diff --git a/build_tools/aws-sdk-code-generator/lib/aws-sdk-code-generator/service.rb b/build_tools/aws-sdk-code-generator/lib/aws-sdk-code-generator/service.rb
index 334e3b5a9ee..f96c03851f0 100644
--- a/build_tools/aws-sdk-code-generator/lib/aws-sdk-code-generator/service.rb
+++ b/build_tools/aws-sdk-code-generator/lib/aws-sdk-code-generator/service.rb
@@ -192,6 +192,31 @@ def deprecated?
       @deprecated
     end
 
+    # @return list of validation messages
+    def validate
+      errors = []
+      @api.fetch('metadata', {}).keys.sort.each do |key|
+        if AwsSdkCodeGenerator::Views::ClientApiModule::METADATA_KEYS[key].nil?
+          errors << {
+            type: :invalid_key,
+            message: "invalid/unsupported metadata key `#{key}`"
+          }
+        end
+      end
+
+      @api.fetch('shapes', {}).each do |shape_name, shape|
+        shape.each_pair do |key, _|
+          unless AwsSdkCodeGenerator::Views::ClientApiModule::SHAPE_KEYS.key?(key)
+            errors << {
+              type: :invalid_key,
+              message: "invalid/unsupported shape key `#{key}` on `#{shape_name}`"
+            }
+          end
+        end
+      end
+      errors
+    end
+
     # @api private
     def inspect
       "#<#{self.class.name}>"
diff --git a/build_tools/aws-sdk-code-generator/lib/aws-sdk-code-generator/views/client_api_module.rb b/build_tools/aws-sdk-code-generator/lib/aws-sdk-code-generator/views/client_api_module.rb
index 452fd4c0924..5a838a41b48 100644
--- a/build_tools/aws-sdk-code-generator/lib/aws-sdk-code-generator/views/client_api_module.rb
+++ b/build_tools/aws-sdk-code-generator/lib/aws-sdk-code-generator/views/client_api_module.rb
@@ -192,7 +192,7 @@ def metadata
               value: @service.api['metadata'][key].inspect
             }
           elsif METADATA_KEYS[key].nil?
-            raise "unhandled metadata key #{key.inspect}"
+            warn "unhandled metadata key #{key.inspect}"
           end
         end
         metadata
@@ -317,7 +317,7 @@ def shape_constructor_args(shape_name, shape)
 
             args << "#{key}: #{value.inspect}"
           elsif SHAPE_KEYS[key].nil?
-            raise "unhandled shape key #{key.inspect}"
+            warn "unhandled shape key #{key.inspect}"
           end
         end
         args.join(', ')