adding wrapper dsl query docs

_query-dsl/specialized/index.md

@@ -28,4 +28,4 @@ OpenSearch supports the following specialized queries:
 
 - [`script_score`]({{site.url}}{{site.baseurl}}/query-dsl/specialized/script-score/): Calculates a custom score for matching documents using a script.
 
-- `wrapper`: Accepts other queries as JSON or YAML strings.
+- [`wrapper`]({{site.url}}{{site.baseurl}}/query-dsl/specialized/wrapper/): Accepts other queries as JSON or YAML strings.

_query-dsl/specialized/wrapper.md

@@ -0,0 +1,47 @@
+---
+
+layout: default
+title: Wrapper
+parent: Specialized queries
+nav_order: 80
+---
+
+# Wrapper
+
+The `wrapper` query lets you submit a complete query in Base64-encoded JSON format. It is useful when the query must be embedded in contexts that only support string values.
+
+Use this query only when you need to work around system constraints. For readability and maintainability, it's better to use standard JSON-based queries when possible.
+
+## Example use case
+
+If you want to run the following query:
+
+```json
+{
+  "match": {
+    "title": "headphones"
+  }
+}
+```
+
+Encode this JSON as a Base64 string. The Base64-encoded version is:
+
+```
+eyAibWF0Y2giOiB7InRpdGxlIjogImhlYWRwaG9uZXMifSB9
+```
+
+Wrap this base64 encoded string in a `wrapper` query:
+
+```json
+POST /products/_search
+{
+  "query": {
+    "wrapper": {
+      "query": "eyAibWF0Y2giOiB7InRpdGxlIjogImhlYWRwaG9uZXMifSB9"
+    }
+  }
+}
+```
+{% include copy-curl.html %}
+
+This executes the same query as the original `match` clause.