diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1bc5edb..f6da954 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [1.0.15] - 2026-05-15
+
+### Added
+
+- `channelGroup` optional field to `ReleaseSpec` in GCP cluster model (GCP-696)
+
 ## [1.0.14] - 2026-05-15
 
 ### Removed
@@ -138,7 +144,8 @@ First official stable release of the HyperFleet API specification.
 - Interactive API documentation
 
 <!-- Links -->
-[Unreleased]: https://github.com/openshift-hyperfleet/hyperfleet-api-spec/compare/v1.0.14...HEAD
+[Unreleased]: https://github.com/openshift-hyperfleet/hyperfleet-api-spec/compare/v1.0.15...HEAD
+[1.0.15]: https://github.com/openshift-hyperfleet/hyperfleet-api-spec/compare/v1.0.14...v1.0.15
 [1.0.14]: https://github.com/openshift-hyperfleet/hyperfleet-api-spec/compare/v1.0.13...v1.0.14
 [1.0.13]: https://github.com/openshift-hyperfleet/hyperfleet-api-spec/compare/v1.0.12...v1.0.13
 [1.0.12]: https://github.com/openshift-hyperfleet/hyperfleet-api-spec/compare/v1.0.11...v1.0.12
diff --git a/aliases.tsp b/aliases.tsp
index efa1472..d42dbb3 120000
--- a/aliases.tsp
+++ b/aliases.tsp
@@ -1 +1 @@
-aliases-gcp.tsp
\ No newline at end of file
+aliases-core.tsp
\ No newline at end of file
diff --git a/main.tsp b/main.tsp
index 741967c..a0f0913 100644
--- a/main.tsp
+++ b/main.tsp
@@ -21,7 +21,7 @@ using OpenAPI;
  */
 @service(#{ title: "HyperFleet API" })
 @info(#{
-  version: "1.0.14",
+  version: "1.0.15",
   contact: #{
     name: "HyperFleet Team",
     url: "https://github.com/openshift-hyperfleet",
diff --git a/models-gcp/cluster/example_cluster.tsp b/models-gcp/cluster/example_cluster.tsp
index 603f58f..9c8cdff 100644
--- a/models-gcp/cluster/example_cluster.tsp
+++ b/models-gcp/cluster/example_cluster.tsp
@@ -20,8 +20,9 @@ const exampleCluster: Cluster = #{
       },
     },
     release: #{
-      image: "registry.redhat.io/openshift4/ose-cluster-version-operator:v4.14.0",
-      version: "4.14.0",
+      image: "registry.redhat.io/openshift4/ose-cluster-version-operator:v4.22.0-ec.4",
+      version: "4.22.0-ec.4",
+      channelGroup: "candidate",
     },
     networking: #{
       clusterNetwork: #[ #{ cidr: "10.10.0.0/16", hostPrefix: 24 } ],
@@ -100,8 +101,9 @@ const exampleDeletedCluster: Cluster = #{
       },
     },
     release: #{
-      image: "registry.redhat.io/openshift4/ose-cluster-version-operator:v4.14.0",
-      version: "4.14.0",
+      image: "registry.redhat.io/openshift4/ose-cluster-version-operator:v4.22.0-ec.4",
+      version: "4.22.0-ec.4",
+      channelGroup: "candidate",
     },
     networking: #{
       clusterNetwork: #[ #{ cidr: "10.10.0.0/16", hostPrefix: 24 } ],
diff --git a/models-gcp/cluster/example_patch.tsp b/models-gcp/cluster/example_patch.tsp
index ff7a0e7..4f4be3f 100644
--- a/models-gcp/cluster/example_patch.tsp
+++ b/models-gcp/cluster/example_patch.tsp
@@ -14,8 +14,9 @@ const exampleClusterPatchRequest: ClusterPatchRequest = #{
       },
     },
     release: #{
-      image: "registry.redhat.io/openshift4/ose-cluster-version-operator:v4.14.0",
-      version: "4.14.0",
+      image: "registry.redhat.io/openshift4/ose-cluster-version-operator:v4.22.0-ec.4",
+      version: "4.22.0-ec.4",
+      channelGroup: "candidate",
     },
     networking: #{
       clusterNetwork: #[#{ cidr: "10.10.0.0/16", hostPrefix: 24 }],
diff --git a/models-gcp/cluster/example_post.tsp b/models-gcp/cluster/example_post.tsp
index b685235..79f5d6b 100644
--- a/models-gcp/cluster/example_post.tsp
+++ b/models-gcp/cluster/example_post.tsp
@@ -17,8 +17,9 @@ const exampleClusterCreateRequest: ClusterCreateRequest = #{
       },
     },
     release: #{
-      image: "registry.redhat.io/openshift4/ose-cluster-version-operator:v4.14.0",
-      version: "4.14.0",
+      image: "registry.redhat.io/openshift4/ose-cluster-version-operator:v4.22.0-ec.4",
+      version: "4.22.0-ec.4",
+      channelGroup: "candidate",
     },
     networking: #{
       clusterNetwork: #[#{ cidr: "10.10.0.0/16", hostPrefix: 24 }],
diff --git a/models-gcp/cluster/model.tsp b/models-gcp/cluster/model.tsp
index ca7dd7c..a98abb9 100644
--- a/models-gcp/cluster/model.tsp
+++ b/models-gcp/cluster/model.tsp
@@ -22,6 +22,7 @@ model ClusterPlatform {
 model ReleaseSpec {
     image?: string;
     version?: string;
+    channelGroup?: string;
 }
 
 model NetworkingSpec {
diff --git a/schemas/core/openapi.yaml b/schemas/core/openapi.yaml
index c85003a..e89e8de 100644
--- a/schemas/core/openapi.yaml
+++ b/schemas/core/openapi.yaml
@@ -1,7 +1,7 @@
 openapi: 3.0.0
 info:
   title: HyperFleet API
-  version: 1.0.14
+  version: 1.0.15
   contact:
     name: HyperFleet Team
     url: https://github.com/openshift-hyperfleet
diff --git a/schemas/core/swagger.yaml b/schemas/core/swagger.yaml
index b1ee316..d307cb3 100644
--- a/schemas/core/swagger.yaml
+++ b/schemas/core/swagger.yaml
@@ -17,7 +17,7 @@ info:
     name: Apache 2.0
     url: 'https://www.apache.org/licenses/LICENSE-2.0'
   title: HyperFleet API
-  version: 1.0.14
+  version: 1.0.15
 host: hyperfleet.redhat.com
 basePath: /
 schemes:
diff --git a/schemas/gcp/openapi.yaml b/schemas/gcp/openapi.yaml
index 3b624a0..460246d 100644
--- a/schemas/gcp/openapi.yaml
+++ b/schemas/gcp/openapi.yaml
@@ -1,7 +1,7 @@
 openapi: 3.0.0
 info:
   title: HyperFleet API
-  version: 1.0.14
+  version: 1.0.15
   contact:
     name: HyperFleet Team
     url: https://github.com/openshift-hyperfleet
@@ -194,8 +194,9 @@ paths:
                       network: network-123
                       subnet: subnet-123
                   release:
-                    image: registry.redhat.io/openshift4/ose-cluster-version-operator:v4.14.0
-                    version: 4.14.0
+                    image: registry.redhat.io/openshift4/ose-cluster-version-operator:v4.22.0-ec.4
+                    version: 4.22.0-ec.4
+                    channelGroup: candidate
                   networking:
                     clusterNetwork:
                       - cidr: 10.10.0.0/16
@@ -995,8 +996,9 @@ components:
               network: network-123
               subnet: subnet-123
           release:
-            image: registry.redhat.io/openshift4/ose-cluster-version-operator:v4.14.0
-            version: 4.14.0
+            image: registry.redhat.io/openshift4/ose-cluster-version-operator:v4.22.0-ec.4
+            version: 4.22.0-ec.4
+            channelGroup: candidate
           networking:
             clusterNetwork:
               - cidr: 10.10.0.0/16
@@ -1088,8 +1090,9 @@ components:
               network: network-123
               subnet: subnet-123
           release:
-            image: registry.redhat.io/openshift4/ose-cluster-version-operator:v4.14.0
-            version: 4.14.0
+            image: registry.redhat.io/openshift4/ose-cluster-version-operator:v4.22.0-ec.4
+            version: 4.22.0-ec.4
+            channelGroup: candidate
           networking:
             clusterNetwork:
               - cidr: 10.10.0.0/16
@@ -1149,8 +1152,9 @@ components:
               network: network-123
               subnet: subnet-123
           release:
-            image: registry.redhat.io/openshift4/ose-cluster-version-operator:v4.14.0
-            version: 4.14.0
+            image: registry.redhat.io/openshift4/ose-cluster-version-operator:v4.22.0-ec.4
+            version: 4.22.0-ec.4
+            channelGroup: candidate
           networking:
             clusterNetwork:
               - cidr: 10.10.0.0/16
@@ -1753,6 +1757,8 @@ components:
           type: string
         version:
           type: string
+        channelGroup:
+          type: string
     ResourceCondition:
       type: object
       required:
diff --git a/schemas/gcp/swagger.yaml b/schemas/gcp/swagger.yaml
index c3801b6..d5942a6 100644
--- a/schemas/gcp/swagger.yaml
+++ b/schemas/gcp/swagger.yaml
@@ -17,7 +17,7 @@ info:
     name: Apache 2.0
     url: 'https://www.apache.org/licenses/LICENSE-2.0'
   title: HyperFleet API
-  version: 1.0.14
+  version: 1.0.15
 host: hyperfleet.redhat.com
 basePath: /
 schemes:
@@ -170,9 +170,10 @@ paths:
                     zone: us-central1-a
                   type: gcp
                 release:
+                  channelGroup: candidate
                   image: >-
-                    registry.redhat.io/openshift4/ose-cluster-version-operator:v4.14.0
-                  version: 4.14.0
+                    registry.redhat.io/openshift4/ose-cluster-version-operator:v4.22.0-ec.4
+                  version: 4.22.0-ec.4
               status:
                 conditions:
                   - created_time: '2021-01-01T10:00:00Z'
@@ -1069,8 +1070,10 @@ definitions:
             zone: us-central1-a
           type: gcp
         release:
-          image: 'registry.redhat.io/openshift4/ose-cluster-version-operator:v4.14.0'
-          version: 4.14.0
+          channelGroup: candidate
+          image: >-
+            registry.redhat.io/openshift4/ose-cluster-version-operator:v4.22.0-ec.4
+          version: 4.22.0-ec.4
       status:
         conditions:
           - created_time: '2021-01-01T10:00:00Z'
@@ -1204,8 +1207,10 @@ definitions:
             zone: us-central1-a
           type: gcp
         release:
-          image: 'registry.redhat.io/openshift4/ose-cluster-version-operator:v4.14.0'
-          version: 4.14.0
+          channelGroup: candidate
+          image: >-
+            registry.redhat.io/openshift4/ose-cluster-version-operator:v4.22.0-ec.4
+          version: 4.22.0-ec.4
     properties:
       href:
         description: Resource URI
@@ -1287,8 +1292,10 @@ definitions:
             zone: us-central1-a
           type: gcp
         release:
-          image: 'registry.redhat.io/openshift4/ose-cluster-version-operator:v4.14.0'
-          version: 4.14.0
+          channelGroup: candidate
+          image: >-
+            registry.redhat.io/openshift4/ose-cluster-version-operator:v4.22.0-ec.4
+          version: 4.22.0-ec.4
     minProperties: 1
     properties:
       labels:
@@ -1917,6 +1924,8 @@ definitions:
     type: string
   ReleaseSpec:
     properties:
+      channelGroup:
+        type: string
       image:
         type: string
       version: