diff --git a/.github/workflows/test-spec.yml b/.github/workflows/test-spec.yml
index 4837c221f..8af9cc891 100644
--- a/.github/workflows/test-spec.yml
+++ b/.github/workflows/test-spec.yml
@@ -20,7 +20,7 @@ jobs:
   test-opensearch-spec:
     runs-on: ubuntu-latest
     env:
-      OPENSEARCH_VERSION: 2.12.0
+      OPENSEARCH_VERSION: 2.15.0
       OPENSEARCH_PASSWORD: myStrongPassword123!
     steps:
       - name: Checkout Repo
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 55248104d..12ce686f3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -63,6 +63,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - Fixed optional field in `/_nodes` ([#365](https://github.com/opensearch-project/opensearch-api-specification/pull/365))
 - Fixed `/{index}/_open` can return a `task` ([#376](https://github.com/opensearch-project/opensearch-api-specification/pull/376))
 - Fixed `_source` in `bulk` responses ([#375](https://github.com/opensearch-project/opensearch-api-specification/pull/375))
+- Fixed `/{index}/_dangling` that can return `nodes` and `cluster_name` ([#391](https://github.com/opensearch-project/opensearch-api-specification/pull/391))
 
 ### Security
 
diff --git a/spec/namespaces/dangling_indices.yaml b/spec/namespaces/dangling_indices.yaml
index 9af8528c8..75113107c 100644
--- a/spec/namespaces/dangling_indices.yaml
+++ b/spec/namespaces/dangling_indices.yaml
@@ -71,6 +71,10 @@ components:
           schema:
             type: object
             properties:
+              _nodes:
+                $ref: '../schemas/_common.yaml#/components/schemas/NodeStatistics'
+              cluster_name:
+                $ref: '../schemas/_common.yaml#/components/schemas/Name'
               dangling_indices:
                 type: array
                 items:
diff --git a/tests/_core/aliases.yaml b/tests/indices/aliases.yaml
similarity index 100%
rename from tests/_core/aliases.yaml
rename to tests/indices/aliases.yaml
diff --git a/tests/indices/clone.yaml b/tests/indices/clone.yaml
new file mode 100644
index 000000000..c56f2b142
--- /dev/null
+++ b/tests/indices/clone.yaml
@@ -0,0 +1,39 @@
+$schema: ../../json_schemas/test_story.schema.yaml
+
+description: Test cloning an index.
+prologues:
+  - path: /movies
+    method: PUT
+epilogues:
+  - path: /movies
+    method: DELETE
+    status: [200, 404]
+  - path: /games
+    method: DELETE
+    status: [200, 404]
+chapters:
+  - synopsis: Block writes to the source index.
+    path: /{index}/_settings
+    method: PUT
+    parameters:
+      index: movies
+    request_body:
+      payload:
+        settings:
+          index.blocks.write: true
+  - synopsis: Clone an index.
+    path: /{index}/_clone/{target}
+    method: POST
+    parameters:
+      index: movies
+      target: games
+      wait_for_active_shards: 1
+      cluster_manager_timeout: 10s
+      timeout: 10s
+      wait_for_completion: true
+    response:
+      status: 200
+      payload:
+        shards_acknowledged: true
+        acknowledged: true
+        index: games
diff --git a/tests/indices/dangling.yaml b/tests/indices/dangling.yaml
new file mode 100644
index 000000000..5accfcce8
--- /dev/null
+++ b/tests/indices/dangling.yaml
@@ -0,0 +1,7 @@
+$schema: ../../json_schemas/test_story.schema.yaml
+
+description: Test dangling indexes.
+chapters:
+  - synopsis: Get dangling indexes.
+    path: /_dangling
+    method: GET
diff --git a/tests/indices/flush.yaml b/tests/indices/flush.yaml
new file mode 100644
index 000000000..a38c4c65b
--- /dev/null
+++ b/tests/indices/flush.yaml
@@ -0,0 +1,49 @@
+$schema: ../../json_schemas/test_story.schema.yaml
+
+description: Test flushing an index.
+prologues:
+  - path: /movies
+    method: PUT
+epilogues:
+  - path: /movies
+    method: DELETE
+    status: [200, 404]
+chapters:
+  - synopsis: Flush all indexes (GET).
+    path: /_flush
+    method: GET
+    parameters:
+      allow_no_indices: true
+      expand_wildcards: none
+      force: true
+      ignore_unavailable: true
+      wait_if_ongoing: true
+    response:
+      status: 200
+      payload:
+        _shards: {}
+  - synopsis: Flush all indexes (POST).
+    path: /_flush
+    method: POST
+    response:
+      status: 200
+      payload:
+        _shards: {}
+  - synopsis: Flush an index (GET).
+    path: /{index}/_flush
+    method: GET
+    parameters:
+      index: movies
+    response:
+      status: 200
+      payload:
+        _shards: {}
+  - synopsis: Flush an index (POST).
+    path: /{index}/_flush
+    method: POST
+    parameters:
+      index: movies
+    response:
+      status: 200
+      payload:
+        _shards: {}
diff --git a/tests/indices/forcemerge.yaml b/tests/indices/forcemerge.yaml
new file mode 100644
index 000000000..c35313aa6
--- /dev/null
+++ b/tests/indices/forcemerge.yaml
@@ -0,0 +1,47 @@
+
+$schema: ../../json_schemas/test_story.schema.yaml
+
+description: Test force merging an index.
+prologues:
+  - path: /movies
+    method: PUT
+  - path: /games
+    method: PUT
+epilogues:
+  - path: /movies,games
+    method: DELETE
+    status: [200, 404]
+chapters:
+  - synopsis: Force merge all indexes.
+    path: /_forcemerge
+    method: POST
+    parameters:
+      allow_no_indices: true
+      expand_wildcards: none
+      flush: true
+      max_num_segments: 1
+      only_expunge_deletes: true
+      primary_only: false
+      ignore_unavailable: true
+    response:
+      status: 200
+      payload:
+        _shards: {}
+  - synopsis: Force merge an index.
+    path: /{index}/_forcemerge
+    method: POST
+    parameters:
+      index: movies
+    response:
+      status: 200
+      payload:
+        _shards: {}
+  - synopsis: Force merge multiple indexes.
+    path: /{index}/_forcemerge
+    method: POST
+    parameters:
+      index: movies,games
+    response:
+      status: 200
+      payload:
+        _shards: {}
diff --git a/tests/indices/index.yaml b/tests/indices/index.yaml
index 3ccd60aee..541d76205 100644
--- a/tests/indices/index.yaml
+++ b/tests/indices/index.yaml
@@ -39,6 +39,12 @@ chapters:
     method: HEAD
     parameters:
       index: books
+      allow_no_indices: true
+      expand_wildcards: none
+      flat_settings: true
+      include_defaults: true
+      ignore_unavailable: true
+      local: true
 
   - synopsis: Check if the index `movies` exists. It should not.
     path: /{index}
diff --git a/tests/indices/_refresh.yaml b/tests/indices/refresh.yaml
similarity index 100%
rename from tests/indices/_refresh.yaml
rename to tests/indices/refresh.yaml
diff --git a/tests/indices/settings.yaml b/tests/indices/settings.yaml
new file mode 100644
index 000000000..e8cd4aa5d
--- /dev/null
+++ b/tests/indices/settings.yaml
@@ -0,0 +1,69 @@
+
+$schema: ../../json_schemas/test_story.schema.yaml
+
+description: Test settings for an index.
+prologues:
+  - path: /movies
+    method: PUT
+epilogues:
+  - path: /movies
+    method: DELETE
+    status: [200, 404]
+chapters:
+  - synopsis: Get global settings.
+    path: /_settings
+    method: GET
+    parameters:
+      allow_no_indices: true
+      expand_wildcards: none
+      flat_settings: true
+      include_defaults: true
+      ignore_unavailable: true
+      local: true
+      cluster_manager_timeout: 1s
+    response:
+      status: 200
+  - synopsis: Write a setting to an index.
+    path: /{index}/_settings
+    method: PUT
+    parameters:
+      index: movies
+    request_body:
+      payload:
+        settings:
+          index.blocks.write: true
+          index:
+            number_of_replicas: 4
+  - synopsis: Get settings for an index.
+    path: /{index}/_settings
+    method: GET
+    parameters:
+      index: movies
+      allow_no_indices: true
+      expand_wildcards: none
+    response:
+      status: 200
+      payload:
+        movies:
+          settings:
+            index:
+              provided_name: movies
+              blocks:
+                write: 'true'
+  - synopsis: Get a specific setting for an index.
+    path: /{index}/_settings/{name}
+    method: GET
+    parameters:
+      index: movies
+      name: index.blocks.write
+    response:
+      status: 200
+      payload:
+        movies:
+          settings:
+            index:
+              blocks:
+                write: 'true'
+
+
+
diff --git a/tests/indices/shrink.yaml b/tests/indices/shrink.yaml
new file mode 100644
index 000000000..91359baa6
--- /dev/null
+++ b/tests/indices/shrink.yaml
@@ -0,0 +1,62 @@
+$schema: ../../json_schemas/test_story.schema.yaml
+
+description: Test shrinking an index.
+prologues:
+  - path: /movies
+    method: PUT
+    request_body:
+      payload:
+        settings:
+          index.number_of_shards: 3
+epilogues:
+  - path: /movies
+    method: DELETE
+    status: [200, 404]
+  - path: /movies1
+    method: DELETE
+    status: [200, 404]
+  - path: /movies2
+    method: DELETE
+    status: [200, 404]
+chapters:
+  - synopsis: Block writes to the source index.
+    path: /{index}/_settings
+    method: PUT
+    parameters:
+      index: movies
+    request_body:
+      payload:
+        settings:
+          index.blocks.write: true
+  - synopsis: Shrink an index (POST).
+    path: /{index}/_shrink/{target}
+    method: POST
+    parameters:
+      index: movies
+      target: movies1
+      wait_for_active_shards: 1
+      cluster_manager_timeout: 10s
+      timeout: 10s
+      wait_for_completion: true
+    response:
+      status: 200
+      payload:
+        shards_acknowledged: true
+        acknowledged: true
+        index: movies1
+  - synopsis: Shrink an index (PUT).
+    path: /{index}/_shrink/{target}
+    method: PUT
+    parameters:
+      index: movies
+      target: movies2
+      wait_for_active_shards: 1
+      cluster_manager_timeout: 10s
+      timeout: 10s
+      wait_for_completion: true
+    response:
+      status: 200
+      payload:
+        shards_acknowledged: true
+        acknowledged: true
+        index: movies2
\ No newline at end of file
diff --git a/tests/indices/split.yaml b/tests/indices/split.yaml
new file mode 100644
index 000000000..a4399a984
--- /dev/null
+++ b/tests/indices/split.yaml
@@ -0,0 +1,72 @@
+$schema: ../../json_schemas/test_story.schema.yaml
+
+description: Test splitting an index.
+prologues:
+  - path: /movies
+    method: PUT
+    request_body:
+      payload:
+        settings:
+          index.number_of_shards: 3
+epilogues:
+  - path: /movies
+    method: DELETE
+    status: [200, 404]
+  - path: /movies1
+    method: DELETE
+    status: [200, 404]
+  - path: /movies2
+    method: DELETE
+    status: [200, 404]
+chapters:
+  - synopsis: Block writes to the source index.
+    path: /{index}/_settings
+    method: PUT
+    parameters:
+      index: movies
+    request_body:
+      payload:
+        settings:
+          index.blocks.write: true
+  - synopsis: Split an index (POST).
+    path: /{index}/_split/{target}
+    method: POST
+    parameters:
+      index: movies
+      target: movies1
+      wait_for_active_shards: 1
+      cluster_manager_timeout: 10s
+      timeout: 10s
+      wait_for_completion: true
+    request_body:
+      payload:
+        settings:
+          index:
+            number_of_shards: 6
+    response:
+      status: 200
+      payload:
+        shards_acknowledged: true
+        acknowledged: true
+        index: movies1
+  - synopsis: Split an index (PUT).
+    path: /{index}/_split/{target}
+    method: PUT
+    parameters:
+      index: movies
+      target: movies2
+      wait_for_active_shards: 1
+      cluster_manager_timeout: 10s
+      timeout: 10s
+      wait_for_completion: true
+    request_body:
+      payload:
+        settings:
+          index:
+            number_of_shards: 6
+    response:
+      status: 200
+      payload:
+        shards_acknowledged: true
+        acknowledged: true
+        index: movies2
\ No newline at end of file