Port seeded random Ages and authored Rocks to 26.3 beta

.gitignore

@@ -32,6 +32,10 @@ bin/
 ### Mac OS ###
 .DS_Store
 
+### Python tools ###
+__pycache__/
+*.pyc
+
 ### Minecraft Modding ###
 run/
 logs/

docs/MINECRAFT_26_3_PORT.md

@@ -480,6 +480,48 @@ symbol-page data and authoring pipeline, not just drawing more placeholders.
 The local `1.0.1.15-alpha.1` follow-up changes the missing-panel cue to the
 Link Panel's 16×16 item icon while preserving its red pulse and tooltip.
 
+The local `1.0.1.33-beta.1` slice adds Flat and Void terrain to authored Binder
+books. Flat uses vanilla superflat layers and can use one authored Biome; Void
+generates no terrain but can use one authored Biome for environmental behavior.
+Without a Biome page, Void uses `minecraft:the_void`. Books with multiple Biome
+pages and Flat/Void terrain remain unassembled until their custom distribution
+generator is ported. The dedicated-server smoke creates, samples, and reloads
+both terrain families in a disposable world.
+
+The local `1.0.1.34-beta.1` follow-up moves Flat ground to Y=0 and targets its
+surface for travel. `1.0.1.35-beta.1` enables the selected biome's decoration
+on Flat. `1.0.1.36-beta.1` ports a multi-biome Flat/Void chunk generator and
+accepts the existing authored distribution pages for those terrains. New Flat
+chunks can vary vegetation by biome; Void keeps biome climate without adding
+a floor or decorations. These are beta-port slices, not full 1.21.1 parity.
+
+The local `1.0.1.37-beta.1` slice ports Cave terrain authoring using the
+26.3 caves noise preset. Cave and Nether Biome pages can be distributed
+through an Age, and travel searches for footing from Y=64 downward rather
+than mistaking the cave roof for the surface. Nether-style cave material
+replacement from 1.21.1 remains a separate port task. The local
+`1.0.1.38-beta.1` follow-up
+keeps Cave Ages dry by default: the vanilla 26.3 Cave preset otherwise fills
+low openings with water. This changes newly generated chunks only; a future
+Flooded page will deliberately set an authored water level in both maintained
+versions.
+The local `1.0.1.39-beta.1` follow-up makes the 26.3 landing search reject
+fluid at feet and head height and prevents a submerged fallback platform.
+
+The local `1.0.1.40-beta.1` slice gives pageless Descriptive Books a
+seed-selected terrain and biome plan. It follows the 1.21.1 rank weights for
+terrain and biome distribution, selects registered Cave/Nether biomes for Cave
+Ages and overworld-source biomes for other non-Void terrains, and persists the
+resolved choices. Other random Age traits remain a later port task.
+
+The local `1.0.1.41-beta.1` slice adds the first Age-scoped feature wrapper to
+the 26.3 generator. A Block page followed by Rocks now places clusters of the
+chosen block in new Standard, Amplified, Island, or Flat terrain chunks. The
+Age index persists that selection, and the wrapper delegates all vanilla
+terrain, biome, and structure generation. Cave and Void are intentionally
+excluded until their feature placement rules are ported. This is not yet the
+full 1.21.1 feature grammar or instability system.
+
 ## Verification of this first slice
 
 The 1.21.1 `compileJava` and `build` tasks passed offline after the backend

docs/PUBLISHING_APIS.md

@@ -0,0 +1,82 @@
+# Publishing Rivencraft with the Gitea, Modrinth, and CurseForge APIs
+
+The local helper is [`scripts/publish_mod_sites.py`](../scripts/publish_mod_sites.py).
+It previews a release unless `--publish` is explicitly supplied. The current
+configuration is for the Minecraft **26.3** artifact only. The 1.21.1 line needs
+its required external dependencies mapped on both sites before API publishing
+is enabled for it.
+
+## One-time token setup
+
+For Gitea, an existing personal access token is sufficient if it has
+`write:repository` scope. That scope covers release creation and attachment
+upload; do not grant `all` if a narrower token is available. Create or inspect
+tokens under [Gitea user settings → Applications](https://git.paddedcell.org/user/settings/applications).
+The helper checks token identity and scope without displaying the secret.
+
+Create a [Modrinth personal access token](https://docs.modrinth.com/api/#authentication)
+in account settings with `VERSION_CREATE` (upload) and `USER_READ` (read-only
+credential check) scopes. Create a
+[CurseForge Upload API token](https://support.curseforge.com/support/solutions/articles/9000197321)
+from the author's API Tokens page. Treat both as passwords: never put them in
+git, chat, a release note, or a command-line argument.
+
+In a terminal at the repository root, run these one at a time and paste the
+corresponding token into the hidden prompt:
+
+```sh
+python3 scripts/publish_mod_sites.py store-token modrinth
+python3 scripts/publish_mod_sites.py store-token curseforge
+python3 scripts/publish_mod_sites.py store-token gitea
+```
+
+The tokens are stored in the desktop Secret Service keyring under
+`application=rivencraft-publishing`, separately by site. The script also accepts
+`RIVENCRAFT_MODRINTH_TOKEN` or `RIVENCRAFT_CURSEFORGE_TOKEN` environment variables,
+but these take precedence over keyring entries and should not be put in shell
+history or startup files.
+
+Verify the credentials without uploading anything:
+
+```sh
+python3 scripts/publish_mod_sites.py check-token modrinth
+python3 scripts/publish_mod_sites.py check-token curseforge
+python3 scripts/publish_mod_sites.py check-token gitea
+```
+
+## Release workflow
+
+Build the JAR, write a Markdown changelog, and preview the metadata:
+
+```sh
+python3 scripts/publish_mod_sites.py release \
+  --jar ports/mc263/build/libs/rivencraft-26.3-1.0.1.32-beta.1.jar \
+  --changelog ports/mc263/RELEASE_NOTES_1.0.1.32-beta.1.md \
+  --version 1.0.1.32-beta.1 \
+  --name 'Rivencraft 1.0.1.32-beta.1 — NeoForge 26.3' \
+  --minecraft 26.3 --java 25 --channel beta
+```
+
+For a *new* version only, append `--publish` to upload to both sites. Use
+`--site modrinth` or `--site curseforge` to target one site. Modrinth rejects an
+existing version number; CurseForge may not, so check its file list before any
+retry after a partial failure. CurseForge approval may take additional time.
+
+The default destination is now all three sites. The Gitea release step requires
+the annotated version tag to have been pushed first. Gitea's `Vx.y.z.b-mc26.3-beta.1`
+tag convention is derived from the version and channel; an existing release
+with different title or notes is never overwritten. If release creation
+succeeds but its JAR upload fails, rerun with `--site gitea --publish` to resume
+only the missing attachment. `--site both` retains the earlier Modrinth and
+CurseForge-only behavior.
+
+The helper uses Gitea's documented
+[`POST /repos/{owner}/{repo}/releases`](https://docs.gitea.com/api/operations/repo-create-release/)
+and [release attachment endpoint](https://docs.gitea.com/api/operations/repo-create-release-attachment/),
+plus Modrinth's documented multipart
+[`POST /version`](https://docs.modrinth.com/api/operations/createversion/) and
+CurseForge's documented
+[`POST /api/projects/{projectId}/upload-file`](https://support.curseforge.com/support/solutions/articles/9000197321)
+with the JAR, changelog, version channel, NeoForge, Minecraft version, Java
+version, and client/server environment. It sets no external dependencies for
+26.3, which uses Rivencraft's first-party Age backend.

ports/mc263/README.md

@@ -1,15 +1,16 @@
-# Minecraft 26.3 port workspace
+# Minecraft 26.3 beta port workspace
 
-This is an **experimental alpha port** for issues #97–#104, not gameplay parity
-with the Minecraft 1.21.1 release. It registers basic items and a runtime Age
-prototype with persisted seeds. The operator-only `rivencraft_port age`
-commands create and inspect separate vanilla-terrain levels. The current
-development slice can name an unbound Descriptive Book to create a prototype
-Age, then enter it from the book GUI; the player verified this interaction in game.
-Named Linking Book binding/travel works as a limited probe. Authored
-generation, most content, recipes, workstations, portal systems, most modifiers and
-the destination preview renderer remain unported. Use a test world and keep a
-backup; do not substitute this JAR for the 1.21.1 mod or import 1.21.1 saves.
+This is an **experimental beta port** for issues #97–#104, not gameplay parity
+with the Minecraft 1.21.1 release. The 26.3 backend persists separate Ages and
+their seeds. Books, the Book Binder, and the Ink Mixer work, and the Binder can
+author Standard, Amplified, Island, Flat, Void, or Cave terrain with supported
+biome-distribution pages. Other terrain families, feature/material effects,
+portals, and much of
+the 1.21.1 gameplay remain unported. Use a test world and keep a backup; do not
+substitute this JAR for the 1.21.1 mod or import 1.21.1 saves.
+
+The entries below record how the port was built, including earlier alpha-only
+limitations that were addressed by later slices.
 
 The creative tab contains the two Books, Crystal Block and Crystal Shard;
 the player verified these in game. Unbound Linking Books use the Legacy
@@ -80,6 +81,136 @@ The local `1.0.1.15-alpha.1` Binder polish uses the Link Panel's actual 16×16
 item icon for the missing-panel cue instead of a full-size page sprite. The
 red pulse and tooltip remain confined to that icon.
 
+The local `1.0.1.16-alpha.1` slice adds the bundled 1.21.1 symbol-page
+identities to the 26.3 creative menu, grouped by category. Their names and
+descriptions are reused from the 1.21.1 translations, and the Page item now
+persists each symbol ID. These pages currently use the generic symbol-page
+artwork; the Legacy-style runtime glyph compositor has not been ported.
+They cannot yet be inserted into the Binder or change Age generation. This is
+the page-data foundation for the next authored-writing slice.
+
+The local `1.0.1.17-alpha.1` follow-up derives biome pages from the active
+26.3 biome registry instead of only the older bundled list. It excludes the
+TerraBlender staging placeholder and separates cave/Nether biomes. Full-block
+materials and true source-fluid blocks also receive registry-derived pages,
+covering eligible new and modded blocks. Five 26.3 feature symbols cover
+poplar trees, fallen poplars, shelf mushrooms, red shrubs, and abandoned
+camps. These feature pages are identities only until their Age-generation
+handlers are ported. Biome, material, and feature pages still use generic
+artwork and cannot yet be placed in the Binder.
+
+The local `1.0.1.18-alpha.1` follow-up restores the 1.21.1 animated redaction
+for Corrupted Page names and descriptions. It does not yet port the dynamic
+glyph artwork used for other symbol pages.
+
+The local `1.0.1.19-alpha.1` slice ports the runtime glyph compositor for
+symbol Page items. It uses the shared Legacy component sheet and page
+parchment with a bounded 256-texture client cache; generated textures are
+released on resource reload. Registry-derived biome and material pages use
+the same deterministic four-word poem pattern as 1.21.1. No per-symbol PNGs
+are generated in the source tree. Binder insertion and authored Age generation
+are still unported.
+
+The local `1.0.1.20-alpha.1` visual follow-up enlarges symbol artwork on Page
+items, slightly thickens the component strokes, and centers number glyphs at a
+larger size so they remain readable in inventory and creative-menu icons.
+
+The local `1.0.1.21-alpha.1` slice ports the Binder's ordered, scrollable
+symbol-page strip. Pages persist in its block inventory and can be inserted,
+removed, and moved via the cursor or shift-click. A Binder with symbol pages
+cannot yet produce a book: authored Age compilation is the next port step, and
+silently producing a random Age would consume the player's writing incorrectly.
+
+The local `1.0.1.22-alpha.1` visual follow-up gives large Binder pages the
+transparent, full-size Legacy glyph composition. Item icons retain their
+separate parchment-backed, reduced-size artwork.
+
+The local `1.0.1.23-alpha.1` follow-up places Binder glyph overlays in a later
+26.3 GUI stratum than the page atlas, preventing texture batching from drawing
+the opaque page backgrounds over the dynamic artwork.
+
+The local `1.0.1.24-alpha.1` follow-up renders Binder page glyphs through
+their working special item model, scaled to the page thumbnail. Direct GUI
+blitting of the generated texture remained blank in the 26.3 client.
+
+The local `1.0.1.25-alpha.1` follow-up marks temporary Binder preview stacks
+for glyph-only special-model rendering. The full-size transparent artwork now
+uses the working item pipeline without drawing a second, smaller page outline.
+
+The local `1.0.1.26-alpha.1` corrects the temporary preview component's codec
+registration, which NeoForge 26.3 requires during bootstrap.
+
+The local `1.0.1.27-alpha.1` slice applies the first authored Age subset:
+Standard terrain plus at most one Biome page. The selected biome is persisted
+with the Age and used by a fixed-biome Overworld noise generator on creation
+and reload. Ordered page IDs are stored on the finished book. Other page
+combinations remain in the Binder and cannot yet be assembled, preventing
+silent loss of unsupported writing. Multi-biome distribution, other terrain
+profiles, and feature/material pages still need their 26.3 generation ports.
+
+The `1.0.1.28`–`1.0.1.32` slices add Tiled, Grid, Native, and five scaled
+biome distributions; multiple authored Biome pages; Amplified and Island
+terrain; and saved terrain/biome plans across reload. A Binder or Ink Mixer
+beside another block no longer hides that block's faces. Unsupported authoring
+still stays in the Binder rather than silently producing an incorrect Age.
+
+The local `1.0.1.33-beta.1` slice adds Flat and Void terrain to Binder
+authoring. Flat uses vanilla's superflat layers; Void has no generated floor
+and uses the selected Biome for its environmental rules. Each accepts zero or
+one authored Biome page. Unsupported multi-biome Flat/Void books remain in the
+Binder until their custom generator is ported. The operator probe can create
+test Ages with `rivencraft_port age create <name> <seed> flat|void`.
+
+The local `1.0.1.34-beta.1` follow-up starts Flat's solid layers at Y=0
+(bedrock at 0, dirt at 1–2, grass at 3) and lands players at the ground surface
+instead of creating an elevated fallback platform. This affects newly
+generated Flat chunks; previously generated Age chunks are not rewritten.
+
+The local `1.0.1.35-beta.1` follow-up enables biome decoration on newly
+generated Flat chunks, allowing the selected biome's trees, vegetation, and
+other placed features to appear on the Flat surface. Void remains undecorated.
+
+The local `1.0.1.36-beta.1` slice accepts multiple Biome pages with Flat and
+Void terrain. It ports the 1.21.1 authored-biome Flat generator to 26.3, so
+Tiled, Grid, and scaled regions affect climate in both terrain types and
+surface decoration in Flat. Void continues to generate no floor or biome
+decoration. The operator-only `age create_multi` probe creates two-biome test
+Ages for the dedicated-server smoke test.
+
+The local `1.0.1.37-beta.1` slice adds the Cave terrain page to Binder
+authoring. It uses Minecraft's caves noise settings, accepts Cave and Nether
+biome pages (including multi-biome distribution), and searches below Y=64 for
+a safe arrival instead of landing on the roof. The 26.3 vanilla Cave preset
+defaults to water below Y=32, so this port derives a dry Cave setting with
+air as its default fluid and the sea level below the world floor. This applies
+to newly generated Cave chunks; it does not drain existing chunks. Cave-specific Nether surface
+materials from 1.21.1 are not ported yet. The dedicated-server smoke now
+creates and reloads Cave Ages alongside the other terrain families.
+
+The dry-Cave follow-up is packaged as `1.0.1.38-beta.1`; no 26.3 release is
+published until the in-game check passes and publication is explicitly requested.
+
+The local `1.0.1.39-beta.1` follow-up rejects fluid at both feet and head
+height during safe-landing searches. It also refuses to carve the fallback
+platform into submerged space if no dry footing can be found.
+
+The `1.0.1.40-beta.1` port slice seeds terrain and biome selection for
+Descriptive Books with no authored symbol pages. It uses the same terrain and
+biome-controller rank weights as the 1.21.1 line, freezes the resulting plan
+in the Age index, and accepts the result after restart. The operator-only
+`age create_random <name> <seed>` probe exercises this path. Random feature,
+sky, weather, and instability choices are not yet ported; this slice covers
+terrain and biomes only.
+
+The `1.0.1.41-beta.1` slice establishes an Age-scoped decoration wrapper
+for 26.3 and accepts one Block material page immediately before a Rocks feature
+page. Newly generated surface chunks place small rock clusters made from that
+block without modifying the shared biome registry. The selected block and
+generator survive a restart. Cave and Void terrain remain unsupported for this
+first surface-feature path; unsupported combinations stay in the Binder.
+Random feature selection, unpaired materials, duplicate feature pages, and
+instability scoring remain future port steps.
+
 From the repository root:
 
 ```sh
@@ -94,7 +225,7 @@ Minecraft 1.21.1/Java 21 build:
 ./gradlew build
 ```
 
-The alpha JAR is under `ports/mc263/build/libs`. Continue the port and its
+The beta JAR is under `ports/mc263/build/libs`. Continue the port and its
 full dual-version validation in issues #98–#104 before calling 26.3 stable.
 
 The dedicated development server uses `build/run-server`, with its own world

ports/mc263/RELEASE_NOTES_1.0.1.32-beta.1.md

@@ -0,0 +1,19 @@
+# Rivencraft 26.3 beta 1.0.1.32-beta.1
+
+This is the first 26.3 beta, focused on authored Age generation. It is not yet
+feature-complete with the separate Minecraft 1.21.1 release.
+
+- Ported the Book Binder's ordered symbol-page strip and Legacy-inspired GUI,
+  plus runtime symbol artwork, creative pages, and registry-derived biome pages.
+- Ported the Ink Mixer, its additive modifiers, and one-paper/one-ink-unit Link
+  Panel creation.
+- Added authored Standard, Amplified, and Island terrain; fixed, Tiled, Grid,
+  Native, and Tiny through Huge biome distributions; and persistent Age plans.
+- Fixed workstation block-face occlusion beside the Book Binder and Ink Mixer.
+
+Feature/material writing, Cave/Flat/Void terrain, portals, and other 1.21.1
+systems are still being ported. Use a test world and keep a backup. Minecraft
+1.21.1 saves are not supported by this beta.
+
+Requires Minecraft 26.3, NeoForge 26.3.0.99 or a compatible 26.3 build, and
+Java 25.

ports/mc263/RELEASE_NOTES_1.0.1.36-beta.1.md

@@ -0,0 +1,12 @@
+# Rivencraft 26.3 beta 1.0.1.36-beta.1
+
+This beta adds Flat and Void terrain to authored Ages on Minecraft 26.3.
+
+- Bind Descriptive Books with Flat or Void terrain, including multiple Biome pages and supported biome-distribution pages.
+- Flat ground starts at Y=0; travel lands on its surface rather than on an elevated fallback platform.
+- Flat Ages generate the selected biomes' surface decorations, including trees and vegetation. Void Ages remain empty while retaining authored biome climate.
+- Expanded dedicated-server checks for Flat and Void terrain, biome distribution, and persistence after restart.
+
+This 26.3 port is still experimental and does not yet include all features of the separate Minecraft 1.21.1 version. Use a test world and keep a backup. Minecraft 1.21.1 saves are not supported by this beta.
+
+Requires Minecraft 26.3, NeoForge 26.3.0.99 or a compatible 26.3 build, and Java 25.

ports/mc263/RELEASE_NOTES_1.0.1.39-beta.1.md

@@ -0,0 +1,14 @@
+# Rivencraft 26.3 beta 1.0.1.39-beta.1
+
+This beta adds Cave terrain to authored Ages on Minecraft 26.3.
+
+- Bind Descriptive Books with the Cave terrain page and Cave or Nether biome pages, including supported multi-biome distributions.
+- Cave Ages use the cave noise shape but remain dry by default. Newly generated chunks no longer flood below the vanilla cave sea level.
+- Cave travel searches from Y=64 downward for dry, properly footed space instead of landing on the cave roof or underwater.
+- Expanded dedicated-server checks for Cave creation, biome distribution, and persistence after restart.
+
+The player verified the Cave and safe-landing changes in game. Existing generated chunks are not drained or regenerated. A future Flooded page will provide an authored water level; see [issue #107](https://git.paddedcell.org/dnorberg/rivencraft/issues/107).
+
+This 26.3 port is still experimental and does not yet include all features of the separate Minecraft 1.21.1 version. Use a test world and keep a backup. Minecraft 1.21.1 saves are not supported by this beta.
+
+Requires Minecraft 26.3, NeoForge 26.3.0.99 or a compatible 26.3 build, and Java 25.

ports/mc263/RELEASE_NOTES_1.0.1.41-beta.1.md

@@ -0,0 +1,13 @@
+# Rivencraft 26.3 beta 1.0.1.41-beta.1
+
+This beta expands Age generation on Minecraft 26.3.
+
+- Descriptive Books with no authored symbol pages now choose a seeded random terrain and biome distribution. The chosen plan is saved with the Age and restored after restart.
+- A Block material page followed by a Rocks feature page now generates small clusters of that block in newly generated surface chunks. This first feature path supports Standard, Amplified, Island, and Flat terrain; Cave and Void combinations remain unsupported.
+- Expanded dedicated-server checks cover random Age plans and authored Rocks generation across restart.
+
+The player verified the Rocks feature in game. Random feature selection, duplicate feature pages, unpaired materials, and instability scoring are not yet ported. Existing chunks are not regenerated.
+
+This 26.3 port is still experimental and does not yet include all features of the separate Minecraft 1.21.1 version. Use a test world and keep a backup. Minecraft 1.21.1 saves are not supported by this beta.
+
+Requires Minecraft 26.3, NeoForge 26.3.0.99 or a compatible 26.3 build, and Java 25.

ports/mc263/build.gradle

@@ -59,12 +59,77 @@ def generateModMetadata = tasks.register('generateModMetadata', ProcessResources
 sourceSets.main.resources.srcDir generateModMetadata
 neoForge.ideSyncTask generateModMetadata
 
+// Keep the bundled page list in step with the 1.21.1 symbol definitions.
+abstract class GeneratePortSymbolIndex extends DefaultTask {
+    @InputDirectory abstract DirectoryProperty getSymbolsDir()
+    @InputDirectory abstract DirectoryProperty getPortSymbolsDir()
+    @OutputDirectory abstract DirectoryProperty getIndexDir()
+
+    @TaskAction void generate() {
+        File root = symbolsDir.get().asFile
+        def definitions = new LinkedHashMap<String, Object>()
+        java.nio.file.Files.walk(root.toPath()).withCloseable { paths ->
+            paths.filter { java.nio.file.Files.isRegularFile(it) && it.toString().endsWith('.json') }
+                    .sorted().forEach { source ->
+                        String path = root.toPath().relativize(source).toString()
+                                .replace('\\', '/').replaceAll(/\.json$/, '')
+                        definitions["rivencraft:${path}"] = new groovy.json.JsonSlurper().parse(source.toFile())
+                    }
+        }
+        File portRoot = portSymbolsDir.get().asFile
+        java.nio.file.Files.walk(portRoot.toPath()).withCloseable { paths ->
+            paths.filter { java.nio.file.Files.isRegularFile(it) && it.toString().endsWith('.json') }
+                    .sorted().forEach { source ->
+                        String path = portRoot.toPath().relativize(source).toString()
+                                .replace('\\', '/').replaceAll(/\.json$/, '')
+                        definitions["rivencraft:${path}"] = new groovy.json.JsonSlurper().parse(source.toFile())
+                    }
+        }
+        File index = new File(indexDir.get().asFile, 'assets/rivencraft/creative_symbol_pages.json')
+        index.parentFile.mkdirs()
+        index.text = groovy.json.JsonOutput.prettyPrint(groovy.json.JsonOutput.toJson(definitions)) + '\n'
+    }
+}
+
+def generatePortSymbolIndex = tasks.register('generatePortSymbolIndex', GeneratePortSymbolIndex) {
+    symbolsDir.set(layout.projectDirectory.dir('../../src/main/resources/data/rivencraft/rivencraft/symbols'))
+    portSymbolsDir.set(layout.projectDirectory.dir('src/main/resources/data/rivencraft/rivencraft/symbols'))
+    indexDir.set(layout.buildDirectory.dir('generated/resources/creativeSymbols'))
+}
+sourceSets.main.resources.srcDir generatePortSymbolIndex
+
+// Use the established symbol names/descriptions without overwriting 26.3-only strings.
+abstract class GeneratePortLanguage extends DefaultTask {
+    @InputFile abstract RegularFileProperty getBaseLanguage()
+    @InputFile abstract RegularFileProperty getPortLanguage()
+    @OutputDirectory abstract DirectoryProperty getOutputDir()
+
+    @TaskAction void generate() {
+        def base = new groovy.json.JsonSlurper().parse(baseLanguage.get().asFile) as Map
+        def port = new groovy.json.JsonSlurper().parse(portLanguage.get().asFile) as Map
+        base.putAll(port)
+        File result = new File(outputDir.get().asFile, 'assets/rivencraft/lang/en_us.json')
+        result.parentFile.mkdirs()
+        result.text = groovy.json.JsonOutput.prettyPrint(groovy.json.JsonOutput.toJson(base)) + '\n'
+    }
+}
+
+def generatePortLanguage = tasks.register('generatePortLanguage', GeneratePortLanguage) {
+    baseLanguage.set(layout.projectDirectory.file('../../src/main/resources/assets/rivencraft/lang/en_us.json'))
+    portLanguage.set(layout.projectDirectory.file('port_en_us.json'))
+    outputDir.set(layout.buildDirectory.dir('generated/resources/portLanguage'))
+}
+sourceSets.main.resources.srcDir generatePortLanguage
+
 tasks.named('processResources', ProcessResources).configure {
     // Reuse the existing sprite and base model without copying binary assets.
     from('../../src/main/resources') {
         include 'assets/rivencraft/textures/item/crystal_shard.png'
         include 'assets/rivencraft/textures/item/page.png'
         include 'assets/rivencraft/textures/item/page_link_panel.png'
+        include 'assets/rivencraft/textures/item/page_symbol.png'
+        include 'assets/rivencraft/models/item/page_symbol.json'
+        include 'assets/rivencraft/textures/gui/symbolcomponents.png'
         include 'assets/rivencraft/models/item/page_link_panel.json'
         include 'assets/rivencraft/textures/item/ink_vial.png'
         include 'assets/rivencraft/textures/item/ink_vial.png.mcmeta'

ports/mc263/gradle.properties

@@ -7,4 +7,4 @@ neo_version=26.3.0.99
 mod_id=rivencraft
 mod_name=Rivencraft
 mod_license=LGPL-3.0-or-later
-mod_version=1.0.1.15-alpha.1
+mod_version=1.0.1.41-beta.1

ports/mc263/port_en_us.json

@@ -5,6 +5,8 @@
   "item.rivencraft.page": "Page",
   "item.rivencraft.page.blank": "Blank Page",
   "item.rivencraft.page.link_panel": "Link Panel Page",
+  "item.rivencraft.page.unresolved": "Unknown Symbol Page",
+  "item.rivencraft.page.symbol.port_status": "Binder currently supports Standard terrain and one Biome page; other effects are still being ported.",
   "item.rivencraft.link_property.disarm": "Disarm",
   "item.rivencraft.link_property.maintain_momentum": "Maintain Momentum",
   "item.rivencraft.link_property.intra_linking": "Intra-Linking",
@@ -16,6 +18,7 @@
   "block.rivencraft.book_binder": "Book Binder",
   "container.rivencraft.book_binder": "Book Binder",
   "screen.rivencraft.book_binder.missing_panel": "Link Panel required",
+  "screen.rivencraft.book_binder.authored_pending": "Writing not yet ported",
   "block.rivencraft.ink_mixer": "Ink Mixer",
   "container.rivencraft.ink_mixer": "Ink Mixer",
   "screen.rivencraft.ink_mixer.ink": "Ink: %s/%s",
@@ -28,5 +31,15 @@
   "block.rivencraft.large_crystal_bud": "Large Crystal Bud",
   "block.rivencraft.crystal_cluster": "Crystal Cluster",
   "itemGroup.rivencraft": "Rivencraft",
-  "itemGroup.rivencraft.pages.link": "Rivencraft Link Pages"
+  "itemGroup.rivencraft.pages.link": "Rivencraft Link Pages",
+  "symbol.rivencraft.feature.poplar_trees": "Poplar Trees",
+  "symbol.rivencraft.feature.poplar_trees.description": "Poplar tree generation symbol.",
+  "symbol.rivencraft.feature.fallen_poplar_trees": "Fallen Poplar Trees",
+  "symbol.rivencraft.feature.fallen_poplar_trees.description": "Fallen poplar tree generation symbol.",
+  "symbol.rivencraft.feature.shelf_mushrooms": "Shelf Mushrooms",
+  "symbol.rivencraft.feature.shelf_mushrooms.description": "Shelf mushroom generation symbol.",
+  "symbol.rivencraft.feature.red_shrubs": "Red Shrubs",
+  "symbol.rivencraft.feature.red_shrubs.description": "Red shrub generation symbol.",
+  "symbol.rivencraft.feature.abandoned_camps": "Abandoned Camps",
+  "symbol.rivencraft.feature.abandoned_camps.description": "Abandoned camp structure generation symbol."
 }

ports/mc263/src/main/java/net/dnorberg/rivencraft/Rivencraft.java

@@ -20,6 +20,8 @@ import net.dnorberg.rivencraft.item.LinkingBookItem;
 import net.dnorberg.rivencraft.item.PageItem;
 import net.dnorberg.rivencraft.network.PortBookNetworking;
 import net.dnorberg.rivencraft.registry.ModCreativeTabs;
+import net.dnorberg.rivencraft.registry.PortBiomeSources;
+import net.dnorberg.rivencraft.registry.PortChunkGenerators;
 import net.dnorberg.rivencraft.writing.LinkingBookRecipe;
 import net.minecraft.core.component.DataComponentType;
 import net.minecraft.core.registries.Registries;
@@ -71,6 +73,18 @@ public final class Rivencraft {
     public static final Supplier<DataComponentType<Boolean>> LINK_PANEL_PAGE = COMPONENTS.registerComponentType(
             "link_panel_page", builder -> builder.persistent(Codec.BOOL)
                     .networkSynchronized(ByteBufCodecs.BOOL));
+    public static final Supplier<DataComponentType<Identifier>> SYMBOL_PAGE_ID = COMPONENTS.registerComponentType(
+            "symbol_page_id", builder -> builder.persistent(Identifier.CODEC)
+                    .networkSynchronized(Identifier.STREAM_CODEC));
+    /** Ordered authored page IDs remain on the finished book for later port slices. */
+    public static final Supplier<DataComponentType<java.util.List<Identifier>>> BOOK_SYMBOLS = COMPONENTS.registerComponentType(
+            "book_symbols", builder -> builder.persistent(Identifier.CODEC.listOf())
+                    .networkSynchronized(ByteBufCodecs.<io.netty.buffer.ByteBuf, Identifier>list(252)
+                            .apply(Identifier.STREAM_CODEC)));
+    /** Set only on temporary GUI stacks; NeoForge 26.3 requires a registered codec. */
+    public static final Supplier<DataComponentType<Boolean>> PAGE_GLYPH_ONLY = COMPONENTS.registerComponentType(
+            "page_glyph_only", builder -> builder.persistent(Codec.BOOL)
+                    .networkSynchronized(ByteBufCodecs.BOOL));
     public static final Supplier<DataComponentType<Integer>> INK_REMAINING = COMPONENTS.registerComponentType(
             "ink_remaining", builder -> builder.persistent(Codec.INT)
                     .networkSynchronized(ByteBufCodecs.VAR_INT));
@@ -82,11 +96,11 @@ public final class Rivencraft {
             Block::new, () -> BlockBehaviour.Properties.ofFullCopy(Blocks.AMETHYST_BLOCK));
     public static final DeferredBlock<PortBookBinderBlock> BOOK_BINDER = BLOCKS.registerBlock(
             "book_binder", PortBookBinderBlock::new,
-            () -> BlockBehaviour.Properties.ofFullCopy(Blocks.CRAFTING_TABLE));
+            () -> BlockBehaviour.Properties.ofFullCopy(Blocks.CRAFTING_TABLE).noOcclusion());
     public static final DeferredItem<BlockItem> BOOK_BINDER_ITEM = ITEMS.registerSimpleBlockItem(BOOK_BINDER);
     public static final DeferredBlock<InkMixerBlock> INK_MIXER = BLOCKS.registerBlock(
             "ink_mixer", InkMixerBlock::new,
-            () -> BlockBehaviour.Properties.ofFullCopy(Blocks.CRAFTING_TABLE));
+            () -> BlockBehaviour.Properties.ofFullCopy(Blocks.CRAFTING_TABLE).noOcclusion());
     public static final DeferredItem<BlockItem> INK_MIXER_ITEM = ITEMS.registerSimpleBlockItem(INK_MIXER);
     public static final Supplier<BlockEntityType<PortBookBinderBlockEntity>> BOOK_BINDER_BLOCK_ENTITY =
             BLOCK_ENTITY_TYPES.register("book_binder", () ->
@@ -138,6 +152,8 @@ public final class Rivencraft {
         COMPONENTS.register(modEventBus);
         RECIPE_SERIALIZERS.register(modEventBus);
         ModCreativeTabs.register(modEventBus);
+        PortBiomeSources.register(modEventBus);
+        PortChunkGenerators.register(modEventBus);
         NeoForge.EVENT_BUS.addListener(RuntimeAgeBackend::onLevelLoad);
         NeoForge.EVENT_BUS.addListener(PortAgeCommands::register);
         NeoForge.EVENT_BUS.addListener(AgeCatalogSync::onLogin);

ports/mc263/src/main/java/net/dnorberg/rivencraft/age/AgeLevelIndex.java

@@ -17,7 +17,16 @@ final class AgeLevelIndex extends SavedData {
     private static final Codec<AgeLevelIndex> CODEC = RecordCodecBuilder.create(instance -> instance.group(
             Codec.unboundedMap(Identifier.CODEC, Codec.LONG).fieldOf("ages").forGetter(index -> index.ages),
             Identifier.CODEC.listOf().optionalFieldOf("retired", List.of())
-                    .forGetter(index -> List.copyOf(index.retired))
+                    .forGetter(index -> List.copyOf(index.retired)),
+            Codec.unboundedMap(Identifier.CODEC, Identifier.CODEC).optionalFieldOf("biome_overrides", Map.of())
+                    .forGetter(index -> index.biomeOverrides),
+            Codec.unboundedMap(Identifier.CODEC, PortBiomePlan.CODEC).optionalFieldOf("biome_plans", Map.of())
+                    .forGetter(index -> index.biomePlans),
+            Codec.unboundedMap(Identifier.CODEC,
+                    Codec.STRING.xmap(PortAgeTerrain::valueOf, PortAgeTerrain::name))
+                    .optionalFieldOf("terrain", Map.of()).forGetter(index -> index.terrain),
+            Codec.unboundedMap(Identifier.CODEC, PortRockPlan.CODEC).optionalFieldOf("rocks", Map.of())
+                    .forGetter(index -> index.rocks)
     ).apply(instance, AgeLevelIndex::new));
 
     static final SavedDataType<AgeLevelIndex> TYPE = new SavedDataType<>(
@@ -28,15 +37,31 @@ final class AgeLevelIndex extends SavedData {
 
     private final Map<Identifier, Long> ages;
     private final Set<Identifier> retired;
+    private final Map<Identifier, Identifier> biomeOverrides;
+    private final Map<Identifier, PortBiomePlan> biomePlans;
+    private final Map<Identifier, PortAgeTerrain> terrain;
+    private final Map<Identifier, PortRockPlan> rocks;
 
     private AgeLevelIndex() {
         this.ages = new LinkedHashMap<>();
         this.retired = new LinkedHashSet<>();
+        this.biomeOverrides = new LinkedHashMap<>();
+        this.biomePlans = new LinkedHashMap<>();
+        this.terrain = new LinkedHashMap<>();
+        this.rocks = new LinkedHashMap<>();
     }
 
-    private AgeLevelIndex(Map<Identifier, Long> ages, List<Identifier> retired) {
+    private AgeLevelIndex(Map<Identifier, Long> ages, List<Identifier> retired,
+                          Map<Identifier, Identifier> biomeOverrides,
+                          Map<Identifier, PortBiomePlan> biomePlans,
+                          Map<Identifier, PortAgeTerrain> terrain,
+                          Map<Identifier, PortRockPlan> rocks) {
         this.ages = new LinkedHashMap<>(ages);
         this.retired = new LinkedHashSet<>(retired);
+        this.biomeOverrides = new LinkedHashMap<>(biomeOverrides);
+        this.biomePlans = new LinkedHashMap<>(biomePlans);
+        this.terrain = new LinkedHashMap<>(terrain);
+        this.rocks = new LinkedHashMap<>(rocks);
     }
 
     Map<Identifier, Long> entries() {
@@ -51,23 +76,48 @@ final class AgeLevelIndex extends SavedData {
         return ages.get(id);
     }
 
-    void add(Identifier id, long seed) {
+    PortBiomePlan biomePlan(Identifier id) {
+        PortBiomePlan plan = biomePlans.get(id);
+        if (plan != null) return plan;
+        Identifier oldBiome = biomeOverrides.get(id);
+        return oldBiome == null ? null : new PortBiomePlan(PortBiomePlan.Distribution.SINGLE, List.of(oldBiome));
+    }
+
+    PortAgeTerrain terrain(Identifier id) {
+        return terrain.getOrDefault(id, PortAgeTerrain.STANDARD);
+    }
+
+    PortRockPlan rocks(Identifier id) { return rocks.get(id); }
+
+    void add(Identifier id, long seed, PortBiomePlan biomePlan, PortAgeTerrain ageTerrain,
+             PortRockPlan rockPlan) {
         if (contains(id)) {
             throw new IllegalArgumentException("Age already exists: " + id);
         }
         ages.put(id, seed);
+        if (biomePlan != null) biomePlans.put(id, biomePlan);
+        if (ageTerrain != PortAgeTerrain.STANDARD) terrain.put(id, ageTerrain);
+        if (rockPlan != null) rocks.put(id, rockPlan);
         setDirty();
     }
 
     void retire(Identifier id) {
         if (ages.remove(id) == null) throw new IllegalArgumentException("Age not indexed: " + id);
+        biomeOverrides.remove(id);
+        biomePlans.remove(id);
+        terrain.remove(id);
+        rocks.remove(id);
         retired.add(id);
         setDirty();
     }
 
-    void restoreAfterFailedRetirement(Identifier id, long seed) {
+    void restoreAfterFailedRetirement(Identifier id, long seed, PortBiomePlan biomePlan,
+                                      PortAgeTerrain ageTerrain, PortRockPlan rockPlan) {
         if (!retired.remove(id)) throw new IllegalStateException("Age is not retired: " + id);
         ages.put(id, seed);
+        if (biomePlan != null) biomePlans.put(id, biomePlan);
+        if (ageTerrain != PortAgeTerrain.STANDARD) terrain.put(id, ageTerrain);
+        if (rockPlan != null) rocks.put(id, rockPlan);
         setDirty();
     }
 

ports/mc263/src/main/java/net/dnorberg/rivencraft/age/PortAgeCommands.java

@@ -3,9 +3,11 @@ package net.dnorberg.rivencraft.age;
 import com.mojang.brigadier.arguments.LongArgumentType;
 import com.mojang.brigadier.arguments.IntegerArgumentType;
 import com.mojang.brigadier.arguments.StringArgumentType;
+import com.mojang.brigadier.context.CommandContext;
 import net.dnorberg.rivencraft.Rivencraft;
 import net.dnorberg.rivencraft.item.LinkBookTarget;
 import net.minecraft.commands.Commands;
+import net.minecraft.commands.CommandSourceStack;
 import net.minecraft.core.registries.Registries;
 import net.minecraft.core.component.DataComponents;
 import net.minecraft.network.chat.Component;
@@ -20,6 +22,7 @@ import net.neoforged.neoforge.event.RegisterCommandsEvent;
 import net.neoforged.fml.ModList;
 import java.util.Map;
 import java.util.TreeMap;
+import java.util.Locale;
 
 /** Operator-only backend and synchronized-travel probes, not normal book behavior. */
 public final class PortAgeCommands {
@@ -64,25 +67,69 @@ public final class PortAgeCommands {
                                 })))
                 .then(Commands.literal("age")
                         .then(Commands.literal("create")
+                                .then(Commands.argument("name", StringArgumentType.word())
+                                        .then(Commands.argument("seed", LongArgumentType.longArg())
+                                                .executes(context -> createAge(context, PortAgeTerrain.STANDARD))
+                                                .then(Commands.argument("terrain", StringArgumentType.word())
+                                                        .executes(context -> {
+                                                            PortAgeTerrain terrain;
+                                                            try {
+                                                                terrain = PortAgeTerrain.valueOf(StringArgumentType.getString(
+                                                                        context, "terrain").toUpperCase(Locale.ROOT));
+                                                            } catch (IllegalArgumentException exception) {
+                                                                context.getSource().sendFailure(Component.literal(
+                                                                        "Unknown terrain; use standard, amplified, island, cave, flat, or void"));
+                                                                return 0;
+                                                            }
+                                                            return createAge(context, terrain);
+                                                        })))))
+                        .then(Commands.literal("create_multi")
+                                .then(Commands.argument("name", StringArgumentType.word())
+                                        .then(Commands.argument("seed", LongArgumentType.longArg())
+                                                .then(Commands.argument("terrain", StringArgumentType.word())
+                                                        .executes(context -> {
+                                                            PortAgeTerrain terrain;
+                                                            try {
+                                                                terrain = PortAgeTerrain.valueOf(StringArgumentType.getString(
+                                                                        context, "terrain").toUpperCase(Locale.ROOT));
+                                                            } catch (IllegalArgumentException exception) {
+                                                                context.getSource().sendFailure(Component.literal(
+                                                                        "Unknown terrain; use cave, flat, or void"));
+                                                                return 0;
+                                                            }
+                                                            if (terrain != PortAgeTerrain.CAVE
+                                                                    && terrain != PortAgeTerrain.FLAT
+                                                                    && terrain != PortAgeTerrain.VOID) {
+                                                                context.getSource().sendFailure(Component.literal(
+                                                                        "Multi-biome probe supports cave, flat, or void only"));
+                                                                return 0;
+                                                            }
+                                                            return createAge(context, terrain, new PortBiomePlan(
+                                                                    PortBiomePlan.Distribution.TILED,
+                                                                    terrain == PortAgeTerrain.CAVE
+                                                                            ? java.util.List.of(Identifier.withDefaultNamespace("lush_caves"),
+                                                                                    Identifier.withDefaultNamespace("dripstone_caves"))
+                                                                            : java.util.List.of(Identifier.withDefaultNamespace("plains"),
+                                                                                    Identifier.withDefaultNamespace("forest"))));
+                                                        })))))
+                        .then(Commands.literal("create_random")
                                 .then(Commands.argument("name", StringArgumentType.word())
                                         .then(Commands.argument("seed", LongArgumentType.longArg())
                                                 .executes(context -> {
-                                                    String name = StringArgumentType.getString(context, "name");
-                                                    Identifier id = Identifier.fromNamespaceAndPath(
-                                                            Rivencraft.MOD_ID, "age/" + name);
                                                     long seed = LongArgumentType.getLong(context, "seed");
-                                                    ServerLevel level;
-                                                    try {
-                                                        level = RuntimeAgeBackend.create(
-                                                                context.getSource().getServer(), id, seed);
-                                                    } catch (IllegalArgumentException | IllegalStateException exception) {
-                                                        context.getSource().sendFailure(Component.literal(exception.getMessage()));
-                                                        return 0;
-                                                    }
-                                                    context.getSource().sendSuccess(() -> Component.literal(
-                                                            "Created " + id + " with seed " + level.getSeed()), true);
-                                                    return 1;
+                                                    PortRandomAgeSelection.Selection selected = PortRandomAgeSelection.select(
+                                                            context.getSource().getServer(), seed);
+                                                    int created = createAge(context, selected.terrain(), selected.biomes());
+                                                    if (created != 0) context.getSource().sendSuccess(() -> Component.literal(
+                                                            "Random Age plan: terrain=" + selected.terrain()
+                                                                    + " biomes=" + selected.biomes()), false);
+                                                    return created;
                                                 }))))
+                        .then(Commands.literal("create_rocks")
+                                .then(Commands.argument("name", StringArgumentType.word())
+                                        .then(Commands.argument("seed", LongArgumentType.longArg())
+                                                .executes(context -> createAge(context, PortAgeTerrain.FLAT,
+                                                        null, new PortRockPlan(Identifier.withDefaultNamespace("gold_block")))))))
                         .then(Commands.literal("list")
                                 .executes(context -> {
                                     var ages = RuntimeAgeBackend.savedAges(context.getSource().getServer());
@@ -185,7 +232,60 @@ public final class PortAgeCommands {
                                         .executes(context -> sampleAge(context, 0))
                                         .then(Commands.argument("chunkOffset", IntegerArgumentType.integer(0))
                                                 .executes(context -> sampleAge(context,
-                                                        IntegerArgumentType.getInteger(context, "chunkOffset"))))))));
+                                                        IntegerArgumentType.getInteger(context, "chunkOffset"))))))
+                        .then(Commands.literal("rocks_probe")
+                                .then(Commands.argument("name", StringArgumentType.word())
+                                        .executes(PortAgeCommands::probeRocks)))
+                        .then(Commands.literal("biome")
+                                .then(Commands.argument("name", StringArgumentType.word())
+                                        .then(Commands.argument("x", IntegerArgumentType.integer())
+                                                .then(Commands.argument("z", IntegerArgumentType.integer())
+                                                        .executes(PortAgeCommands::sampleBiome)))))));
+    }
+
+    private static int createAge(CommandContext<CommandSourceStack> context, PortAgeTerrain terrain) {
+        return createAge(context, terrain, null);
+    }
+
+    private static int createAge(CommandContext<CommandSourceStack> context,
+                                 PortAgeTerrain terrain, PortBiomePlan biomePlan) {
+        return createAge(context, terrain, biomePlan, null);
+    }
+
+    private static int probeRocks(CommandContext<CommandSourceStack> context) {
+        Identifier id = ageId(context);
+        ServerLevel level = context.getSource().getServer().getLevel(ResourceKey.create(Registries.DIMENSION, id));
+        if (level == null || !(level.getChunkSource().getGenerator() instanceof PortRockChunkGenerator rocks)) {
+            context.getSource().sendFailure(Component.literal("Age has no loaded Rocks generator: " + id));
+            return 0;
+        }
+        var material = net.minecraft.core.registries.BuiltInRegistries.BLOCK.getValue(rocks.rocks().material());
+        int count = 0;
+        for (int x = 0; x < 64; x++) for (int z = 0; z < 64; z++) {
+            int y = level.getHeight(Heightmap.Types.MOTION_BLOCKING, x, z) - 1;
+            if (level.getBlockState(new net.minecraft.core.BlockPos(x, y, z)).is(material)) count++;
+        }
+        int placed = count;
+        context.getSource().sendSuccess(() -> Component.literal(
+                "Rocks probe " + id + " material=" + rocks.rocks().material() + " count=" + placed), false);
+        return placed;
+    }
+
+    private static int createAge(CommandContext<CommandSourceStack> context,
+                                 PortAgeTerrain terrain, PortBiomePlan biomePlan, PortRockPlan rockPlan) {
+        String name = StringArgumentType.getString(context, "name");
+        Identifier id = Identifier.fromNamespaceAndPath(Rivencraft.MOD_ID, "age/" + name);
+        long seed = LongArgumentType.getLong(context, "seed");
+        ServerLevel level;
+        try {
+            level = RuntimeAgeBackend.create(context.getSource().getServer(), id, seed, biomePlan, terrain, rockPlan);
+        } catch (IllegalArgumentException | IllegalStateException exception) {
+            context.getSource().sendFailure(Component.literal(exception.getMessage()));
+            return 0;
+        }
+        context.getSource().sendSuccess(() -> Component.literal(
+                "Created " + id + " with seed " + level.getSeed() + " terrain=" + terrain), true);
+        return 1;
     }
 
     private static int sampleAge(com.mojang.brigadier.context.CommandContext<net.minecraft.commands.CommandSourceStack> context,
@@ -213,6 +313,23 @@ public final class PortAgeCommands {
         return 1;
     }
 
+    private static int sampleBiome(CommandContext<CommandSourceStack> context) {
+        Identifier id = ageId(context);
+        ServerLevel level = context.getSource().getServer().getLevel(ResourceKey.create(Registries.DIMENSION, id));
+        if (level == null) {
+            context.getSource().sendFailure(Component.literal("Age not loaded: " + id));
+            return 0;
+        }
+        int x = IntegerArgumentType.getInteger(context, "x");
+        int z = IntegerArgumentType.getInteger(context, "z");
+        level.getChunk(x >> 4, z >> 4);
+        Identifier biome = level.getBiome(new net.minecraft.core.BlockPos(x, 4, z))
+                .unwrapKey().orElseThrow().identifier();
+        context.getSource().sendSuccess(() -> Component.literal(
+                id + " biome at " + x + "," + z + "=" + biome), false);
+        return 1;
+    }
+
     private static Identifier ageId(com.mojang.brigadier.context.CommandContext<net.minecraft.commands.CommandSourceStack> context) {
         return Identifier.fromNamespaceAndPath(Rivencraft.MOD_ID,
                 "age/" + StringArgumentType.getString(context, "name"));

ports/mc263/src/main/java/net/dnorberg/rivencraft/age/PortAgeTerrain.java

@@ -0,0 +1,11 @@
+package net.dnorberg.rivencraft.age;
+
+/** Terrain variants currently backed by 26.3 vanilla noise settings. */
+public enum PortAgeTerrain {
+    STANDARD,
+    AMPLIFIED,
+    ISLAND,
+    CAVE,
+    FLAT,
+    VOID
+}

ports/mc263/src/main/java/net/dnorberg/rivencraft/age/PortAgeTravel.java

@@ -11,6 +11,8 @@ import net.minecraft.server.level.ServerLevel;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.level.block.Blocks;
 import net.minecraft.world.level.levelgen.Heightmap;
+import net.minecraft.world.level.levelgen.FlatLevelSource;
+import net.minecraft.world.level.levelgen.flat.FlatLevelGeneratorSettings;
 
 /** Shared, server-authoritative landing for the 26.3 book and operator probe. */
 public final class PortAgeTravel {
@@ -31,16 +33,49 @@ public final class PortAgeTravel {
     }
 
     private static BlockPos findLanding(ServerLevel target) {
+        net.minecraft.world.level.chunk.ChunkGenerator generator = target.getChunkSource().getGenerator();
+        if (generator instanceof PortRockChunkGenerator rocks) generator = rocks.base();
+        if (generator instanceof net.minecraft.world.level.levelgen.NoiseBasedChunkGenerator noise
+                && noise.generatorSettings().value().noiseSettings().equals(target.registryAccess()
+                .lookupOrThrow(Registries.NOISE_SETTINGS)
+                .getOrThrow(net.minecraft.world.level.levelgen.NoiseGeneratorSettings.CAVES)
+                .value().noiseSettings())) {
+            // The cave roof is not a valid arrival surface. Search down from
+            // Legacy's Y=64 start, then construct the normal safety platform
+            // at that height only when no footed opening can be found.
+            for (int radius = 0; radius <= 16; radius++) {
+                for (int x = -radius; x <= radius; x++) {
+                    for (int z = -radius; z <= radius; z++) {
+                        if (Math.max(Math.abs(x), Math.abs(z)) != radius) continue;
+                        for (int y = Math.min(64, target.getMaxY() - 2); y > target.getMinY(); y--) {
+                            BlockPos foot = new BlockPos(x, y, z);
+                            if (hasFooting(target, foot)) return foot;
+                        }
+                    }
+                }
+            }
+            return makePlatform(target, new BlockPos(0, 64, 0));
+        }
+        // A Flat Age has a known surface. Use it directly before a heightmap
+        // fallback can place a platform in the air above a low superflat world.
+        FlatLevelGeneratorSettings flatSettings = switch (generator) {
+            case FlatLevelSource flat -> flat.settings();
+            case PortFlatChunkGenerator flat -> flat.settings();
+            default -> null;
+        };
+        if (flatSettings != null && !flatSettings.getLayersInfo().isEmpty()) {
+            int surfaceY = target.getMinY() + flatSettings.getLayersInfo().stream()
+                    .mapToInt(layer -> layer.getHeight()).sum();
+            BlockPos surface = new BlockPos(0, surfaceY, 0);
+            if (hasFooting(target, surface)) return surface;
+        }
         for (int radius = 0; radius <= 16; radius++) {
             for (int x = -radius; x <= radius; x++) {
                 for (int z = -radius; z <= radius; z++) {
                     if (Math.max(Math.abs(x), Math.abs(z)) != radius) continue;
                     int y = target.getHeight(Heightmap.Types.MOTION_BLOCKING, x, z);
                     BlockPos foot = new BlockPos(x, y, z);
-                    BlockPos floor = foot.below();
-                    if (target.getBlockState(floor).isFaceSturdy(target, floor, Direction.UP)
-                            && target.getBlockState(foot).getCollisionShape(target, foot).isEmpty()
-                            && target.getBlockState(foot.above()).getCollisionShape(target, foot.above()).isEmpty()) {
+                    if (hasFooting(target, foot)) {
                         return foot;
                     }
                 }
@@ -50,14 +85,34 @@ public final class PortAgeTravel {
         // origin is ocean or foliage. Final book landing rules are ported later.
         int y = Math.max(64, target.getHeight(Heightmap.Types.MOTION_BLOCKING, 0, 0) + 2);
         if (y + 2 >= target.getMaxY()) return null;
-        BlockPos foot = new BlockPos(0, y, 0);
+        return makePlatform(target, new BlockPos(0, y, 0));
+    }
+
+    private static BlockPos makePlatform(ServerLevel target, BlockPos foot) {
+        if (foot.getY() <= target.getMinY() || foot.getY() + 2 >= target.getMaxY()) return null;
+        // A carved pocket inside a flooded cave immediately refills. Refuse
+        // that landing instead of placing the player in submerged spawn space.
+        if (!target.getFluidState(foot).isEmpty() || !target.getFluidState(foot.above()).isEmpty()) return null;
+        for (Direction direction : Direction.Plane.HORIZONTAL) {
+            if (!target.getFluidState(foot.relative(direction)).isEmpty()
+                    || !target.getFluidState(foot.above().relative(direction)).isEmpty()) return null;
+        }
         for (int x = -1; x <= 1; x++) {
             for (int z = -1; z <= 1; z++) {
-                target.setBlock(new BlockPos(x, y - 1, z), Rivencraft.CRYSTAL_BLOCK.get().defaultBlockState(), 3);
+                target.setBlock(foot.offset(x, -1, z), Rivencraft.CRYSTAL_BLOCK.get().defaultBlockState(), 3);
             }
         }
         target.setBlock(foot, Blocks.AIR.defaultBlockState(), 3);
         target.setBlock(foot.above(), Blocks.AIR.defaultBlockState(), 3);
         return foot;
     }
+
+    private static boolean hasFooting(ServerLevel target, BlockPos foot) {
+        BlockPos floor = foot.below();
+        return target.getBlockState(floor).isFaceSturdy(target, floor, Direction.UP)
+                && target.getFluidState(foot).isEmpty()
+                && target.getFluidState(foot.above()).isEmpty()
+                && target.getBlockState(foot).getCollisionShape(target, foot).isEmpty()
+                && target.getBlockState(foot.above()).getCollisionShape(target, foot.above()).isEmpty();
+    }
 }

ports/mc263/src/main/java/net/dnorberg/rivencraft/age/PortBiomePlan.java

@@ -0,0 +1,25 @@
+package net.dnorberg.rivencraft.age;
+
+import com.mojang.serialization.Codec;
+import com.mojang.serialization.codecs.RecordCodecBuilder;
+import java.util.List;
+import net.minecraft.resources.Identifier;
+
+/** Frozen authored biome choice; repeated entries retain their selection weight. */
+public record PortBiomePlan(Distribution distribution, List<Identifier> biomes) {
+    public enum Distribution { NATIVE, SINGLE, TILED, GRID, TINY, SMALL, MEDIUM, LARGE, HUGE }
+
+    public static final Codec<PortBiomePlan> CODEC = RecordCodecBuilder.create(instance -> instance.group(
+            Codec.STRING.xmap(Distribution::valueOf, Distribution::name).fieldOf("distribution")
+                    .forGetter(PortBiomePlan::distribution),
+            Identifier.CODEC.listOf().fieldOf("biomes").forGetter(PortBiomePlan::biomes)
+    ).apply(instance, PortBiomePlan::new));
+
+    public PortBiomePlan {
+        biomes = List.copyOf(biomes);
+        if (distribution == Distribution.NATIVE && !biomes.isEmpty()
+                || distribution == Distribution.SINGLE && biomes.size() != 1
+                || distribution != Distribution.NATIVE && distribution != Distribution.SINGLE && biomes.size() < 2)
+            throw new IllegalArgumentException("Invalid authored biome distribution");
+    }
+}

ports/mc263/src/main/java/net/dnorberg/rivencraft/age/PortFlatChunkGenerator.java

@@ -0,0 +1,142 @@
+package net.dnorberg.rivencraft.age;
+
+import com.mojang.serialization.MapCodec;
+import com.mojang.serialization.codecs.RecordCodecBuilder;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.CompletableFuture;
+import java.util.stream.Stream;
+import net.minecraft.core.BlockPos;
+import net.minecraft.core.Holder;
+import net.minecraft.core.HolderLookup;
+import net.minecraft.core.HolderSet;
+import net.minecraft.server.level.WorldGenRegion;
+import net.minecraft.world.level.LevelHeightAccessor;
+import net.minecraft.world.level.NoiseColumn;
+import net.minecraft.world.level.StructureManager;
+import net.minecraft.world.level.biome.Biome;
+import net.minecraft.world.level.biome.BiomeGenerationSettings;
+import net.minecraft.world.level.biome.BiomeManager;
+import net.minecraft.world.level.biome.BiomeSource;
+import net.minecraft.world.level.block.Blocks;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.level.chunk.ChunkAccess;
+import net.minecraft.world.level.chunk.ChunkGenerator;
+import net.minecraft.world.level.chunk.ChunkGeneratorStructureState;
+import net.minecraft.world.level.levelgen.GenerationStep;
+import net.minecraft.world.level.levelgen.Heightmap;
+import net.minecraft.world.level.levelgen.RandomState;
+import net.minecraft.world.level.levelgen.blending.Blender;
+import net.minecraft.world.level.levelgen.densityfunction.SamplerContext;
+import net.minecraft.world.level.levelgen.flat.FlatLevelGeneratorSettings;
+import net.minecraft.world.level.levelgen.placement.PlacedFeature;
+import net.minecraft.world.level.levelgen.structure.StructureSet;
+import net.neoforged.neoforge.common.util.MemoizedFunction;
+import org.jspecify.annotations.Nullable;
+
+/** Flat layers with the authored biome distribution used by 1.21.1 Ages. */
+public final class PortFlatChunkGenerator extends ChunkGenerator {
+    public static final MapCodec<PortFlatChunkGenerator> CODEC = RecordCodecBuilder.mapCodec(instance -> instance.group(
+            BiomeSource.CODEC.fieldOf("biome_source").forGetter(generator -> generator.biomeSource),
+            FlatLevelGeneratorSettings.CODEC.fieldOf("settings").forGetter(PortFlatChunkGenerator::settings)
+    ).apply(instance, PortFlatChunkGenerator::new));
+
+    private final FlatLevelGeneratorSettings settings;
+    private final MemoizedFunction<Holder<Biome>, BiomeGenerationSettings> generationSettingsGetter;
+
+    public PortFlatChunkGenerator(BiomeSource biomeSource, FlatLevelGeneratorSettings settings) {
+        super(biomeSource, this.generationSettingsGetter = MemoizedFunction.of(
+                biome -> generationSettings(settings, biome)));
+        this.settings = settings;
+    }
+
+    public FlatLevelGeneratorSettings settings() {
+        return settings;
+    }
+
+    private static BiomeGenerationSettings generationSettings(FlatLevelGeneratorSettings settings, Holder<Biome> biome) {
+        // Void biomes still control climate, but must not place terrain features.
+        if (settings.getLayersInfo().isEmpty()) return BiomeGenerationSettings.EMPTY;
+        if (biome.equals(settings.getBiome())) return settings.adjustGenerationSettings(biome);
+        BiomeGenerationSettings.PlainBuilder builder = new BiomeGenerationSettings.PlainBuilder();
+        List<HolderSet<PlacedFeature>> features = biome.value().getGenerationSettings().features();
+        for (int step = 0; step < features.size(); step++) {
+            if (step == GenerationStep.Decoration.UNDERGROUND_STRUCTURES.ordinal()
+                    || step == GenerationStep.Decoration.SURFACE_STRUCTURES.ordinal()) continue;
+            for (Holder<PlacedFeature> feature : features.get(step)) builder.addFeature(step, feature);
+        }
+        return builder.build();
+    }
+
+    @Override
+    protected MapCodec<? extends ChunkGenerator> codec() {
+        return CODEC;
+    }
+
+    @Override
+    public ChunkGeneratorStructureState createState(HolderLookup<StructureSet> structures,
+                                                    RandomState random, long seed) {
+        Stream<Holder<StructureSet>> entries = settings.structureOverrides()
+                .map(HolderSet::stream)
+                .orElseGet(() -> structures.listElements().map(holder -> (Holder<StructureSet>) holder));
+        return ChunkGeneratorStructureState.createForFlat(random, seed, getOrigin(random), biomeSource, entries);
+    }
+
+    @Override
+    public int getSpawnHeight(LevelHeightAccessor height) {
+        return height.getMinY() + Math.min(height.getHeight(), settings.getLayers().size());
+    }
+
+    @Override
+    public CompletableFuture<ChunkAccess> buildTerrain(ChunkAccess chunk, Blender blender,
+            RandomState random, StructureManager structures, BiomeManager biomes,
+            @Nullable WorldGenRegion carverBiomeRegion, Set<Holder<Biome>> possibleBiomes) {
+        List<BlockState> layers = settings.getLayers();
+        BlockPos.MutableBlockPos pos = new BlockPos.MutableBlockPos();
+        Heightmap floor = chunk.getOrCreateHeightmapUnprimed(Heightmap.Types.OCEAN_FLOOR_WG);
+        Heightmap surface = chunk.getOrCreateHeightmapUnprimed(Heightmap.Types.WORLD_SURFACE_WG);
+        for (int layer = 0; layer < Math.min(chunk.getHeight(), layers.size()); layer++) {
+            BlockState state = layers.get(layer);
+            if (state == null) continue;
+            int y = chunk.getMinY() + layer;
+            for (int x = 0; x < 16; x++) for (int z = 0; z < 16; z++) {
+                chunk.setBlockState(pos.set(x, y, z), state);
+                floor.update(x, y, z, state);
+                surface.update(x, y, z, state);
+            }
+        }
+        return CompletableFuture.completedFuture(chunk);
+    }
+
+    @Override
+    public int getBaseHeight(int x, int z, Heightmap.Types type,
+                             LevelHeightAccessor height, RandomState random) {
+        List<BlockState> layers = settings.getLayers();
+        for (int layer = Math.min(layers.size() - 1, height.getHeight() - 1); layer >= 0; layer--) {
+            BlockState state = layers.get(layer);
+            if (state != null && type.isOpaque().test(state)) return height.getMinY() + layer + 1;
+        }
+        return height.getMinY();
+    }
+
+    @Override
+    public NoiseColumn getBaseColumn(int x, int z, LevelHeightAccessor height, RandomState random) {
+        return new NoiseColumn(height.getMinY(), settings.getLayers().stream().limit(height.getHeight())
+                .map(state -> state == null ? Blocks.AIR.defaultBlockState() : state)
+                .toArray(BlockState[]::new));
+    }
+
+    @Override public void addDebugScreenInfo(List<String> info, RandomState random,
+                                             BlockPos pos, SamplerContext context) { }
+    @Override public void spawnOriginalMobs(WorldGenRegion level) { }
+    @Override public int getMinY() { return 0; }
+    @Override public int getGenDepth() { return 384; }
+    @Override public int getSeaLevel() { return -63; }
+
+    @Override
+    public void refreshFeaturesPerStep() {
+        super.refreshFeaturesPerStep();
+        generationSettingsGetter.clear();
+        settings.updateLayers();
+    }
+}

ports/mc263/src/main/java/net/dnorberg/rivencraft/age/PortRandomAgeSelection.java

@@ -0,0 +1,81 @@
+package net.dnorberg.rivencraft.age;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+import java.util.Random;
+import net.dnorberg.rivencraft.writing.PortRegistryPages;
+import net.minecraft.core.registries.Registries;
+import net.minecraft.resources.Identifier;
+import net.minecraft.server.MinecraftServer;
+
+/** Seed-frozen terrain and biome choices for a book with no authored symbols. */
+public final class PortRandomAgeSelection {
+    private PortRandomAgeSelection() {}
+
+    public record Selection(PortAgeTerrain terrain, PortBiomePlan biomes) {}
+
+    public static Selection select(MinecraftServer server, long seed) {
+        // Match the 1.21.1 Legacy-rank choices: Standard and Flat are common;
+        // the other terrain families are rarer. The sorted order is deliberate.
+        PortAgeTerrain terrain = weighted(new Random(seed ^ 0x5445525241494E4CL),
+                List.of(PortAgeTerrain.AMPLIFIED, PortAgeTerrain.CAVE, PortAgeTerrain.FLAT,
+                        PortAgeTerrain.ISLAND, PortAgeTerrain.STANDARD, PortAgeTerrain.VOID),
+                new int[]{1, 1, 5, 1, 6, 1});
+        if (terrain == PortAgeTerrain.VOID)
+            return new Selection(terrain, new PortBiomePlan(PortBiomePlan.Distribution.SINGLE,
+                    List.of(Identifier.withDefaultNamespace("the_void"))));
+
+        PortBiomePlan.Distribution distribution = weighted(new Random(seed ^ 0x524956454E435241L),
+                List.of(PortBiomePlan.Distribution.NATIVE, PortBiomePlan.Distribution.SINGLE,
+                        PortBiomePlan.Distribution.MEDIUM, PortBiomePlan.Distribution.TILED,
+                        PortBiomePlan.Distribution.GRID, PortBiomePlan.Distribution.TINY,
+                        PortBiomePlan.Distribution.SMALL, PortBiomePlan.Distribution.LARGE,
+                        PortBiomePlan.Distribution.HUGE),
+                new int[]{3, 3, 3, 1, 1, 1, 1, 1, 1});
+        List<Identifier> eligible = eligibleBiomes(server, terrain);
+        if (eligible.size() < 2 && distribution != PortBiomePlan.Distribution.NATIVE)
+            distribution = PortBiomePlan.Distribution.SINGLE;
+        // 26.3 has no native multi-cave biome source; choose a seeded Cave
+        // biome rather than silently using Lush Caves for every random Age.
+        if (terrain == PortAgeTerrain.CAVE && distribution == PortBiomePlan.Distribution.NATIVE)
+            distribution = PortBiomePlan.Distribution.SINGLE;
+        if (distribution == PortBiomePlan.Distribution.NATIVE)
+            return new Selection(terrain, new PortBiomePlan(distribution, List.of()));
+
+        int count = distribution == PortBiomePlan.Distribution.SINGLE ? 1 : 2;
+        if (count > 1) {
+            Random countRandom = new Random(seed ^ 0x42494F4D45434F55L);
+            while (count < eligible.size() && countRandom.nextInt(3) != 0) count++;
+        }
+        List<Identifier> shuffled = new ArrayList<>(eligible);
+        Collections.shuffle(shuffled, new Random(seed ^ 0x42494F4D45504F4FL));
+        return new Selection(terrain, new PortBiomePlan(distribution, shuffled.subList(0, count)));
+    }
+
+    private static List<Identifier> eligibleBiomes(MinecraftServer server, PortAgeTerrain terrain) {
+        if (terrain == PortAgeTerrain.CAVE) {
+            List<Identifier> caves = server.registryAccess().lookupOrThrow(Registries.BIOME).listElements()
+                    .filter(PortRegistryPages::isCaveBiome)
+                    .map(holder -> holder.key().identifier())
+                    .sorted().toList();
+            return caves.isEmpty() ? List.of(Identifier.withDefaultNamespace("lush_caves")) : caves;
+        }
+        List<Identifier> surface = server.overworld().getChunkSource().getGenerator().getBiomeSource()
+                .possibleBiomes().stream().flatMap(holder -> holder.unwrapKey().stream())
+                .map(key -> key.identifier()).distinct().sorted(Comparator.naturalOrder()).toList();
+        return surface.isEmpty() ? List.of(Identifier.withDefaultNamespace("plains")) : surface;
+    }
+
+    private static <T> T weighted(Random random, List<T> choices, int[] weights) {
+        int total = 0;
+        for (int weight : weights) total += weight;
+        int ticket = random.nextInt(total);
+        for (int index = 0; index < choices.size(); index++) {
+            ticket -= weights[index];
+            if (ticket < 0) return choices.get(index);
+        }
+        throw new IllegalStateException("Random Age ticket was not consumed");
+    }
+}

ports/mc263/src/main/java/net/dnorberg/rivencraft/age/PortRockChunkGenerator.java

@@ -0,0 +1,134 @@
+package net.dnorberg.rivencraft.age;
+
+import com.mojang.serialization.MapCodec;
+import com.mojang.serialization.codecs.RecordCodecBuilder;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.CompletableFuture;
+import net.minecraft.core.BlockPos;
+import net.minecraft.core.Holder;
+import net.minecraft.core.HolderLookup;
+import net.minecraft.core.RegistryAccess;
+import net.minecraft.core.registries.BuiltInRegistries;
+import net.minecraft.resources.Identifier;
+import net.minecraft.resources.ResourceKey;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.server.level.WorldGenRegion;
+import net.minecraft.util.RandomSource;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.LevelHeightAccessor;
+import net.minecraft.world.level.NoiseColumn;
+import net.minecraft.world.level.StructureManager;
+import net.minecraft.world.level.WorldGenLevel;
+import net.minecraft.world.level.biome.Biome;
+import net.minecraft.world.level.biome.BiomeManager;
+import net.minecraft.world.level.chunk.ChunkAccess;
+import net.minecraft.world.level.chunk.ChunkGenerator;
+import net.minecraft.world.level.chunk.ChunkGeneratorStructureState;
+import net.minecraft.world.level.levelgen.Heightmap;
+import net.minecraft.world.level.levelgen.RandomState;
+import net.minecraft.world.level.levelgen.blending.Blender;
+import net.minecraft.world.level.levelgen.densityfunction.SamplerContext;
+import net.minecraft.world.level.levelgen.structure.StructureSet;
+import net.minecraft.world.level.levelgen.structure.Structure;
+import net.minecraft.world.level.levelgen.structure.templatesystem.StructureTemplateManager;
+import com.mojang.datafixers.util.Pair;
+import net.minecraft.core.HolderSet;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.block.state.BlockState;
+
+/** Delegates 26.3 terrain generation and adds one Age-scoped Rocks decoration. */
+public final class PortRockChunkGenerator extends ChunkGenerator {
+    public static final MapCodec<PortRockChunkGenerator> CODEC = RecordCodecBuilder.mapCodec(instance -> instance.group(
+            ChunkGenerator.CODEC.fieldOf("base").forGetter(generator -> generator.base),
+            PortRockPlan.CODEC.fieldOf("rocks").forGetter(generator -> generator.rocks),
+            com.mojang.serialization.Codec.LONG.fieldOf("age_seed").forGetter(generator -> generator.ageSeed)
+    ).apply(instance, PortRockChunkGenerator::new));
+
+    private final ChunkGenerator base;
+    private final PortRockPlan rocks;
+    private final long ageSeed;
+
+    public PortRockChunkGenerator(ChunkGenerator base, PortRockPlan rocks, long ageSeed) {
+        super(base.getBiomeSource(), base::getBiomeGenerationSettings);
+        this.base = base;
+        this.rocks = rocks;
+        this.ageSeed = ageSeed;
+    }
+
+    public ChunkGenerator base() { return base; }
+    public PortRockPlan rocks() { return rocks; }
+
+    @Override protected MapCodec<? extends ChunkGenerator> codec() { return CODEC; }
+    @Override public void validate() { base.validate(); }
+    @Override public ChunkPos getOrigin(RandomState random) { return base.getOrigin(random); }
+    @Override public java.util.Optional<Identifier> getTypeNameForDataFixer() { return base.getTypeNameForDataFixer(); }
+    @Override public CompletableFuture<ChunkAccess> createBiomes(RandomState random, Blender blender,
+                                                                  StructureManager structures, ChunkAccess chunk) {
+        return base.createBiomes(random, blender, structures, chunk);
+    }
+    @Override public ChunkGeneratorStructureState createState(HolderLookup<StructureSet> sets,
+                                                               RandomState random, long seed) {
+        return base.createState(sets, random, seed);
+    }
+    @Override public void createStructures(RegistryAccess registries, ChunkGeneratorStructureState state,
+                                           StructureManager structures, ChunkAccess chunk,
+                                           StructureTemplateManager templates, ResourceKey<Level> dimension) {
+        base.createStructures(registries, state, structures, chunk, templates, dimension);
+    }
+    @Override public void createReferences(WorldGenLevel level, StructureManager structures, ChunkAccess chunk) {
+        base.createReferences(level, structures, chunk);
+    }
+    @Override public Pair<BlockPos, Holder<Structure>> findNearestMapStructure(ServerLevel level,
+            HolderSet<Structure> targets, BlockPos origin, int radius, boolean skipKnown) {
+        return base.findNearestMapStructure(level, targets, origin, radius, skipKnown);
+    }
+    @Override public void spawnOriginalMobs(WorldGenRegion level) { base.spawnOriginalMobs(level); }
+    @Override public int getSpawnHeight(LevelHeightAccessor height) { return base.getSpawnHeight(height); }
+    @Override public int getGenDepth() { return base.getGenDepth(); }
+    @Override public int getSeaLevel() { return base.getSeaLevel(); }
+    @Override public int getMinY() { return base.getMinY(); }
+    @Override public CompletableFuture<ChunkAccess> buildTerrain(ChunkAccess chunk, Blender blender,
+            RandomState random, StructureManager structures, BiomeManager biomes,
+            WorldGenRegion carverBiomeRegion, Set<Holder<Biome>> possibleBiomes) {
+        return base.buildTerrain(chunk, blender, random, structures, biomes, carverBiomeRegion, possibleBiomes);
+    }
+    @Override public int getBaseHeight(int x, int z, Heightmap.Types type,
+                                       LevelHeightAccessor height, RandomState random) {
+        return base.getBaseHeight(x, z, type, height, random);
+    }
+    @Override public NoiseColumn getBaseColumn(int x, int z, LevelHeightAccessor height, RandomState random) {
+        return base.getBaseColumn(x, z, height, random);
+    }
+    @Override public void addDebugScreenInfo(List<String> info, RandomState random,
+                                              BlockPos pos, SamplerContext context) {
+        base.addDebugScreenInfo(info, random, pos, context);
+    }
+    @Override public void refreshFeaturesPerStep() {
+        base.refreshFeaturesPerStep();
+        super.refreshFeaturesPerStep();
+    }
+
+    @Override public void applyBiomeDecoration(WorldGenLevel level, ChunkAccess chunk,
+                                                StructureManager structures) {
+        base.applyBiomeDecoration(level, chunk, structures);
+        ChunkPos chunkPos = chunk.getPos();
+        long seed = ageSeed ^ (long) chunkPos.x() * 341873128712L ^ (long) chunkPos.z() * 132897987541L;
+        RandomSource random = RandomSource.create(seed);
+        if (random.nextInt(5) != 0) return;
+        BlockState material = BuiltInRegistries.BLOCK.getValue(rocks.material()).defaultBlockState();
+        int centerX = chunkPos.getMinBlockX() + 2 + random.nextInt(12);
+        int centerZ = chunkPos.getMinBlockZ() + 2 + random.nextInt(12);
+        for (int dx = -1; dx <= 1; dx++) for (int dz = -1; dz <= 1; dz++) {
+            if (random.nextInt(4) == 0) continue;
+            int x = centerX + dx;
+            int z = centerZ + dz;
+            int y = level.getHeight(Heightmap.Types.WORLD_SURFACE_WG, x, z);
+            BlockPos place = new BlockPos(x, y, z);
+            if (level.getBlockState(place).isAir()
+                    && level.getFluidState(place).isEmpty()
+                    && level.getBlockState(place.below()).isFaceSturdy(level, place.below(), net.minecraft.core.Direction.UP))
+                level.setBlock(place, material, 2);
+        }
+    }
+}

ports/mc263/src/main/java/net/dnorberg/rivencraft/age/PortRockPlan.java

@@ -0,0 +1,12 @@
+package net.dnorberg.rivencraft.age;
+
+import com.mojang.serialization.Codec;
+import com.mojang.serialization.codecs.RecordCodecBuilder;
+import net.minecraft.resources.Identifier;
+
+/** First frozen authored feature: one Rocks page with an explicit block material. */
+public record PortRockPlan(Identifier material) {
+    public static final Codec<PortRockPlan> CODEC = RecordCodecBuilder.create(instance -> instance.group(
+            Identifier.CODEC.fieldOf("material").forGetter(PortRockPlan::material)
+    ).apply(instance, PortRockPlan::new));
+}

ports/mc263/src/main/java/net/dnorberg/rivencraft/age/PortScaledBiomeSource.java

@@ -0,0 +1,91 @@
+package net.dnorberg.rivencraft.age;
+
+import com.mojang.serialization.Codec;
+import com.mojang.serialization.MapCodec;
+import com.mojang.serialization.codecs.RecordCodecBuilder;
+import java.util.stream.Stream;
+import net.minecraft.core.Holder;
+import net.minecraft.core.HolderSet;
+import net.minecraft.world.level.biome.Biome;
+import net.minecraft.world.level.biome.BiomeResolver;
+import net.minecraft.world.level.biome.BiomeSource;
+import net.minecraft.world.level.biome.Climate;
+
+/** 26.3 resolver port of the seeded 1.21.1 Mystcraft-style region distribution. */
+public final class PortScaledBiomeSource extends BiomeSource implements BiomeResolver {
+    public static final MapCodec<PortScaledBiomeSource> CODEC = RecordCodecBuilder.mapCodec(instance -> instance.group(
+            Biome.LIST_CODEC.fieldOf("biomes").forGetter(source -> source.biomes),
+            Codec.LONG.fieldOf("seed").forGetter(source -> source.seed),
+            Codec.intRange(0, 4).fieldOf("scale").forGetter(source -> source.scale)
+    ).apply(instance, PortScaledBiomeSource::new));
+
+    private final HolderSet<Biome> biomes;
+    private final long seed;
+    private final int scale;
+    private final int cellWidth;
+
+    public PortScaledBiomeSource(HolderSet<Biome> biomes, long seed, int scale) {
+        if (biomes.size() < 2 || scale < 0 || scale > 4)
+            throw new IllegalArgumentException("Scaled regions need two biomes and scale 0..4");
+        this.biomes = biomes;
+        this.seed = seed;
+        this.scale = scale;
+        // Quart coordinates; Tiny starts at 16 blocks and each scale doubles.
+        this.cellWidth = 4 << scale;
+    }
+
+    @Override
+    protected MapCodec<? extends BiomeSource> codec() {
+        return CODEC;
+    }
+
+    @Override
+    protected Stream<Holder<Biome>> collectPossibleBiomes() {
+        return biomes.stream();
+    }
+
+    @Override
+    public BiomeResolver createResolver(Climate.Sampler sampler) {
+        return this;
+    }
+
+    @Override
+    public Holder<Biome> getNoiseBiome(int x, int y, int z) {
+        int baseX = Math.floorDiv(x, cellWidth);
+        int baseZ = Math.floorDiv(z, cellWidth);
+        int closestX = baseX;
+        int closestZ = baseZ;
+        double closestDistance = Double.POSITIVE_INFINITY;
+        for (int cellX = baseX - 1; cellX <= baseX + 1; cellX++) {
+            for (int cellZ = baseZ - 1; cellZ <= baseZ + 1; cellZ++) {
+                long cellSeed = mix(seed, cellX, cellZ);
+                double centerX = (cellX + 0.5D + jitter(cellSeed) * 0.8D) * cellWidth;
+                double centerZ = (cellZ + 0.5D + jitter(mix64(cellSeed)) * 0.8D) * cellWidth;
+                double deltaX = x - centerX;
+                double deltaZ = z - centerZ;
+                double distance = deltaX * deltaX + deltaZ * deltaZ;
+                if (distance < closestDistance) {
+                    closestDistance = distance;
+                    closestX = cellX;
+                    closestZ = cellZ;
+                }
+            }
+        }
+        return biomes.get(Math.floorMod((int) mix(seed ^ 0x42494F4D45534CL,
+                closestX, closestZ), biomes.size()));
+    }
+
+    private static double jitter(long value) {
+        return ((value >>> 11) * 0x1.0p-53) - 0.5D;
+    }
+
+    private static long mix(long seed, int x, int z) {
+        return mix64(seed ^ (long) x * 0x9E3779B97F4A7C15L ^ (long) z * 0xC2B2AE3D27D4EB4FL);
+    }
+
+    private static long mix64(long value) {
+        value = (value ^ value >>> 30) * 0xBF58476D1CE4E5B9L;
+        value = (value ^ value >>> 27) * 0x94D049BB133111EBL;
+        return value ^ value >>> 31;
+    }
+}

ports/mc263/src/main/java/net/dnorberg/rivencraft/age/RuntimeAgeBackend.java

@@ -8,9 +8,13 @@ import java.nio.file.Path;
 import java.nio.file.StandardCopyOption;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.OptionalLong;
 import net.dnorberg.rivencraft.Rivencraft;
+import net.dnorberg.rivencraft.writing.PortRegistryPages;
 import net.minecraft.core.registries.Registries;
+import net.minecraft.core.Holder;
+import net.minecraft.core.HolderSet;
 import net.minecraft.resources.Identifier;
 import net.minecraft.resources.ResourceKey;
 import net.minecraft.server.MinecraftServer;
@@ -18,7 +22,18 @@ import net.minecraft.server.level.ServerLevel;
 import net.minecraft.world.level.Level;
 import net.minecraft.world.level.TicketStorage;
 import net.minecraft.world.level.biome.BiomeManager;
+import net.minecraft.world.level.biome.BiomeSource;
+import net.minecraft.world.level.biome.FixedBiomeSource;
+import net.minecraft.world.level.biome.Biome;
+import net.minecraft.world.level.biome.Biomes;
+import net.minecraft.world.level.biome.CheckerboardColumnBiomeSource;
 import net.minecraft.world.level.dimension.LevelStem;
+import net.minecraft.world.level.levelgen.FlatLevelSource;
+import net.minecraft.world.level.levelgen.NoiseBasedChunkGenerator;
+import net.minecraft.world.level.levelgen.NoiseGeneratorSettings;
+import net.minecraft.world.level.levelgen.flat.FlatLevelGeneratorSettings;
+import net.minecraft.world.level.levelgen.flat.FlatLayerInfo;
+import net.minecraft.world.level.block.Blocks;
 import net.minecraft.world.level.storage.DerivedLevelData;
 import net.minecraft.world.level.storage.LevelResource;
 import net.neoforged.neoforge.common.NeoForge;
@@ -41,7 +56,8 @@ public final class RuntimeAgeBackend {
         AgeLevelIndex index = index(server);
         for (Map.Entry<Identifier, Long> age : index.entries().entrySet()) {
             try {
-                load(server, age.getKey(), age.getValue());
+                load(server, age.getKey(), age.getValue(), index.biomePlan(age.getKey()),
+                        index.terrain(age.getKey()), index.rocks(age.getKey()));
             } catch (RuntimeException exception) {
                 Rivencraft.LOGGER.error("Could not restore Age {}. Its saved index remains intact.", age.getKey(), exception);
             }
@@ -50,12 +66,26 @@ public final class RuntimeAgeBackend {
 
     /** Creates a server level, then commits its identity only after successful construction. */
     public static ServerLevel create(MinecraftServer server, Identifier id, long seed) {
+        return create(server, id, seed, null);
+    }
+
+    public static ServerLevel create(MinecraftServer server, Identifier id, long seed, PortBiomePlan biomePlan) {
+        return create(server, id, seed, biomePlan, PortAgeTerrain.STANDARD);
+    }
+
+    public static ServerLevel create(MinecraftServer server, Identifier id, long seed,
+                                     PortBiomePlan biomePlan, PortAgeTerrain terrain) {
+        return create(server, id, seed, biomePlan, terrain, null);
+    }
+
+    public static ServerLevel create(MinecraftServer server, Identifier id, long seed,
+                                     PortBiomePlan biomePlan, PortAgeTerrain terrain, PortRockPlan rocks) {
         checkServerThread(server);
         ageName(id);
         AgeLevelIndex index = index(server);
         if (index.contains(id)) throw new IllegalArgumentException("Age already exists: " + id);
-        ServerLevel level = load(server, id, seed);
-        index.add(id, seed);
+        ServerLevel level = load(server, id, seed, biomePlan, terrain, rocks);
+        index.add(id, seed, biomePlan, terrain, rocks);
         // A newly bound book may be used immediately. Persist its Age identity
         // before publishing the catalog so a later crash cannot leave that
         // book pointing at a world omitted from the on-disk index.
@@ -75,7 +105,8 @@ public final class RuntimeAgeBackend {
     public static ServerLevel reload(MinecraftServer server, Identifier id) {
         checkServerThread(server);
         long seed = requireSeed(server, id);
-        ServerLevel level = load(server, id, seed);
+        ServerLevel level = load(server, id, seed, index(server).biomePlan(id), index(server).terrain(id),
+                index(server).rocks(id));
         AgeCatalogSync.onCatalogChanged(server);
         return level;
     }
@@ -85,18 +116,21 @@ public final class RuntimeAgeBackend {
         checkServerThread(server);
         AgeLevelIndex index = index(server);
         long previousSeed = requireSeed(server, id);
+        PortBiomePlan biomePlan = index.biomePlan(id);
+        PortAgeTerrain terrain = index.terrain(id);
+        PortRockPlan rocks = index.rocks(id);
         if (previousSeed == seed) return;
         boolean loaded = server.getLevel(dimensionKey(id)) != null;
         if (loaded) unloadLoaded(server, id);
         try {
-            if (loaded) load(server, id, seed);
+            if (loaded) load(server, id, seed, biomePlan, terrain, rocks);
             index.reseed(id, seed);
             server.overworld().getDataStorage().saveAndJoin();
             if (loaded) AgeCatalogSync.onCatalogChanged(server);
         } catch (RuntimeException exception) {
             if (loaded) {
                 try {
-                    load(server, id, previousSeed);
+                    load(server, id, previousSeed, biomePlan, terrain, rocks);
                     AgeCatalogSync.onCatalogChanged(server);
                 } catch (RuntimeException rollbackFailure) {
                     exception.addSuppressed(rollbackFailure);
@@ -112,6 +146,9 @@ public final class RuntimeAgeBackend {
         String name = ageName(id);
         AgeLevelIndex index = index(server);
         long seed = requireSeed(server, id);
+        PortBiomePlan biomePlan = index.biomePlan(id);
+        PortAgeTerrain terrain = index.terrain(id);
+        PortRockPlan rocks = index.rocks(id);
         boolean loaded = server.getLevel(dimensionKey(id)) != null;
         ArchivePaths paths = archivePaths(server, name);
         if (loaded) unloadLoaded(server, id);
@@ -130,14 +167,14 @@ public final class RuntimeAgeBackend {
             }
         } catch (IOException | RuntimeException exception) {
             try {
-                index.restoreAfterFailedRetirement(id, seed);
+                index.restoreAfterFailedRetirement(id, seed, biomePlan, terrain, rocks);
                 server.overworld().getDataStorage().saveAndJoin();
             } catch (RuntimeException rollbackFailure) {
                 exception.addSuppressed(rollbackFailure);
             }
             if (loaded) {
                 try {
-                    load(server, id, seed);
+                    load(server, id, seed, biomePlan, terrain, rocks);
                 } catch (RuntimeException rollbackFailure) {
                     exception.addSuppressed(rollbackFailure);
                 }
@@ -233,17 +270,99 @@ public final class RuntimeAgeBackend {
     private record ArchivePaths(Path live, Path archive) {
     }
 
-    private static ServerLevel load(MinecraftServer server, Identifier id, long seed) {
+    private static BiomeSource authoredBiomeSource(MinecraftServer server, PortBiomePlan plan, long seed) {
+        if (plan.distribution() == PortBiomePlan.Distribution.NATIVE)
+            throw new IllegalArgumentException("Native biome distribution has no authored source");
+        var registry = server.registryAccess().lookupOrThrow(Registries.BIOME);
+        List<Holder<Biome>> biomes = plan.biomes().stream().map(id ->
+                (Holder<Biome>) registry.get(ResourceKey.create(Registries.BIOME, id))
+                        .orElseThrow(() -> new IllegalArgumentException("Unknown authored biome: " + id)))
+                .toList();
+        return switch (plan.distribution()) {
+            case NATIVE -> throw new IllegalStateException("Native is not an override");
+            case SINGLE -> new FixedBiomeSource(biomes.getFirst());
+            case TILED, GRID -> new CheckerboardColumnBiomeSource(HolderSet.direct(biomes),
+                    plan.distribution() == PortBiomePlan.Distribution.GRID ? 0 : 4);
+            case TINY, SMALL, MEDIUM, LARGE, HUGE -> new PortScaledBiomeSource(
+                    HolderSet.direct(biomes), seed, plan.distribution().ordinal() -
+                            PortBiomePlan.Distribution.TINY.ordinal());
+        };
+    }
+
+    private static ServerLevel load(MinecraftServer server, Identifier id, long seed,
+                                    PortBiomePlan biomePlan, PortAgeTerrain terrain, PortRockPlan rocks) {
         ResourceKey<Level> key = ResourceKey.create(Registries.DIMENSION, id);
         if (server.getLevel(key) != null) throw new IllegalArgumentException("Level already loaded: " + id);
 
-        // This prototype uses vanilla Overworld terrain until issue #98 ports
-        // authored ChunkGenerators. LevelStem.seedOverride controls chunk random
-        // state as well as ServerLevel.getSeed() in NeoForge 26.3.
+        // Noise terrains reuse the Overworld biome source unless a
+        // non-Native authored distribution replaces it.
+        // LevelStem.seedOverride controls chunk random state and getSeed().
         LevelStem overworldStem = server.registryAccess().lookupOrThrow(Registries.LEVEL_STEM)
                 .getValue(LevelStem.OVERWORLD);
         if (overworldStem == null) throw new IllegalStateException("Missing Overworld LevelStem");
-        LevelStem stem = new LevelStem(overworldStem.type(), overworldStem.generator(), OptionalLong.of(seed));
+        var generator = overworldStem.generator();
+        if (terrain == PortAgeTerrain.FLAT || terrain == PortAgeTerrain.VOID) {
+            var biomes = server.registryAccess().lookupOrThrow(Registries.BIOME);
+            Holder<Biome> biome = biomes.getOrThrow(terrain == PortAgeTerrain.VOID
+                    ? Biomes.THE_VOID : Biomes.PLAINS);
+            if (biomePlan != null && !biomePlan.biomes().isEmpty()) {
+                Identifier biomeId = biomePlan.biomes().getFirst();
+                biome = biomes.get(ResourceKey.create(Registries.BIOME, biomeId))
+                        .orElseThrow(() -> new IllegalArgumentException("Unknown authored biome: " + biomeId));
+            }
+            FlatLevelGeneratorSettings settings;
+            if (terrain == PortAgeTerrain.FLAT) {
+                settings = FlatLevelGeneratorSettings.getDefault(biomes,
+                        server.registryAccess().lookupOrThrow(Registries.STRUCTURE_SET),
+                        server.registryAccess().lookupOrThrow(Registries.PLACED_FEATURE));
+                // Vanilla superflat begins at the modern minimum build height.
+                // Pad the column with air so the first solid layer begins at Y=0.
+                int airBelowZero = Math.max(0, -server.overworld().getMinY());
+                if (airBelowZero > 0)
+                    settings.getLayersInfo().addFirst(new FlatLayerInfo(airBelowZero, Blocks.AIR));
+                settings = settings.withBiomeAndLayers(settings.getLayersInfo(),
+                        settings.structureOverrides(), biome);
+                settings.setDecoration();
+            } else {
+                settings = new FlatLevelGeneratorSettings(Optional.empty(), biome, List.of());
+                settings.updateLayers();
+            }
+            generator = biomePlan != null && biomePlan.biomes().size() > 1
+                    ? new PortFlatChunkGenerator(authoredBiomeSource(server, biomePlan, seed), settings)
+                    : new FlatLevelSource(settings);
+        } else if ((biomePlan != null && biomePlan.distribution() != PortBiomePlan.Distribution.NATIVE)
+                || terrain != PortAgeTerrain.STANDARD) {
+            if (!(generator instanceof NoiseBasedChunkGenerator noise))
+                throw new IllegalStateException("Overworld generator cannot accept authored noise settings");
+            var source = terrain == PortAgeTerrain.CAVE
+                    ? new FixedBiomeSource(server.registryAccess().lookupOrThrow(Registries.BIOME)
+                            .getOrThrow(Biomes.LUSH_CAVES))
+                    : generator.getBiomeSource();
+            if (terrain == PortAgeTerrain.CAVE && biomePlan != null) {
+                var biomes = server.registryAccess().lookupOrThrow(Registries.BIOME);
+                for (Identifier biomeId : biomePlan.biomes()) {
+                    var holder = biomes.get(ResourceKey.create(Registries.BIOME, biomeId))
+                            .orElseThrow(() -> new IllegalArgumentException("Unknown authored biome: " + biomeId));
+                    if (!PortRegistryPages.isCaveBiome(holder))
+                        throw new IllegalArgumentException("Cave terrain requires a Cave or Nether biome: " + biomeId);
+                }
+            }
+            if (biomePlan != null && biomePlan.distribution() != PortBiomePlan.Distribution.NATIVE) {
+                source = authoredBiomeSource(server, biomePlan, seed);
+            }
+            var settings = switch (terrain) {
+                case STANDARD -> noise.generatorSettings();
+                case AMPLIFIED -> server.registryAccess().lookupOrThrow(Registries.NOISE_SETTINGS)
+                        .getOrThrow(NoiseGeneratorSettings.AMPLIFIED);
+                case ISLAND -> server.registryAccess().lookupOrThrow(Registries.NOISE_SETTINGS)
+                        .getOrThrow(NoiseGeneratorSettings.FLOATING_ISLANDS);
+                case CAVE -> dryCaveSettings(server);
+                case FLAT, VOID -> throw new IllegalStateException("Flat terrain should use FlatLevelSource");
+            };
+            generator = new NoiseBasedChunkGenerator(source, settings);
+        }
+        if (rocks != null) generator = new PortRockChunkGenerator(generator, rocks, seed);
+        LevelStem stem = new LevelStem(overworldStem.type(), generator, OptionalLong.of(seed));
         long biomeZoomSeed = BiomeManager.obfuscateSeed(server.getWorldGenSettings().options().seed());
         ServerLevel level = new ServerLevel(server, server.executor, server.storageSource,
                 new DerivedLevelData(server.getWorldData(), server.getWorldData().overworldData()),
@@ -273,4 +392,14 @@ public final class RuntimeAgeBackend {
             throw exception;
         }
     }
+
+    private static Holder<NoiseGeneratorSettings> dryCaveSettings(MinecraftServer server) {
+        NoiseGeneratorSettings caves = server.registryAccess().lookupOrThrow(Registries.NOISE_SETTINGS)
+                .getOrThrow(NoiseGeneratorSettings.CAVES).value();
+        return Holder.direct(new NoiseGeneratorSettings(
+                caves.noiseSettings(), caves.defaultBlock(), Blocks.AIR.defaultBlockState(),
+                caves.noiseRouter(), caves.materialRule(), caves.spawnTarget(),
+                caves.noiseSettings().minY() - 1, caves.disableMobGeneration(), Optional.empty(),
+                caves.useLegacyRandomSource(), caves.debugFunctions()));
+    }
 }

ports/mc263/src/main/java/net/dnorberg/rivencraft/block/entity/PortBookBinderBlockEntity.java

@@ -1,7 +1,10 @@
 package net.dnorberg.rivencraft.block.entity;
 
+import java.util.ArrayList;
+import java.util.List;
 import net.dnorberg.rivencraft.Rivencraft;
 import net.dnorberg.rivencraft.item.PageItem;
+import net.minecraft.resources.Identifier;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.NonNullList;
 import net.minecraft.world.Container;
@@ -14,12 +17,14 @@ import net.minecraft.world.level.block.state.BlockState;
 import net.minecraft.world.level.storage.ValueInput;
 import net.minecraft.world.level.storage.ValueOutput;
 
-/** Persistent, server-owned inputs and output for the first 26.3 Binder slice. */
+/** Persistent, server-owned Binder inputs. */
 public final class PortBookBinderBlockEntity extends BlockEntity implements Container {
     public static final int COVER = 0;
     public static final int PANEL = 1;
     public static final int OUTPUT = 2;
-    public static final int SIZE = 3;
+    public static final int FIRST_PAGE = 3;
+    public static final int PAGE_COUNT = 252;
+    public static final int SIZE = FIRST_PAGE + PAGE_COUNT;
     private NonNullList<ItemStack> items = NonNullList.withSize(SIZE, ItemStack.EMPTY);
     private String title = "";
 
@@ -61,11 +66,61 @@ public final class PortBookBinderBlockEntity extends BlockEntity implements Cont
         setChanged();
     }
     @Override public boolean canPlaceItem(int slot, ItemStack stack) {
-        return switch (slot) {
-            case COVER -> stack.is(Items.LEATHER);
-            case PANEL -> PageItem.isLinkPanel(stack);
-            default -> false;
-        };
+        if (slot == COVER) return stack.is(Items.LEATHER);
+        if (slot == PANEL) return PageItem.isLinkPanel(stack);
+        return slot >= FIRST_PAGE && slot < SIZE && validSymbolPage(stack);
+    }
+    private static boolean validSymbolPage(ItemStack stack) {
+        return stack.is(Rivencraft.PAGE.get()) && !PageItem.isLinkPanel(stack)
+                && stack.has(Rivencraft.SYMBOL_PAGE_ID.get());
+    }
+
+    public boolean hasSymbolPages() {
+        for (int slot = FIRST_PAGE; slot < SIZE; slot++)
+            if (!items.get(slot).isEmpty()) return true;
+        return false;
+    }
+
+    public List<Identifier> symbolPages() {
+        List<Identifier> pages = new ArrayList<>();
+        for (int slot = FIRST_PAGE; slot < SIZE; slot++) {
+            Identifier symbol = items.get(slot).get(Rivencraft.SYMBOL_PAGE_ID.get());
+            if (symbol != null) pages.add(symbol);
+        }
+        return List.copyOf(pages);
+    }
+
+    public void clearSymbolPages() {
+        for (int slot = FIRST_PAGE; slot < SIZE; slot++) items.set(slot, ItemStack.EMPTY);
+        setChanged();
+    }
+
+    public int nextPageIndex() {
+        for (int index = PAGE_COUNT - 1; index >= 0; index--)
+            if (!items.get(FIRST_PAGE + index).isEmpty()) return index + 1;
+        return 0;
+    }
+
+    public boolean insertPage(int index, ItemStack page) {
+        int end = nextPageIndex();
+        if (index < 0 || index > end || end >= PAGE_COUNT || page.getCount() != 1
+                || !validSymbolPage(page)) return false;
+        for (int current = end; current > index; current--)
+            items.set(FIRST_PAGE + current, items.get(FIRST_PAGE + current - 1));
+        items.set(FIRST_PAGE + index, page.copy());
+        setChanged();
+        return true;
+    }
+
+    public ItemStack takePage(int index) {
+        int end = nextPageIndex();
+        if (index < 0 || index >= end) return ItemStack.EMPTY;
+        ItemStack removed = items.get(FIRST_PAGE + index);
+        for (int current = index; current < end - 1; current++)
+            items.set(FIRST_PAGE + current, items.get(FIRST_PAGE + current + 1));
+        items.set(FIRST_PAGE + end - 1, ItemStack.EMPTY);
+        setChanged();
+        return removed;
     }
     @Override public boolean stillValid(Player player) {
         return level != null && level.getBlockEntity(worldPosition) == this

ports/mc263/src/main/java/net/dnorberg/rivencraft/client/PortBookBinderClientEvents.java

@@ -5,6 +5,10 @@ import net.neoforged.api.distmarker.Dist;
 import net.neoforged.bus.api.SubscribeEvent;
 import net.neoforged.fml.common.EventBusSubscriber;
 import net.neoforged.neoforge.client.event.RegisterMenuScreensEvent;
+import net.neoforged.neoforge.client.event.RegisterSpecialModelRendererEvent;
+import net.neoforged.neoforge.client.event.AddClientReloadListenersEvent;
+import net.minecraft.resources.Identifier;
+import net.minecraft.server.packs.resources.ResourceManagerReloadListener;
 
 @EventBusSubscriber(modid = Rivencraft.MOD_ID, value = Dist.CLIENT)
 public final class PortBookBinderClientEvents {
@@ -15,4 +19,16 @@ public final class PortBookBinderClientEvents {
         event.register(Rivencraft.BOOK_BINDER_MENU.get(), PortBookBinderScreen::new);
         event.register(Rivencraft.INK_MIXER_MENU.get(), InkMixerScreen::new);
     }
+
+    @SubscribeEvent
+    public static void registerPageRenderer(RegisterSpecialModelRendererEvent event) {
+        event.register(Identifier.fromNamespaceAndPath(Rivencraft.MOD_ID, "symbol_page"),
+                PortSymbolPageRenderer.Unbaked.MAP_CODEC);
+    }
+
+    @SubscribeEvent
+    public static void registerPageTextureReload(AddClientReloadListenersEvent event) {
+        event.addListener(Identifier.fromNamespaceAndPath(Rivencraft.MOD_ID, "symbol_page_textures"),
+                (ResourceManagerReloadListener) manager -> PortSymbolPageTextures.clear());
+    }
 }

ports/mc263/src/main/java/net/dnorberg/rivencraft/client/PortBookBinderScreen.java

@@ -2,11 +2,13 @@ package net.dnorberg.rivencraft.client;
 
 import com.mojang.blaze3d.platform.InputConstants;
 import net.dnorberg.rivencraft.Rivencraft;
+import net.dnorberg.rivencraft.block.entity.PortBookBinderBlockEntity;
 import net.dnorberg.rivencraft.item.PageItem;
 import net.dnorberg.rivencraft.menu.PortBookBinderMenu;
 import net.dnorberg.rivencraft.network.AssembleBinderPayload;
 import net.dnorberg.rivencraft.network.PortBookNetworking;
 import net.dnorberg.rivencraft.network.SetBinderTitlePayload;
+import net.dnorberg.rivencraft.writing.PortAuthoredWriting;
 import net.minecraft.client.gui.GuiGraphicsExtractor;
 import net.minecraft.client.gui.components.EditBox;
 import net.minecraft.client.gui.screens.inventory.AbstractContainerScreen;
@@ -28,12 +30,19 @@ public final class PortBookBinderScreen extends AbstractContainerScreen<PortBook
     private static final int PAGE_Y = 48;
     private static final int PAGE_WIDTH = 26;
     private static final int PAGE_HEIGHT = 34;
+    private static final int PAGE_STEP = 28;
+    private static final int VISIBLE_PAGES = 5;
+    private static final int STRIP_X = 7;
+    private static final int STRIP_Y = 45;
+    private static final int STRIP_WIDTH = 162;
+    private static final int STRIP_HEIGHT = 40;
     private static final int MISSING_PANEL_X = 27;
     private static final int MISSING_PANEL_Y = 26;
     private static final int MISSING_PANEL_SIZE = 16;
     private static final ItemStack MISSING_PANEL_ICON = PageItem.createLinkPanelPage();
     private EditBox titleInput;
     private boolean stripClickPendingRelease;
+    private int firstVisible;
 
     public PortBookBinderScreen(PortBookBinderMenu menu, Inventory inventory, Component title) {
         super(menu, inventory, title, 176, 181);
@@ -65,19 +74,43 @@ public final class PortBookBinderScreen extends AbstractContainerScreen<PortBook
         graphics.blit(RenderPipelines.GUI_TEXTURED, BACKGROUND, left, top, 0, 0,
                 imageWidth, imageHeight, 256, 256);
         graphics.fill(left + 7, top + 9, left + 123, top + 23, 0xFF000000);
-        // The strip grows only when a page is present or the player is carrying
-        // a page to insert, just as the 1.21.1 Binder does.
-        boolean panelPresent = !menu.getSlot(1).getItem().isEmpty();
-        if (panelPresent || PageItem.isLinkPanel(menu.getCarried())) {
-            int x = left + 16;
+        firstVisible = Math.min(firstVisible, maxFirstVisible());
+        int visibleCount = Math.min(VISIBLE_PAGES, visiblePageCount() - firstVisible);
+        for (int visible = 0; visible < visibleCount; visible++) {
+            int x = left + 16 + visible * PAGE_STEP;
             graphics.blit(RenderPipelines.GUI_TEXTURED, PAGE_ATLAS,
                     x, top + PAGE_Y, 156, 0, PAGE_WIDTH, PAGE_HEIGHT, 256, 256);
-            if (!panelPresent)
-                graphics.fill(x, top + PAGE_Y, x + PAGE_WIDTH, top + PAGE_Y + PAGE_HEIGHT,
-                        0xAA000000);
-            else graphics.fill(x + 5, top + PAGE_Y + 6, x + 22, top + PAGE_Y + 17,
-                    0xFF000000);
         }
+        // GUI extraction batches textures within a stratum. The glyphs need a
+        // later stratum so another atlas page cannot cover their transparent quad.
+        graphics.nextStratum();
+        for (int visible = 0; visible < visibleCount; visible++) {
+            int index = firstVisible + visible;
+            int x = left + 16 + visible * PAGE_STEP;
+            int y = top + PAGE_Y;
+            ItemStack page = pageAt(index);
+            if (page.isEmpty()) {
+                graphics.fill(x, y, x + PAGE_WIDTH, y + PAGE_HEIGHT, 0xAA000000);
+            } else if (PageItem.isLinkPanel(page)) {
+                graphics.fill(x + 5, y + 6, x + 22, y + 17, 0xFF000000);
+            } else {
+                // Render the full-size transparent glyph through the working
+                // item pipeline, without its small parchment-backed icon.
+                ItemStack glyphOnly = page.copy();
+                glyphOnly.set(Rivencraft.PAGE_GLYPH_ONLY.get(), true);
+                graphics.pose().pushMatrix();
+                graphics.pose().translate(x + 1, y + 5);
+                graphics.pose().scale(1.5F, 1.5F);
+                graphics.fakeItem(glyphOnly, 0, 0);
+                graphics.pose().popMatrix();
+            }
+        }
+        graphics.fill(left + STRIP_X, top + STRIP_Y, left + STRIP_X + 8,
+                top + STRIP_Y + STRIP_HEIGHT, firstVisible == 0 ? 0x33000000 : 0xAA000000);
+        graphics.fill(left + STRIP_X + STRIP_WIDTH - 8, top + STRIP_Y,
+                left + STRIP_X + STRIP_WIDTH, top + STRIP_Y + STRIP_HEIGHT,
+                firstVisible >= maxFirstVisible() ? 0x33000000 : 0xAA000000);
+        boolean panelPresent = !menu.getSlot(PortBookBinderBlockEntity.PANEL).getItem().isEmpty();
         if (titleInput == null || titleInput.getValue().isBlank()) {
             graphics.fill(left + 7, top + 9, left + 123, top + 10, 0xFFFF3030);
             graphics.fill(left + 7, top + 22, left + 123, top + 23, 0xFFFF3030);
@@ -92,7 +125,10 @@ public final class PortBookBinderScreen extends AbstractContainerScreen<PortBook
                     top + MISSING_PANEL_Y + MISSING_PANEL_SIZE,
                     (alpha << 24) | 0x00B02020);
         }
-        if (menu.getSlot(2).getItem().isEmpty() && !menu.getSlot(0).getItem().isEmpty()
+        if (hasUnsupportedPages()) graphics.text(font,
+                Component.translatable("screen.rivencraft.book_binder.authored_pending"),
+                left + 75, top + 31, 0xFFB84B42, false);
+        if (!hasUnsupportedPages() && menu.getSlot(2).getItem().isEmpty() && !menu.getSlot(0).getItem().isEmpty()
                 && !menu.getSlot(1).getItem().isEmpty() && titleInput != null
                 && !titleInput.getValue().isBlank()) {
             graphics.fakeItem(new ItemStack(Rivencraft.DESCRIPTIVE_BOOK.get()), left + 152, top + 27);
@@ -112,32 +148,74 @@ public final class PortBookBinderScreen extends AbstractContainerScreen<PortBook
                 && menu.getSlot(1).getItem().isEmpty()) {
             graphics.setTooltipForNextFrame(font,
                     Component.translatable("screen.rivencraft.book_binder.missing_panel"), mouseX, mouseY);
-        } else if (x >= 16 && x < 16 + PAGE_WIDTH && y >= PAGE_Y && y < PAGE_Y + PAGE_HEIGHT
-                && !menu.getSlot(1).getItem().isEmpty()) {
-            graphics.setTooltipForNextFrame(font, menu.getSlot(1).getItem(), mouseX, mouseY);
+        } else {
+            int index = pageIndexAt(mouseX, mouseY);
+            if (index >= 0 && !pageAt(index).isEmpty())
+                graphics.setTooltipForNextFrame(font, pageAt(index), mouseX, mouseY);
         }
     }
 
+    private ItemStack pageAt(int index) {
+        return menu.getSlot(index == 0 ? PortBookBinderBlockEntity.PANEL
+                : PortBookBinderBlockEntity.FIRST_PAGE + index - 1).getItem();
+    }
+
+    private int displayedPages() {
+        for (int index = PortBookBinderBlockEntity.PAGE_COUNT; index >= 1; index--)
+            if (!pageAt(index).isEmpty()) return index + 1;
+        return pageAt(0).isEmpty() ? 0 : 1;
+    }
+
+    private boolean hasUnsupportedPages() {
+        java.util.List<Identifier> pages = new java.util.ArrayList<>();
+        for (int index = 1; index <= PortBookBinderBlockEntity.PAGE_COUNT; index++) {
+            Identifier id = pageAt(index).get(Rivencraft.SYMBOL_PAGE_ID.get());
+            if (id != null) pages.add(id);
+        }
+        return !PortAuthoredWriting.supports(pages);
+    }
+
+    private int visiblePageCount() {
+        return Math.min(PortBookBinderBlockEntity.PAGE_COUNT + 1,
+                displayedPages() + (menu.getCarried().isEmpty() ? 0 : 1));
+    }
+
+    private int maxFirstVisible() { return Math.max(0, visiblePageCount() - VISIBLE_PAGES); }
+
+    private int pageIndexAt(double mouseX, double mouseY) {
+        int x = (int) mouseX - leftPos;
+        int y = (int) mouseY - topPos;
+        if (x < 16 || x >= STRIP_X + STRIP_WIDTH - 8 || y < STRIP_Y || y >= STRIP_Y + STRIP_HEIGHT)
+            return -1;
+        int visible = (x - 16) / PAGE_STEP;
+        return visible < VISIBLE_PAGES ? firstVisible + visible : -1;
+    }
+
     @Override public boolean mouseClicked(MouseButtonEvent event, boolean doubleClick) {
         int left = (width - imageWidth) / 2;
         int top = (height - imageHeight) / 2;
         if ((event.button() == InputConstants.MOUSE_BUTTON_LEFT
                 || event.button() == InputConstants.MOUSE_BUTTON_RIGHT)
-                && event.x() >= left + 16 && event.x() < left + 16 + PAGE_WIDTH
-                && event.y() >= top + PAGE_Y && event.y() < top + PAGE_Y + PAGE_HEIGHT) {
-            boolean hasPanel = !menu.getSlot(1).getItem().isEmpty();
-            if (hasPanel && menu.getCarried().isEmpty()
-                    || !hasPanel && PageItem.isLinkPanel(menu.getCarried())) {
-                minecraft.gameMode.handleInventoryButtonClick(menu.containerId,
-                        PortBookBinderMenu.STRIP_CLICK_PANEL);
-                stripClickPendingRelease = true;
-                return true;
+                && event.x() >= left + STRIP_X && event.x() < left + STRIP_X + STRIP_WIDTH
+                && event.y() >= top + STRIP_Y && event.y() < top + STRIP_Y + STRIP_HEIGHT) {
+            stripClickPendingRelease = true;
+            if (event.x() < left + STRIP_X + 8) firstVisible = Math.max(0, firstVisible - 1);
+            else if (event.x() >= left + STRIP_X + STRIP_WIDTH - 8)
+                firstVisible = Math.min(maxFirstVisible(), firstVisible + 1);
+            else {
+                int index = pageIndexAt(event.x(), event.y());
+                if (index >= 0 && index <= displayedPages()
+                        && (index < displayedPages() || !menu.getCarried().isEmpty()))
+                    minecraft.gameMode.handleInventoryButtonClick(menu.containerId,
+                            PortBookBinderMenu.STRIP_CLICK_BASE + index);
             }
+            return true;
         }
         if (event.button() == InputConstants.MOUSE_BUTTON_LEFT
                 && event.x() >= left + 151 && event.x() < left + 170
                 && event.y() >= top + 26 && event.y() < top + 45
-                && menu.getSlot(2).getItem().isEmpty() && menu.getCarried().isEmpty()) {
+                && !hasUnsupportedPages() && menu.getSlot(2).getItem().isEmpty()
+                && menu.getCarried().isEmpty()) {
             String name = titleInput.getValue().strip();
             if (!name.isEmpty()) ClientPacketDistributor.sendToServer(new AssembleBinderPayload(name));
             return true;
@@ -153,6 +231,15 @@ public final class PortBookBinderScreen extends AbstractContainerScreen<PortBook
         return super.mouseReleased(event);
     }
 
+    @Override public boolean mouseScrolled(double mouseX, double mouseY, double scrollX, double scrollY) {
+        if (mouseX >= leftPos + STRIP_X && mouseX < leftPos + STRIP_X + STRIP_WIDTH
+                && mouseY >= topPos + STRIP_Y && mouseY < topPos + STRIP_Y + STRIP_HEIGHT) {
+            firstVisible = Math.clamp(firstVisible - (int) Math.signum(scrollY), 0, maxFirstVisible());
+            return true;
+        }
+        return super.mouseScrolled(mouseX, mouseY, scrollX, scrollY);
+    }
+
     @Override public boolean keyPressed(KeyEvent event) {
         if (titleInput != null && titleInput.isFocused()) {
             if (event.isEscape()) {

ports/mc263/src/main/java/net/dnorberg/rivencraft/client/PortSymbolPageRenderer.java

@@ -0,0 +1,63 @@
+package net.dnorberg.rivencraft.client;
+
+import com.mojang.blaze3d.vertex.PoseStack;
+import com.mojang.blaze3d.vertex.VertexConsumer;
+import com.mojang.serialization.MapCodec;
+import java.util.function.Consumer;
+import net.dnorberg.rivencraft.Rivencraft;
+import net.minecraft.client.renderer.SubmitNodeCollector;
+import net.minecraft.client.renderer.rendertype.RenderTypes;
+import net.minecraft.client.renderer.special.SpecialModelRenderer;
+import net.minecraft.resources.Identifier;
+import net.minecraft.world.item.ItemStack;
+import org.joml.Vector3f;
+
+/** Flat item geometry textured with a page composed from its symbol stack. */
+public final class PortSymbolPageRenderer implements SpecialModelRenderer<PortSymbolPageRenderer.PageArt> {
+    @Override
+    public PageArt extractArgument(ItemStack stack) {
+        Identifier symbol = stack.get(Rivencraft.SYMBOL_PAGE_ID.get());
+        return symbol == null ? null : new PageArt(symbol,
+                stack.getOrDefault(Rivencraft.PAGE_GLYPH_ONLY.get(), false));
+    }
+
+    @Override
+    public void submit(PageArt art, PoseStack pose, SubmitNodeCollector collector,
+                       int light, int overlay, boolean hasFoil, int outlineColor) {
+        if (art == null) return;
+        Identifier texture = art.glyphOnly()
+                ? PortSymbolPageTextures.forPage(art.symbol())
+                : PortSymbolPageTextures.forItem(art.symbol());
+        collector.submitCustomGeometry(pose, RenderTypes.entityCutout(texture),
+                (matrix, vertices) -> {
+                    vertex(vertices, matrix, 0, 0, 0, 1, light, overlay);
+                    vertex(vertices, matrix, 1, 0, 1, 1, light, overlay);
+                    vertex(vertices, matrix, 1, 1, 1, 0, light, overlay);
+                    vertex(vertices, matrix, 0, 1, 0, 0, light, overlay);
+                });
+    }
+
+    @Override
+    public void getExtents(Consumer<org.joml.Vector3fc> extents) {
+        extents.accept(new Vector3f(0, 0, 0.5F));
+        extents.accept(new Vector3f(1, 1, 0.5F));
+    }
+
+    private static void vertex(VertexConsumer vertices, PoseStack.Pose pose,
+                               float x, float y, float u, float v, int light, int overlay) {
+        vertices.addVertex(pose, x, y, 0.5F).setColor(255, 255, 255, 255)
+                .setUv(u, v).setOverlay(overlay).setLight(light).setNormal(pose, 0, 0, 1);
+    }
+
+    public record PageArt(Identifier symbol, boolean glyphOnly) {}
+
+    public record Unbaked() implements SpecialModelRenderer.Unbaked<PageArt> {
+        public static final Unbaked INSTANCE = new Unbaked();
+        public static final MapCodec<Unbaked> MAP_CODEC = MapCodec.unit(INSTANCE);
+
+        @Override public MapCodec<Unbaked> type() { return MAP_CODEC; }
+        @Override public SpecialModelRenderer<PageArt> bake(BakingContext context) {
+            return new PortSymbolPageRenderer();
+        }
+    }
+}

ports/mc263/src/main/java/net/dnorberg/rivencraft/client/PortSymbolPageTextures.java

@@ -0,0 +1,189 @@
+package net.dnorberg.rivencraft.client;
+
+import com.mojang.blaze3d.platform.NativeImage;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.LinkedHashMap;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Random;
+import net.dnorberg.rivencraft.Rivencraft;
+import net.dnorberg.rivencraft.writing.PortSymbolNumerals;
+import net.dnorberg.rivencraft.writing.PortSymbolPages;
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.renderer.texture.DynamicTexture;
+import net.minecraft.resources.Identifier;
+import net.minecraft.server.packs.resources.ResourceManager;
+import net.minecraft.util.ARGB;
+
+/** The 1.21.1 Legacy-style glyph compositor adapted to 26.3's texture API. */
+public final class PortSymbolPageTextures {
+    private static final int SIZE = 128;
+    private static final int GLYPH = 51;
+    private static final int ITEM_SYMBOL_SIZE = 15;
+    private static final int NUMBER_GLYPH_SIZE = 64;
+    private static final int CACHE_LIMIT = 256;
+    private static final Identifier PAGE = texture("item/page");
+    private static final Identifier COMPONENTS = texture("gui/symbolcomponents");
+    private static final Identifier FALLBACK = texture("item/page_symbol");
+    private static final Map<String, Identifier> CACHE = new LinkedHashMap<>(16, .75F, true);
+    private static final Map<String, int[]> WORD_CACHE = new LinkedHashMap<>(16, .75F, true);
+    private static NativeImage page;
+    private static NativeImage components;
+    private static int nextId;
+
+    // WordData from Mystcraft Legacy 0.13.7.06, matching the 1.21.1 compositor.
+    private static final Map<String, int[]> WORDS = Map.ofEntries(
+            Map.entry("Terrain", new int[] {6,10,12,13,16,19,24,25,27}),
+            Map.entry("Form", new int[] {4,6,8,9,10,11,13,14,16,23}),
+            Map.entry("Tradition", new int[] {4,6,7,8,9,14,17,18,20}),
+            Map.entry("Flow", new int[] {4,7,12,13,17,18}),
+            Map.entry("Constraint", new int[] {5,6,9,11,13,20,22,23}),
+            Map.entry("Nature", new int[] {5,6,8,10,11,12,15,16,17,22}),
+            Map.entry("Sustain", new int[] {6,16,19,20,21,23}),
+            Map.entry("Ethereal", new int[] {4,6,8,13,14,16,18,21,23}),
+            Map.entry("Dynamic", new int[] {4,5,6,12,13,17,18,22,23}),
+            Map.entry("Cycle", new int[] {4,5,7,16,17,18}),
+            Map.entry("Balance", new int[] {4,6,9,10,16,19}),
+            Map.entry("Transform", new int[] {4,5,6,8,11,14,18,20,21}),
+            Map.entry("Time", new int[] {4,5,7,12,13,19,20,21,22,23}),
+            Map.entry("System", new int[] {10,12,14,15,16,20,21,22}),
+            Map.entry("Void", new int[] {4,5,6,16,17,18,23})
+    );
+
+    private PortSymbolPageTextures() {}
+
+    public static Identifier forItem(Identifier id) {
+        return forSymbol(id, true);
+    }
+
+    /** Transparent, full-size glyphs layered over the Binder's page atlas. */
+    public static Identifier forPage(Identifier id) {
+        return forSymbol(id, false);
+    }
+
+    private static Identifier forSymbol(Identifier id, boolean item) {
+        PortSymbolPages.Entry entry = PortSymbolPages.find(id);
+        if (entry == null) return FALLBACK;
+        String poem = entry.poem();
+        if (!poem.matches("[A-Za-z]+(?: [A-Za-z]+){3}")) poem = "";
+        String key = id + "|" + poem + (item ? "|item" : "|page");
+        Identifier cached = CACHE.get(key);
+        if (cached != null) return cached;
+        try {
+            loadSources(Minecraft.getInstance().getResourceManager());
+            NativeImage image = compose(id, poem, item);
+            Identifier location = Identifier.fromNamespaceAndPath(Rivencraft.MOD_ID,
+                    "generated/page_" + nextId++);
+            Minecraft.getInstance().getTextureManager().register(location,
+                    new DynamicTexture(() -> "Rivencraft symbol page " + id, image));
+            CACHE.put(key, location);
+            if (CACHE.size() > CACHE_LIMIT) {
+                String eldest = CACHE.keySet().iterator().next();
+                Minecraft.getInstance().getTextureManager().release(CACHE.remove(eldest));
+            }
+            return location;
+        } catch (IOException exception) {
+            Rivencraft.LOGGER.error("Could not compose symbol page {}", id, exception);
+            return FALLBACK;
+        }
+    }
+
+    public static void clear() {
+        var textures = Minecraft.getInstance().getTextureManager();
+        CACHE.values().forEach(textures::release);
+        CACHE.clear();
+        WORD_CACHE.clear();
+        if (page != null) page.close();
+        if (components != null) components.close();
+        page = null;
+        components = null;
+    }
+
+    private static void loadSources(ResourceManager manager) throws IOException {
+        if (page != null && components != null) return;
+        try (InputStream pageStream = manager.getResourceOrThrow(PAGE).open();
+             InputStream componentsStream = manager.getResourceOrThrow(COMPONENTS).open()) {
+            page = NativeImage.read(pageStream);
+            components = NativeImage.read(componentsStream);
+        }
+    }
+
+    private static NativeImage compose(Identifier id, String poem, boolean item) {
+        NativeImage image = new NativeImage(SIZE, SIZE, true);
+        if (item) {
+            for (int y = 0; y < SIZE; y++) for (int x = 0; x < SIZE; x++) {
+                image.setPixel(x, y, page.getPixel(x * page.getWidth() / SIZE,
+                        y * page.getHeight() / SIZE));
+            }
+        }
+        String numberPath = id.getPath().startsWith("number/")
+                ? id.getPath().substring("number/".length()) : "";
+        if (id.getNamespace().equals(Rivencraft.MOD_ID)
+                && numberPath.matches("(?:[0-9]|1[0-9]|2[0-4])")) {
+            int digit = Integer.parseInt(numberPath);
+            int glyphSize = item ? NUMBER_GLYPH_SIZE : GLYPH;
+            int origin = item ? (SIZE - glyphSize) / 2 : 38;
+            for (int component : PortSymbolNumerals.componentsForDigit(digit))
+                blendComponent(image, component, origin, origin, glyphSize);
+            return image;
+        }
+        String[] words = poem.isBlank() ? generatedWords(id) : poem.split(" ");
+        int[] offsetsX = {38, 77, 38, 0};
+        int[] offsetsY = {0, 38, 77, 38};
+        int glyphSize = item ? GLYPH * ITEM_SYMBOL_SIZE / 16 : GLYPH;
+        for (int word = 0; word < 4; word++) {
+            int x = item ? scaleForItem(offsetsX[word]) : offsetsX[word];
+            int y = item ? scaleForItem(offsetsY[word]) : offsetsY[word];
+            for (int component : glyphs(words[word]))
+                blendComponent(image, component, x, y, glyphSize);
+        }
+        return image;
+    }
+
+    private static void blendComponent(NativeImage image, int component, int x0, int y0, int size) {
+        int cellX = (component % 8) * 64;
+        int cellY = (component / 8) * 64;
+        for (int y = 0; y < size; y++) for (int x = 0; x < size; x++) {
+            int sourceX = cellX + x * 64 / size;
+            int sourceY = cellY + y * 64 / size;
+            // One source-pixel of coverage keeps the thin Legacy strokes legible
+            // when Minecraft shrinks this 128px composite to a 16px item icon.
+            int alpha = ARGB.alpha(components.getPixel(sourceX, sourceY));
+            if (sourceX > cellX) alpha = Math.max(alpha, ARGB.alpha(components.getPixel(sourceX - 1, sourceY)));
+            if (sourceX < cellX + 63) alpha = Math.max(alpha, ARGB.alpha(components.getPixel(sourceX + 1, sourceY)));
+            if (sourceY > cellY) alpha = Math.max(alpha, ARGB.alpha(components.getPixel(sourceX, sourceY - 1)));
+            if (sourceY < cellY + 63) alpha = Math.max(alpha, ARGB.alpha(components.getPixel(sourceX, sourceY + 1)));
+            if (alpha != 0) image.setPixel(x0 + x, y0 + y,
+                    ARGB.alphaBlend(image.getPixel(x0 + x, y0 + y),
+                            (alpha << 24) | 0x001A212B));
+        }
+    }
+
+    private static int scaleForItem(int coordinate) {
+        return SIZE / 2 + Math.round((coordinate - SIZE / 2F) * ITEM_SYMBOL_SIZE / 16F);
+    }
+
+    private static String[] generatedWords(Identifier id) {
+        String stem = id.toString();
+        return new String[] {stem + 'a', stem + 'b', stem + 'c', stem + 'd'};
+    }
+
+    private static int[] glyphs(String word) {
+        int[] known = WORDS.get(word);
+        if (known != null) return known;
+        String key = word.toLowerCase(Locale.ROOT);
+        int[] cached = WORD_CACHE.get(key);
+        if (cached != null) return cached;
+        Random random = new Random(key.hashCode());
+        int[] result = new int[random.nextInt(10) + 3];
+        for (int i = 0; i < result.length; i++) result[i] = random.nextInt(20) + 4;
+        WORD_CACHE.put(key, result);
+        if (WORD_CACHE.size() > CACHE_LIMIT) WORD_CACHE.remove(WORD_CACHE.keySet().iterator().next());
+        return result;
+    }
+
+    private static Identifier texture(String path) {
+        return Identifier.fromNamespaceAndPath(Rivencraft.MOD_ID, "textures/" + path + ".png");
+    }
+}

ports/mc263/src/main/java/net/dnorberg/rivencraft/item/PageItem.java

@@ -2,8 +2,11 @@ package net.dnorberg.rivencraft.item;
 
 import java.util.function.Consumer;
 import net.dnorberg.rivencraft.Rivencraft;
+import net.dnorberg.rivencraft.writing.PortSymbolPages;
+import net.minecraft.ChatFormatting;
 import net.minecraft.core.component.DataComponents;
 import net.minecraft.network.chat.Component;
+import net.minecraft.resources.Identifier;
 import net.minecraft.world.item.Item;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.TooltipFlag;
@@ -30,10 +33,28 @@ public final class PageItem extends Item {
         return stack.is(Rivencraft.PAGE.get()) && stack.getOrDefault(Rivencraft.LINK_PANEL_PAGE.get(), false);
     }
 
+    public static ItemStack createSymbolPage(Identifier id) {
+        if (PortSymbolPages.find(id) == null)
+            throw new IllegalArgumentException("Unknown bundled symbol " + id);
+        ItemStack stack = new ItemStack(Rivencraft.PAGE.get());
+        stack.set(Rivencraft.SYMBOL_PAGE_ID.get(), id);
+        return stack;
+    }
+
     @Override
     public Component getName(ItemStack stack) {
         Component customName = stack.get(DataComponents.CUSTOM_NAME);
         if (customName != null) return customName;
+        Identifier symbolId = stack.get(Rivencraft.SYMBOL_PAGE_ID.get());
+        if (symbolId != null) {
+            PortSymbolPages.Entry entry = PortSymbolPages.find(symbolId);
+            if (entry != null) {
+                Component name = Component.translatableWithFallback(
+                        entry.nameKey(), PortSymbolPages.fallbackName(symbolId));
+                return isCorrupted(symbolId) ? name.copy().withStyle(ChatFormatting.OBFUSCATED) : name;
+            }
+            return Component.translatableWithFallback("item.rivencraft.page.unresolved", "Unknown Symbol Page");
+        }
         return Component.translatable(isLinkPanel(stack)
                 ? "item.rivencraft.page.link_panel" : "item.rivencraft.page.blank");
     }
@@ -41,6 +62,20 @@ public final class PageItem extends Item {
     @Override
     public void appendHoverText(ItemStack stack, TooltipContext context, TooltipDisplay display,
                                 Consumer<Component> tooltip, TooltipFlag flag) {
+        Identifier symbolId = stack.get(Rivencraft.SYMBOL_PAGE_ID.get());
+        if (symbolId != null) {
+            PortSymbolPages.Entry entry = PortSymbolPages.find(symbolId);
+            if (entry != null) {
+                Component description = Component.translatableWithFallback(
+                        entry.descriptionKey(), PortSymbolPages.fallbackName(symbolId));
+                tooltip.accept(isCorrupted(symbolId)
+                        ? description.copy().withStyle(ChatFormatting.GRAY, ChatFormatting.OBFUSCATED)
+                        : description.copy().withStyle(ChatFormatting.GRAY));
+            }
+            tooltip.accept(Component.translatable("item.rivencraft.page.symbol.port_status")
+                    .withStyle(ChatFormatting.DARK_GRAY));
+            return;
+        }
         LinkProperties properties = stack.getOrDefault(Rivencraft.LINK_PROPERTIES.get(), LinkProperties.NONE);
         if (properties.has(LinkProperties.DISARM))
             tooltip.accept(Component.translatable("item.rivencraft.link_property.disarm"));
@@ -52,4 +87,8 @@ public final class PageItem extends Item {
                 ? "item.rivencraft.page.link_panel.port_status"
                 : "item.rivencraft.page.blank.port_status"));
     }
+
+    private static boolean isCorrupted(Identifier id) {
+        return id.getNamespace().equals(Rivencraft.MOD_ID) && id.getPath().startsWith("corrupted/");
+    }
 }

ports/mc263/src/main/java/net/dnorberg/rivencraft/menu/PortBookBinderMenu.java

@@ -4,6 +4,7 @@ import net.dnorberg.rivencraft.Rivencraft;
 import net.dnorberg.rivencraft.block.entity.PortBookBinderBlockEntity;
 import net.dnorberg.rivencraft.item.PageItem;
 import net.dnorberg.rivencraft.network.PortBookNetworking;
+import net.dnorberg.rivencraft.writing.PortAuthoredWriting;
 import net.minecraft.core.component.DataComponents;
 import net.minecraft.network.RegistryFriendlyByteBuf;
 import net.minecraft.network.chat.Component;
@@ -19,7 +20,7 @@ import net.minecraft.world.item.Items;
 
 /** Binder inputs persist in the block; assembling places the finished book on the cursor. */
 public final class PortBookBinderMenu extends AbstractContainerMenu {
-    public static final int STRIP_CLICK_PANEL = 3000;
+    public static final int STRIP_CLICK_BASE = 3000;
     private final Container binder;
     private final PortBookBinderBlockEntity blockEntity;
     private final String initialTitle;
@@ -48,6 +49,14 @@ public final class PortBookBinderMenu extends AbstractContainerMenu {
         addSlot(new Slot(binder, PortBookBinderBlockEntity.OUTPUT, 152, 27) {
             @Override public boolean mayPlace(ItemStack stack) { return false; }
         });
+        for (int page = 0; page < PortBookBinderBlockEntity.PAGE_COUNT; page++) {
+            addSlot(new Slot(binder, PortBookBinderBlockEntity.FIRST_PAGE + page, -1000, -1000) {
+                @Override public boolean mayPlace(ItemStack stack) {
+                    return binder.canPlaceItem(getContainerSlot(), stack);
+                }
+                @Override public int getMaxStackSize() { return 1; }
+            });
+        }
         addStandardInventorySlots(inventory, 8, 99);
     }
 
@@ -58,19 +67,26 @@ public final class PortBookBinderMenu extends AbstractContainerMenu {
     public String title() { return initialTitle; }
 
     @Override public boolean clickMenuButton(Player player, int id) {
-        if (id != STRIP_CLICK_PANEL || !stillValid(player)) return false;
+        if (id < STRIP_CLICK_BASE || id > STRIP_CLICK_BASE + PortBookBinderBlockEntity.PAGE_COUNT
+                || !stillValid(player)) return false;
+        if (player.level().isClientSide()) return true;
+        int index = id - STRIP_CLICK_BASE;
         ItemStack carried = getCarried();
-        if (carried.isEmpty()) {
-            ItemStack panel = binder.removeItem(PortBookBinderBlockEntity.PANEL, 1);
-            if (panel.isEmpty()) return false;
-            setCarried(panel);
-        } else {
-            if (!PageItem.isLinkPanel(carried)
-                    || !binder.getItem(PortBookBinderBlockEntity.PANEL).isEmpty()) return false;
-            binder.setItem(PortBookBinderBlockEntity.PANEL, carried.copyWithCount(1));
+        if (!carried.isEmpty()) {
+            if (index == 0) {
+                if (!PageItem.isLinkPanel(carried)
+                        || !binder.getItem(PortBookBinderBlockEntity.PANEL).isEmpty()) return false;
+                binder.setItem(PortBookBinderBlockEntity.PANEL, carried.copyWithCount(1));
+            } else if (!blockEntity.insertPage(index - 1, carried.copyWithCount(1))) return false;
             ItemStack remainder = carried.copy();
             remainder.shrink(1);
             setCarried(remainder);
+        } else {
+            ItemStack removed = index == 0
+                    ? binder.removeItem(PortBookBinderBlockEntity.PANEL, 1)
+                    : blockEntity.takePage(index - 1);
+            if (removed.isEmpty()) return false;
+            setCarried(removed);
         }
         broadcastChanges();
         return true;
@@ -84,22 +100,26 @@ public final class PortBookBinderMenu extends AbstractContainerMenu {
     public void assemble(ServerPlayer player, String title) {
         if (!stillValid(player) || title.isBlank() || title.length() > PortBookNetworking.MAX_BOOK_TITLE_LENGTH
                 || !binder.getItem(PortBookBinderBlockEntity.OUTPUT).isEmpty()
+                || !PortAuthoredWriting.supports(blockEntity.symbolPages())
                 || !getCarried().isEmpty()) return;
         ItemStack cover = binder.getItem(PortBookBinderBlockEntity.COVER);
         ItemStack panel = binder.getItem(PortBookBinderBlockEntity.PANEL);
         if (!cover.is(Items.LEATHER) || !PageItem.isLinkPanel(panel)) return;
         blockEntity.setTitle(title);
         ItemStack book = new ItemStack(Rivencraft.DESCRIPTIVE_BOOK.get());
-        var id = PortBookNetworking.createAge(player, title);
+        var id = PortBookNetworking.createAge(player, title, blockEntity.symbolPages());
         if (id == null) return;
         book.set(Rivencraft.AGE_BOOK_ID.get(), id);
         book.set(DataComponents.CUSTOM_NAME, Component.literal(title));
+        if (blockEntity.hasSymbolPages())
+            book.set(Rivencraft.BOOK_SYMBOLS.get(), blockEntity.symbolPages());
         var modifiers = panel.get(Rivencraft.LINK_PROPERTIES.get());
         if (modifiers != null) book.set(Rivencraft.LINK_PROPERTIES.get(), modifiers);
         cover.shrink(1);
         panel.shrink(1);
         binder.setItem(PortBookBinderBlockEntity.COVER, cover);
         binder.setItem(PortBookBinderBlockEntity.PANEL, panel);
+        blockEntity.clearSymbolPages();
         setCarried(book);
         broadcastChanges();
     }
@@ -108,6 +128,15 @@ public final class PortBookBinderMenu extends AbstractContainerMenu {
         if (!stillValid(player) || index < 0 || index >= slots.size()) return ItemStack.EMPTY;
         Slot slot = slots.get(index);
         if (!slot.hasItem()) return ItemStack.EMPTY;
+        if (index >= PortBookBinderBlockEntity.FIRST_PAGE && index < PortBookBinderBlockEntity.SIZE) {
+            ItemStack page = slot.getItem().copy();
+            ItemStack remainder = page.copy();
+            if (!moveItemStackTo(remainder, PortBookBinderBlockEntity.SIZE, slots.size(), true)
+                    || !remainder.isEmpty()) return ItemStack.EMPTY;
+            blockEntity.takePage(index - PortBookBinderBlockEntity.FIRST_PAGE);
+            broadcastChanges();
+            return page;
+        }
         ItemStack stack = slot.getItem();
         ItemStack original = stack.copy();
         boolean moved;
@@ -119,6 +148,9 @@ public final class PortBookBinderMenu extends AbstractContainerMenu {
         } else if (PageItem.isLinkPanel(stack)) {
             moved = moveItemStackTo(stack, PortBookBinderBlockEntity.PANEL,
                     PortBookBinderBlockEntity.PANEL + 1, false);
+        } else if (stack.is(Rivencraft.PAGE.get()) && stack.has(Rivencraft.SYMBOL_PAGE_ID.get())) {
+            moved = moveItemStackTo(stack, PortBookBinderBlockEntity.FIRST_PAGE,
+                    PortBookBinderBlockEntity.SIZE, false);
         } else return ItemStack.EMPTY;
         if (!moved) return ItemStack.EMPTY;
         if (stack.isEmpty()) slot.setByPlayer(ItemStack.EMPTY);

ports/mc263/src/main/java/net/dnorberg/rivencraft/network/PortBookNetworking.java

@@ -2,11 +2,14 @@ package net.dnorberg.rivencraft.network;
 
 import net.dnorberg.rivencraft.Rivencraft;
 import net.dnorberg.rivencraft.age.PortAgeTravel;
+import net.dnorberg.rivencraft.age.PortAgeTerrain;
 import net.dnorberg.rivencraft.age.RuntimeAgeBackend;
+import net.dnorberg.rivencraft.age.PortRandomAgeSelection;
 import net.dnorberg.rivencraft.item.LinkBookTarget;
 import net.dnorberg.rivencraft.item.LinkProperties;
 import net.dnorberg.rivencraft.item.LinkingBookItem;
 import net.dnorberg.rivencraft.menu.PortBookBinderMenu;
+import net.dnorberg.rivencraft.writing.PortAuthoredWriting;
 import net.minecraft.core.component.DataComponents;
 import net.minecraft.network.chat.Component;
 import net.minecraft.resources.Identifier;
@@ -19,6 +22,7 @@ import net.minecraft.server.level.ServerLevel;
 import net.minecraft.world.phys.Vec3;
 import net.neoforged.neoforge.network.event.RegisterPayloadHandlersEvent;
 import java.util.Locale;
+import java.util.List;
 
 /** Server-authoritative handheld Linking Book binding and travel. */
 public final class PortBookNetworking {
@@ -99,7 +103,18 @@ public final class PortBookNetworking {
 
     /** Shared name resolution and Age creation for handheld books and the Binder. */
     public static Identifier createAge(ServerPlayer player, String title) {
+        return createAge(player, title, List.of());
+    }
+
+    public static Identifier createAge(ServerPlayer player, String title, List<Identifier> pages) {
         if (title == null || title.isBlank() || title.length() > MAX_BOOK_TITLE_LENGTH) return null;
+        net.dnorberg.rivencraft.age.PortBiomePlan biomePlan;
+        try {
+            biomePlan = PortAuthoredWriting.biomePlan(pages, player.registryAccess());
+        } catch (IllegalArgumentException exception) {
+            player.sendOverlayMessage(Component.literal("Age writing unavailable: " + exception.getMessage()));
+            return null;
+        }
         String base = title.toLowerCase(Locale.ROOT).replaceAll("[^a-z0-9._-]+", "_")
                 .replaceAll("^[_\\.-]+|[_\\.-]+$", "");
         if (base.isEmpty()) base = "age";
@@ -112,7 +127,15 @@ public final class PortBookNetworking {
             id = Identifier.fromNamespaceAndPath(Rivencraft.MOD_ID, "age/" + name);
         }
         try {
-            RuntimeAgeBackend.create(server, id, player.getRandom().nextLong());
+            long seed = player.getRandom().nextLong();
+            PortAgeTerrain terrain = PortAuthoredWriting.terrain(pages);
+            if (pages.isEmpty()) {
+                PortRandomAgeSelection.Selection random = PortRandomAgeSelection.select(server, seed);
+                terrain = random.terrain();
+                biomePlan = random.biomes();
+            }
+            RuntimeAgeBackend.create(server, id, seed, biomePlan, terrain,
+                    PortAuthoredWriting.rockPlan(pages));
         } catch (IllegalArgumentException | IllegalStateException exception) {
             player.sendOverlayMessage(Component.literal("Age creation failed: " + exception.getMessage()));
             return null;

ports/mc263/src/main/java/net/dnorberg/rivencraft/registry/ModCreativeTabs.java

@@ -3,6 +3,7 @@ package net.dnorberg.rivencraft.registry;
 import net.dnorberg.rivencraft.Rivencraft;
 import net.dnorberg.rivencraft.item.PageItem;
 import net.dnorberg.rivencraft.item.LinkProperties;
+import net.dnorberg.rivencraft.writing.PortSymbolPages;
 import net.minecraft.core.registries.Registries;
 import net.minecraft.network.chat.Component;
 import net.minecraft.world.item.CreativeModeTab;
@@ -47,6 +48,18 @@ public final class ModCreativeTabs {
                     }
                 })
                 .build());
+        for (String category : PortSymbolPages.categories()) {
+            String path = category.substring(category.indexOf(':') + 1);
+            TABS.register("rivencraft_pages_" + path, () -> CreativeModeTab.builder()
+                    .title(Component.translatableWithFallback("itemGroup.rivencraft.pages." + path,
+                            "Rivencraft " + PortSymbolPages.fallbackName(
+                                    net.minecraft.resources.Identifier.fromNamespaceAndPath(Rivencraft.MOD_ID, path))
+                                    + " Pages"))
+                    .icon(() -> PortSymbolPages.icon(category))
+                    .displayItems((parameters, output) ->
+                            PortSymbolPages.pages(category, parameters.holders()).forEach(output::accept))
+                    .build());
+        }
     }
 
     private ModCreativeTabs() {

ports/mc263/src/main/java/net/dnorberg/rivencraft/registry/PortBiomeSources.java

@@ -0,0 +1,25 @@
+package net.dnorberg.rivencraft.registry;
+
+import com.mojang.serialization.MapCodec;
+import net.dnorberg.rivencraft.Rivencraft;
+import net.dnorberg.rivencraft.age.PortScaledBiomeSource;
+import net.minecraft.core.registries.Registries;
+import net.minecraft.world.level.biome.BiomeSource;
+import net.neoforged.bus.api.IEventBus;
+import net.neoforged.neoforge.registries.DeferredRegister;
+
+/** Serializes the custom biome resolver in saved 26.3 Age level stems. */
+public final class PortBiomeSources {
+    private static final DeferredRegister<MapCodec<? extends BiomeSource>> SOURCES =
+            DeferredRegister.create(Registries.BIOME_SOURCE, Rivencraft.MOD_ID);
+
+    static {
+        SOURCES.register("scaled", () -> PortScaledBiomeSource.CODEC);
+    }
+
+    private PortBiomeSources() {}
+
+    public static void register(IEventBus bus) {
+        SOURCES.register(bus);
+    }
+}

ports/mc263/src/main/java/net/dnorberg/rivencraft/registry/PortChunkGenerators.java

@@ -0,0 +1,27 @@
+package net.dnorberg.rivencraft.registry;
+
+import com.mojang.serialization.MapCodec;
+import net.dnorberg.rivencraft.Rivencraft;
+import net.dnorberg.rivencraft.age.PortFlatChunkGenerator;
+import net.dnorberg.rivencraft.age.PortRockChunkGenerator;
+import net.minecraft.core.registries.Registries;
+import net.minecraft.world.level.chunk.ChunkGenerator;
+import net.neoforged.bus.api.IEventBus;
+import net.neoforged.neoforge.registries.DeferredRegister;
+
+/** Codec for the authored Flat/Void biome source and layer combination. */
+public final class PortChunkGenerators {
+    private static final DeferredRegister<MapCodec<? extends ChunkGenerator>> GENERATORS =
+            DeferredRegister.create(Registries.CHUNK_GENERATOR, Rivencraft.MOD_ID);
+
+    static {
+        GENERATORS.register("age_flat", () -> PortFlatChunkGenerator.CODEC);
+        GENERATORS.register("age_rocks", () -> PortRockChunkGenerator.CODEC);
+    }
+
+    private PortChunkGenerators() {}
+
+    public static void register(IEventBus bus) {
+        GENERATORS.register(bus);
+    }
+}

ports/mc263/src/main/java/net/dnorberg/rivencraft/writing/PortAuthoredWriting.java

@@ -0,0 +1,144 @@
+package net.dnorberg.rivencraft.writing;
+
+import java.util.List;
+import java.util.ArrayList;
+import net.dnorberg.rivencraft.age.PortBiomePlan;
+import net.dnorberg.rivencraft.age.PortAgeTerrain;
+import net.dnorberg.rivencraft.age.PortRockPlan;
+import net.dnorberg.rivencraft.Rivencraft;
+import net.minecraft.core.HolderLookup;
+import net.minecraft.core.registries.Registries;
+import net.minecraft.resources.Identifier;
+import net.minecraft.resources.ResourceKey;
+
+/** Authored noise terrain and biome distribution supported by the 26.3 backend. */
+public final class PortAuthoredWriting {
+    private static final int MAX_AUTHORED_BIOMES = 252;
+    private static final Identifier STANDARD_TERRAIN = Identifier.fromNamespaceAndPath(
+            Rivencraft.MOD_ID, "terrain/standard");
+    private static final Identifier AMPLIFIED_TERRAIN = Identifier.fromNamespaceAndPath(
+            Rivencraft.MOD_ID, "terrain/amplified");
+    private static final Identifier ISLAND_TERRAIN = Identifier.fromNamespaceAndPath(
+            Rivencraft.MOD_ID, "terrain/island");
+    private static final Identifier FLAT_TERRAIN = Identifier.fromNamespaceAndPath(
+            Rivencraft.MOD_ID, "terrain/flat");
+    private static final Identifier VOID_TERRAIN = Identifier.fromNamespaceAndPath(
+            Rivencraft.MOD_ID, "terrain/void");
+    private static final Identifier CAVE_TERRAIN = Identifier.fromNamespaceAndPath(
+            Rivencraft.MOD_ID, "terrain/cave");
+    private static final Identifier ROCKS = Identifier.fromNamespaceAndPath(
+            Rivencraft.MOD_ID, "feature/rocks");
+
+    private PortAuthoredWriting() {}
+
+    /** A page never disappears into an Age unless this port can apply its effect. */
+    public static boolean supports(List<Identifier> pages) {
+        boolean terrain = false;
+        int biomes = 0;
+        int controllers = 0;
+        boolean material = false;
+        boolean rocks = false;
+        for (Identifier page : pages) {
+            if (isTerrain(page) && !terrain) {
+                terrain = true;
+            } else if (controller(page) != null && controllers++ == 0) {
+                // An explicit controller needs an authored pool.
+            } else if (isBlockPage(page) && !material && !rocks
+                    && PortSymbolPages.find(page) != null
+                    && PortSymbolPages.find(page).category().equals("rivencraft:block")) {
+                material = true;
+            } else if (page.equals(ROCKS) && material && !rocks) {
+                rocks = true;
+            } else if (page.getNamespace().equals(Rivencraft.MOD_ID)
+                    && page.getPath().startsWith("biome/") && biomes < MAX_AUTHORED_BIOMES
+                    && PortSymbolPages.find(page) != null
+                    && PortSymbolPages.find(page).category().equals("rivencraft:biome")
+                    && PortRegistryPages.biomeId(page) != null) {
+                biomes++;
+            } else return false;
+        }
+        if (material != rocks || rocks && (pages.contains(CAVE_TERRAIN) || pages.contains(VOID_TERRAIN))) return false;
+        if (controllers != 0) {
+            PortBiomePlan.Distribution distribution = pages.stream().map(PortAuthoredWriting::controller)
+                    .filter(value -> value != null).findFirst().orElseThrow();
+            boolean valid = switch (distribution) {
+                case NATIVE -> biomes == 0;
+                case SINGLE -> biomes == 1;
+                default -> biomes >= 2;
+            };
+            return valid;
+        }
+        return true;
+    }
+
+    private static boolean isTerrain(Identifier page) {
+        return page.equals(STANDARD_TERRAIN) || page.equals(AMPLIFIED_TERRAIN)
+                || page.equals(ISLAND_TERRAIN) || page.equals(FLAT_TERRAIN)
+                || page.equals(VOID_TERRAIN) || page.equals(CAVE_TERRAIN);
+    }
+
+    private static boolean isBlockPage(Identifier page) {
+        return page.getNamespace().equals(Rivencraft.MOD_ID) && page.getPath().startsWith("block/");
+    }
+
+    private static PortBiomePlan.Distribution controller(Identifier page) {
+        if (!page.getNamespace().equals(Rivencraft.MOD_ID)) return null;
+        return switch (page.getPath()) {
+            case "biome/native" -> PortBiomePlan.Distribution.NATIVE;
+            case "biome/single" -> PortBiomePlan.Distribution.SINGLE;
+            case "biome/tiled" -> PortBiomePlan.Distribution.TILED;
+            case "biome/grid" -> PortBiomePlan.Distribution.GRID;
+            case "biome/tiny" -> PortBiomePlan.Distribution.TINY;
+            case "biome/small" -> PortBiomePlan.Distribution.SMALL;
+            case "biome/medium" -> PortBiomePlan.Distribution.MEDIUM;
+            case "biome/large" -> PortBiomePlan.Distribution.LARGE;
+            case "biome/huge" -> PortBiomePlan.Distribution.HUGE;
+            default -> null;
+        };
+    }
+
+    public static PortAgeTerrain terrain(List<Identifier> pages) {
+        if (!supports(pages)) throw new IllegalArgumentException("Unsupported authored Age pages");
+        if (pages.contains(AMPLIFIED_TERRAIN)) return PortAgeTerrain.AMPLIFIED;
+        if (pages.contains(ISLAND_TERRAIN)) return PortAgeTerrain.ISLAND;
+        if (pages.contains(FLAT_TERRAIN)) return PortAgeTerrain.FLAT;
+        if (pages.contains(VOID_TERRAIN)) return PortAgeTerrain.VOID;
+        if (pages.contains(CAVE_TERRAIN)) return PortAgeTerrain.CAVE;
+        return PortAgeTerrain.STANDARD;
+    }
+
+    public static PortRockPlan rockPlan(List<Identifier> pages) {
+        if (!supports(pages)) throw new IllegalArgumentException("Unsupported authored Age pages");
+        return pages.contains(ROCKS) ? new PortRockPlan(pages.stream()
+                .filter(PortAuthoredWriting::isBlockPage).map(PortRegistryPages::blockId)
+                .findFirst().orElseThrow()) : null;
+    }
+
+    /** Resolves all authored biomes from the active registry before creating a level. */
+    public static PortBiomePlan biomePlan(List<Identifier> pages, HolderLookup.Provider registries) {
+        if (!supports(pages)) throw new IllegalArgumentException(
+                "Unsupported terrain or biome-page combination in this port slice");
+        List<Identifier> biomes = new ArrayList<>();
+        PortBiomePlan.Distribution distribution = null;
+        boolean caveTerrain = pages.contains(CAVE_TERRAIN);
+        for (Identifier page : pages) {
+            if (isTerrain(page) || page.equals(ROCKS) || isBlockPage(page)) continue;
+            PortBiomePlan.Distribution selected = controller(page);
+            if (selected != null) { distribution = selected; continue; }
+            Identifier biome = PortRegistryPages.biomeId(page);
+            var registry = registries.lookupOrThrow(Registries.BIOME);
+            var holder = registry.get(ResourceKey.create(Registries.BIOME, biome))
+                    .orElseThrow(() -> new IllegalArgumentException("Unknown authored biome: " + biome));
+            if (caveTerrain && !PortRegistryPages.isCaveBiome(holder))
+                throw new IllegalArgumentException("Cave terrain requires a Cave or Nether biome: " + biome);
+            biomes.add(biome);
+        }
+        if (distribution == PortBiomePlan.Distribution.NATIVE)
+            return new PortBiomePlan(distribution, List.of());
+        if (biomes.isEmpty()) return null;
+        if (distribution == null) distribution = biomes.size() == 1
+                ? PortBiomePlan.Distribution.SINGLE : biomes.size() == 2
+                ? PortBiomePlan.Distribution.TILED : PortBiomePlan.Distribution.MEDIUM;
+        return new PortBiomePlan(distribution, biomes);
+    }
+}

ports/mc263/src/main/java/net/dnorberg/rivencraft/writing/PortRegistryPages.java

@@ -0,0 +1,136 @@
+package net.dnorberg.rivencraft.writing;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Locale;
+import net.dnorberg.rivencraft.Rivencraft;
+import net.dnorberg.rivencraft.item.PageItem;
+import net.minecraft.core.BlockPos;
+import net.minecraft.core.HolderLookup;
+import net.minecraft.core.registries.BuiltInRegistries;
+import net.minecraft.core.registries.Registries;
+import net.minecraft.resources.Identifier;
+import net.minecraft.tags.BiomeTags;
+import net.minecraft.tags.TagKey;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.level.EmptyBlockGetter;
+import net.minecraft.world.level.block.Block;
+import net.minecraft.world.level.block.Blocks;
+import net.minecraft.world.level.block.EntityBlock;
+
+/** Registry-derived 26.3 biome and material pages, with the same IDs as 1.21.1. */
+public final class PortRegistryPages {
+    private static final TagKey<net.minecraft.world.level.biome.Biome> CAVE_BIOMES = TagKey.create(
+            Registries.BIOME, Identifier.fromNamespaceAndPath(Rivencraft.MOD_ID, "cave_biomes"));
+    private static final Identifier DEFERRED_PLACEHOLDER = Identifier.fromNamespaceAndPath(
+            "terrablender", "deferred_placeholder");
+
+    private PortRegistryPages() {}
+
+    public static Identifier biomePageId(Identifier biome) {
+        return Identifier.fromNamespaceAndPath(Rivencraft.MOD_ID, "biome/"
+                + (biome.getNamespace().equals("minecraft") ? "" : biome.getNamespace() + "/")
+                + biome.getPath());
+    }
+
+    public static Identifier blockPageId(Identifier block) {
+        return Identifier.fromNamespaceAndPath(Rivencraft.MOD_ID,
+                "block/" + block.getNamespace() + "/" + block.getPath());
+    }
+
+    public static PortSymbolPages.Entry find(Identifier symbol) {
+        if (!symbol.getNamespace().equals(Rivencraft.MOD_ID)) return null;
+        String path = symbol.getPath();
+        if (path.startsWith("biome/")) {
+            Identifier biome = biomeId(symbol);
+            if (biome == null) return null;
+            String key = biome.getNamespace().equals("minecraft")
+                    ? "symbol.rivencraft.biome." + biome.getPath()
+                    : "biome." + biome.getNamespace() + "." + biome.getPath().replace('/', '.');
+            return new PortSymbolPages.Entry(symbol, "rivencraft:biome", key,
+                    "symbol.rivencraft.biome.generated.description",
+                    "Nature Form " + glyphWord(biome.getPath(), "World") + " Biome");
+        }
+        if (path.startsWith("block/")) {
+            Identifier block = blockId(symbol);
+            if (block == null) return null;
+            String category = materialCategory(BuiltInRegistries.BLOCK.getValue(block));
+            if (category == null) return null;
+            return new PortSymbolPages.Entry(symbol, category,
+                    "block." + block.getNamespace() + "." + block.getPath().replace('/', '_'),
+                    "symbol.rivencraft.block.generated.description",
+                    "Modifier Constraint " + glyphWord(block.getPath(), "Stone") + " Form");
+        }
+        return null;
+    }
+
+    public static List<ItemStack> biomePages(HolderLookup.Provider registries, boolean caves) {
+        return registries.lookupOrThrow(Registries.BIOME).listElements()
+                .filter(holder -> !holder.key().identifier().equals(DEFERRED_PLACEHOLDER))
+                .filter(holder -> isCaveBiome(holder) == caves)
+                .map(holder -> PageItem.createSymbolPage(biomePageId(holder.key().identifier())))
+                .sorted((left, right) -> left.get(Rivencraft.SYMBOL_PAGE_ID.get()).toString()
+                        .compareTo(right.get(Rivencraft.SYMBOL_PAGE_ID.get()).toString()))
+                .toList();
+    }
+
+    public static List<ItemStack> materialPages(boolean fluids) {
+        String category = fluids ? "rivencraft:fluid" : "rivencraft:block";
+        return BuiltInRegistries.BLOCK.keySet().stream().sorted()
+                .filter(id -> category.equals(materialCategory(BuiltInRegistries.BLOCK.getValue(id))))
+                .map(id -> PageItem.createSymbolPage(blockPageId(id))).toList();
+    }
+
+    public static boolean isCaveBiome(net.minecraft.core.Holder.Reference<net.minecraft.world.level.biome.Biome> holder) {
+        String path = holder.key().identifier().getPath();
+        return holder.is(CAVE_BIOMES) || holder.is(BiomeTags.IS_NETHER)
+                || path.equals("deep_dark") || path.endsWith("_caves");
+    }
+
+    private static String materialCategory(Block block) {
+        if (block == null || block == Blocks.AIR || block == Blocks.CAVE_AIR || block == Blocks.VOID_AIR
+                || block instanceof EntityBlock || block.defaultBlockState().hasBlockEntity()) return null;
+        var state = block.defaultBlockState();
+        var fluid = state.getFluidState();
+        if (fluid.isSource() && fluid.createLegacyBlock().getBlock() == block) return "rivencraft:fluid";
+        return fluid.isEmpty() && state.isCollisionShapeFullBlock(EmptyBlockGetter.INSTANCE, BlockPos.ZERO)
+                ? "rivencraft:block" : null;
+    }
+
+    public static Identifier biomeId(Identifier symbol) {
+        String path = symbol.getPath().substring("biome/".length());
+        int slash = path.indexOf('/');
+        if (slash < 0) return Identifier.fromNamespaceAndPath("minecraft", path);
+        return Identifier.fromNamespaceAndPath(path.substring(0, slash), path.substring(slash + 1));
+    }
+
+    public static Identifier blockId(Identifier symbol) {
+        String path = symbol.getPath().substring("block/".length());
+        int slash = path.indexOf('/');
+        if (slash < 1) return null;
+        return Identifier.fromNamespaceAndPath(path.substring(0, slash), path.substring(slash + 1));
+    }
+
+    public static String fallbackName(Identifier symbol) {
+        boolean biome = symbol.getPath().startsWith("biome/");
+        Identifier source = biome ? biomeId(symbol) : blockId(symbol);
+        if (source == null) return symbol.toString();
+        String words = Arrays.stream(source.getPath().replace('/', '_').split("_"))
+                .filter(word -> !word.isEmpty())
+                .map(word -> word.substring(0, 1).toUpperCase(Locale.ROOT) + word.substring(1))
+                .reduce((a, b) -> a + " " + b).orElse("Unknown");
+        return words + (biome ? " Biome" : "rivencraft:fluid".equals(find(symbol).category())
+                ? " Fluid" : " Material")
+                + (source.getNamespace().equals("minecraft") ? "" : " (" + source.getNamespace() + ")");
+    }
+
+    private static String glyphWord(String path, String fallback) {
+        String word = Arrays.stream(path.replace('/', '_').split("_"))
+                .map(part -> part.replaceAll("[^A-Za-z]", ""))
+                .filter(part -> !part.isEmpty())
+                .map(part -> part.substring(0, 1).toUpperCase(Locale.ROOT) + part.substring(1))
+                .reduce("", String::concat);
+        if (word.isEmpty()) word = fallback;
+        return word.length() > 48 ? word.substring(0, 48) : word;
+    }
+}

ports/mc263/src/main/java/net/dnorberg/rivencraft/writing/PortSymbolNumerals.java

@@ -0,0 +1,16 @@
+package net.dnorberg.rivencraft.writing;
+
+/** Mystcraft Legacy's layered base-25 numeral components, shared with 1.21.1. */
+public final class PortSymbolNumerals {
+    private PortSymbolNumerals() {}
+
+    public static int[] componentsForDigit(int digit) {
+        if (digit < 0 || digit >= 25) throw new IllegalArgumentException("Base-25 digit must be in [0, 24]");
+        if (digit == 0) return new int[] {1};
+        int fifths = digit / 5;
+        int remainder = digit % 5;
+        if (fifths == 0) return new int[] {55 + remainder};
+        if (remainder == 0) return new int[] {59 + fifths};
+        return new int[] {59 + fifths, 55 + remainder};
+    }
+}

ports/mc263/src/main/java/net/dnorberg/rivencraft/writing/PortSymbolPages.java

@@ -0,0 +1,101 @@
+package net.dnorberg.rivencraft.writing;
+
+import com.google.gson.JsonParser;
+import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.LinkedHashSet;
+import net.dnorberg.rivencraft.Rivencraft;
+import net.minecraft.resources.Identifier;
+import net.minecraft.core.HolderLookup;
+import net.minecraft.world.item.ItemStack;
+import net.dnorberg.rivencraft.item.PageItem;
+
+/** Bundled 1.21.1 symbol identities, shared by the port's creative pages. */
+public final class PortSymbolPages {
+    public record Entry(Identifier id, String category, String nameKey, String descriptionKey, String poem) {}
+
+    private static final Map<Identifier, Entry> ENTRIES = load();
+
+    private PortSymbolPages() {}
+
+    public static Entry find(Identifier id) {
+        Entry bundled = ENTRIES.get(id);
+        return bundled != null ? bundled : PortRegistryPages.find(id);
+    }
+
+    public static List<String> categories() {
+        LinkedHashSet<String> categories = new LinkedHashSet<>();
+        ENTRIES.values().stream().map(Entry::category).forEach(categories::add);
+        categories.add("rivencraft:cave_biome");
+        categories.add("rivencraft:block");
+        categories.add("rivencraft:fluid");
+        return List.copyOf(categories);
+    }
+
+    public static List<ItemStack> pages(String category, HolderLookup.Provider registries) {
+        List<ItemStack> pages = new ArrayList<>();
+        ENTRIES.values().stream().filter(entry -> entry.category().equals(category))
+                .filter(entry -> !category.equals("rivencraft:biome")
+                        || !entry.id().getPath().startsWith("biome/"))
+                .forEach(entry -> pages.add(PageItem.createSymbolPage(entry.id())));
+        if (category.equals("rivencraft:biome")) pages.addAll(PortRegistryPages.biomePages(registries, false));
+        if (category.equals("rivencraft:cave_biome")) pages.addAll(PortRegistryPages.biomePages(registries, true));
+        if (category.equals("rivencraft:block")) pages.addAll(PortRegistryPages.materialPages(false));
+        if (category.equals("rivencraft:fluid")) pages.addAll(PortRegistryPages.materialPages(true));
+        return List.copyOf(pages);
+    }
+
+    public static ItemStack icon(String category) {
+        if (category.equals("rivencraft:cave_biome"))
+            return PageItem.createSymbolPage(PortRegistryPages.biomePageId(
+                    Identifier.fromNamespaceAndPath("minecraft", "lush_caves")));
+        if (category.equals("rivencraft:block") || category.equals("rivencraft:fluid"))
+            return PageItem.createSymbolPage(PortRegistryPages.blockPageId(
+                    Identifier.fromNamespaceAndPath("minecraft",
+                            category.equals("rivencraft:fluid") ? "water" : "stone")));
+        return ENTRIES.values().stream().filter(entry -> entry.category().equals(category))
+                .findFirst().map(entry -> PageItem.createSymbolPage(entry.id()))
+                .orElseGet(PageItem::createLinkPanelPage);
+    }
+
+    public static String fallbackName(Identifier id) {
+        if (id.getPath().startsWith("biome/") || id.getPath().startsWith("block/"))
+            return PortRegistryPages.fallbackName(id);
+        String path = id.getPath();
+        String stem = path.substring(path.lastIndexOf('/') + 1).replace('_', ' ');
+        if (stem.isEmpty()) return id.toString();
+        return Character.toUpperCase(stem.charAt(0)) + stem.substring(1);
+    }
+
+    private static Map<Identifier, Entry> load() {
+        String resource = "/assets/rivencraft/creative_symbol_pages.json";
+        try (var stream = PortSymbolPages.class.getResourceAsStream(resource)) {
+            if (stream == null) throw new IllegalStateException("Missing generated symbol index " + resource);
+            var json = JsonParser.parseReader(new InputStreamReader(stream, StandardCharsets.UTF_8))
+                    .getAsJsonObject();
+            Map<Identifier, Entry> entries = new LinkedHashMap<>();
+            json.entrySet().forEach(item -> {
+                String[] parts = item.getKey().split(":", 2);
+                if (parts.length != 2 || !parts[0].equals(Rivencraft.MOD_ID))
+                    throw new IllegalStateException("Unexpected bundled symbol " + item.getKey());
+                Identifier id = Identifier.fromNamespaceAndPath(parts[0], parts[1]);
+                var definition = item.getValue().getAsJsonObject();
+                String category = definition.get("category").getAsString();
+                if (definition.has("semantics") && definition.getAsJsonObject("semantics")
+                        .get("role").getAsString().equals("biome_controller"))
+                    category = "rivencraft:biome_generation";
+                entries.put(id, new Entry(id, category, definition.get("name").getAsString(),
+                        definition.get("description").getAsString(),
+                        definition.has("poem") ? definition.get("poem").getAsString() : ""));
+            });
+            return Collections.unmodifiableMap(entries);
+        } catch (java.io.IOException exception) {
+            throw new IllegalStateException("Could not read bundled symbol index", exception);
+        }
+    }
+}

ports/mc263/src/main/resources/assets/rivencraft/items/page.json

@@ -4,6 +4,16 @@
     "property": "minecraft:has_component",
     "component": "rivencraft:link_panel_page",
     "on_true": {"type": "minecraft:model", "model": "rivencraft:item/page_link_panel"},
-    "on_false": {"type": "minecraft:model", "model": "rivencraft:item/page"}
+    "on_false": {
+      "type": "minecraft:condition",
+      "property": "minecraft:has_component",
+      "component": "rivencraft:symbol_page_id",
+      "on_true": {
+        "type": "minecraft:special",
+        "base": "rivencraft:item/page",
+        "model": {"type": "rivencraft:symbol_page"}
+      },
+      "on_false": {"type": "minecraft:model", "model": "rivencraft:item/page"}
+    }
   }
 }

ports/mc263/src/main/resources/data/rivencraft/rivencraft/symbols/feature/abandoned_camps.json

@@ -0,0 +1,8 @@
+{
+  "schema_version": 2,
+  "name": "symbol.rivencraft.feature.abandoned_camps",
+  "description": "symbol.rivencraft.feature.abandoned_camps.description",
+  "category": "rivencraft:feature",
+  "semantics": { "role": "feature", "value": "rivencraft:abandoned_camps" },
+  "poem": "Terrain Form Abandoned Camp"
+}

ports/mc263/src/main/resources/data/rivencraft/rivencraft/symbols/feature/fallen_poplar_trees.json

@@ -0,0 +1,8 @@
+{
+  "schema_version": 2,
+  "name": "symbol.rivencraft.feature.fallen_poplar_trees",
+  "description": "symbol.rivencraft.feature.fallen_poplar_trees.description",
+  "category": "rivencraft:feature",
+  "semantics": { "role": "feature", "value": "rivencraft:fallen_poplar_trees" },
+  "poem": "Nature Form Poplar Fallen"
+}

ports/mc263/src/main/resources/data/rivencraft/rivencraft/symbols/feature/poplar_trees.json

@@ -0,0 +1,8 @@
+{
+  "schema_version": 2,
+  "name": "symbol.rivencraft.feature.poplar_trees",
+  "description": "symbol.rivencraft.feature.poplar_trees.description",
+  "category": "rivencraft:feature",
+  "semantics": { "role": "feature", "value": "rivencraft:poplar_trees" },
+  "poem": "Nature Form Poplar Growth"
+}

ports/mc263/src/main/resources/data/rivencraft/rivencraft/symbols/feature/red_shrubs.json

@@ -0,0 +1,8 @@
+{
+  "schema_version": 2,
+  "name": "symbol.rivencraft.feature.red_shrubs",
+  "description": "symbol.rivencraft.feature.red_shrubs.description",
+  "category": "rivencraft:feature",
+  "semantics": { "role": "feature", "value": "rivencraft:red_shrubs" },
+  "poem": "Nature Form Red Growth"
+}

ports/mc263/src/main/resources/data/rivencraft/rivencraft/symbols/feature/shelf_mushrooms.json

@@ -0,0 +1,8 @@
+{
+  "schema_version": 2,
+  "name": "symbol.rivencraft.feature.shelf_mushrooms",
+  "description": "symbol.rivencraft.feature.shelf_mushrooms.description",
+  "category": "rivencraft:feature",
+  "semantics": { "role": "feature", "value": "rivencraft:shelf_mushrooms" },
+  "poem": "Nature Form Shelf Fungi"
+}

ports/mc263/src/main/resources/data/rivencraft/tags/worldgen/biome/cave_biomes.json

@@ -0,0 +1,8 @@
+{
+  "replace": false,
+  "values": [
+    "minecraft:lush_caves",
+    "minecraft:dripstone_caves",
+    "minecraft:deep_dark"
+  ]
+}

scripts/publish_mod_sites.py

@@ -0,0 +1,283 @@
+#!/usr/bin/env python3
+"""Publish a Rivencraft JAR to Gitea, Modrinth, and/or CurseForge.
+
+Preview is the default. Tokens live in the Secret Service keyring, never in git.
+"""
+
+import argparse
+import getpass
+import json
+import mimetypes
+import os
+from pathlib import Path
+import secrets
+import subprocess
+import sys
+import urllib.error
+import urllib.request
+
+
+MODRINTH_PROJECT = "GH2xfZJ8"
+CURSEFORGE_PROJECT = "1766326"
+GITEA_API = "https://git.paddedcell.org/api/v1/repos/dnorberg/rivencraft"
+USER_AGENT = "RivencraftReleaseTool/1.0 (https://git.paddedcell.org/dnorberg/rivencraft)"
+SITES = ("gitea", "modrinth", "curseforge")
+
+
+def token_for(site: str) -> str:
+    environment = os.environ.get(f"RIVENCRAFT_{site.upper()}_TOKEN", "").strip()
+    if environment:
+        return environment
+    result = subprocess.run(
+        ["secret-tool", "lookup", "application", "rivencraft-publishing", "site", site],
+        text=True,
+        capture_output=True,
+        check=False,
+    )
+    if result.returncode:
+        raise RuntimeError(f"Could not read {site} token from the system keyring")
+    token = result.stdout.strip()
+    if not token:
+        raise RuntimeError(f"No {site} token found; run `store-token {site}` first")
+    return token
+
+
+def store_token(site: str) -> None:
+    token = getpass.getpass(f"Paste the {site} API token (input hidden): ").strip()
+    if not token:
+        raise RuntimeError("Empty token; nothing was stored")
+    subprocess.run(
+        [
+            "secret-tool", "store", "--label", f"Rivencraft {site} publishing token",
+            "application", "rivencraft-publishing", "site", site,
+        ],
+        input=token + "\n",
+        text=True,
+        check=True,
+    )
+    print(f"Stored {site} token in the system keyring")
+
+
+def check_token(site: str) -> None:
+    token = token_for(site)
+    if site == "gitea":
+        account = request_json("https://git.paddedcell.org/api/v1/token", token=f"token {token}")
+        scopes = account.get("scopes", [])
+        if "write:repository" not in scopes and "all" not in scopes:
+            raise RuntimeError("Gitea token is valid but lacks write:repository scope")
+        print(f"Gitea API access works for {account['user']['login']} (write:repository)")
+    elif site == "modrinth":
+        try:
+            account = request_json("https://api.modrinth.com/v2/user", token=token)
+        except RuntimeError as error:
+            raise RuntimeError(
+                "Modrinth check failed. The token needs USER_READ for this "
+                "read-only check, plus VERSION_CREATE for publishing. "
+                f"API response: {error}"
+            ) from None
+        print(f"Modrinth API access works for {account['username']}")
+    else:
+        versions = request_json(
+            "https://www.curseforge.com/api/game/versions",
+            token=token, token_header="X-Api-Token",
+        )
+        if not isinstance(versions, list):
+            raise RuntimeError("CurseForge returned an unexpected response")
+        print("CurseForge API token accepted")
+
+
+def request_json(url: str, *, token: str | None = None, token_header: str = "Authorization",
+                 payload: bytes | None = None, content_type: str | None = None,
+                 method: str = "GET", not_found_ok: bool = False) -> dict | list | None:
+    headers = {"User-Agent": USER_AGENT, "Accept": "application/json"}
+    if token:
+        headers[token_header] = token
+    if content_type:
+        headers["Content-Type"] = content_type
+    request = urllib.request.Request(url, data=payload, headers=headers, method=method)
+    try:
+        with urllib.request.urlopen(request, timeout=120) as response:
+            return json.load(response)
+    except urllib.error.HTTPError as error:
+        if error.code == 404 and not_found_ok:
+            return None
+        # Error bodies can contain server details, but never echo tokens.
+        detail = error.read(600).decode("utf-8", "replace")
+        raise RuntimeError(f"{url}: HTTP {error.code}: {detail}") from None
+
+
+def multipart(fields: dict[str, str], jar: Path, *, file_field: str = "file") -> tuple[bytes, str]:
+    boundary = "rivencraft-" + secrets.token_hex(16)
+    chunks = []
+    for name, value in fields.items():
+        chunks.extend((
+            f"--{boundary}\r\nContent-Disposition: form-data; name=\"{name}\"\r\n\r\n".encode(),
+            value.encode(), b"\r\n",
+        ))
+    filename = jar.name.replace('"', "")
+    mime = mimetypes.guess_type(filename)[0] or "application/java-archive"
+    chunks.extend((
+        f"--{boundary}\r\nContent-Disposition: form-data; name=\"{file_field}\"; filename=\"{filename}\"\r\nContent-Type: {mime}\r\n\r\n".encode(),
+        jar.read_bytes(), b"\r\n", f"--{boundary}--\r\n".encode(),
+    ))
+    return b"".join(chunks), f"multipart/form-data; boundary={boundary}"
+
+
+def release_metadata(args: argparse.Namespace) -> tuple[dict, dict]:
+    changelog = args.changelog.read_text(encoding="utf-8")
+    if not changelog.strip():
+        raise RuntimeError("Changelog is empty")
+    modrinth = {
+        "name": args.name,
+        "version_number": args.version,
+        "changelog": changelog,
+        "dependencies": [],
+        "game_versions": [args.minecraft],
+        "version_type": args.channel,
+        "loaders": ["neoforge"],
+        "featured": False,
+        "status": "listed",
+        "project_id": MODRINTH_PROJECT,
+        "file_parts": ["file"],
+        "primary_file": "file",
+        "environment": "client_and_server",
+    }
+    curseforge = {
+        "changelog": changelog,
+        "changelogType": "markdown",
+        "displayName": args.name,
+        "gameVersionNames": [args.minecraft, "NeoForge", "Client", "Server", f"Java {args.java}"],
+        "releaseType": args.channel,
+        "isMarkedForManualRelease": False,
+    }
+    return modrinth, curseforge
+
+
+def publish_modrinth(metadata: dict, jar: Path) -> None:
+    token = token_for("modrinth")
+    versions = request_json(
+        f"https://api.modrinth.com/v2/project/{MODRINTH_PROJECT}/version",
+        token=token,
+    )
+    if any(version.get("version_number") == metadata["version_number"] for version in versions):
+        raise RuntimeError(f"Modrinth version {metadata['version_number']} already exists")
+    body, content_type = multipart({"data": json.dumps(metadata)}, jar)
+    result = request_json(
+        "https://api.modrinth.com/v2/version", token=token, payload=body,
+        content_type=content_type, method="POST",
+    )
+    print(f"Modrinth: https://modrinth.com/mod/rivencraft/version/{result['version_number']}")
+
+
+def publish_curseforge(metadata: dict, jar: Path) -> None:
+    token = token_for("curseforge")
+    body, content_type = multipart({"metadata": json.dumps(metadata)}, jar)
+    result = request_json(
+        f"https://www.curseforge.com/api/projects/{CURSEFORGE_PROJECT}/upload-file",
+        token=token, token_header="X-Api-Token", payload=body,
+        content_type=content_type, method="POST",
+    )
+    print(f"CurseForge: https://www.curseforge.com/minecraft/mc-mods/rivencraft/files/{result['id']} (pending approval)")
+
+
+def publish_gitea(args: argparse.Namespace) -> None:
+    base_version, suffix = args.version.split("-", 1)
+    if suffix != f"{args.channel}.1":
+        raise RuntimeError("Gitea tag convention requires a version ending in the selected channel and .1")
+    tag = f"V{base_version}-mc{args.minecraft}-{suffix}"
+    # The release must refer to a tag already pushed by the normal Git workflow.
+    remote_tag = subprocess.run(
+        ["git", "ls-remote", "origin", f"refs/tags/{tag}"],
+        text=True, capture_output=True, check=True,
+    )
+    if not remote_tag.stdout.strip():
+        raise RuntimeError(f"Push the Gitea tag {tag} before publishing")
+
+    token = f"token {token_for('gitea')}"
+    release_url = f"{GITEA_API}/releases/tags/{tag}"
+    release = request_json(release_url, token=token, not_found_ok=True)
+    notes = args.changelog.read_text(encoding="utf-8")
+    title = f"Rivencraft {args.minecraft} {args.channel} {args.version}"
+    if release is None:
+        metadata = {
+            "tag_name": tag,
+            "target_commitish": "main",
+            "name": title,
+            "body": notes,
+            "draft": False,
+            "prerelease": args.channel != "release",
+        }
+        release = request_json(
+            f"{GITEA_API}/releases", token=token,
+            payload=json.dumps(metadata).encode(), content_type="application/json", method="POST",
+        )
+    elif release.get("name") != title or release.get("body", "").strip() != notes.strip():
+        raise RuntimeError(f"Gitea release {tag} exists with different notes or title; inspect it before retrying")
+
+    assets = release.get("assets", [])
+    if any(asset.get("name") == args.jar.name for asset in assets):
+        raise RuntimeError(f"Gitea release {tag} already has {args.jar.name}")
+    body, content_type = multipart({}, args.jar, file_field="attachment")
+    attachment = request_json(
+        f"{GITEA_API}/releases/{release['id']}/assets", token=token,
+        payload=body, content_type=content_type, method="POST",
+    )
+    if attachment.get("name") != args.jar.name or attachment.get("size") != args.jar.stat().st_size:
+        raise RuntimeError("Gitea returned unexpected attachment metadata; inspect the release")
+    print(f"Gitea: {release['html_url']}")
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(description=__doc__)
+    sub = parser.add_subparsers(dest="command", required=True)
+    store = sub.add_parser("store-token", help="Securely save a token in the system keyring")
+    store.add_argument("site", choices=SITES)
+    check = sub.add_parser("check-token", help="Verify stored token with a read-only API call")
+    check.add_argument("site", choices=SITES)
+    publish = sub.add_parser("release", help="Preview or publish a JAR release")
+    publish.add_argument("--jar", type=Path, required=True)
+    publish.add_argument("--changelog", type=Path, required=True)
+    publish.add_argument("--version", required=True)
+    publish.add_argument("--name", required=True)
+    publish.add_argument("--minecraft", required=True)
+    publish.add_argument("--java", required=True)
+    publish.add_argument("--channel", choices=("alpha", "beta", "release"), required=True)
+    publish.add_argument("--site", choices=(*SITES, "both", "all"), default="all")
+    publish.add_argument("--publish", action="store_true", help="Actually upload; omitted by default")
+    args = parser.parse_args()
+    if args.command == "store-token":
+        store_token(args.site)
+        return
+    if args.command == "check-token":
+        check_token(args.site)
+        return
+    if not args.jar.is_file() or args.jar.suffix != ".jar":
+        raise RuntimeError(f"JAR does not exist: {args.jar}")
+    if not args.changelog.is_file():
+        raise RuntimeError(f"Changelog does not exist: {args.changelog}")
+    if args.minecraft != "26.3":
+        raise RuntimeError("Only the 26.3 line is configured; 1.21.1 needs required dependency relations")
+    if args.jar.name != f"rivencraft-{args.minecraft}-{args.version}.jar":
+        raise RuntimeError("JAR filename does not match Minecraft and release versions")
+    modrinth, curseforge = release_metadata(args)
+    sites = SITES if args.site == "all" else (("modrinth", "curseforge") if args.site == "both" else (args.site,))
+    print(f"JAR: {args.jar.resolve()} ({args.jar.stat().st_size} bytes)")
+    print(f"Release: {args.version} | {args.channel} | Minecraft {args.minecraft} | NeoForge | Java {args.java}")
+    print(f"Destinations: {', '.join(sites)}")
+    if not args.publish:
+        print("PREVIEW ONLY: add --publish to upload")
+        return
+    if "gitea" in sites:
+        publish_gitea(args)
+    if "modrinth" in sites:
+        publish_modrinth(modrinth, args.jar)
+    if "curseforge" in sites:
+        publish_curseforge(curseforge, args.jar)
+
+
+if __name__ == "__main__":
+    try:
+        main()
+    except (OSError, ValueError, RuntimeError, subprocess.CalledProcessError) as error:
+        print(f"Publishing failed: {error}", file=sys.stderr)
+        sys.exit(1)

scripts/smoke_server_263.sh

@@ -69,6 +69,14 @@ start_server first
 send_and_wait 'rivencraft_port compat' 'Registered biomes by namespace:'
 send_and_wait 'rivencraft_port age create smoke_alpha 123456789' 'Created rivencraft:age/smoke_alpha with seed 123456789'
 send_and_wait 'rivencraft_port age create smoke_beta 987654321' 'Created rivencraft:age/smoke_beta with seed 987654321'
+send_and_wait 'rivencraft_port age create smoke_flat 24680 flat' 'Created rivencraft:age/smoke_flat with seed 24680 terrain=FLAT'
+send_and_wait 'rivencraft_port age create smoke_void 13579 void' 'Created rivencraft:age/smoke_void with seed 13579 terrain=VOID'
+send_and_wait 'rivencraft_port age create smoke_cave 112233 cave' 'Created rivencraft:age/smoke_cave with seed 112233 terrain=CAVE'
+send_and_wait 'rivencraft_port age create_multi smoke_flat_multi 24681 flat' 'Created rivencraft:age/smoke_flat_multi with seed 24681 terrain=FLAT'
+send_and_wait 'rivencraft_port age create_multi smoke_void_multi 13580 void' 'Created rivencraft:age/smoke_void_multi with seed 13580 terrain=VOID'
+send_and_wait 'rivencraft_port age create_multi smoke_cave_multi 112234 cave' 'Created rivencraft:age/smoke_cave_multi with seed 112234 terrain=CAVE'
+send_and_wait 'rivencraft_port age create_random smoke_random 889900' 'Random Age plan: terrain='
+send_and_wait 'rivencraft_port age create_rocks smoke_rocks 445566' 'Created rivencraft:age/smoke_rocks with seed 445566 terrain=FLAT'
 # The index must reach disk while the server is still running. A graceful
 # shutdown would hide the interrupted-save regression this checks.
 index_file="$server_dir/world/dimensions/minecraft/overworld/data/rivencraft/runtime_ages.dat"
@@ -78,26 +86,104 @@ index_file="$server_dir/world/dimensions/minecraft/overworld/data/rivencraft/run
 }
 gzip -dc "$index_file" | strings | grep -Fq 'rivencraft:age/smoke_alpha'
 gzip -dc "$index_file" | strings | grep -Fq 'rivencraft:age/smoke_beta'
+gzip -dc "$index_file" | strings | grep -Fq 'rivencraft:age/smoke_flat'
+gzip -dc "$index_file" | strings | grep -Fq 'rivencraft:age/smoke_void'
+gzip -dc "$index_file" | strings | grep -Fq 'rivencraft:age/smoke_cave'
+gzip -dc "$index_file" | strings | grep -Fq 'rivencraft:age/smoke_flat_multi'
+gzip -dc "$index_file" | strings | grep -Fq 'rivencraft:age/smoke_void_multi'
+gzip -dc "$index_file" | strings | grep -Fq 'rivencraft:age/smoke_cave_multi'
+gzip -dc "$index_file" | strings | grep -Fq 'rivencraft:age/smoke_random'
+gzip -dc "$index_file" | strings | grep -Fq 'rivencraft:age/smoke_rocks'
 send_and_wait 'rivencraft_port age sample smoke_alpha' 'rivencraft:age/smoke_alpha seed=123456789 chunkOffset=0 terrain='
 send_and_wait 'rivencraft_port age sample smoke_beta' 'rivencraft:age/smoke_beta seed=987654321 chunkOffset=0 terrain='
+send_and_wait 'rivencraft_port age sample smoke_flat' 'rivencraft:age/smoke_flat seed=24680 chunkOffset=0 terrain='
+send_and_wait 'rivencraft_port age sample smoke_void' 'rivencraft:age/smoke_void seed=13579 chunkOffset=0 terrain='
+send_and_wait 'rivencraft_port age sample smoke_cave' 'rivencraft:age/smoke_cave seed=112233 chunkOffset=0 terrain='
+send_and_wait 'rivencraft_port age sample smoke_flat_multi' 'rivencraft:age/smoke_flat_multi seed=24681 chunkOffset=0 terrain='
+send_and_wait 'rivencraft_port age sample smoke_void_multi' 'rivencraft:age/smoke_void_multi seed=13580 chunkOffset=0 terrain='
+send_and_wait 'rivencraft_port age sample smoke_cave_multi' 'rivencraft:age/smoke_cave_multi seed=112234 chunkOffset=0 terrain='
+send_and_wait 'rivencraft_port age sample smoke_random' 'rivencraft:age/smoke_random seed=889900 chunkOffset=0 terrain='
+send_and_wait 'rivencraft_port age sample smoke_rocks' 'rivencraft:age/smoke_rocks seed=445566 chunkOffset=0 terrain='
+send_and_wait 'execute in rivencraft:age/smoke_flat run forceload add 0 0' 'Marked chunk [0, 0] in rivencraft:age/smoke_flat to be force loaded'
+send_and_wait 'execute in rivencraft:age/smoke_void run forceload add 0 0' 'Marked chunk [0, 0] in rivencraft:age/smoke_void to be force loaded'
+send_and_wait 'execute in rivencraft:age/smoke_flat_multi run forceload add 0 0' 'Marked chunk [0, 0] in rivencraft:age/smoke_flat_multi to be force loaded'
+send_and_wait 'execute in rivencraft:age/smoke_void_multi run forceload add 0 0' 'Marked chunk [0, 0] in rivencraft:age/smoke_void_multi to be force loaded'
+send_and_wait 'execute in rivencraft:age/smoke_cave run forceload add 0 0' 'Marked chunk [0, 0] in rivencraft:age/smoke_cave to be force loaded'
+send_and_wait 'execute in rivencraft:age/smoke_cave_multi run forceload add 0 0' 'Marked chunk [0, 0] in rivencraft:age/smoke_cave_multi to be force loaded'
+send_and_wait 'execute in rivencraft:age/smoke_rocks run forceload add 0 0' 'Marked chunk [0, 0] in rivencraft:age/smoke_rocks to be force loaded'
+send_and_wait 'rivencraft_port age rocks_probe smoke_rocks' 'Rocks probe rivencraft:age/smoke_rocks material=minecraft:gold_block count='
+rocks_before=$(grep -F 'Rocks probe rivencraft:age/smoke_rocks material=minecraft:gold_block count=' "$log_file" | tail -1 | sed 's/.*count=//')
+[[ "$rocks_before" =~ ^[1-9][0-9]*$ ]] || {
+    printf 'Authored Rocks placed no gold blocks: %s\n' "$rocks_before" >&2
+    exit 1
+}
+send_and_wait 'execute in rivencraft:age/smoke_flat if block 0 0 0 minecraft:bedrock run say Flat bedrock starts at Y0' 'Flat bedrock starts at Y0'
+send_and_wait 'execute in rivencraft:age/smoke_flat if block 0 3 0 minecraft:grass_block run say Flat surface is Y3' 'Flat surface is Y3'
+send_and_wait 'execute in rivencraft:age/smoke_void if block 0 0 0 minecraft:air run say Void remains empty' 'Void remains empty'
+send_and_wait 'execute in rivencraft:age/smoke_flat_multi if block 0 0 0 minecraft:bedrock run say Multi Flat bedrock starts at Y0' 'Multi Flat bedrock starts at Y0'
+send_and_wait 'execute in rivencraft:age/smoke_void_multi if block 0 0 0 minecraft:air run say Multi Void remains empty' 'Multi Void remains empty'
+# Check region interiors after loading the sampled chunks.
+send_and_wait 'rivencraft_port age biome smoke_flat_multi 128 128' 'rivencraft:age/smoke_flat_multi biome at 128,128=minecraft:plains'
+send_and_wait 'rivencraft_port age biome smoke_flat_multi 384 128' 'rivencraft:age/smoke_flat_multi biome at 384,128=minecraft:forest'
+send_and_wait 'rivencraft_port age biome smoke_void_multi 384 128' 'rivencraft:age/smoke_void_multi biome at 384,128=minecraft:forest'
+send_and_wait 'rivencraft_port age biome smoke_cave_multi 128 128' 'rivencraft:age/smoke_cave_multi biome at 128,128=minecraft:lush_caves'
+send_and_wait 'rivencraft_port age biome smoke_cave_multi 384 128' 'rivencraft:age/smoke_cave_multi biome at 384,128=minecraft:dripstone_caves'
 alpha_before=$(grep -F 'rivencraft:age/smoke_alpha seed=123456789 chunkOffset=0 terrain=' "$log_file" | tail -1 | sed 's/.*terrain=//')
 beta_before=$(grep -F 'rivencraft:age/smoke_beta seed=987654321 chunkOffset=0 terrain=' "$log_file" | tail -1 | sed 's/.*terrain=//')
+flat_before=$(grep -F 'rivencraft:age/smoke_flat seed=24680 chunkOffset=0 terrain=' "$log_file" | tail -1 | sed 's/.*terrain=//')
+void_before=$(grep -F 'rivencraft:age/smoke_void seed=13579 chunkOffset=0 terrain=' "$log_file" | tail -1 | sed 's/.*terrain=//')
+random_before=$(grep -F 'rivencraft:age/smoke_random seed=889900 chunkOffset=0 terrain=' "$log_file" | tail -1 | sed 's/.*terrain=//')
 if [[ "$alpha_before" == "$beta_before" ]]; then
     printf 'Different Age seeds produced the same terrain probe: %s\n' "$alpha_before" >&2
     exit 1
 fi
+if [[ "$flat_before" == "$void_before" ]]; then
+    printf 'Flat and Void Ages produced the same height probe: %s\n' "$flat_before" >&2
+    exit 1
+fi
 stop_server
 
 start_server restart
 send_and_wait 'rivencraft_port age list' 'smoke_alpha'
 send_and_wait 'rivencraft_port age sample smoke_alpha' 'rivencraft:age/smoke_alpha seed=123456789 chunkOffset=0 terrain='
 send_and_wait 'rivencraft_port age sample smoke_beta' 'rivencraft:age/smoke_beta seed=987654321 chunkOffset=0 terrain='
+send_and_wait 'rivencraft_port age sample smoke_flat' 'rivencraft:age/smoke_flat seed=24680 chunkOffset=0 terrain='
+send_and_wait 'rivencraft_port age sample smoke_void' 'rivencraft:age/smoke_void seed=13579 chunkOffset=0 terrain='
+send_and_wait 'rivencraft_port age sample smoke_cave' 'rivencraft:age/smoke_cave seed=112233 chunkOffset=0 terrain='
+send_and_wait 'rivencraft_port age sample smoke_flat_multi' 'rivencraft:age/smoke_flat_multi seed=24681 chunkOffset=0 terrain='
+send_and_wait 'rivencraft_port age sample smoke_void_multi' 'rivencraft:age/smoke_void_multi seed=13580 chunkOffset=0 terrain='
+send_and_wait 'rivencraft_port age sample smoke_cave_multi' 'rivencraft:age/smoke_cave_multi seed=112234 chunkOffset=0 terrain='
+send_and_wait 'rivencraft_port age sample smoke_random' 'rivencraft:age/smoke_random seed=889900 chunkOffset=0 terrain='
+send_and_wait 'rivencraft_port age sample smoke_rocks' 'rivencraft:age/smoke_rocks seed=445566 chunkOffset=0 terrain='
+send_and_wait 'rivencraft_port age rocks_probe smoke_rocks' 'Rocks probe rivencraft:age/smoke_rocks material=minecraft:gold_block count='
+rocks_after=$(grep -F 'Rocks probe rivencraft:age/smoke_rocks material=minecraft:gold_block count=' "$log_file" | tail -1 | sed 's/.*count=//')
+send_and_wait 'rivencraft_port age biome smoke_flat_multi 384 128' 'rivencraft:age/smoke_flat_multi biome at 384,128=minecraft:forest'
+send_and_wait 'rivencraft_port age biome smoke_void_multi 384 128' 'rivencraft:age/smoke_void_multi biome at 384,128=minecraft:forest'
+send_and_wait 'rivencraft_port age biome smoke_cave_multi 384 128' 'rivencraft:age/smoke_cave_multi biome at 384,128=minecraft:dripstone_caves'
 alpha_after=$(grep -F 'rivencraft:age/smoke_alpha seed=123456789 chunkOffset=0 terrain=' "$log_file" | tail -1 | sed 's/.*terrain=//')
 beta_after=$(grep -F 'rivencraft:age/smoke_beta seed=987654321 chunkOffset=0 terrain=' "$log_file" | tail -1 | sed 's/.*terrain=//')
+flat_after=$(grep -F 'rivencraft:age/smoke_flat seed=24680 chunkOffset=0 terrain=' "$log_file" | tail -1 | sed 's/.*terrain=//')
+void_after=$(grep -F 'rivencraft:age/smoke_void seed=13579 chunkOffset=0 terrain=' "$log_file" | tail -1 | sed 's/.*terrain=//')
+random_after=$(grep -F 'rivencraft:age/smoke_random seed=889900 chunkOffset=0 terrain=' "$log_file" | tail -1 | sed 's/.*terrain=//')
 [[ "$alpha_before" == "$alpha_after" && "$beta_before" == "$beta_after" ]] || {
     printf 'Age terrain changed across restart: %s/%s -> %s/%s\n' \
         "$alpha_before" "$beta_before" "$alpha_after" "$beta_after" >&2
     exit 1
 }
+[[ "$flat_before" == "$flat_after" && "$void_before" == "$void_after" ]] || {
+    printf 'Flat/Void terrain changed across restart: %s/%s -> %s/%s\n' \
+        "$flat_before" "$void_before" "$flat_after" "$void_after" >&2
+    exit 1
+}
+[[ "$random_before" == "$random_after" ]] || {
+    printf 'Random Age terrain changed across restart: %s -> %s\n' \
+        "$random_before" "$random_after" >&2
+    exit 1
+}
+[[ "$rocks_before" == "$rocks_after" ]] || {
+    printf 'Authored Rocks changed across restart: %s -> %s\n' \
+        "$rocks_before" "$rocks_after" >&2
+    exit 1
+}
 stop_server
-printf '26.3 dedicated-server smoke passed: two distinct Ages persisted across restart.\n'
+printf '26.3 dedicated-server smoke passed: Standard, Flat, Void, Cave, random and authored Rocks Ages persisted across restart.\n'