feat(desktop): enable Quilt instances and protect unfinished installer loaders

Author: WieszczY85

README.md

@@ -358,8 +358,8 @@ Loader support is intentionally staged:
 
 - Fabric — v0.4
 - NeoForge — v0.7
-- Forge — v0.8
-- Quilt — v0.8
+- Forge — v0.8 (official Maven discovery; processor installation not yet implemented)
+- Quilt — v0.8 (official Quilt Meta v3 profile and instance selection; actual game acceptance pending)
 
 Local mod management arrives in v0.5, followed by Modrinth integration and dependency resolution in v0.6.
 

docs/ROADMAP.md

@@ -506,7 +506,7 @@ Goal: add a second major loader and prove the loader architecture is genuinely r
 
 ## NeoForge provider
 
-- [ ] Discover compatible NeoForge versions.
+- [ ] 🚧 IN PROGRESS — Discover official NeoForge Maven versions; processor installation and actual launch remain unimplemented.
 - [ ] Parse/install NeoForge metadata/processors as required.
 - [ ] Resolve required libraries.
 - [ ] Integrate generated/processed artifacts safely.
@@ -533,7 +533,7 @@ Goal: broaden loader support while preserving historical-version compatibility d
 
 ## Forge
 
-- [ ] Discover compatible Forge versions.
+- [ ] 🚧 IN PROGRESS — Discover official Forge Maven versions; processor installation and actual launch remain unimplemented.
 - [ ] Support required Forge installation metadata/processors for targeted Minecraft ranges.
 - [ ] Document exact supported Minecraft/Forge range if universal support is not practical.
 - [ ] Launch Forge through common pipeline.

docs/WORKLOG.md

@@ -8,6 +8,39 @@ Every code/build/documentation/CI task must add an entry according to `AGENTS.md
 
 ---
 
+## 2026-10-20 — Quilt loader integration and Forge-family discovery
+
+**Milestone:** v0.7 NeoForge / v0.8 Forge and Quilt  
+**Author/Agent:** GPT-6  
+**Status:** Partial — GitHub CI and game acceptance pending
+
+### Completed
+- Added Quilt Meta v3 provider with compatible loader versions and official profile merge, reusing generic loader boundaries.
+- Added Quilt to instance creation/editing and instance-scoped local/Modrinth JAR operation.
+- Registered NeoForge and Forge Maven version-discovery adapters with safe metadata parsing and fail-closed launch behavior.
+- Explicitly withheld the NeoForge/Forge UI choices until processor-based installation is implemented; exposing a download as a playable loader would be misleading.
+
+### Changed files
+- `launcher-core/src/main/kotlin/pl/syntaxdevteam/syntaxlauncher/core/loader/*`, `launcher-core/src/test/kotlin/pl/syntaxdevteam/syntaxlauncher/core/loader/*`
+- `launcher-desktop/src/main/kotlin/pl/syntaxdevteam/syntaxlauncher/desktop/Main.kt`
+- `launcher-desktop/src/main/kotlin/pl/syntaxdevteam/syntaxlauncher/desktop/ui/InstanceWorkspace.kt`, `InstanceSettingsDialog.kt`, `SyntaxLauncherApp.kt`, `LocalModsDialog.kt`
+- `launcher-core/src/main/kotlin/pl/syntaxdevteam/syntaxlauncher/core/mods/LocalModManager.kt`, `ModrinthInstaller.kt`
+- `README.md`, `docs/ROADMAP.md`, `docs/WORKLOG.md`
+
+### Verification
+- `./gradlew test`, `./gradlew build` — NOT RUN locally; hosted CI required.
+- Real game launch — NOT RUN; Quilt support is unverified, Forge and NeoForge are intentionally not launchable.
+
+### Roadmap updates
+- v0.7/v0.8 official version discovery and Quilt adapter marked 🚧.
+- Forge/NeoForge processors and generated artifacts remain unchecked.
+
+### Follow-ups / known issues
+- Implement verified official installer processors, generated libraries and Minecraft-version-specific support matrix for NeoForge/Forge.
+- Confirm Quilt API and actual game boot on real installations before declaring v0.8 complete.
+
+---
+
 ## 2026-10-20 — Transactional managed Modrinth updates and rollback
 
 **Milestone:** v0.6 — Modrinth Integration  

launcher-core/src/main/kotlin/pl/syntaxdevteam/syntaxlauncher/core/mods/LocalModManager.kt

@@ -59,7 +59,7 @@ class LocalModManager(private val instances: MinecraftInstanceRepository) {
     suspend fun importJar(instanceId: String, source: Path): LocalModInventory =
         withContext(Dispatchers.IO) {
             instances.withInactiveInstance(instanceId) { instance ->
-                require(instance.loader?.id == "fabric") {
+                require(instance.loader?.id in setOf("fabric", "quilt")) {
                     "Local mod imports currently require a Fabric instance."
                 }
                 require(Files.isRegularFile(source, LinkOption.NOFOLLOW_LINKS)) {
@@ -107,7 +107,7 @@ class LocalModManager(private val instances: MinecraftInstanceRepository) {
                 "Managed identity must match each downloaded JAR."
             }
             instances.withInactiveInstance(instanceId) { instance ->
-                require(instance.loader?.id == "fabric") { "Only Fabric installation is available." }
+                require(instance.loader?.id in setOf("fabric", "quilt")) { "Only Fabric installation is available." }
                 val mods = modsDirectory(instance, create = true)
                 val names = sources.map { it.fileName.toString() }
                 require(names.distinct().size == names.size && names.all(::validJarName)) {
@@ -185,7 +185,7 @@ class LocalModManager(private val instances: MinecraftInstanceRepository) {
         withContext(Dispatchers.IO) {
             require(replacements.isNotEmpty() && replacements.size <= 32)
             instances.withInactiveInstance(instanceId) { instance ->
-                require(instance.loader?.id == "fabric") { "Managed updates require a Fabric instance." }
+                require(instance.loader?.id in setOf("fabric", "quilt")) { "Managed updates require a Fabric instance." }
                 val game = instances.gameDirectory(instance)
                 val mods = modsDirectory(instance)
                 val tracked = managedStore.read(game)
@@ -446,7 +446,7 @@ class LocalModManager(private val instances: MinecraftInstanceRepository) {
         }
         val sorted = found.sortedWith(compareBy(String.CASE_INSENSITIVE_ORDER) { it.fileName })
         val active = sorted.filter { it.enabled }
-        if (active.isNotEmpty() && instance.loader?.id != "fabric") {
+        if (active.isNotEmpty() && instance.loader?.id !in setOf("fabric", "quilt")) {
             warnings += "Local JARs are present, but this instance has no Fabric loader."
         }
         val identifiers = active.mapNotNull { mod -> mod.metadata?.id?.let { it to mod.fileName } }

launcher-core/src/main/kotlin/pl/syntaxdevteam/syntaxlauncher/core/mods/ModrinthInstaller.kt

@@ -22,7 +22,7 @@ class ModrinthInstaller(
     suspend fun install(instanceId: String, plan: ModrinthInstallPlan): LocalModInventory =
         withContext(Dispatchers.IO) {
             val instance = instances.get(instanceId)
-            require(instance.loader?.id == "fabric" &&
+            require(instance.loader?.id in setOf("fabric", "quilt") &&
                 instance.loader.id == plan.loaderId &&
                 instance.minecraftVersionId == plan.minecraftVersionId) {
                 "Instance loader or Minecraft version changed. Review the installation again."
@@ -77,7 +77,7 @@ class ModrinthInstaller(
                 "Empty or conflicting Modrinth update selection."
             }
             val instance = instances.get(instanceId)
-            require(instance.loader?.id == "fabric") { "Modrinth updates currently require Fabric." }
+            require(instance.loader?.id in setOf("fabric", "quilt")) { "Modrinth updates currently require Fabric." }
             val game = instances.gameDirectory(instance)
             require(Files.isDirectory(game, LinkOption.NOFOLLOW_LINKS))
             val current = mods.list(instanceId).mods

launcher-desktop/src/main/kotlin/pl/syntaxdevteam/syntaxlauncher/desktop/Main.kt

@@ -18,6 +18,9 @@ import pl.syntaxdevteam.syntaxlauncher.core.java.MojangJavaRuntimeManager
 import pl.syntaxdevteam.syntaxlauncher.core.instance.MinecraftInstanceRepository
 import pl.syntaxdevteam.syntaxlauncher.core.loader.ModLoaderRegistry
 import pl.syntaxdevteam.syntaxlauncher.core.loader.FabricLoaderProvider
+import pl.syntaxdevteam.syntaxlauncher.core.loader.QuiltLoaderProvider
+import pl.syntaxdevteam.syntaxlauncher.core.loader.NeoForgeLoaderProvider
+import pl.syntaxdevteam.syntaxlauncher.core.loader.ForgeLoaderProvider
 import pl.syntaxdevteam.syntaxlauncher.core.launch.LaunchPlanBuilder
 import pl.syntaxdevteam.syntaxlauncher.core.launch.MinecraftLaunchCoordinator
 import pl.syntaxdevteam.syntaxlauncher.core.launch.MinecraftProcessManager
@@ -54,7 +57,10 @@ fun main(args: Array<String>) {
             LauncherVersion.parse(LauncherBuildInfo.version))
     } else null
     val processManager = MinecraftProcessManager(paths.logsDir)
-    val modLoaders = ModLoaderRegistry(listOf(FabricLoaderProvider(httpClient)))
+    val modLoaders = ModLoaderRegistry(listOf(
+        FabricLoaderProvider(httpClient), QuiltLoaderProvider(httpClient),
+        NeoForgeLoaderProvider(httpClient), ForgeLoaderProvider(httpClient),
+    ))
     val session = DesktopLauncherSession(
         versionCatalog = MinecraftVersionCatalog(httpClient),
         versionResolver = MinecraftVersionResolver(httpClient),

launcher-desktop/src/main/kotlin/pl/syntaxdevteam/syntaxlauncher/desktop/ui/InstanceSettingsDialog.kt

@@ -33,7 +33,7 @@ import pl.syntaxdevteam.syntaxlauncher.core.loader.ModLoaderVersion
 fun InstanceSettingsDialog(
     instance: MinecraftInstance,
     availableVersions: List<String>,
-    loadFabricVersions: suspend (String) -> List<ModLoaderVersion> = { emptyList() },
+    loadLoaderVersions: suspend (String, String) -> List<ModLoaderVersion> = { _, _ -> emptyList() },
     onSave: (MinecraftInstance) -> Unit,
     onCancel: () -> Unit,
 ) {
@@ -71,10 +71,10 @@ fun InstanceSettingsDialog(
     LaunchedEffect(versionId, loaderId) {
         compatible = emptyList()
         loaderError = null
-        if (loaderId == "fabric" && versionValid) {
+        if (loaderId in setOf("fabric", "quilt") && versionValid) {
             loaderLoading = true
             try {
-                compatible = loadFabricVersions(versionId)
+                compatible = loadLoaderVersions(loaderId, versionId)
                 if (compatible.isEmpty()) {
                     loaderError = "Fabric is not available for Minecraft $versionId."
                 } else if (compatible.none { it.version == fabricVersion }) {
@@ -154,12 +154,15 @@ fun InstanceSettingsDialog(
                     TextButton(onClick = { loaderId = "fabric" }) {
                         Text(if (loaderId == "fabric") "✓ Fabric" else "Fabric")
                     }
+                    TextButton(onClick = { loaderId = "quilt" }) {
+                        Text(if (loaderId == "quilt") "✓ Quilt" else "Quilt")
+                    }
                 }
-                if (loaderId == "fabric") {
+                if (loaderId in setOf("fabric", "quilt")) {
                     OutlinedTextField(
                         value = fabricVersion,
                         onValueChange = { fabricVersion = it },
-                        label = { Text("Fabric loader version") },
+                        label = { Text(loaderId.replaceFirstChar { it.uppercase() } + " loader version") },
                         modifier = Modifier.fillMaxWidth(),
                         singleLine = true,
                         isError = !fabricValid,
@@ -231,7 +234,7 @@ fun InstanceSettingsDialog(
                         minimumMemoryMiB = minRam!!,
                         maximumMemoryMiB = maxRam!!,
                         extraJvmArguments = args,
-                        loader = if (loaderId == "fabric") ModLoaderSelection("fabric", fabricVersion) else null,
+                        loader = if (loaderId in setOf("fabric", "quilt")) ModLoaderSelection(loaderId, fabricVersion) else null,
                     ))
                 },
             ) { Text("Save settings") }

launcher-desktop/src/main/kotlin/pl/syntaxdevteam/syntaxlauncher/desktop/ui/InstanceWorkspace.kt

@@ -79,7 +79,7 @@ fun InstanceWorkspace(
     hasLegacyGame: Boolean,
     latestVersion: String,
     availableVersions: List<String>,
-    loadFabricVersions: suspend (String) -> List<ModLoaderVersion> = { emptyList() },
+    loadLoaderVersions: suspend (String, String) -> List<ModLoaderVersion> = { _, _ -> emptyList() },
     error: String?,
     preview: InstanceCopyPreview?,
     copyProgress: InstanceCopyProgress?,
@@ -114,10 +114,10 @@ fun InstanceWorkspace(
     LaunchedEffect(newVersion, newLoader) {
         compatible = emptyList()
         fabricError = null
-        if (newLoader == "fabric" && newVersion in availableVersions) {
+        if (newLoader in setOf("fabric", "quilt") && newVersion in availableVersions) {
             fabricLoading = true
             try {
-                compatible = loadFabricVersions(newVersion)
+                compatible = loadLoaderVersions(newLoader, newVersion)
                 if (compatible.isEmpty()) {
                     fabricError = "Fabric is not available for Minecraft $newVersion."
                 } else if (compatible.none { it.version == newFabricVersion }) {
@@ -261,7 +261,7 @@ fun InstanceWorkspace(
                                 Button(onClick = { onEdit(selected) }, enabled = canModify) {
                                     Text("Settings")
                                 }
-                                if (selected.loader?.id == "fabric") {
+                                if (selected.loader?.id in setOf("fabric", "quilt")) {
                                     OutlinedButton(onClick = { onManageMods(selected) },
                                         enabled = canModify) { Text("Mods") }
                                 }
@@ -309,12 +309,15 @@ fun InstanceWorkspace(
                             TextButton(onClick = { newLoader = "fabric" }, enabled = canModify) {
                                 Text(if (newLoader == "fabric") "✓ Fabric" else "Fabric")
                             }
+                            TextButton(onClick = { newLoader = "quilt" }, enabled = canModify) {
+                                Text(if (newLoader == "quilt") "✓ Quilt" else "Quilt")
+                            }
                         }
-                        if (newLoader == "fabric") {
+                        if (newLoader in setOf("fabric", "quilt")) {
                             OutlinedTextField(
                                 value = newFabricVersion,
                                 onValueChange = { newFabricVersion = it },
-                                label = { Text("Fabric loader version") },
+                                label = { Text(newLoader.replaceFirstChar { it.uppercase() } + " loader version") },
                                 singleLine = true, enabled = canModify,
                                 isError = !fabricValid,
                                 modifier = Modifier.fillMaxWidth(),
@@ -332,9 +335,12 @@ fun InstanceWorkspace(
                                 color = MaterialTheme.colorScheme.error,
                                 style = MaterialTheme.typography.bodySmall)
                         }
+                        Text("NeoForge and Forge need processor-based installation; not selectable yet.",
+                            style = MaterialTheme.typography.labelSmall,
+                            color = MaterialTheme.colorScheme.onSurfaceVariant)
                         Button(onClick = {
                             onCreate(newName.trim(), newVersion.trim(),
-                                if (newLoader == "fabric") ModLoaderSelection("fabric", newFabricVersion) else null)
+                                if (newLoader in setOf("fabric", "quilt")) ModLoaderSelection(newLoader, newFabricVersion) else null)
                         },
                             enabled = canModify && newName.trim().length in 1..48 &&
                                 newVersion in availableVersions && fabricValid) { Text("Create instance") }

launcher-desktop/src/main/kotlin/pl/syntaxdevteam/syntaxlauncher/desktop/ui/LocalModsDialog.kt

@@ -127,7 +127,7 @@ fun LocalModsDialog(
                 confirmButton = {
                     TextButton(enabled = canModify && !busy, onClick = {
                         confirmingUpdates = null
-                        operate { installer.update(instance.id, updates) }
+                        operate(operation = { installer.update(instance.id, updates) })
                     }) { Text("Update mods") }
                 },
                 dismissButton = { TextButton(onClick = { confirmingUpdates = null }) { Text("Cancel") } },
@@ -170,7 +170,7 @@ fun LocalModsDialog(
                             style = MaterialTheme.typography.labelMedium)
                         Text(instance.name, style = MaterialTheme.typography.titleLarge,
                             fontWeight = FontWeight.SemiBold)
-                        Text("Fabric · Minecraft ${instance.minecraftVersionId} · Files stay in this instance",
+                        Text("${instance.loader?.id ?: "Vanilla"} · Minecraft ${instance.minecraftVersionId} · Files stay in this instance",
                             style = MaterialTheme.typography.bodySmall,
                             color = MaterialTheme.colorScheme.onSurfaceVariant)
                     }
@@ -185,7 +185,7 @@ fun LocalModsDialog(
                         onClick = { browsing = true }) { Text("Discover on Modrinth") }
                     Button(enabled = canModify && !busy, onClick = {
                         val picker = JFileChooser().apply {
-                            dialogTitle = "Import a local Fabric mod"
+                            dialogTitle = "Import a local mod for this instance"
                             fileFilter = FileNameExtensionFilter("Minecraft mod JAR (*.jar)", "jar")
                             isAcceptAllFileFilterUsed = false
                         }
@@ -241,7 +241,7 @@ fun LocalModsDialog(
                         }
                     }
                     OutlinedButton(enabled = canModify && !busy,
-                        onClick = { operate { installer.rollback(instance.id) } }) {
+                        onClick = { operate(operation = { installer.rollback(instance.id) }) }) {
                         Text("Rollback last Modrinth update")
                     }
                 }

launcher-desktop/src/main/kotlin/pl/syntaxdevteam/syntaxlauncher/desktop/ui/SyntaxLauncherApp.kt

@@ -498,7 +498,7 @@ private fun LauncherPanel(
         InstanceSettingsDialog(
             instance = editing,
             availableVersions = manifest.versions.map { it.id },
-            loadFabricVersions = { game -> session.loaders?.compatibleVersions("fabric", game).orEmpty() },
+            loadLoaderVersions = { id, game -> session.loaders?.compatibleVersions(id, game).orEmpty() },
             onSave = { updated ->
                 modifyInstance { session.instances.update(updated) }
                 editingInstance = null
@@ -519,7 +519,7 @@ private fun LauncherPanel(
             // not an unrelated newer release that might convert world data.
             latestVersion = legacyVersionId.ifBlank { manifest.latestRelease },
             availableVersions = manifest.versions.map { it.id },
-            loadFabricVersions = { game -> session.loaders?.compatibleVersions("fabric", game).orEmpty() },
+            loadLoaderVersions = { id, game -> session.loaders?.compatibleVersions(id, game).orEmpty() },
             error = instanceError,
             preview = copyPreview,
             copyProgress = copyProgress,