diff --git a/independent-projects/tools/devtools-common/src/main/java/io/quarkus/devtools/commands/handlers/CreateProjectCommandHandler.java b/independent-projects/tools/devtools-common/src/main/java/io/quarkus/devtools/commands/handlers/CreateProjectCommandHandler.java
index bdf3f6f86f61d..64ae6a2224ef2 100644
--- a/independent-projects/tools/devtools-common/src/main/java/io/quarkus/devtools/commands/handlers/CreateProjectCommandHandler.java
+++ b/independent-projects/tools/devtools-common/src/main/java/io/quarkus/devtools/commands/handlers/CreateProjectCommandHandler.java
@@ -182,8 +182,8 @@ private List<Extension> computeRequiredExtensions(ExtensionCatalog catalog,
     @SuppressWarnings("unchecked")
     private List<ExtensionCatalog> getExtensionOrigins(ExtensionCatalog extensionCatalog, List<Extension> extensionsToAdd)
             throws QuarkusCommandException {
-        final ElementCatalog<ExtensionCatalog> ec = (ElementCatalog<ExtensionCatalog>) extensionCatalog.getMetadata()
-                .get("element-catalog");
+        final ElementCatalog<ExtensionCatalog> ec = ElementCatalogBuilder.getElementCatalog(extensionCatalog,
+                ExtensionCatalog.class);
         if (ec == null) {
             return Collections.emptyList();
         }
diff --git a/independent-projects/tools/devtools-common/src/main/java/io/quarkus/platform/tools/ToolsUtils.java b/independent-projects/tools/devtools-common/src/main/java/io/quarkus/platform/tools/ToolsUtils.java
index 8e2fc59613cf6..9e0348c1201df 100644
--- a/independent-projects/tools/devtools-common/src/main/java/io/quarkus/platform/tools/ToolsUtils.java
+++ b/independent-projects/tools/devtools-common/src/main/java/io/quarkus/platform/tools/ToolsUtils.java
@@ -7,13 +7,17 @@
 import io.quarkus.bootstrap.resolver.maven.MavenArtifactResolver;
 import io.quarkus.devtools.messagewriter.MessageWriter;
 import io.quarkus.maven.ArtifactCoords;
+import io.quarkus.registry.PlatformStackIndex;
 import io.quarkus.registry.catalog.ExtensionCatalog;
 import io.quarkus.registry.catalog.json.JsonCatalogMapperHelper;
 import io.quarkus.registry.catalog.json.JsonCatalogMerger;
 import io.quarkus.registry.catalog.json.JsonExtensionCatalog;
+import io.quarkus.registry.union.ElementCatalogBuilder;
+import io.quarkus.registry.union.ElementCatalogBuilder.UnionBuilder;
 import java.io.IOException;
 import java.nio.file.Path;
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
@@ -115,11 +119,54 @@ public static ExtensionCatalog resolvePlatformDescriptorDirectly(String bomGroup
                 throw new RuntimeException("Failed to resolve the default platform JSON descriptor", e);
             }
         }
+        ExtensionCatalog catalog;
         try {
-            return JsonCatalogMapperHelper.deserialize(platformJson, JsonExtensionCatalog.class);
+            catalog = JsonCatalogMapperHelper.deserialize(platformJson, JsonExtensionCatalog.class);
         } catch (IOException e) {
             throw new RuntimeException("Failed to deserialize extension catalog " + platformJson, e);
         }
+        Map<String, Object> md = catalog.getMetadata();
+        if (md != null) {
+            Object o = md.get("platform-release");
+            if (o instanceof Map) {
+                Object members = ((Map<?, ?>) o).get("members");
+                if (members instanceof Collection) {
+                    final Collection<?> memberList = (Collection<?>) members;
+                    final List<ExtensionCatalog> catalogs = new ArrayList<>(memberList.size());
+                    final ElementCatalogBuilder<ExtensionCatalog> elementsBuilder = ElementCatalogBuilder.newInstance();
+                    final UnionBuilder<ExtensionCatalog> union = elementsBuilder
+                            .getOrCreateUnion(PlatformStackIndex.initial());
+
+                    for (Object m : memberList) {
+                        if (!(m instanceof String)) {
+                            continue;
+                        }
+                        final ExtensionCatalog memberCatalog;
+                        if (catalog.getId().equals(m)) {
+                            memberCatalog = catalog;
+                        } else {
+                            try {
+                                final ArtifactCoords coords = ArtifactCoords.fromString((String) m);
+                                catalogCoords = new DefaultArtifact(coords.getGroupId(), coords.getArtifactId(),
+                                        coords.getClassifier(), coords.getType(), coords.getVersion());
+                                log.debug("Resolving platform descriptor %s", catalogCoords);
+                                final Path jsonPath = artifactResolver.resolve(catalogCoords).getArtifact().getFile().toPath();
+                                memberCatalog = JsonCatalogMapperHelper.deserialize(jsonPath,
+                                        JsonExtensionCatalog.class);
+                            } catch (Exception e) {
+                                log.warn("Failed to resolve member catalog " + m, e);
+                                continue;
+                            }
+                        }
+                        catalogs.add(memberCatalog);
+                        ElementCatalogBuilder.addUnionMember(union, memberCatalog);
+                    }
+                    catalog = JsonCatalogMerger.merge(catalogs);
+                    ElementCatalogBuilder.setElementCatalog(catalog, elementsBuilder.build());
+                }
+            }
+        }
+        return catalog;
     }
 
     public static ExtensionCatalog mergePlatforms(List<ArtifactCoords> platforms, MavenArtifactResolver artifactResolver) {
diff --git a/independent-projects/tools/registry-client/src/main/java/io/quarkus/registry/ExtensionCatalogResolver.java b/independent-projects/tools/registry-client/src/main/java/io/quarkus/registry/ExtensionCatalogResolver.java
index 121ce08b79f07..d2a8183e6bd43 100644
--- a/independent-projects/tools/registry-client/src/main/java/io/quarkus/registry/ExtensionCatalogResolver.java
+++ b/independent-projects/tools/registry-client/src/main/java/io/quarkus/registry/ExtensionCatalogResolver.java
@@ -19,9 +19,7 @@
 import io.quarkus.registry.config.RegistriesConfig;
 import io.quarkus.registry.config.RegistriesConfigLocator;
 import io.quarkus.registry.config.RegistryConfig;
-import io.quarkus.registry.union.ElementCatalog;
 import io.quarkus.registry.union.ElementCatalogBuilder;
-import io.quarkus.registry.union.ElementCatalogBuilder.MemberBuilder;
 import io.quarkus.registry.union.ElementCatalogBuilder.UnionBuilder;
 import java.io.File;
 import java.net.URL;
@@ -280,7 +278,7 @@ public ExtensionCatalog resolveExtensionCatalog() throws RegistryResolutionExcep
                         for (ArtifactCoords bom : release.getMemberBoms()) {
                             final ExtensionCatalog ec = registry.resolvePlatformExtensions(bom);
                             catalogs.add(ec);
-                            addUnion(union, ec);
+                            ElementCatalogBuilder.addUnionMember(union, ec);
                         }
 
                         final Map<String, List<RegistryExtensionResolver>> registriesByQuarkusCore = new HashMap<>(2);
@@ -298,10 +296,7 @@ public ExtensionCatalog resolveExtensionCatalog() throws RegistryResolutionExcep
         }
 
         final ExtensionCatalog catalog = JsonCatalogMerger.merge(catalogs);
-        final ElementCatalog<ExtensionCatalog> elements = catalogBuilder.build();
-        if (!elements.isEmpty()) {
-            catalog.getMetadata().put("element-catalog", elements);
-        }
+        ElementCatalogBuilder.setElementCatalog(catalog, catalogBuilder.build());
         return catalog;
     }
 
@@ -476,7 +471,7 @@ public ExtensionCatalog resolveExtensionCatalog(StreamCoords streamCoords) throw
         for (ArtifactCoords bom : release.getMemberBoms()) {
             final ExtensionCatalog ec = registry.resolvePlatformExtensions(bom);
             catalogs.add(ec);
-            addUnion(union, ec);
+            ElementCatalogBuilder.addUnionMember(union, ec);
         }
 
         final Map<String, List<RegistryExtensionResolver>> registriesByQuarkusCore = new HashMap<>(2);
@@ -490,11 +485,7 @@ public ExtensionCatalog resolveExtensionCatalog(StreamCoords streamCoords) throw
 
         appendNonPlatformExtensions(registriesByQuarkusCore, union, catalogs);
         final ExtensionCatalog catalog = JsonCatalogMerger.merge(catalogs);
-
-        final ElementCatalog<ExtensionCatalog> elements = catalogBuilder.build();
-        if (!elements.isEmpty()) {
-            catalog.getMetadata().put("element-catalog", elements);
-        }
+        ElementCatalogBuilder.setElementCatalog(catalog, catalogBuilder.build());
         return catalog;
     }
 
@@ -505,14 +496,6 @@ private void ensureRegistriesConfigured() throws RegistryResolutionException {
         }
     }
 
-    private void addUnion(final UnionBuilder<ExtensionCatalog> union, final ExtensionCatalog ec) {
-        final MemberBuilder<ExtensionCatalog> builder = union.getOrCreateMember(
-                ec.getId(), ec.getBom().getVersion(), ec);
-        ec.getExtensions()
-                .forEach(e -> builder
-                        .addElement(e.getArtifact().getGroupId() + ":" + e.getArtifact().getArtifactId()));
-    }
-
     public ExtensionCatalog resolveExtensionCatalog(Collection<ArtifactCoords> platforms)
             throws RegistryResolutionException {
         if (platforms.isEmpty()) {
@@ -587,7 +570,8 @@ private void appendNonPlatformExtensions(
                 if (nonPlatformCatalog != null) {
                     extensionCatalogs.add(nonPlatformCatalog);
                     if (union != null) {
-                        addUnion(union, nonPlatformCatalog);
+                        final UnionBuilder<ExtensionCatalog> union1 = union;
+                        ElementCatalogBuilder.addUnionMember(union1, nonPlatformCatalog);
                     }
                 }
             }
diff --git a/independent-projects/tools/registry-client/src/main/java/io/quarkus/registry/PlatformStackIndex.java b/independent-projects/tools/registry-client/src/main/java/io/quarkus/registry/PlatformStackIndex.java
index 59c25284b7b9c..4ea9c74bc9494 100644
--- a/independent-projects/tools/registry-client/src/main/java/io/quarkus/registry/PlatformStackIndex.java
+++ b/independent-projects/tools/registry-client/src/main/java/io/quarkus/registry/PlatformStackIndex.java
@@ -2,9 +2,9 @@
 
 import io.quarkus.registry.union.UnionVersion;
 
-class PlatformStackIndex implements UnionVersion {
+public class PlatformStackIndex implements UnionVersion {
 
-    static PlatformStackIndex initial() {
+    public static PlatformStackIndex initial() {
         return new PlatformStackIndex(0, 0, 0);
     }
 
diff --git a/independent-projects/tools/registry-client/src/main/java/io/quarkus/registry/union/ElementCatalogBuilder.java b/independent-projects/tools/registry-client/src/main/java/io/quarkus/registry/union/ElementCatalogBuilder.java
index 43f3fefb61a55..0ae02049675f9 100644
--- a/independent-projects/tools/registry-client/src/main/java/io/quarkus/registry/union/ElementCatalogBuilder.java
+++ b/independent-projects/tools/registry-client/src/main/java/io/quarkus/registry/union/ElementCatalogBuilder.java
@@ -1,5 +1,6 @@
 package io.quarkus.registry.union;
 
+import io.quarkus.registry.catalog.ExtensionCatalog;
 import java.io.PrintStream;
 import java.util.ArrayList;
 import java.util.Collection;
@@ -367,4 +368,21 @@ public static <T> List<T> getMembersForElements(ElementCatalog<T> elementCatalog
         return Collections.emptyList();
     }
 
+    public static void addUnionMember(final UnionBuilder<ExtensionCatalog> union, final ExtensionCatalog ec) {
+        final MemberBuilder<ExtensionCatalog> builder = union.getOrCreateMember(
+                ec.getId(), ec.getBom().getVersion(), ec);
+        ec.getExtensions()
+                .forEach(e -> builder
+                        .addElement(e.getArtifact().getGroupId() + ":" + e.getArtifact().getArtifactId()));
+    }
+
+    public static void setElementCatalog(ExtensionCatalog extCatalog, ElementCatalog<?> elemCatalog) {
+        if (!elemCatalog.isEmpty()) {
+            extCatalog.getMetadata().put("element-catalog", elemCatalog);
+        }
+    }
+
+    public static <T> ElementCatalog<T> getElementCatalog(ExtensionCatalog extCatalog, Class<T> t) {
+        return (ElementCatalog<T>) extCatalog.getMetadata().get("element-catalog");
+    }
 }