page.getCount() != 1) return ItemStack.EMPTY;
            if (PageItem.content(page).kind() == PageContent.Kind.LINK_PANEL) {
-                if (link || !items.get(LINK_PANEL).isEmpty()) return ItemStack.EMPTY;
-                link = true;
+                if (!linkPanel.isEmpty() || !items.get(LINK_PANEL).isEmpty()) return ItemStack.EMPTY;
+                linkPanel = page;
            } else if (validPage(page)) writing.add(page);
            else return ItemStack.EMPTY;
        }
-        if (end + writing.size() > PAGE_COUNT || writing.isEmpty() && !link) return ItemStack.EMPTY;
-        if (link) {
-            for (ItemStack page : pages) {
-                if (!page.isEmpty() && PageItem.content(page).kind() == PageContent.Kind.LINK_PANEL) {
-                    items.set(LINK_PANEL, page.copy());
-                    break;
-                }
-            }
-        }
+        if (end + writing.size() > PAGE_COUNT || writing.isEmpty() && linkPanel.isEmpty()) return ItemStack.EMPTY;
+        if (!linkPanel.isEmpty()) items.set(LINK_PANEL, linkPanel.copy());
        for (int current = end - 1; current >= index; current--)
            items.set(FIRST_PAGE + current + writing.size(), items.get(FIRST_PAGE + current));
        for (ItemStack page : writing) items.set(FIRST_PAGE + index++, page.copy());
@@ -0,0 +1,121 @@
+package net.dnorberg.rivencraft.block.entity;
+
+import net.dnorberg.rivencraft.item.InkVialItem;
+import net.dnorberg.rivencraft.writing.InkVialExchange;
+import net.dnorberg.rivencraft.registry.ModBlockEntities;
+import net.dnorberg.rivencraft.registry.ModItems;
+import net.dnorberg.rivencraft.writing.WritingInkService;
+import net.minecraft.core.BlockPos;
+import net.minecraft.core.HolderLookup;
+import net.minecraft.core.NonNullList;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.world.Container;
+import net.minecraft.world.ContainerHelper;
+import net.minecraft.world.entity.player.Player;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.Items;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.block.entity.BlockEntity;
+import net.minecraft.world.level.block.state.BlockState;
+
+/** Baseline Link Panel mixer. Modifier ingredients belong to the symbol/ink-effects milestone. */
+public final class InkMixerBlockEntity extends BlockEntity implements Container {
+    public static final int INK = 0;
+    public static final int PAPER = 1;
+    public static final int BOTTLES = 2;
+    public static final int SIZE = 3;
+
+    private NonNullList<ItemStack> items = NonNullList.withSize(SIZE, ItemStack.EMPTY);
+    private int inkRemaining;
+
+    public InkMixerBlockEntity(BlockPos pos, BlockState state) {
+        super(ModBlockEntities.INK_MIXER.get(), pos, state);
+    }
+
+    public int inkRemaining() { return inkRemaining; }
+
+    @Override public int getContainerSize() { return SIZE; }
+    @Override public boolean isEmpty() { return items.stream().allMatch(ItemStack::isEmpty); }
+    @Override public ItemStack getItem(int slot) { return items.get(slot); }
+    @Override public ItemStack removeItem(int slot, int amount) {
+        ItemStack removed = ContainerHelper.removeItem(items, slot, amount);
+        if (!removed.isEmpty()) {
+            setChanged();
+            if (slot == BOTTLES) refillEmptyBasin();
+        }
+        return removed;
+    }
+    @Override public ItemStack removeItemNoUpdate(int slot) { return ContainerHelper.takeItem(items, slot); }
+    @Override public void setItem(int slot, ItemStack stack) {
+        items.set(slot, stack);
+        if (stack.getCount() > getMaxStackSize()) stack.setCount(getMaxStackSize());
+        setChanged();
+        if (slot == INK || slot == BOTTLES) refillEmptyBasin();
+    }
+    @Override public boolean canPlaceItem(int slot, ItemStack stack) {
+        return switch (slot) {
+            case INK -> stack.is(ModItems.INK_VIAL.get());
+            case PAPER -> stack.is(Items.PAPER);
+            default -> false;
+        };
+    }
+    @Override public boolean stillValid(Player player) {
+        return level != null && level.isLoaded(worldPosition) && level.getBlockEntity(worldPosition) == this
+                && player.distanceToSqr(worldPosition.getX() + 0.5, worldPosition.getY() + 0.5,
+                        worldPosition.getZ() + 0.5) <= 64.0;
+    }
+
+    /** No server tick: refill only when ink, bottle space, or consumption changes. */
+    private void refillEmptyBasin() {
+        if (level != null && !level.isClientSide && inkRemaining == 0) {
+            int addedInk = InkVialExchange.exchange(items, INK, BOTTLES);
+            if (addedInk > 0) {
+                inkRemaining = addedInk;
+                setChanged();
+            }
+        }
+    }
+
+    public boolean canCreateLinkPanel() {
+        if (!items.get(PAPER).is(Items.PAPER)) return false;
+        int cost = WritingInkService.linkPanelCost();
+        return InkVialExchange.canPay(items, INK, BOTTLES, inkRemaining, cost);
+    }
+
+    /** Commit inputs only when a virtual output is actually taken. */
+    public boolean consumeLinkPanelMaterials() {
+        if (!canCreateLinkPanel()) return false;
+        int cost = WritingInkService.linkPanelCost();
+        if (inkRemaining < cost) {
+            inkRemaining += InkVialExchange.exchange(items, INK, BOTTLES);
+        }
+        inkRemaining -= cost;
+        items.get(PAPER).shrink(1);
+        if (items.get(PAPER).isEmpty()) items.set(PAPER, ItemStack.EMPTY);
+        setChanged();
+        if (inkRemaining == 0) refillEmptyBasin();
+        return true;
+    }
+
+    @Override public void setLevel(Level level) {
+        super.setLevel(level);
+        refillEmptyBasin();
+    }
+    @Override public void clearContent() {
+        items = NonNullList.withSize(SIZE, ItemStack.EMPTY);
+        inkRemaining = 0;
+        setChanged();
+    }
+    @Override protected void loadAdditional(CompoundTag tag, HolderLookup.Provider registries) {
+        super.loadAdditional(tag, registries);
+        items = NonNullList.withSize(SIZE, ItemStack.EMPTY);
+        ContainerHelper.loadAllItems(tag, items, registries);
+        inkRemaining = Math.clamp(tag.getInt("InkRemaining"), 0, InkVialItem.CAPACITY);
+        refillEmptyBasin();
+    }
+    @Override protected void saveAdditional(CompoundTag tag, HolderLookup.Provider registries) {
+        super.saveAdditional(tag, registries);
+        ContainerHelper.saveAllItems(tag, items, registries);
+        tag.putInt("InkRemaining", inkRemaining);
+    }
+}
@@ -1,6 +1,7 @@
 package net.dnorberg.rivencraft.block.entity;

 import net.dnorberg.rivencraft.item.InkVialItem;
+import net.dnorberg.rivencraft.writing.InkVialExchange;
 import net.dnorberg.rivencraft.writing.WritingInkService;
 import net.dnorberg.rivencraft.registry.ModBlockEntities;
 import net.dnorberg.rivencraft.registry.ModItems;
@@ -92,26 +93,15 @@ public final class WritingDeskBlockEntity extends BlockEntity implements Contain
        };
    }

-    private boolean hasBottleSpace() {
-        ItemStack returned = items.get(RETURN);
-        return returned.isEmpty() || returned.is(Items.GLASS_BOTTLE)
-                && returned.getCount() < returned.getMaxStackSize();
-    }
-
    /** Consume one vial only when the empty meter can return its glass bottle. */
    private void refillEmptyInkBar() {
-        if (level == null || level.isClientSide || inkRemaining != 0 || !hasBottleSpace()) return;
-        ItemStack vial = items.get(INK);
-        if (!vial.is(ModItems.INK_VIAL.get())) return;
-        int ink = Math.clamp(InkVialItem.remaining(vial), 0, InkVialItem.CAPACITY);
-        if (ink == 0) return;
-        inkRemaining = ink;
-        vial.shrink(1);
-        if (vial.isEmpty()) items.set(INK, ItemStack.EMPTY);
-        ItemStack returned = items.get(RETURN);
-        if (returned.isEmpty()) items.set(RETURN, new ItemStack(Items.GLASS_BOTTLE));
-        else returned.grow(1);
-        setChanged();
+        if (level != null && !level.isClientSide && inkRemaining == 0) {
+            int addedInk = InkVialExchange.exchange(items, INK, RETURN);
+            if (addedInk > 0) {
+                inkRemaining = addedInk;
+                setChanged();
+            }
+        }
    }

    /** The output is virtual; inputs are committed only after a result can be given to a player. */
@@ -119,23 +109,14 @@ public final class WritingDeskBlockEntity extends BlockEntity implements Contain
        ItemStack paper = items.get(PAPER);
        if (!canPlaceItem(PAPER, paper) || paper.isEmpty()) return false;
        int cost = WritingInkService.symbolCopyCost();
-        if (inkRemaining >= cost) return true;
-        ItemStack vial = items.get(INK);
-        return vial.is(ModItems.INK_VIAL.get()) && inkRemaining + InkVialItem.remaining(vial) >= cost
-                && hasBottleSpace();
+        return InkVialExchange.canPay(items, INK, RETURN, inkRemaining, cost);
    }

    public boolean consumeCopyMaterials() {
        if (!canConsumeCopyMaterials()) return false;
        int cost = WritingInkService.symbolCopyCost();
        if (inkRemaining < cost) {
-            ItemStack vial = items.get(INK);
-            inkRemaining += Math.clamp(InkVialItem.remaining(vial), 0, InkVialItem.CAPACITY);
-            vial.shrink(1);
-            if (vial.isEmpty()) items.set(INK, ItemStack.EMPTY);
-            ItemStack returned = items.get(RETURN);
-            if (returned.isEmpty()) items.set(RETURN, new ItemStack(Items.GLASS_BOTTLE));
-            else returned.grow(1);
+            inkRemaining += InkVialExchange.exchange(items, INK, RETURN);
        }
        inkRemaining -= cost;
        removeItem(PAPER, 1);
@@ -148,7 +129,6 @@ public final class WritingDeskBlockEntity extends BlockEntity implements Contain
        refillEmptyInkBar();
    }
    @Override public void clearContent() {
-        items.clear();
        items = NonNullList.withSize(SIZE, ItemStack.EMPTY);
        inkRemaining = 0;
        displayPage = ItemStack.EMPTY;
@@ -16,6 +16,7 @@ import net.neoforged.neoforge.client.event.RegisterMenuScreensEvent;
 import net.dnorberg.rivencraft.client.screen.NotebookScreen;
 import net.dnorberg.rivencraft.client.screen.WritingDeskScreen;
 import net.dnorberg.rivencraft.client.screen.BookBinderScreen;
+import net.dnorberg.rivencraft.client.screen.InkMixerScreen;
 import net.dnorberg.rivencraft.registry.ModMenus;

@EventBusSubscriber(modid = Rivencraft.MOD_ID, value = Dist.CLIENT)
@@ -34,6 +35,7 @@ public final class ClientEvents {
        event.register(ModMenus.NOTEBOOK.get(), NotebookScreen::new);
        event.register(ModMenus.WRITING_DESK.get(), WritingDeskScreen::new);
        event.register(ModMenus.BOOK_BINDER.get(), BookBinderScreen::new);
+        event.register(ModMenus.INK_MIXER.get(), InkMixerScreen::new);
    }

    @SubscribeEvent
@@ -13,6 +13,7 @@ import net.minecraft.resources.ResourceLocation;
 import net.minecraft.world.entity.player.Inventory;
 import net.minecraft.world.item.ItemStack;
 import net.neoforged.neoforge.network.PacketDistributor;
+import org.lwjgl.glfw.GLFW;

 /** Legacy-sized binder: cover and result flank a scrolling strip of full page thumbnails. */
 public final class BookBinderScreen extends AbstractContainerScreen<BookBinderMenu> {
@@ -41,6 +42,8 @@ public final class BookBinderScreen extends AbstractContainerScreen<BookBinderMe
        inventoryLabelY = 87;
    }

+    @Override public boolean isPauseScreen() { return false; }
+
    @Override protected void init() {
        super.init();
        titleInput = new EditBox(font, leftPos + 9, topPos + 10, 112, 12,
@@ -94,6 +97,13 @@ public final class BookBinderScreen extends AbstractContainerScreen<BookBinderMe
        }
        graphics.disableScissor();
        drawScrollEnds(graphics);
+        if (mouseY >= topPos + STRIP_Y && mouseY < topPos + STRIP_Y + STRIP_HEIGHT) {
+            if (firstVisible > 0 && mouseX >= leftPos + STRIP_X && mouseX < leftPos + STRIP_X + 8)
+                graphics.renderTooltip(font, Component.translatable("screen.rivencraft.book_binder.previous_pages"), mouseX, mouseY);
+            else if (firstVisible < maxFirstVisible() && mouseX >= leftPos + STRIP_X + STRIP_WIDTH - 8
+                    && mouseX < leftPos + STRIP_X + STRIP_WIDTH)
+                graphics.renderTooltip(font, Component.translatable("screen.rivencraft.book_binder.next_pages"), mouseX, mouseY);
+        }
        if (pageAtIndex(0).isEmpty() && mouseX >= leftPos + 27 && mouseX < leftPos + 45
                && mouseY >= topPos + 26 && mouseY < topPos + 44) {
            graphics.renderTooltip(font,
@@ -210,6 +220,14 @@ public final class BookBinderScreen extends AbstractContainerScreen<BookBinderMe
            } else titleInput.keyPressed(keyCode, scanCode, modifiers);
            return true;
        }
+        if (keyCode == GLFW.GLFW_KEY_LEFT && firstVisible > 0) {
+            firstVisible--;
+            return true;
+        }
+        if (keyCode == GLFW.GLFW_KEY_RIGHT && firstVisible < maxFirstVisible()) {
+            firstVisible++;
+            return true;
+        }
        return super.keyPressed(keyCode, scanCode, modifiers);
    }
 }
@@ -20,14 +20,18 @@ import net.dnorberg.rivencraft.client.preview.DestinationPreviewRenderers;
 import net.minecraft.core.BlockPos;
 import net.minecraft.client.gui.GuiGraphics;
 import net.minecraft.client.gui.screens.Screen;
+import net.minecraft.client.resources.sounds.SimpleSoundInstance;
 import net.minecraft.client.gui.components.Button;
 import net.minecraft.client.gui.components.EditBox;
+import net.minecraft.client.gui.components.Tooltip;
 import net.minecraft.network.chat.Component;
 import net.minecraft.resources.ResourceLocation;
+import net.minecraft.sounds.SoundEvents;
 import net.minecraft.util.FormattedCharSequence;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.InteractionHand;
 import net.neoforged.neoforge.network.PacketDistributor;
+import org.lwjgl.glfw.GLFW;
 import org.jetbrains.annotations.Nullable;

 public final class DescriptiveBookScreen extends Screen implements ExplorableBookScreen {
@@ -113,7 +117,8 @@ public final class DescriptiveBookScreen extends Screen implements ExplorableBoo
            if (preview.supportsExploration()) {
                exploreButton = addRenderableWidget(Button.builder(
                                EXPLORE_ICON, button -> enterExploreOverlay())
-                        .bounds(left + 229, top + 145, 20, 20).build());
+                        .bounds(left + 229, top + 145, 20, 20)
+                        .tooltip(Tooltip.create(Component.translatable("screen.rivencraft.book.explore"))).build());
                exploreButton.active = bookStandPos == null;
                exploreButton.visible = pageIndex == 0;
            }
@@ -150,6 +155,14 @@ public final class DescriptiveBookScreen extends Screen implements ExplorableBoo
    public void render(GuiGraphics graphics, int mouseX, int mouseY, float partialTick) {
        renderBook(graphics, partialTick);
        super.render(graphics, mouseX, mouseY, partialTick);
+        int left = (width - BOOK_WIDTH) / 2;
+        int top = (height - BOOK_HEIGHT) / 2;
+        if (mouseY >= top + 164 && mouseY < top + 195) {
+            if (pageIndex > 0 && mouseX >= left + 7 && mouseX < left + 35)
+                graphics.renderTooltip(font, Component.translatable("screen.rivencraft.book.previous_page"), mouseX, mouseY);
+            else if (pageIndex < pageCount() && mouseX >= left + 293 && mouseX < left + 320)
+                graphics.renderTooltip(font, Component.translatable("screen.rivencraft.book.next_page"), mouseX, mouseY);
+        }
    }

    private void renderBook(GuiGraphics graphics, float partialTick) {
@@ -239,7 +252,10 @@ public final class DescriptiveBookScreen extends Screen implements ExplorableBoo
    }

    private void turnPage(int direction) {
-        pageIndex = Math.max(0, Math.min(pageCount(), pageIndex + direction));
+        int nextPage = Math.max(0, Math.min(pageCount(), pageIndex + direction));
+        if (nextPage == pageIndex) return;
+        pageIndex = nextPage;
+        minecraft.getSoundManager().play(SimpleSoundInstance.forUI(SoundEvents.BOOK_PAGE_TURN, 1.0F, 0.65F));
        if (titleInput != null) titleInput.visible = pageIndex == 0;
        if (createButton != null) createButton.visible = pageIndex == 0;
        if (cancelButton != null) cancelButton.visible = pageIndex == 0;
@@ -303,6 +319,10 @@ public final class DescriptiveBookScreen extends Screen implements ExplorableBoo

    @Override
    public boolean keyPressed(int keyCode, int scanCode, int modifiers) {
+        if (titleInput == null || !titleInput.isFocused()) {
+            if (keyCode == GLFW.GLFW_KEY_LEFT && pageIndex > 0) { turnPage(-1); return true; }
+            if (keyCode == GLFW.GLFW_KEY_RIGHT && pageIndex < pageCount()) { turnPage(1); return true; }
+        }
        return preview != null && preview.keyPressed(keyCode, scanCode)
                || super.keyPressed(keyCode, scanCode, modifiers);
    }
@@ -0,0 +1,52 @@
+package net.dnorberg.rivencraft.client.screen;
+
+import net.dnorberg.rivencraft.Rivencraft;
+import net.dnorberg.rivencraft.item.InkVialItem;
+import net.dnorberg.rivencraft.menu.InkMixerMenu;
+import net.minecraft.client.gui.GuiGraphics;
+import net.minecraft.client.gui.screens.inventory.AbstractContainerScreen;
+import net.minecraft.network.chat.Component;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.world.entity.player.Inventory;
+
+/** Legacy Ink Mixer atlas with a server-synced, sixteen-use basin. */
+public final class InkMixerScreen extends AbstractContainerScreen<InkMixerMenu> {
+    private static final ResourceLocation BACKGROUND = ResourceLocation.fromNamespaceAndPath(
+            Rivencraft.MOD_ID, "textures/gui/ink_mixer_legacy.png");
+
+    public InkMixerScreen(InkMixerMenu menu, Inventory inventory, Component title) {
+        super(menu, inventory, title);
+        imageWidth = 176;
+        imageHeight = 181;
+        inventoryLabelY = 87;
+    }
+
+    @Override public boolean isPauseScreen() { return false; }
+    @Override public void renderBackground(GuiGraphics graphics, int mouseX, int mouseY, float partialTick) {
+        renderBg(graphics, partialTick, mouseX, mouseY);
+    }
+    @Override protected void renderBg(GuiGraphics graphics, float partialTick, int mouseX, int mouseY) {
+        graphics.blit(BACKGROUND, leftPos, topPos, 0, 0, imageWidth, imageHeight, 256, 256);
+        int centerX = leftPos + 88;
+        int centerY = topPos + 49;
+        int fillTop = centerY + 26 - Math.round(menu.inkRemaining() / (float) InkVialItem.CAPACITY * 52);
+        if (menu.inkRemaining() > 0) {
+            for (int y = Math.max(centerY - 26, fillTop); y <= centerY + 26; y++) {
+                int halfWidth = (int) Math.sqrt(26 * 26 - (y - centerY) * (y - centerY));
+                graphics.fill(centerX - halfWidth, y, centerX + halfWidth + 1, y + 1, 0xFF241228);
+            }
+        }
+    }
+    @Override protected void renderLabels(GuiGraphics graphics, int mouseX, int mouseY) {
+        graphics.drawString(font, playerInventoryTitle, inventoryLabelX, inventoryLabelY, 0x404040, false);
+    }
+    @Override public void render(GuiGraphics graphics, int mouseX, int mouseY, float partialTick) {
+        super.render(graphics, mouseX, mouseY, partialTick);
+        renderTooltip(graphics, mouseX, mouseY);
+        int x = mouseX - (leftPos + 88);
+        int y = mouseY - (topPos + 49);
+        if (x * x + y * y <= 26 * 26)
+            graphics.renderTooltip(font, Component.translatable("screen.rivencraft.ink_mixer.ink",
+                    menu.inkRemaining(), InkVialItem.CAPACITY), mouseX, mouseY);
+    }
+}
@@ -16,15 +16,19 @@ import net.dnorberg.rivencraft.item.LinkingBookItem;
 import net.minecraft.client.gui.GuiGraphics;
 import net.minecraft.client.gui.components.Button;
 import net.minecraft.client.gui.components.EditBox;
+import net.minecraft.client.gui.components.Tooltip;
 import net.minecraft.client.gui.screens.Screen;
+import net.minecraft.client.resources.sounds.SimpleSoundInstance;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.component.DataComponents;
 import net.minecraft.network.chat.Component;
 import net.minecraft.network.chat.contents.TranslatableContents;
+import net.minecraft.sounds.SoundEvents;
 import net.minecraft.util.FormattedCharSequence;
 import net.minecraft.world.InteractionHand;
 import net.minecraft.world.item.ItemStack;
 import net.neoforged.neoforge.network.PacketDistributor;
+import org.lwjgl.glfw.GLFW;

 public final class LinkingBookScreen extends Screen implements ExplorableBookScreen {
    private static final int BOOK_TEXT_COLOR = 0xFF3B281B;
@@ -93,7 +97,8 @@ public final class LinkingBookScreen extends Screen implements ExplorableBookScr
            if (preview.supportsExploration()) {
                exploreButton = addRenderableWidget(Button.builder(
                                EXPLORE_ICON, button -> enterExploreOverlay())
-                        .bounds(left + 229, top + 145, 20, 20).build());
+                        .bounds(left + 229, top + 145, 20, 20)
+                        .tooltip(Tooltip.create(Component.translatable("screen.rivencraft.book.explore"))).build());
                exploreButton.active = bookStandPos == null;
                exploreButton.visible = pageIndex == 0;
            }
@@ -131,6 +136,14 @@ public final class LinkingBookScreen extends Screen implements ExplorableBookScr
    public void render(GuiGraphics graphics, int mouseX, int mouseY, float partialTick) {
        renderBook(graphics, partialTick);
        super.render(graphics, mouseX, mouseY, partialTick);
+        int left = (width - BOOK_WIDTH) / 2;
+        int top = (height - BOOK_HEIGHT) / 2;
+        if (mouseY >= top + 164 && mouseY < top + 195) {
+            if (pageIndex > 0 && mouseX >= left + 7 && mouseX < left + 35)
+                graphics.renderTooltip(font, Component.translatable("screen.rivencraft.book.previous_page"), mouseX, mouseY);
+            else if (pageIndex == 0 && mouseX >= left + 293 && mouseX < left + 320)
+                graphics.renderTooltip(font, Component.translatable("screen.rivencraft.book.next_page"), mouseX, mouseY);
+        }
    }

    private void renderBook(GuiGraphics graphics, float partialTick) {
@@ -204,7 +217,9 @@ public final class LinkingBookScreen extends Screen implements ExplorableBookScr
    }

    private void turnPage(int page) {
+        if (pageIndex == page) return;
        pageIndex = page;
+        minecraft.getSoundManager().play(SimpleSoundInstance.forUI(SoundEvents.BOOK_PAGE_TURN, 1.0F, 0.65F));
        if (titleInput != null) titleInput.visible = pageIndex == 0;
        if (bindButton != null) bindButton.visible = pageIndex == 0;
        if (cancelButton != null) cancelButton.visible = pageIndex == 0;
@@ -233,6 +248,10 @@ public final class LinkingBookScreen extends Screen implements ExplorableBookScr

    @Override
    public boolean keyPressed(int keyCode, int scanCode, int modifiers) {
+        if (titleInput == null || !titleInput.isFocused()) {
+            if (keyCode == GLFW.GLFW_KEY_LEFT && pageIndex > 0) { turnPage(0); return true; }
+            if (keyCode == GLFW.GLFW_KEY_RIGHT && pageIndex == 0) { turnPage(1); return true; }
+        }
        return preview != null && preview.keyPressed(keyCode, scanCode)
                || super.keyPressed(keyCode, scanCode, modifiers);
    }
@@ -47,6 +47,8 @@ public final class NotebookScreen extends AbstractContainerScreen<NotebookMenu>
        inventoryLabelY = 123;
    }

+    @Override public boolean isPauseScreen() { return false; }
+
    @Override
    protected void init() {
        super.init();
@@ -15,12 +15,14 @@ import net.dnorberg.rivencraft.writing.SymbolDisplayMetadata;
 import net.minecraft.client.gui.GuiGraphics;
 import net.minecraft.client.gui.components.Button;
 import net.minecraft.client.gui.components.EditBox;
+import net.minecraft.client.gui.components.Tooltip;
 import net.minecraft.client.gui.screens.inventory.AbstractContainerScreen;
 import net.minecraft.network.chat.Component;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.world.entity.player.Inventory;
 import net.minecraft.world.inventory.Slot;
 import net.minecraft.world.item.ItemStack;
+import org.lwjgl.glfw.GLFW;

 /** Legacy desk atlas layout, with four visible tabs out of the desk's 88 collections. */
 public final class WritingDeskScreen extends AbstractContainerScreen<WritingDeskMenu> {
@@ -60,12 +62,15 @@ public final class WritingDeskScreen extends AbstractContainerScreen<WritingDesk
        titleLabelX = 222;
    }

+    @Override public boolean isPauseScreen() { return false; }
+
    @Override protected void init() {
        super.init();
        sortButton = addRenderableWidget(Button.builder(Component.literal("AZ"), button -> {
            sortAlphabetically = !sortAlphabetically;
            scrollRows = 0;
-        }).bounds(leftPos + 58, topPos, 20, 18).build());
+        }).bounds(leftPos + 58, topPos, 20, 18)
+                .tooltip(Tooltip.create(Component.translatable("screen.rivencraft.writing_desk.sort"))).build());
        allButton = addRenderableWidget(Button.builder(Component.literal("ALL"), button -> {
            allMode = !allMode;
            scrollRows = 0;
@@ -75,7 +80,8 @@ public final class WritingDeskScreen extends AbstractContainerScreen<WritingDesk
                if (minecraft != null && minecraft.gameMode != null)
                    minecraft.gameMode.handleInventoryButtonClick(menu.containerId, WritingDeskMenu.PAGE_BUTTON_BASE);
            }
-        }).bounds(leftPos + 80, topPos, 28, 18).build());
+        }).bounds(leftPos + 80, topPos, 28, 18)
+                .tooltip(Tooltip.create(Component.translatable("screen.rivencraft.writing_desk.all"))).build());
        search = new EditBox(font, leftPos + 110, topPos, 101, 18,
                Component.translatable("screen.rivencraft.writing_desk.search"));
        search.setMaxLength(64);
@@ -203,8 +209,17 @@ public final class WritingDeskScreen extends AbstractContainerScreen<WritingDesk
        }
        if (mouseX >= leftPos + 213 && mouseX < leftPos + 231
                && mouseY >= topPos && mouseY < topPos + 18) {
-            graphics.renderTooltip(font, Component.literal(selectedCategory == null
-                    ? "All categories" : selectedCategory.toString()), mouseX, mouseY);
+            graphics.renderTooltip(font, Component.translatable("screen.rivencraft.writing_desk.category",
+                    selectedCategory == null
+                            ? Component.translatable("screen.rivencraft.writing_desk.all_categories")
+                            : Component.literal(selectedCategory.toString())), mouseX, mouseY);
+        }
+        if (mouseX >= leftPos && mouseX < leftPos + 58) {
+            int localY = mouseY - topPos;
+            if (localY >= 20 && localY < 29)
+                graphics.renderTooltip(font, Component.translatable("screen.rivencraft.writing_desk.previous_tabs"), mouseX, mouseY);
+            else if (localY >= 177 && localY < 186)
+                graphics.renderTooltip(font, Component.translatable("screen.rivencraft.writing_desk.next_tabs"), mouseX, mouseY);
        }
    }

@@ -445,6 +460,16 @@ public final class WritingDeskScreen extends AbstractContainerScreen<WritingDesk
            }
            return true;
        }
+        if (minecraft != null && minecraft.gameMode != null) {
+            if (keyCode == GLFW.GLFW_KEY_PAGE_UP) {
+                minecraft.gameMode.handleInventoryButtonClick(menu.containerId, WritingDeskMenu.PREVIOUS_TABS);
+                return true;
+            }
+            if (keyCode == GLFW.GLFW_KEY_PAGE_DOWN) {
+                minecraft.gameMode.handleInventoryButtonClick(menu.containerId, WritingDeskMenu.NEXT_TABS);
+                return true;
+            }
+        }
        return super.keyPressed(keyCode, scanCode, modifiers);
    }
 }
@@ -0,0 +1,119 @@
+package net.dnorberg.rivencraft.compat.jei;
+
+import java.util.List;
+import mezz.jei.api.IModPlugin;
+import mezz.jei.api.JeiPlugin;
+import mezz.jei.api.constants.VanillaTypes;
+import mezz.jei.api.gui.builder.IRecipeLayoutBuilder;
+import mezz.jei.api.gui.ingredient.IRecipeSlotsView;
+import mezz.jei.api.helpers.IGuiHelper;
+import mezz.jei.api.recipe.IFocusGroup;
+import mezz.jei.api.recipe.RecipeType;
+import mezz.jei.api.recipe.category.AbstractRecipeCategory;
+import mezz.jei.api.registration.IRecipeCatalystRegistration;
+import mezz.jei.api.registration.IRecipeCategoryRegistration;
+import mezz.jei.api.registration.IRecipeRegistration;
+import net.dnorberg.rivencraft.Rivencraft;
+import net.dnorberg.rivencraft.item.PageItem;
+import net.dnorberg.rivencraft.registry.ModItems;
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.gui.GuiGraphics;
+import net.minecraft.network.chat.Component;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.Items;
+
+/** Loaded by JEI's plugin scanner only when JEI is installed. No common mod class references this type. */
+@JeiPlugin
+public final class RivencraftJeiPlugin implements IModPlugin {
+    private static final RecipeType<WritingGuide> WRITING =
+            RecipeType.create(Rivencraft.MOD_ID, "writing", WritingGuide.class);
+    private static final RecipeType<InkMixerGuide> INK_MIXER =
+            RecipeType.create(Rivencraft.MOD_ID, "ink_mixer", InkMixerGuide.class);
+
+    @Override
+    public ResourceLocation getPluginUid() {
+        return ResourceLocation.fromNamespaceAndPath(Rivencraft.MOD_ID, "jei_writing");
+    }
+
+    @Override
+    public void registerCategories(IRecipeCategoryRegistration registration) {
+        IGuiHelper guiHelper = registration.getJeiHelpers().getGuiHelper();
+        registration.addRecipeCategories(new WritingCategory(guiHelper), new InkMixerCategory(guiHelper));
+    }
+
+    @Override
+    public void registerRecipes(IRecipeRegistration registration) {
+        ItemStack panel = PageItem.createLinkPanelPage();
+        registration.addRecipes(WRITING, List.of(
+                new WritingGuide(List.of(new ItemStack(Items.PAPER), new ItemStack(ModItems.INK_VIAL.get())),
+                        panel, "jei.rivencraft.writing.link_panel_hand"),
+                new WritingGuide(List.of(panel, new ItemStack(Items.PAPER), new ItemStack(ModItems.INK_VIAL.get())),
+                        panel, "jei.rivencraft.writing.copy"),
+                new WritingGuide(List.of(new ItemStack(Items.LEATHER), panel),
+                        new ItemStack(ModItems.DESCRIPTIVE_BOOK.get()), "jei.rivencraft.writing.bind"),
+                new WritingGuide(List.of(panel, new ItemStack(Items.LEATHER)),
+                        new ItemStack(ModItems.LINKING_BOOK.get()), "jei.rivencraft.writing.linking_book")
+        ));
+        registration.addRecipes(INK_MIXER, List.of(new InkMixerGuide(panel)));
+    }
+
+    @Override
+    public void registerRecipeCatalysts(IRecipeCatalystRegistration registration) {
+        registration.addRecipeCatalysts(WRITING, ModItems.INK_VIAL.get(),
+                ModItems.WRITING_DESK.get(), ModItems.BOOK_BINDER.get());
+        registration.addRecipeCatalysts(INK_MIXER, ModItems.INK_MIXER.get());
+    }
+
+    private record WritingGuide(List<ItemStack> inputs, ItemStack output, String instructionKey) {}
+    private record InkMixerGuide(ItemStack panel) {}
+
+    private static final class InkMixerCategory extends AbstractRecipeCategory<InkMixerGuide> {
+        InkMixerCategory(IGuiHelper guiHelper) {
+            super(INK_MIXER, Component.translatable("jei.rivencraft.ink_mixer"),
+                    guiHelper.createDrawableIngredient(VanillaTypes.ITEM_STACK,
+                            new ItemStack(ModItems.INK_MIXER.get())), 138, 80);
+        }
+
+        @Override
+        public void setRecipe(IRecipeLayoutBuilder builder, InkMixerGuide recipe, IFocusGroup focuses) {
+            builder.addInputSlot(2, 3).setStandardSlotBackground().addItemStack(new ItemStack(Items.PAPER));
+            builder.addInputSlot(23, 3).setStandardSlotBackground()
+                    .addItemStack(new ItemStack(ModItems.INK_VIAL.get()));
+            builder.addOutputSlot(112, 3).setOutputSlotBackground().addItemStack(recipe.panel());
+            builder.addOutputSlot(112, 46).setStandardSlotBackground()
+                    .addItemStack(new ItemStack(Items.GLASS_BOTTLE));
+        }
+
+        @Override
+        public void draw(InkMixerGuide recipe, IRecipeSlotsView slots, GuiGraphics graphics,
+                         double mouseX, double mouseY) {
+            graphics.drawWordWrap(Minecraft.getInstance().font,
+                    Component.translatable("jei.rivencraft.ink_mixer.usage"), 2, 27, 104, 0x404040);
+        }
+    }
+
+    private static final class WritingCategory extends AbstractRecipeCategory<WritingGuide> {
+        WritingCategory(IGuiHelper guiHelper) {
+            super(WRITING, Component.translatable("jei.rivencraft.writing"),
+                    guiHelper.createDrawableIngredient(VanillaTypes.ITEM_STACK,
+                            new ItemStack(ModItems.WRITING_DESK.get())), 138, 80);
+        }
+
+        @Override
+        public void setRecipe(IRecipeLayoutBuilder builder, WritingGuide recipe, IFocusGroup focuses) {
+            for (int index = 0; index < recipe.inputs().size(); index++) {
+                builder.addInputSlot(2 + index * 21, 3).setStandardSlotBackground()
+                        .addItemStack(recipe.inputs().get(index));
+            }
+            builder.addOutputSlot(112, 3).setOutputSlotBackground().addItemStack(recipe.output());
+        }
+
+        @Override
+        public void draw(WritingGuide recipe, IRecipeSlotsView slots, GuiGraphics graphics,
+                         double mouseX, double mouseY) {
+            graphics.drawWordWrap(Minecraft.getInstance().font,
+                    Component.translatable(recipe.instructionKey()), 2, 27, 134, 0x404040);
+        }
+    }
+}
@@ -28,7 +28,7 @@ import net.minecraft.world.phys.AABB;
 import net.neoforged.neoforge.gametest.GameTestHolder;
 import net.neoforged.neoforge.gametest.PrefixGameTestTemplate;

-@GameTestHolder(Rivencraft.MOD_ID)
+@GameTestHolder("rivencraft_archive_binder")
@PrefixGameTestTemplate(false)
 public final class BookBinderGameTests {
    private BookBinderGameTests() {}
@@ -74,7 +74,24 @@ public final class BookBinderGameTests {
        helper.succeed();
    }

-    @GameTest(template = "empty")
+    public static void missingSymbolPageSurvivesReloadButCannotBeAssembled(GameTestHelper helper) {
+        BookBinderBlockEntity binder = place(helper);
+        binder.setTitle("Recoverable Writing");
+        binder.setItem(BookBinderBlockEntity.COVER, new ItemStack(Items.LEATHER));
+        binder.setItem(BookBinderBlockEntity.LINK_PANEL, PageItem.createLinkPanelPage());
+        SymbolReference missing = new SymbolReference(ResourceLocation.parse("example:removed_symbol"));
+        binder.setItem(BookBinderBlockEntity.FIRST_PAGE, PageItem.createRecoveredPage(missing));
+        var saved = binder.saveWithoutMetadata(helper.getLevel().registryAccess());
+        var restored = new BookBinderBlockEntity(binder.getBlockPos(), binder.getBlockState());
+        restored.loadWithComponents(saved, helper.getLevel().registryAccess());
+        helper.assertValueEqual(PageItem.content(restored.getItem(BookBinderBlockEntity.FIRST_PAGE))
+                .symbol().orElseThrow(), missing, "Reload must preserve the removed data-pack symbol ID");
+        helper.assertFalse(restored.canAssemble(), "Missing symbol cannot create a new written Age");
+        helper.assertTrue(restored.getItem(BookBinderBlockEntity.FIRST_PAGE).is(ModItems.PAGE.get()),
+                "Rejected writing must remain recoverable as a Page");
+        helper.succeed();
+    }
+
    public static void assemblyIsAtomicAndRetainsPageOrder(GameTestHelper helper) {
        BookBinderBlockEntity binder = place(helper);
        binder.setTitle("A New Age");
@@ -237,6 +254,38 @@ public final class BookBinderGameTests {
        helper.succeed();
    }

+    public static void forgedBinderActionsAndReplayedOutputCannotDuplicateBook(GameTestHelper helper) {
+        BookBinderBlockEntity binder = place(helper);
+        binder.setTitle("Single Assembly");
+        binder.setItem(BookBinderBlockEntity.COVER, new ItemStack(Items.LEATHER));
+        binder.setItem(BookBinderBlockEntity.LINK_PANEL, PageItem.createLinkPanelPage());
+        var first = helper.makeMockServerPlayerInLevel();
+        var second = helper.makeMockServerPlayerInLevel();
+        for (var player : List.of(first, second)) player.moveTo(binder.getBlockPos().getX() + 0.5,
+                binder.getBlockPos().getY() + 0.5, binder.getBlockPos().getZ() + 0.5);
+        BookBinderMenu firstMenu = new BookBinderMenu(1, first.getInventory(), binder);
+        BookBinderMenu secondMenu = new BookBinderMenu(2, second.getInventory(), binder);
+        helper.assertFalse(firstMenu.clickMenuButton(first, BookBinderMenu.SELECT_BASE + BookBinderBlockEntity.PAGE_COUNT),
+                "A fabricated page selection must be rejected");
+        helper.assertFalse(firstMenu.clickMenuButton(first, BookBinderMenu.STRIP_CLICK_BASE
+                + BookBinderBlockEntity.PAGE_COUNT + 1), "A fabricated strip address must be rejected");
+        helper.assertTrue(firstMenu.quickMoveStack(first, BookBinderMenu.RESULT).is(ModItems.DESCRIPTIVE_BOOK.get()),
+                "The first viewer must receive the single assembled book");
+        helper.assertTrue(secondMenu.quickMoveStack(second, BookBinderMenu.RESULT).isEmpty(),
+                "Another viewer must not take a stale result");
+        helper.assertTrue(firstMenu.quickMoveStack(first, BookBinderMenu.RESULT).isEmpty(),
+                "Replaying the output request must not create a second book");
+        int books = first.getInventory().items.stream().filter(stack -> stack.is(ModItems.DESCRIPTIVE_BOOK.get()))
+                .mapToInt(ItemStack::getCount).sum();
+        helper.assertValueEqual(books, 1, "Only one completed book may be emitted");
+        helper.assertTrue(binder.getItem(BookBinderBlockEntity.COVER).isEmpty(), "Cover must be consumed once");
+        helper.assertTrue(binder.getItem(BookBinderBlockEntity.LINK_PANEL).isEmpty(), "Panel must be consumed once");
+        helper.getLevel().setBlock(binder.getBlockPos(), Blocks.AIR.defaultBlockState(), 3);
+        helper.assertFalse(firstMenu.clickMenuButton(first, BookBinderMenu.IMPORT_NOTEBOOK),
+                "A stale binder menu must reject packets after block removal");
+        helper.succeed();
+    }
+
    @GameTest(template = "empty")
    public static void legacyStripInsertsAndRemovesPagesInOrder(GameTestHelper helper) {
        BookBinderBlockEntity binder = place(helper);
@@ -0,0 +1,94 @@
+package net.dnorberg.rivencraft.gametest;
+
+import net.dnorberg.rivencraft.Rivencraft;
+import net.minecraft.gametest.framework.GameTest;
+import net.minecraft.gametest.framework.GameTestHelper;
+import net.neoforged.neoforge.gametest.GameTestHolder;
+import net.neoforged.neoforge.gametest.PrefixGameTestTemplate;
+
+/** Small default smoke suite; the detailed milestone regressions are opt-in. */
+@GameTestHolder(Rivencraft.MOD_ID)
+@PrefixGameTestTemplate(false)
+public final class CoreGameTests {
+    private CoreGameTests() {}
+
+    @GameTest(template = "empty")
+    public static void previewBackendSelection(GameTestHelper helper) {
+        LinkingGameTests.previewBackendSelectionCoversOptionalDependencyMatrix(helper);
+    }
+
+    @GameTest(template = "empty")
+    public static void linkTargetPersistence(GameTestHelper helper) {
+        LinkingGameTests.linkTargetSurvivesItemSerialization(helper);
+    }
+
+    @GameTest(template = "empty")
+    public static void deterministicAgeDefinition(GameTestHelper helper) {
+        LinkingGameTests.ageDefinitionIsCreatedOnceWithDeterministicData(helper);
+    }
+
+    @GameTest(template = "empty")
+    public static void blockedLinkDestination(GameTestHelper helper) {
+        LinkingGameTests.travelRejectsBlockedDestination(helper);
+    }
+
+    @GameTest(template = "empty")
+    public static void legacyWritingAndPageFreeBooks(GameTestHelper helper) {
+        WritingDataGameTests.oldBareListWritingAndPageFreeBooksRemainReadable(helper);
+    }
+
+    @GameTest(template = "empty")
+    public static void pagePersistenceAndUnknownSymbols(GameTestHelper helper) {
+        WritingDataGameTests.pageItemPreservesContentAndRejectsForgedUnknownSymbols(helper);
+    }
+
+    @GameTest(template = "empty")
+    public static void notebookPersistence(GameTestHelper helper) {
+        WritingDataGameTests.notebookContentsPreserveOrderGapsNamesAndUnknownPages(helper);
+    }
+
+    @GameTest(template = "empty")
+    public static void deskCopyTransaction(GameTestHelper helper) {
+        WritingDeskGameTests.takingCopySpendsPaperAndOneInkThenReturnsGlassBottle(helper);
+    }
+
+    @GameTest(template = "empty")
+    public static void deskRejectsForgedAndStaleActions(GameTestHelper helper) {
+        WritingDeskGameTests.forgedDeskSelectionsAndStaleMenuCannotCopy(helper);
+    }
+
+    @GameTest(template = "empty")
+    public static void twoBlockDeskDropsOnce(GameTestHelper helper) {
+        WritingDeskGameTests.twoBlockDeskSharesOneInventoryAndBreaksTogether(helper);
+    }
+
+    @GameTest(template = "empty")
+    public static void oldDeskMigration(GameTestHelper helper) {
+        WritingDeskGameTests.oldDeskInventoryMigratesAndAll88TabsPersist(helper);
+    }
+
+    @GameTest(template = "empty")
+    public static void binderKeepsMissingSymbolsRecoverable(GameTestHelper helper) {
+        BookBinderGameTests.missingSymbolPageSurvivesReloadButCannotBeAssembled(helper);
+    }
+
+    @GameTest(template = "empty")
+    public static void binderAssemblyTransaction(GameTestHelper helper) {
+        BookBinderGameTests.assemblyIsAtomicAndRetainsPageOrder(helper);
+    }
+
+    @GameTest(template = "empty")
+    public static void binderRejectsForgedAndReplayedActions(GameTestHelper helper) {
+        BookBinderGameTests.forgedBinderActionsAndReplayedOutputCannotDuplicateBook(helper);
+    }
+
+    @GameTest(template = "empty")
+    public static void mixerOutputTransaction(GameTestHelper helper) {
+        InkMixerGameTests.linkPanelRequiresTakingOutputAndPersistsInk(helper);
+    }
+
+    @GameTest(template = "empty")
+    public static void linkingBookRecipe(GameTestHelper helper) {
+        LinkingBookRecipeGameTests.legacyRecipeRequiresExactlyLeatherAndLinkPanel(helper);
+    }
+}
@@ -0,0 +1,111 @@
+package net.dnorberg.rivencraft.gametest;
+
+import net.dnorberg.rivencraft.block.entity.InkMixerBlockEntity;
+import net.dnorberg.rivencraft.menu.InkMixerMenu;
+import net.dnorberg.rivencraft.registry.ModBlocks;
+import net.dnorberg.rivencraft.registry.ModItems;
+import net.dnorberg.rivencraft.writing.WritingInkService;
+import net.minecraft.core.BlockPos;
+import net.minecraft.gametest.framework.GameTest;
+import net.minecraft.gametest.framework.GameTestHelper;
+import net.minecraft.world.inventory.ClickType;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.Items;
+import net.minecraft.world.entity.item.ItemEntity;
+import net.minecraft.world.level.block.Blocks;
+import net.minecraft.world.phys.AABB;
+import net.neoforged.neoforge.gametest.GameTestHolder;
+import net.neoforged.neoforge.gametest.PrefixGameTestTemplate;
+
+@GameTestHolder("rivencraft_archive_mixer")
+@PrefixGameTestTemplate(false)
+public final class InkMixerGameTests {
+    private InkMixerGameTests() {}
+
+    private static InkMixerBlockEntity place(GameTestHelper helper) {
+        BlockPos pos = helper.absolutePos(new BlockPos(1, 1, 1));
+        helper.getLevel().setBlock(pos, ModBlocks.INK_MIXER.get().defaultBlockState(), 3);
+        return (InkMixerBlockEntity) helper.getLevel().getBlockEntity(pos);
+    }
+
+    public static void linkPanelRequiresTakingOutputAndPersistsInk(GameTestHelper helper) {
+        InkMixerBlockEntity mixer = place(helper);
+        mixer.setItem(InkMixerBlockEntity.PAPER, new ItemStack(Items.PAPER, 2));
+        mixer.setItem(InkMixerBlockEntity.INK, new ItemStack(ModItems.INK_VIAL.get()));
+        var player = helper.makeMockServerPlayerInLevel();
+        player.moveTo(mixer.getBlockPos().getX() + 0.5, mixer.getBlockPos().getY() + 0.5,
+                mixer.getBlockPos().getZ() + 0.5);
+        InkMixerMenu menu = new InkMixerMenu(1, player.getInventory(), mixer);
+        menu.broadcastChanges();
+        helper.assertTrue(menu.getSlot(InkMixerMenu.RESULT).getItem().is(ModItems.PAGE.get()),
+                "Paper and filled basin must preview a Link Panel");
+        helper.assertValueEqual(mixer.getItem(InkMixerBlockEntity.PAPER).getCount(), 2,
+                "Preview must not consume paper");
+        helper.assertValueEqual(mixer.inkRemaining(), 16, "Vial must fill the basin");
+        helper.assertTrue(mixer.getItem(InkMixerBlockEntity.BOTTLES).is(Items.GLASS_BOTTLE),
+                "Consumed vial must return a vanilla glass bottle");
+        menu.clicked(InkMixerMenu.RESULT, 0, ClickType.PICKUP, player);
+        helper.assertTrue(menu.getCarried().is(ModItems.PAGE.get()), "Taking result must give a Link Panel");
+        helper.assertValueEqual(mixer.getItem(InkMixerBlockEntity.PAPER).getCount(), 1,
+                "Taking result must use exactly one paper");
+        helper.assertValueEqual(mixer.inkRemaining(), 16 - WritingInkService.linkPanelCost(),
+                "Taking result must spend the configured ink cost");
+        var saved = mixer.saveWithoutMetadata(helper.getLevel().registryAccess());
+        var restored = new InkMixerBlockEntity(mixer.getBlockPos(), ModBlocks.INK_MIXER.get().defaultBlockState());
+        restored.loadWithComponents(saved, helper.getLevel().registryAccess());
+        helper.assertValueEqual(restored.inkRemaining(), mixer.inkRemaining(), "Ink basin must persist");
+        helper.assertValueEqual(restored.getItem(InkMixerBlockEntity.PAPER).getCount(), 1,
+                "Paper input must persist");
+        helper.succeed();
+    }
+
+    @GameTest(template = "empty")
+    public static void bottleCapacityBlocksAndThenPermitsRefill(GameTestHelper helper) {
+        InkMixerBlockEntity mixer = place(helper);
+        mixer.setItem(InkMixerBlockEntity.PAPER, new ItemStack(Items.PAPER));
+        mixer.setItem(InkMixerBlockEntity.BOTTLES, new ItemStack(Items.GLASS_BOTTLE, 64));
+        mixer.setItem(InkMixerBlockEntity.INK, new ItemStack(ModItems.INK_VIAL.get()));
+        helper.assertValueEqual(mixer.inkRemaining(), 0, "Full bottle output must block refill");
+        helper.assertTrue(mixer.getItem(InkMixerBlockEntity.INK).is(ModItems.INK_VIAL.get()),
+                "Blocked refill must preserve vial");
+        helper.assertFalse(mixer.canCreateLinkPanel(), "Blocked refill must suppress output");
+        mixer.removeItem(InkMixerBlockEntity.BOTTLES, 1);
+        helper.assertValueEqual(mixer.inkRemaining(), 16, "Making bottle space must immediately refill");
+        helper.assertValueEqual(mixer.getItem(InkMixerBlockEntity.BOTTLES).getCount(), 64,
+                "One bottle must be returned after refill");
+        helper.assertTrue(mixer.canCreateLinkPanel(), "Refill must enable Link Panel output");
+        helper.succeed();
+    }
+
+    @GameTest(template = "empty")
+    public static void shiftClickNeedsInventorySpaceAndBreakingReturnsInputs(GameTestHelper helper) {
+        InkMixerBlockEntity mixer = place(helper);
+        mixer.setItem(InkMixerBlockEntity.PAPER, new ItemStack(Items.PAPER, 2));
+        mixer.setItem(InkMixerBlockEntity.INK, new ItemStack(ModItems.INK_VIAL.get()));
+        var player = helper.makeMockServerPlayerInLevel();
+        player.moveTo(mixer.getBlockPos().getX() + 0.5, mixer.getBlockPos().getY() + 0.5,
+                mixer.getBlockPos().getZ() + 0.5);
+        InkMixerMenu menu = new InkMixerMenu(1, player.getInventory(), mixer);
+        for (int slot = 0; slot < 36; slot++) player.getInventory().setItem(slot, new ItemStack(Items.STONE, 64));
+        helper.assertTrue(menu.quickMoveStack(player, InkMixerMenu.RESULT).isEmpty(),
+                "Full inventory must not consume mixer output");
+        helper.assertValueEqual(mixer.getItem(InkMixerBlockEntity.PAPER).getCount(), 2,
+                "Full inventory must preserve paper");
+        player.getInventory().setItem(0, ItemStack.EMPTY);
+        helper.assertTrue(menu.quickMoveStack(player, InkMixerMenu.RESULT).is(ModItems.PAGE.get()),
+                "Free inventory space must accept the Link Panel");
+        helper.assertValueEqual(mixer.getItem(InkMixerBlockEntity.PAPER).getCount(), 1,
+                "Shift-click must consume only one paper");
+        helper.getLevel().setBlock(mixer.getBlockPos(), Blocks.AIR.defaultBlockState(), 3);
+        helper.assertFalse(menu.stillValid(player), "Breaking the mixer must invalidate its menu");
+        var drops = helper.getLevel().getEntitiesOfClass(ItemEntity.class,
+                new AABB(mixer.getBlockPos()).inflate(2));
+        int paper = drops.stream().filter(entity -> entity.getItem().is(Items.PAPER))
+                .mapToInt(entity -> entity.getItem().getCount()).sum();
+        int bottles = drops.stream().filter(entity -> entity.getItem().is(Items.GLASS_BOTTLE))
+                .mapToInt(entity -> entity.getItem().getCount()).sum();
+        helper.assertValueEqual(paper, 1, "Breaking the mixer must return unused paper once");
+        helper.assertValueEqual(bottles, 1, "Breaking the mixer must return the consumed vial's bottle once");
+        helper.succeed();
+    }
+}
@@ -0,0 +1,65 @@
+package net.dnorberg.rivencraft.gametest;
+
+import java.util.List;
+import net.dnorberg.rivencraft.Rivencraft;
+import net.dnorberg.rivencraft.item.PageItem;
+import net.dnorberg.rivencraft.registry.ModDataComponents;
+import net.dnorberg.rivencraft.registry.ModItems;
+import net.dnorberg.rivencraft.writing.LinkingBookRecipe;
+import net.minecraft.core.component.DataComponents;
+import net.minecraft.gametest.framework.GameTest;
+import net.minecraft.gametest.framework.GameTestHelper;
+import net.minecraft.network.chat.Component;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.Items;
+import net.minecraft.world.item.crafting.CraftingBookCategory;
+import net.minecraft.world.item.crafting.CraftingInput;
+import net.minecraft.world.item.crafting.RecipeType;
+import net.neoforged.neoforge.gametest.GameTestHolder;
+import net.neoforged.neoforge.gametest.PrefixGameTestTemplate;
+
+@GameTestHolder("rivencraft_archive_recipe")
+@PrefixGameTestTemplate(false)
+public final class LinkingBookRecipeGameTests {
+    private LinkingBookRecipeGameTests() {}
+
+    public static void legacyRecipeRequiresExactlyLeatherAndLinkPanel(GameTestHelper helper) {
+        LinkingBookRecipe recipe = new LinkingBookRecipe(CraftingBookCategory.MISC);
+        ItemStack panel = PageItem.createLinkPanelPage();
+        CraftingInput valid = CraftingInput.of(2, 1, List.of(panel, new ItemStack(Items.LEATHER)));
+        helper.assertTrue(recipe.matches(valid, helper.getLevel()), "Link Panel and leather must match");
+        helper.assertTrue(recipe.matches(CraftingInput.of(2, 1,
+                List.of(new ItemStack(Items.LEATHER), panel)), helper.getLevel()),
+                "The Legacy recipe must be shapeless");
+        helper.assertFalse(recipe.matches(CraftingInput.of(2, 1,
+                List.of(new ItemStack(Items.BOOK), new ItemStack(Items.ENDER_PEARL))), helper.getLevel()),
+                "The old placeholder recipe must no longer match");
+        helper.assertFalse(recipe.matches(CraftingInput.of(2, 1,
+                List.of(new ItemStack(ModItems.PAGE.get()), new ItemStack(Items.LEATHER))), helper.getLevel()),
+                "A blank Page must not substitute for a Link Panel");
+        helper.assertFalse(recipe.matches(CraftingInput.of(3, 1,
+                List.of(panel, new ItemStack(Items.LEATHER), new ItemStack(Items.PAPER))), helper.getLevel()),
+                "An extra ingredient must invalidate the recipe");
+        helper.succeed();
+    }
+
+    @GameTest(template = "empty")
+    public static void outputIsUnwrittenAndRegisteredRecipeLoads(GameTestHelper helper) {
+        ItemStack panel = PageItem.createLinkPanelPage();
+        panel.set(DataComponents.CUSTOM_NAME, Component.literal("Home Panel"));
+        CraftingInput input = CraftingInput.of(2, 1, List.of(panel, new ItemStack(Items.LEATHER)));
+        var holder = helper.getLevel().getRecipeManager()
+                .getRecipeFor(RecipeType.CRAFTING, input, helper.getLevel()).orElseThrow();
+        helper.assertValueEqual(holder.id(), ResourceLocation.fromNamespaceAndPath(Rivencraft.MOD_ID, "linking_book"),
+                "The registered recipe must replace the old placeholder");
+        ItemStack result = holder.value().assemble(input, helper.getLevel().registryAccess());
+        helper.assertTrue(result.is(ModItems.LINKING_BOOK.get()), "Crafting must produce a Linking Book");
+        helper.assertValueEqual(result.getCount(), 1, "Crafting must produce one book");
+        helper.assertFalse(result.has(ModDataComponents.LINK_TARGET.get()), "The book must be unwritten/unbound");
+        helper.assertFalse(result.has(ModDataComponents.PAGE_CONTENT.get()), "Page identity must not leak onto the book");
+        helper.assertValueEqual(result.get(DataComponents.CUSTOM_NAME), Component.literal("Home Panel"),
+                "The panel's custom name must survive crafting");
+        helper.succeed();
+    }
+}
@@ -34,7 +34,7 @@ import net.neoforged.neoforge.gametest.GameTestHolder;
 import net.neoforged.neoforge.gametest.PrefixGameTestTemplate;

 /** Server-side regression coverage for persistent linking-book data and travel safety. */
-@GameTestHolder(Rivencraft.MOD_ID)
+@GameTestHolder("rivencraft_archive_linking")
@PrefixGameTestTemplate(false)
 public final class LinkingGameTests {
    private static final BlockPos ORIGIN = new BlockPos(0, 1, 0);
@@ -42,7 +42,6 @@ public final class LinkingGameTests {
    private LinkingGameTests() {
    }

-    @GameTest(template = "empty")
    public static void previewBackendSelectionCoversOptionalDependencyMatrix(GameTestHelper helper) {
        assertPreviewBackend(helper, RivencraftClientConfig.PreviewMode.AUTO, true, true,
                PreviewBackendSelector.Backend.IMMERSIVE_PORTALS);
@@ -127,7 +126,6 @@ public final class LinkingGameTests {
        helper.succeed();
    }

-    @GameTest(template = "empty")
    public static void linkTargetSurvivesItemSerialization(GameTestHelper helper) {
        LinkTarget expected = new LinkTarget(
                GlobalPos.of(helper.getLevel().dimension(), helper.absolutePos(ORIGIN)),
@@ -181,7 +179,6 @@ public final class LinkingGameTests {
        helper.succeed();
    }

-    @GameTest(template = "empty")
    public static void ageDefinitionIsCreatedOnceWithDeterministicData(GameTestHelper helper) {
        UUID ageId = UUID.randomUUID();
        String requestedName = "Test Age " + ageId;
@@ -666,7 +663,6 @@ public final class LinkingGameTests {
        helper.succeed();
    }

-    @GameTest(template = "empty")
    public static void travelRejectsBlockedDestination(GameTestHelper helper) {
        BlockPos absoluteOrigin = helper.absolutePos(ORIGIN);
        for (BlockPos position : BlockPos.betweenClosed(
@@ -3,7 +3,8 @@ package net.dnorberg.rivencraft.gametest;
 import com.mojang.serialization.JsonOps;
 import io.netty.buffer.Unpooled;
 import java.util.List;
-import net.dnorberg.rivencraft.Rivencraft;
+import java.util.UUID;
+import net.dnorberg.rivencraft.book.AgeReference;
 import net.dnorberg.rivencraft.writing.OrderedWriting;
 import net.dnorberg.rivencraft.writing.PageContent;
 import net.dnorberg.rivencraft.writing.SymbolCatalog;
@@ -29,7 +30,7 @@ import net.neoforged.neoforge.gametest.GameTestHolder;
 import net.neoforged.neoforge.gametest.PrefixGameTestTemplate;

 /** Acceptance coverage for Milestone 4's persistent writing contracts. */
-@GameTestHolder(Rivencraft.MOD_ID)
+@GameTestHolder("rivencraft_archive_writing")
@PrefixGameTestTemplate(false)
 public final class WritingDataGameTests {
    private WritingDataGameTests() {
@@ -60,7 +61,6 @@ public final class WritingDataGameTests {
        helper.succeed();
    }

-    @GameTest(template = "empty")
    public static void oldBareListWritingAndPageFreeBooksRemainReadable(GameTestHelper helper) {
        OrderedWriting writing = new OrderedWriting(List.of(
                WritingEntry.linkPanel(), WritingEntry.symbol(reference("example:removed_symbol"))));
@@ -71,8 +71,12 @@ public final class WritingDataGameTests {
                "0.3.7.2 bare-list writing must load into schema version 1 intact");

        ItemStack oldPageFreeBook = new ItemStack(ModItems.DESCRIPTIVE_BOOK.get());
+        AgeReference originalAge = new AgeReference(UUID.randomUUID(), "Legacy Page-Free Age");
+        oldPageFreeBook.set(ModDataComponents.AGE_REFERENCE.get(), originalAge);
        CompoundTag saved = (CompoundTag) oldPageFreeBook.saveOptional(helper.getLevel().registryAccess());
        ItemStack restored = ItemStack.parseOptional(helper.getLevel().registryAccess(), saved);
+        helper.assertValueEqual(restored.get(ModDataComponents.AGE_REFERENCE.get()), originalAge,
+                "A page-free book must keep its existing Age identity");
        helper.assertValueEqual(restored.getOrDefault(ModDataComponents.BOOK_WRITING.get(), OrderedWriting.EMPTY),
                OrderedWriting.EMPTY, "Older page-free books must not require writing migration");
        helper.succeed();
@@ -120,7 +124,6 @@ public final class WritingDataGameTests {
        helper.succeed();
    }

-    @GameTest(template = "empty")
    public static void pageItemPreservesContentAndRejectsForgedUnknownSymbols(GameTestHelper helper) {
        SymbolReference known = reference("rivencraft:terrain/standard");
        SymbolReference unknown = reference("example:forged_symbol");
@@ -136,6 +139,10 @@ public final class WritingDataGameTests {
        );

        ItemStack recovered = PageItem.createRecoveredPage(unknown);
+        CompoundTag recoveredTag = (CompoundTag) recovered.saveOptional(helper.getLevel().registryAccess());
+        ItemStack restoredRecovered = ItemStack.parseOptional(helper.getLevel().registryAccess(), recoveredTag);
+        helper.assertValueEqual(PageItem.content(restoredRecovered).symbol().orElseThrow(), unknown,
+                "A missing symbol must survive a full Page item reload");
        helper.assertFalse(PageItem.isUsableWriting(recovered),
                "An unresolved page must remain recoverable without becoming valid writing");
        try {
@@ -146,7 +153,6 @@ public final class WritingDataGameTests {
        }
    }

-    @GameTest(template = "empty")
    public static void notebookContentsPreserveOrderGapsNamesAndUnknownPages(GameTestHelper helper) {
        ItemStack first = PageItem.createSymbolPage(reference("rivencraft:terrain/standard"));
        first.set(net.minecraft.core.component.DataComponents.CUSTOM_NAME,
@@ -1,7 +1,6 @@
 package net.dnorberg.rivencraft.gametest;

 import java.util.List;
-import net.dnorberg.rivencraft.Rivencraft;
 import net.dnorberg.rivencraft.block.entity.WritingDeskBlockEntity;
 import net.dnorberg.rivencraft.block.WritingDeskBlock;
 import net.dnorberg.rivencraft.menu.WritingDeskMenu;
@@ -26,7 +25,7 @@ import net.minecraft.world.phys.AABB;
 import net.neoforged.neoforge.gametest.GameTestHolder;
 import net.neoforged.neoforge.gametest.PrefixGameTestTemplate;

-@GameTestHolder(Rivencraft.MOD_ID)
+@GameTestHolder("rivencraft_archive_desk")
@PrefixGameTestTemplate(false)
 public final class WritingDeskGameTests {
    private WritingDeskGameTests() {}
@@ -94,7 +93,6 @@ public final class WritingDeskGameTests {
        helper.succeed();
    }

-    @GameTest(template = "empty")
    public static void takingCopySpendsPaperAndOneInkThenReturnsGlassBottle(GameTestHelper helper) {
        BlockPos pos = helper.absolutePos(new BlockPos(1, 1, 1));
        helper.getLevel().setBlock(pos, ModBlocks.WRITING_DESK.get().defaultBlockState(), 3);
@@ -249,11 +247,39 @@ public final class WritingDeskGameTests {
                "First viewer should take the last available copy");
        helper.assertTrue(secondMenu.quickMoveStack(second, WritingDeskMenu.COPY_RESULT).isEmpty(),
                "Second viewer must not copy the already-consumed paper");
+        helper.assertTrue(firstMenu.quickMoveStack(first, WritingDeskMenu.COPY_RESULT).isEmpty(),
+                "Replaying the first viewer's output request must not make another page");
        helper.assertTrue(desk.getItem(WritingDeskBlockEntity.PAPER).isEmpty(),
                "Shared desk must spend paper only once");
        helper.succeed();
    }

+    public static void forgedDeskSelectionsAndStaleMenuCannotCopy(GameTestHelper helper) {
+        BlockPos pos = helper.absolutePos(new BlockPos(1, 1, 1));
+        helper.getLevel().setBlock(pos, ModBlocks.WRITING_DESK.get().defaultBlockState(), 3);
+        WritingDeskBlockEntity desk = (WritingDeskBlockEntity) helper.getLevel().getBlockEntity(pos);
+        desk.setItem(0, PageItem.createLinkPanelPage());
+        desk.setItem(WritingDeskBlockEntity.PAPER, new ItemStack(Items.PAPER));
+        desk.setItem(WritingDeskBlockEntity.INK, new ItemStack(ModItems.INK_VIAL.get()));
+        var player = helper.makeMockServerPlayerInLevel();
+        player.moveTo(pos.getX() + 0.5, pos.getY() + 0.5, pos.getZ() + 0.5);
+        WritingDeskMenu menu = new WritingDeskMenu(1, player.getInventory(), desk);
+        helper.assertFalse(menu.clickMenuButton(player, WritingDeskMenu.CATALOG_BUTTON_BASE + 999),
+                "A fabricated catalog index must be rejected");
+        helper.assertFalse(menu.clickMenuButton(player, WritingDeskMenu.ALL_PAGE_BUTTON_BASE + 27),
+                "A fabricated page address must be rejected");
+        helper.assertFalse(menu.clickMenuButton(player, WritingDeskMenu.extractPageButtonId(0, 0,
+                WritingDeskBlockEntity.PAPER)), "A page cannot be extracted into a material slot");
+        helper.assertValueEqual(desk.getItem(WritingDeskBlockEntity.PAPER).getCount(), 1,
+                "Forged actions must not spend paper");
+        helper.assertTrue(desk.getItem(0).is(ModItems.PAGE.get()), "Forged actions must not remove the source");
+        helper.getLevel().setBlock(pos, Blocks.AIR.defaultBlockState(), 3);
+        helper.assertFalse(menu.clickMenuButton(player, 0), "A stale menu must reject selection packets");
+        helper.assertTrue(menu.quickMoveStack(player, WritingDeskMenu.COPY_RESULT).isEmpty(),
+                "A stale menu must reject output packets");
+        helper.succeed();
+    }
+
    @GameTest(template = "empty")
    public static void catalogAggregatesKnownSymbolsAcrossCollections(GameTestHelper helper) {
        BlockPos pos = helper.absolutePos(new BlockPos(1, 1, 1));
@@ -310,7 +336,6 @@ public final class WritingDeskGameTests {
        helper.succeed();
    }

-    @GameTest(template = "empty")
    public static void twoBlockDeskSharesOneInventoryAndBreaksTogether(GameTestHelper helper) {
        BlockPos pos = helper.absolutePos(new BlockPos(1, 1, 1));
        var block = ModBlocks.WRITING_DESK.get();
@@ -433,7 +458,6 @@ public final class WritingDeskGameTests {
        helper.succeed();
    }

-    @GameTest(template = "empty")
    public static void oldDeskInventoryMigratesAndAll88TabsPersist(GameTestHelper helper) {
        BlockPos pos = helper.absolutePos(new BlockPos(1, 1, 1));
        var registries = helper.getLevel().registryAccess();
@@ -1,6 +1,7 @@
 package net.dnorberg.rivencraft.item;

 import java.util.List;
+import net.dnorberg.rivencraft.Rivencraft;
 import net.dnorberg.rivencraft.registry.ModDataComponents;
 import net.dnorberg.rivencraft.registry.ModItems;
 import net.dnorberg.rivencraft.writing.PageContent;
@@ -28,6 +29,23 @@ public final class PageItem extends Item {
        return create(PageContent.symbol(reference));
    }

+    /** Fixed starter examples for the creative tab; the server still validates catalog membership on use. */
+    public static ItemStack createCreativeStarterPage(String path) {
+        if (!List.of("terrain/standard", "biome/native", "lighting/normal", "weather/normal",
+                "celestial/normal_time", "feature/caves").contains(path)) {
+            throw new IllegalArgumentException("Not a starter symbol: " + path);
+        }
+        SymbolReference reference = new SymbolReference(
+                net.minecraft.resources.ResourceLocation.fromNamespaceAndPath(Rivencraft.MOD_ID, path));
+        ItemStack page = create(PageContent.symbol(reference));
+        String key = "symbol.rivencraft." + path.replace('/', '.');
+        page.set(ModDataComponents.PAGE_SYMBOL_DISPLAY.get(), new SymbolDisplayMetadata(
+                reference.id(), key, key + ".description",
+                net.minecraft.resources.ResourceLocation.fromNamespaceAndPath(Rivencraft.MOD_ID, path.split("/")[0]),
+                true));
+        return page;
+    }
+
    public static ItemStack createLinkPanelPage() {
        return create(PageContent.LINK_PANEL);
    }
@@ -0,0 +1,119 @@
+package net.dnorberg.rivencraft.menu;
+
+import net.dnorberg.rivencraft.block.entity.InkMixerBlockEntity;
+import net.dnorberg.rivencraft.item.PageItem;
+import net.dnorberg.rivencraft.registry.ModItems;
+import net.dnorberg.rivencraft.registry.ModMenus;
+import net.minecraft.network.RegistryFriendlyByteBuf;
+import net.minecraft.world.Container;
+import net.minecraft.world.SimpleContainer;
+import net.minecraft.world.entity.player.Inventory;
+import net.minecraft.world.entity.player.Player;
+import net.minecraft.world.inventory.AbstractContainerMenu;
+import net.minecraft.world.inventory.DataSlot;
+import net.minecraft.world.inventory.Slot;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.Items;
+
+/** Server-owned virtual output; taking it spends paper and the configured ink cost once. */
+public final class InkMixerMenu extends AbstractContainerMenu {
+    public static final int RESULT = InkMixerBlockEntity.SIZE;
+    private static final int PLAYER_START = RESULT + 1;
+    private final InkMixerBlockEntity mixer;
+    private final Container inputs;
+    private final SimpleContainer result = new SimpleContainer(1);
+    private final boolean clientSide;
+    private int inkRemaining;
+
+    public InkMixerMenu(int id, Inventory inventory, RegistryFriendlyByteBuf data) {
+        this(id, inventory, inventory.player.level().getBlockEntity(data.readBlockPos())
+                instanceof InkMixerBlockEntity found ? found : null);
+    }
+
+    public InkMixerMenu(int id, Inventory inventory, InkMixerBlockEntity mixer) {
+        super(ModMenus.INK_MIXER.get(), id);
+        this.mixer = mixer;
+        inputs = mixer == null ? new SimpleContainer(InkMixerBlockEntity.SIZE) : mixer;
+        clientSide = inventory.player.level().isClientSide;
+        addDataSlot(new DataSlot() {
+            @Override public int get() { return clientSide ? inkRemaining : mixer.inkRemaining(); }
+            @Override public void set(int value) { inkRemaining = value; }
+        });
+        addSlot(new MixerSlot(InkMixerBlockEntity.INK, 8, 27));
+        addSlot(new MixerSlot(InkMixerBlockEntity.PAPER, 8, 48));
+        addSlot(new MixerSlot(InkMixerBlockEntity.BOTTLES, 152, 27));
+        addSlot(new ResultSlot(152, 48));
+        for (int row = 0; row < 3; row++)
+            for (int column = 0; column < 9; column++)
+                addSlot(new Slot(inventory, column + row * 9 + 9, 8 + column * 18, 99 + row * 18));
+        for (int column = 0; column < 9; column++)
+            addSlot(new Slot(inventory, column, 8 + column * 18, 157));
+        refreshResult();
+    }
+
+    public int inkRemaining() { return inkRemaining; }
+
+    @Override public boolean stillValid(Player player) {
+        return mixer != null && mixer.stillValid(player);
+    }
+
+    @Override public void broadcastChanges() {
+        refreshResult();
+        super.broadcastChanges();
+    }
+
+    private void refreshResult() {
+        if (clientSide) return;
+        ItemStack preview = mixer != null && mixer.canCreateLinkPanel()
+                ? PageItem.createLinkPanelPage() : ItemStack.EMPTY;
+        if (!ItemStack.matches(result.getItem(0), preview)) result.setItem(0, preview);
+    }
+
+    @Override public ItemStack quickMoveStack(Player player, int index) {
+        if (!stillValid(player) || index < 0 || index >= slots.size()) return ItemStack.EMPTY;
+        if (index == RESULT) {
+            refreshResult();
+            if (!mixer.canCreateLinkPanel()) return ItemStack.EMPTY;
+            ItemStack output = result.getItem(0).copy();
+            ItemStack remainder = output.copy();
+            if (!moveItemStackTo(remainder, PLAYER_START, slots.size(), true) || !remainder.isEmpty())
+                return ItemStack.EMPTY;
+            if (!mixer.consumeLinkPanelMaterials()) return ItemStack.EMPTY;
+            refreshResult();
+            return output;
+        }
+        Slot slot = slots.get(index);
+        if (!slot.hasItem()) return ItemStack.EMPTY;
+        ItemStack source = slot.getItem();
+        ItemStack original = source.copy();
+        boolean moved;
+        if (index < RESULT) moved = moveItemStackTo(source, PLAYER_START, slots.size(), true);
+        else if (source.is(ModItems.INK_VIAL.get()))
+            moved = moveItemStackTo(source, InkMixerBlockEntity.INK, InkMixerBlockEntity.INK + 1, false);
+        else if (source.is(Items.PAPER))
+            moved = moveItemStackTo(source, InkMixerBlockEntity.PAPER, InkMixerBlockEntity.PAPER + 1, false);
+        else moved = false;
+        if (!moved) return ItemStack.EMPTY;
+        if (source.isEmpty()) slot.setByPlayer(ItemStack.EMPTY);
+        else slot.setChanged();
+        refreshResult();
+        return original;
+    }
+
+    private final class MixerSlot extends Slot {
+        MixerSlot(int index, int x, int y) { super(inputs, index, x, y); }
+        @Override public boolean mayPlace(ItemStack stack) { return inputs.canPlaceItem(getContainerSlot(), stack); }
+    }
+
+    private final class ResultSlot extends Slot {
+        ResultSlot(int x, int y) { super(result, 0, x, y); }
+        @Override public boolean mayPlace(ItemStack stack) { return false; }
+        @Override public boolean mayPickup(Player player) {
+            return clientSide ? hasItem() : stillValid(player) && mixer.canCreateLinkPanel();
+        }
+        @Override public void onTake(Player player, ItemStack stack) {
+            if (!clientSide && mixer.consumeLinkPanelMaterials()) refreshResult();
+            super.onTake(player, stack);
+        }
+    }
+}
@@ -166,15 +166,12 @@ public final class WritingDeskMenu extends AbstractContainerMenu {
            selectedPage = page;
            selectedSymbol = null;
        } else if (id >= CATALOG_BUTTON_BASE && id < CATALOG_BUTTON_BASE + catalog.size()) {
-            if (!catalog.equals(WritingDeskCatalog.available(blockEntity))) {
-                refreshCatalog();
+            List<SymbolDisplayMetadata> available = WritingDeskCatalog.available(blockEntity);
+            if (!catalog.equals(available)) {
+                refreshCatalog(available);
                return false;
            }
-            ResourceLocation requested = catalog.get(id - CATALOG_BUTTON_BASE).id();
-            if (!WritingDeskCatalog.available(blockEntity).stream().anyMatch(entry -> entry.id().equals(requested))) {
-                return false;
-            }
-            selectedSymbol = requested;
+            selectedSymbol = available.get(id - CATALOG_BUTTON_BASE).id();
        } else return false;
        refreshOutput();
        return true;
@@ -390,7 +387,11 @@ public final class WritingDeskMenu extends AbstractContainerMenu {

    private void refreshCatalog() {
        if (clientSide || blockEntity == null) return;
-        List<SymbolDisplayMetadata> current = WritingDeskCatalog.available(blockEntity);
+        refreshCatalog(WritingDeskCatalog.available(blockEntity));
+    }
+
+    private void refreshCatalog(List<SymbolDisplayMetadata> current) {
+        if (clientSide || blockEntity == null) return;
        if (!current.equals(catalog)) {
            catalog = current;
            if (serverViewer != null && serverViewer.containerMenu == this) {
@@ -4,6 +4,7 @@ import net.dnorberg.rivencraft.Rivencraft;
 import net.dnorberg.rivencraft.block.entity.BookStandBlockEntity;
 import net.dnorberg.rivencraft.block.entity.BookBinderBlockEntity;
 import net.dnorberg.rivencraft.block.entity.WritingDeskBlockEntity;
+import net.dnorberg.rivencraft.block.entity.InkMixerBlockEntity;
 import net.minecraft.core.registries.Registries;
 import net.minecraft.world.level.block.entity.BlockEntityType;
 import net.neoforged.bus.api.IEventBus;
@@ -24,6 +25,9 @@ public final class ModBlockEntities {
    public static final DeferredHolder<BlockEntityType<?>, BlockEntityType<BookBinderBlockEntity>> BOOK_BINDER =
            BLOCK_ENTITIES.register("book_binder", () -> BlockEntityType.Builder
                    .of(BookBinderBlockEntity::new, ModBlocks.BOOK_BINDER.get()).build(null));
+    public static final DeferredHolder<BlockEntityType<?>, BlockEntityType<InkMixerBlockEntity>> INK_MIXER =
+            BLOCK_ENTITIES.register("ink_mixer", () -> BlockEntityType.Builder
+                    .of(InkMixerBlockEntity::new, ModBlocks.INK_MIXER.get()).build(null));

    private ModBlockEntities() {
    }
@@ -4,6 +4,7 @@ import net.dnorberg.rivencraft.Rivencraft;
 import net.dnorberg.rivencraft.block.BookStandBlock;
 import net.dnorberg.rivencraft.block.BookBinderBlock;
 import net.dnorberg.rivencraft.block.WritingDeskBlock;
+import net.dnorberg.rivencraft.block.InkMixerBlock;
 import net.minecraft.world.level.block.Blocks;
 import net.minecraft.world.level.block.state.BlockBehaviour;
 import net.neoforged.bus.api.IEventBus;
@@ -26,6 +27,10 @@ public final class ModBlocks {
            "book_binder", BookBinderBlock::new,
            BlockBehaviour.Properties.ofFullCopy(Blocks.CRAFTING_TABLE).noOcclusion()
    );
+    public static final DeferredBlock<InkMixerBlock> INK_MIXER = BLOCKS.registerBlock(
+            "ink_mixer", InkMixerBlock::new,
+            BlockBehaviour.Properties.ofFullCopy(Blocks.CRAFTING_TABLE).noOcclusion()
+    );

    private ModBlocks() {
    }
@@ -23,6 +23,7 @@ public final class ModCreativeTabs {
                        output.accept(ModItems.NOTEBOOK.get());
                        output.accept(ModItems.INK_VIAL.get());
                        output.accept(ModItems.WRITING_DESK.get());
+                        output.accept(ModItems.INK_MIXER.get());
                        output.accept(ModItems.BOOK_BINDER.get());
                    })
                    .build());
@@ -32,7 +33,12 @@ public final class ModCreativeTabs {
                    .title(Component.translatable("itemGroup.rivencraft.pages"))
                    .icon(PageItem::createLinkPanelPage)
                    .displayItems((parameters, output) -> {
+                        output.accept(ModItems.PAGE.get());
                        output.accept(PageItem.createLinkPanelPage());
+                        for (String id : new String[] {"terrain/standard", "biome/native", "lighting/normal",
+                                "weather/normal", "celestial/normal_time", "feature/caves"}) {
+                            output.accept(PageItem.createCreativeStarterPage(id));
+                        }
                    })
                    .build());

@@ -42,6 +42,7 @@ public final class ModItems {
    );
    public static final DeferredItem<BlockItem> WRITING_DESK = ITEMS.registerSimpleBlockItem(ModBlocks.WRITING_DESK);
    public static final DeferredItem<BlockItem> BOOK_BINDER = ITEMS.registerSimpleBlockItem(ModBlocks.BOOK_BINDER);
+    public static final DeferredItem<BlockItem> INK_MIXER = ITEMS.registerSimpleBlockItem(ModBlocks.INK_MIXER);

    private ModItems() {
    }
@@ -4,6 +4,7 @@ import net.dnorberg.rivencraft.Rivencraft;
 import net.dnorberg.rivencraft.menu.NotebookMenu;
 import net.dnorberg.rivencraft.menu.WritingDeskMenu;
 import net.dnorberg.rivencraft.menu.BookBinderMenu;
+import net.dnorberg.rivencraft.menu.InkMixerMenu;
 import net.minecraft.core.registries.Registries;
 import net.minecraft.world.inventory.MenuType;
 import net.neoforged.bus.api.IEventBus;
@@ -21,6 +22,8 @@ public final class ModMenus {
            MENUS.register("writing_desk", () -> IMenuTypeExtension.create(WritingDeskMenu::new));
    public static final DeferredHolder<MenuType<?>, MenuType<BookBinderMenu>> BOOK_BINDER =
            MENUS.register("book_binder", () -> IMenuTypeExtension.create(BookBinderMenu::new));
+    public static final DeferredHolder<MenuType<?>, MenuType<InkMixerMenu>> INK_MIXER =
+            MENUS.register("ink_mixer", () -> IMenuTypeExtension.create(InkMixerMenu::new));

    private ModMenus() {
    }
@@ -0,0 +1,24 @@
+package net.dnorberg.rivencraft.registry;
+
+import net.dnorberg.rivencraft.Rivencraft;
+import net.dnorberg.rivencraft.writing.LinkingBookRecipe;
+import net.minecraft.core.registries.Registries;
+import net.minecraft.world.item.crafting.RecipeSerializer;
+import net.minecraft.world.item.crafting.SimpleCraftingRecipeSerializer;
+import net.neoforged.bus.api.IEventBus;
+import net.neoforged.neoforge.registries.DeferredHolder;
+import net.neoforged.neoforge.registries.DeferredRegister;
+
+public final class ModRecipeSerializers {
+    private static final DeferredRegister<RecipeSerializer<?>> SERIALIZERS =
+            DeferredRegister.create(Registries.RECIPE_SERIALIZER, Rivencraft.MOD_ID);
+
+    public static final DeferredHolder<RecipeSerializer<?>, RecipeSerializer<LinkingBookRecipe>> LINKING_BOOK =
+            SERIALIZERS.register("linking_book", () -> new SimpleCraftingRecipeSerializer<>(LinkingBookRecipe::new));
+
+    private ModRecipeSerializers() {}
+
+    public static void register(IEventBus modEventBus) {
+        SERIALIZERS.register(modEventBus);
+    }
+}
@@ -0,0 +1,43 @@
+package net.dnorberg.rivencraft.writing;
+
+import net.dnorberg.rivencraft.item.InkVialItem;
+import net.dnorberg.rivencraft.registry.ModItems;
+import net.minecraft.core.NonNullList;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.Items;
+
+/** Shared, server-side vial-to-meter exchange for the Desk and Ink Mixer. */
+public final class InkVialExchange {
+    private InkVialExchange() {}
+
+    public static boolean canPay(NonNullList<ItemStack> items, int inkSlot, int bottleSlot,
+                                 int storedInk, int cost) {
+        return storedInk >= cost || canExchange(items, inkSlot, bottleSlot)
+                && storedInk + vialInk(items.get(inkSlot)) >= cost;
+    }
+
+    /** Returns added ink; zero means no inputs were changed. */
+    public static int exchange(NonNullList<ItemStack> items, int inkSlot, int bottleSlot) {
+        if (!canExchange(items, inkSlot, bottleSlot)) return 0;
+        ItemStack vial = items.get(inkSlot);
+        int addedInk = vialInk(vial);
+        vial.shrink(1);
+        if (vial.isEmpty()) items.set(inkSlot, ItemStack.EMPTY);
+        ItemStack bottles = items.get(bottleSlot);
+        if (bottles.isEmpty()) items.set(bottleSlot, new ItemStack(Items.GLASS_BOTTLE));
+        else bottles.grow(1);
+        return addedInk;
+    }
+
+    private static boolean canExchange(NonNullList<ItemStack> items, int inkSlot, int bottleSlot) {
+        ItemStack vial = items.get(inkSlot);
+        ItemStack bottles = items.get(bottleSlot);
+        return vial.is(ModItems.INK_VIAL.get()) && vialInk(vial) > 0
+                && (bottles.isEmpty() || bottles.is(Items.GLASS_BOTTLE)
+                && bottles.getCount() < bottles.getMaxStackSize());
+    }
+
+    private static int vialInk(ItemStack vial) {
+        return Math.clamp(InkVialItem.remaining(vial), 0, InkVialItem.CAPACITY);
+    }
+}
@@ -0,0 +1,80 @@
+package net.dnorberg.rivencraft.writing;
+
+import net.dnorberg.rivencraft.item.PageItem;
+import net.dnorberg.rivencraft.registry.ModItems;
+import net.dnorberg.rivencraft.registry.ModRecipeSerializers;
+import net.minecraft.core.HolderLookup;
+import net.minecraft.core.NonNullList;
+import net.minecraft.core.component.DataComponents;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.Items;
+import net.minecraft.world.item.crafting.CraftingBookCategory;
+import net.minecraft.world.item.crafting.CraftingInput;
+import net.minecraft.world.item.crafting.CustomRecipe;
+import net.minecraft.world.item.crafting.Ingredient;
+import net.minecraft.world.item.crafting.RecipeSerializer;
+import net.minecraft.world.level.Level;
+import net.neoforged.neoforge.common.crafting.DataComponentIngredient;
+
+/** Legacy's shapeless leather + Link Panel recipe, adapted to page components. */
+public final class LinkingBookRecipe extends CustomRecipe {
+    public LinkingBookRecipe(CraftingBookCategory category) {
+        super(category);
+    }
+
+    private static ItemStack findPanel(CraftingInput input) {
+        if (input.ingredientCount() != 2) return ItemStack.EMPTY;
+        ItemStack panel = ItemStack.EMPTY;
+        boolean leather = false;
+        for (ItemStack stack : input.items()) {
+            if (stack.isEmpty()) continue;
+            if (stack.is(ModItems.PAGE.get()) && PageItem.content(stack).kind() == PageContent.Kind.LINK_PANEL
+                    && panel.isEmpty()) {
+                panel = stack;
+            } else if (stack.is(Items.LEATHER) && !leather) {
+                leather = true;
+            } else {
+                return ItemStack.EMPTY;
+            }
+        }
+        return leather ? panel : ItemStack.EMPTY;
+    }
+
+    @Override
+    public boolean matches(CraftingInput input, Level level) {
+        return !findPanel(input).isEmpty();
+    }
+
+    @Override
+    public ItemStack assemble(CraftingInput input, HolderLookup.Provider registries) {
+        ItemStack panel = findPanel(input);
+        if (panel.isEmpty()) return ItemStack.EMPTY;
+        ItemStack book = new ItemStack(ModItems.LINKING_BOOK.get());
+        // Legacy copied the panel's data. Only its custom name is meaningful to a
+        // 1.21.1 Linking Book today; page-only components must not reach the book.
+        if (panel.has(DataComponents.CUSTOM_NAME)) {
+            book.set(DataComponents.CUSTOM_NAME, panel.get(DataComponents.CUSTOM_NAME));
+        }
+        return book;
+    }
+
+    @Override
+    public boolean canCraftInDimensions(int width, int height) {
+        return width * height >= 2;
+    }
+
+    @Override
+    public NonNullList<Ingredient> getIngredients() {
+        NonNullList<Ingredient> ingredients = NonNullList.create();
+        ingredients.add(DataComponentIngredient.of(false,
+                net.dnorberg.rivencraft.registry.ModDataComponents.PAGE_CONTENT.get(),
+                PageContent.LINK_PANEL, ModItems.PAGE.get()));
+        ingredients.add(Ingredient.of(Items.LEATHER));
+        return ingredients;
+    }
+
+    @Override
+    public RecipeSerializer<?> getSerializer() {
+        return ModRecipeSerializers.LINKING_BOOK.get();
+    }
+}
@@ -2,9 +2,9 @@ package net.dnorberg.rivencraft.writing;

 import java.util.ArrayList;
 import java.util.Comparator;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.TreeMap;
 import net.dnorberg.rivencraft.block.entity.WritingDeskBlockEntity;
 import net.dnorberg.rivencraft.item.PageItem;
 import net.dnorberg.rivencraft.registry.ModDataComponents;
@@ -20,7 +20,7 @@ public final class WritingDeskCatalog {
    private WritingDeskCatalog() {}

    public static List<SymbolDisplayMetadata> available(WritingDeskBlockEntity desk) {
-        Map<ResourceLocation, SymbolDisplayMetadata> unique = new TreeMap<>();
+        Map<ResourceLocation, SymbolDisplayMetadata> unique = new HashMap<>();
        for (int slot = 0; slot < WritingDeskBlockEntity.COLLECTIONS; slot++) {
            ItemStack collection = desk.getItem(slot);
            if (collection.is(ModItems.PAGE.get())) add(unique, collection);
@@ -0,0 +1,5 @@
+{
+  "variants": {
+    "": { "model": "rivencraft:block/ink_mixer" }
+  }
+}
@@ -20,6 +20,9 @@
  "container.rivencraft.writing_desk": "Writing Desk",
  "block.rivencraft.book_binder": "Book Binder",
  "container.rivencraft.book_binder": "Book Binder",
+  "block.rivencraft.ink_mixer": "Ink Mixer",
+  "container.rivencraft.ink_mixer": "Ink Mixer",
+  "screen.rivencraft.ink_mixer.ink": "Ink: %s/%s",
  "screen.rivencraft.book_binder.title": "Book title",
  "screen.rivencraft.book_binder.title_hint": "Name the book",
  "screen.rivencraft.book_binder.missing_panel": "Link Panel required as the first page",
@@ -28,9 +31,17 @@
  "screen.rivencraft.book_binder.import.tooltip": "Move all Notebook pages into the binder in order",
  "screen.rivencraft.book_binder.move_previous": "Move selected page left",
  "screen.rivencraft.book_binder.move_next": "Move selected page right",
+  "screen.rivencraft.book_binder.previous_pages": "Scroll pages left (Left Arrow)",
+  "screen.rivencraft.book_binder.next_pages": "Scroll pages right (Right Arrow)",
  "screen.rivencraft.book_binder.select_hint": "Right-click page to select",
  "screen.rivencraft.writing_desk.ink": "Ink: %s/%s",
  "screen.rivencraft.writing_desk.search": "Search",
+  "screen.rivencraft.writing_desk.sort": "Sort pages by name (A–Z)",
+  "screen.rivencraft.writing_desk.all": "Show pages from all tabs",
+  "screen.rivencraft.writing_desk.category": "Cycle page category: %s",
+  "screen.rivencraft.writing_desk.all_categories": "All categories",
+  "screen.rivencraft.writing_desk.previous_tabs": "Previous four tabs (Page Up)",
+  "screen.rivencraft.writing_desk.next_tabs": "Next four tabs (Page Down)",
  "screen.rivencraft.writing_desk.no_symbols": "No available symbols",
  "item.rivencraft.ink_vial.remaining": "Ink: %s/%s",
  "item.rivencraft.ink_vial.usage": "Use with paper in the other hand to prepare a Link Panel.",
@@ -117,6 +128,15 @@
  "screen.rivencraft.book.explore": "Explore",
  "screen.rivencraft.book.exploring": "Exploring",
  "screen.rivencraft.book.return_from_explore": "Right-click to return",
+  "screen.rivencraft.book.previous_page": "Previous page (Left Arrow)",
+  "screen.rivencraft.book.next_page": "Next page (Right Arrow)",
+  "jei.rivencraft.writing": "Rivencraft Writing",
+  "jei.rivencraft.writing.link_panel_hand": "Hold paper and an Ink Vial in opposite hands; use the vial to make a Link Panel.",
+  "jei.rivencraft.ink_mixer": "Ink Mixer",
+  "jei.rivencraft.ink_mixer.usage": "Paper + ink makes a Link Panel. One vial fills 16 ink; each panel uses the configured ink cost. The empty vial returns as a glass bottle.",
+  "jei.rivencraft.writing.copy": "At a Writing Desk, select a stored Page, add paper and ink, then take the copy. The source Page stays.",
+  "jei.rivencraft.writing.bind": "At a Book Binder, name the Age and add a cover plus Link Panel. Optional symbol Pages follow the panel.",
+  "jei.rivencraft.writing.linking_book": "Craft one Link Panel Page with leather to make an unwritten Linking Book. Open it to name and bind it.",
  "itemGroup.rivencraft": "Rivencraft",
  "itemGroup.rivencraft.pages": "Rivencraft Pages"
 }
@@ -0,0 +1,23 @@
+{
+  "parent": "minecraft:block/block",
+  "textures": {
+    "particle": "rivencraft:block/ink_mixer_side",
+    "side": "rivencraft:block/ink_mixer_side",
+    "top": "rivencraft:block/ink_mixer_top",
+    "bottom": "rivencraft:block/ink_mixer_bottom"
+  },
+  "elements": [
+    {
+      "from": [0, 0, 0],
+      "to": [16, 12, 16],
+      "faces": {
+        "north": { "texture": "#side", "uv": [0, 4, 16, 16] },
+        "east": { "texture": "#side", "uv": [0, 4, 16, 16] },
+        "south": { "texture": "#side", "uv": [0, 4, 16, 16] },
+        "west": { "texture": "#side", "uv": [0, 4, 16, 16] },
+        "up": { "texture": "#top" },
+        "down": { "texture": "#bottom" }
+      }
+    }
+  ]
+}
@@ -0,0 +1,3 @@
+{
+  "parent": "rivencraft:block/ink_mixer"
+}
@@ -0,0 +1,4 @@
+{
+  "type": "minecraft:block",
+  "pools": [{ "rolls": 1, "entries": [{ "type": "minecraft:item", "name": "rivencraft:ink_mixer" }] }]
+}
@@ -0,0 +1,11 @@
+{
+  "type": "minecraft:crafting_shaped",
+  "category": "misc",
+  "pattern": ["S S", "SVS", "PSP"],
+  "key": {
+    "S": { "item": "minecraft:stone" },
+    "V": { "item": "minecraft:glass_bottle" },
+    "P": { "tag": "minecraft:planks" }
+  },
+  "result": { "id": "rivencraft:ink_mixer", "count": 1 }
+}
@@ -1,16 +1,4 @@
 {
-  "type": "minecraft:crafting_shapeless",
-  "category": "misc",
-  "ingredients": [
-    {
-      "item": "minecraft:book"
-    },
-    {
-      "item": "minecraft:ender_pearl"
-    }
-  ],
-  "result": {
-    "count": 1,
-    "id": "rivencraft:linking_book"
-  }
+  "type": "rivencraft:linking_book",
+  "category": "misc"
 }
Author	SHA1	Message	Date
dnorberg	114a6ee21e	Streamline GameTests and writing workstation logic Build / build (push) Canceled after 0s Details	2026-09-29 23:12:35 -04:00
dnorberg	8246640f49	Complete Milestone 4 writing acceptance and migration coverage (#26 , #27 ) Build / build (push) Canceled after 0s Details	2026-09-29 22:51:49 -04:00
dnorberg	ba2faace15	Use Legacy Linking Book recipe and add page-turn audio Build / build (push) Canceled after 0s Details	2026-09-29 22:37:45 -04:00
dnorberg	88355ee276	Add Ink Mixer and optional JEI writing guides Build / build (push) Canceled after 0s Details	2026-09-29 10:35:29 -04:00