diff --git a/.doc_gen/metadata/forecast_metadata.yaml b/.doc_gen/metadata/forecast_metadata.yaml
new file mode 100644
index 00000000000..068611427c1
--- /dev/null
+++ b/.doc_gen/metadata/forecast_metadata.yaml
@@ -0,0 +1,183 @@
+# zexi 0.4.0
+forecast_CreateDataset:
+  title: Create a data set for the &FORlong; using an &AWS; SDK
+  title_abbrev: Create a data set
+  synopsis: create a &FOR; data set.
+  category:
+  languages:
+    Kotlin:
+      versions:
+        - sdk_version: 1
+          github: kotlin/services/forecast
+          sdkguide:
+          excerpts:
+            - description:
+              snippet_tags:
+                - forecast.kotlin.create_forecast_dataset.main
+    Java:
+      versions:
+        - sdk_version: 2
+          github: javav2/example_code/forecast
+          sdkguide:
+          excerpts:
+            - description:
+              snippet_tags:
+                - forecast.java2.create_forecast_dataset.main
+  services:
+    forecast: {CreateDataset}
+forecast_CreateForecast:
+  title: Create a forecast for the &FORlong; using an &AWS; SDK
+  title_abbrev: Create a forecast
+  synopsis: create a &FOR; forecast.
+  category:
+  languages:
+    Kotlin:
+      versions:
+        - sdk_version: 1
+          github: kotlin/services/forecast
+          sdkguide:
+          excerpts:
+            - description:
+              snippet_tags:
+                - forecast.kotlin.create_forecast.main
+    Java:
+      versions:
+        - sdk_version: 2
+          github: javav2/example_code/forecast
+          sdkguide:
+          excerpts:
+            - description:
+              snippet_tags:
+                - forecast.java2.create_forecast.main
+  services:
+    forecast: {CreateForecast}    
+forecast_DeleteForecast:
+  title: Delete a forecast for the &FORlong; using an &AWS; SDK
+  title_abbrev: Delete a forecast
+  synopsis: delete a &FOR; forecast.
+  category:
+  languages:
+    Kotlin:
+      versions:
+        - sdk_version: 1
+          github: kotlin/services/forecast
+          sdkguide:
+          excerpts:
+            - description:
+              snippet_tags:
+                - forecast.kotlin.delete_forecast.main
+    Java:
+      versions:
+        - sdk_version: 2
+          github: javav2/example_code/forecast
+          sdkguide:
+          excerpts:
+            - description:
+              snippet_tags:
+                - forecast.java2.delete_forecast_dataset.main
+  services:
+    forecast: {DeleteForecast}        
+forecast_DeleteDataset:
+  title: Delete a data set for the &FORlong; using an &AWS; SDK
+  title_abbrev: Delete a data set
+  synopsis: delete a &FOR; data set.
+  category:
+  languages:
+    Kotlin:
+      versions:
+        - sdk_version: 1
+          github: kotlin/services/forecast
+          sdkguide:
+          excerpts:
+            - description:
+              snippet_tags:
+                - forecast.kotlin.delete_forecast_dataset.main
+    Java:
+      versions:
+        - sdk_version: 2
+          github: javav2/example_code/forecast
+          sdkguide:
+          excerpts:
+            - description:
+              snippet_tags:
+                - forecast.java2.delete_forecast_dataset.main
+  services:
+    forecast: {DeleteDataset}
+forecast_DescribeForecast:
+  title: Describe a forecast for the &FORlong; using an &AWS; SDK
+  title_abbrev: Describe a forecast
+  synopsis: describe a &FOR; forecast.
+  category:
+  languages:
+    Kotlin:
+      versions:
+        - sdk_version: 1
+          github: kotlin/services/forecast
+          sdkguide:
+          excerpts:
+            - description:
+              snippet_tags:
+                - forecast.kotlin.describe_forecast.main
+    Java:
+      versions:
+        - sdk_version: 2
+          github: javav2/example_code/forecast
+          sdkguide:
+          excerpts:
+            - description:
+              snippet_tags:
+                - forecast.java2.describe_forecast.main
+  services:
+    forecast: {DescribeForecast}
+forecast_ListDatasetGroups:
+  title: List &FORlong; data set groups using an &AWS; SDK
+  title_abbrev: List data set groups
+  synopsis: list &FOR; data set groups.
+  category:
+  languages:
+    Kotlin:
+      versions:
+        - sdk_version: 1
+          github: kotlin/services/forecast
+          sdkguide:
+          excerpts:
+            - description:
+              snippet_tags:
+                - forecast.kotlin.list_forecast_datasetgroups.main
+    Java:
+      versions:
+        - sdk_version: 2
+          github: javav2/example_code/forecast
+          sdkguide:
+          excerpts:
+            - description:
+              snippet_tags:
+                - forecast.java2.list_forecast_datasetgroups.main
+  services:
+    forecast: {ListDatasetGroups}
+forecast_ListForecasts:
+  title: List &FORlong; forecasts using an &AWS; SDK
+  title_abbrev: List forecasts
+  synopsis: list &FOR; forecasts.
+  category:
+  languages:
+    Kotlin:
+      versions:
+        - sdk_version: 1
+          github: kotlin/services/forecast
+          sdkguide:
+          excerpts:
+            - description:
+              snippet_tags:
+                - forecast.kotlin.list_forecasts.main
+    Java:
+      versions:
+        - sdk_version: 2
+          github: javav2/example_code/forecast
+          sdkguide:
+          excerpts:
+            - description:
+              snippet_tags:
+                - forecast.java2.list_forecasts.main
+  services:
+    forecast: {ListForecasts}
diff --git a/.doc_gen/metadata/opensearch_metadata.yaml b/.doc_gen/metadata/opensearch_metadata.yaml
new file mode 100644
index 00000000000..9d402259e1c
--- /dev/null
+++ b/.doc_gen/metadata/opensearch_metadata.yaml
@@ -0,0 +1,105 @@
+# zexi 0.4.0
+opensearch_CreateDomain:
+  title: Create an &ES; domain by using an &AWS; SDK
+  title_abbrev: Create a domain
+  synopsis: create an &ES; domain.
+  category:
+  languages:
+    Kotlin:
+      versions:
+        - sdk_version: 1
+          github: kotlin/services/opensearch
+          sdkguide:
+          excerpts:
+            - description:
+              snippet_tags:
+                - opensearch.kotlin.create_domain.main
+    Java:
+      versions:
+        - sdk_version: 2
+          github: javav2/example_code/opensearch
+          sdkguide:
+          excerpts:
+            - description:
+              snippet_tags:
+                - opensearch.java2.create_domain.main
+  services:
+    opensearch: {CreateDomain}
+opensearch_DeleteDomain:
+  title: Delete an &ES; domain by using an &AWS; SDK
+  title_abbrev: Delete a domain
+  synopsis: delete an &ES; domain.
+  category:
+  languages:
+    Kotlin:
+      versions:
+        - sdk_version: 1
+          github: kotlin/services/opensearch
+          sdkguide:
+          excerpts:
+            - description:
+              snippet_tags:
+                - opensearch.kotlin.delete_domain.main
+    Java:
+      versions:
+        - sdk_version: 2
+          github: javav2/example_code/opensearch
+          sdkguide:
+          excerpts:
+            - description:
+              snippet_tags:
+                - opensearch.java2.delete_domain.main
+  services:
+    opensearch: {DeleteDomain}    
+opensearch_ListDomainNames:
+  title: List &ES; domains by using an &AWS; SDK
+  title_abbrev: List domains
+  synopsis: list &ES; domains.
+  category:
+  languages:
+    Kotlin:
+      versions:
+        - sdk_version: 1
+          github: kotlin/services/opensearch
+          sdkguide:
+          excerpts:
+            - description:
+              snippet_tags:
+                - opensearch.kotlin.list_domains.main
+    Java:
+      versions:
+        - sdk_version: 2
+          github: javav2/example_code/opensearch
+          sdkguide:
+          excerpts:
+            - description:
+              snippet_tags:
+                - opensearch.java2.list_domains.main
+  services:
+    opensearch: {ListDomainNames}
+opensearch_UpdateDomainConfig:
+  title: Modify a cluster configuration of the specified &ES; domain by using an &AWS; SDK
+  title_abbrev: Modify a cluster configuration
+  synopsis: modify a cluster configuration of an &ES; domain.
+  category:
+  languages:
+    Kotlin:
+      versions:
+        - sdk_version: 1
+          github: kotlin/services/opensearch
+          sdkguide:
+          excerpts:
+            - description:
+              snippet_tags:
+                - opensearch.kotlin.update_domain.main
+    Java:
+      versions:
+        - sdk_version: 2
+          github: javav2/example_code/opensearch
+          sdkguide:
+          excerpts:
+            - description:
+              snippet_tags:
+                - opensearch.java2.update_domain.main
+  services:
+    opensearch: {UpdateDomainConfig}
diff --git a/.doc_gen/metadata/services.yaml b/.doc_gen/metadata/services.yaml
index 33ac40a6a40..9e04fca1aa9 100644
--- a/.doc_gen/metadata/services.yaml
+++ b/.doc_gen/metadata/services.yaml
@@ -86,6 +86,7 @@ aurora:
     url: AmazonRDS/latest/AuroraUserGuide/CHAP_AuroraOverview.html
   tags:
     product_categories: {'Databases'}
+  api_client: rds
   version: rds-2014-10-31
   api_ref: AmazonRDS/latest/APIReference/Welcome.html
 auto-scaling:
@@ -439,6 +440,21 @@ firehose:
   version: "firehose-2015-08-04"
   tags:
     product_categories: {'Analytics'}
+forecast: 
+  long: '&FORlong;'
+  short: '&FOR;'
+  sort: Forecast
+  expanded:
+    long: Amazon Forecast Service
+    short: Forecast
+  blurb: a fully managed service that uses statistical and machine learning algorithms to deliver highly accurate time-series forecasts. 
+  guide:
+    subtitle: User Guide
+    url: forecast/latest/dg/getting-started.html
+  api_ref: forecast/latest/dg/api-reference.html
+  tags:
+    product_categories: {'Machine Learning & AI'}
+  version: forecast-2018-06-26
 glacier:
   long: '&GLlong;'
   short: '&GLshort;'
@@ -654,6 +670,21 @@ mediapackage:
   tags:
     product_categories: {'Media Services'}
   version: mediapackage-2017-10-12
+opensearch: 
+  long: '&ESlong;'
+  short: '&ES;'
+  sort: "ES"
+  expanded:
+    long: Amazon OpenSearch Service
+    short: OpenSearch
+  blurb: is a distributed, community-driven, Apache 2.0-licensed, 100% open-source search and analytics suite used for a broad set of use cases like real-time application monitoring, log analytics, and website search.
+  guide:
+    subtitle: User Guide
+    url: opensearch-service/latest/developerguide/gsg.html
+  api_ref: opensearch.org/docs/latest/api-reference/index/
+  tags:
+    product_categories: {'Analytics'}
+  version: es-2021-01-01
 organizations:
   long: '&AOlong;'
   short: '&AO;'