diff --git a/doc/api/pipelines.md b/doc/api/pipelines.md
index bc96b3a0bdf..0e752056642 100644
--- a/doc/api/pipelines.md
+++ b/doc/api/pipelines.md
@@ -102,7 +102,7 @@ POST /projects/:id/pipeline
 |------------|---------|----------|---------------------|
 | `id`       | integer/string | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
 | `ref`       | string | yes      | Reference to commit |
-| `variables_attributes` | array | no | An array containing the variables available in the pipeline matching the structure [{ 'key' => 'UPLOAD_TO_S3', 'value' => 'true' }] |
+| `variables` | array | no | An array containing the variables available in the pipeline matching the structure [{ 'key' => 'UPLOAD_TO_S3', 'value' => 'true' }] |
 
 ```
 curl --request POST --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitlab.example.com/api/v4/projects/1/pipeline?ref=master"
diff --git a/lib/api/pipelines.rb b/lib/api/pipelines.rb
index 85e073ce662..378d9585eb8 100644
--- a/lib/api/pipelines.rb
+++ b/lib/api/pipelines.rb
@@ -41,7 +41,7 @@ module API
       end
       params do
         requires :ref, type: String,  desc: 'Reference'
-        optional :variables_attributes, Array, desc: 'Array of variables available in the pipeline'
+        optional :variables, Array, desc: 'Array of variables available in the pipeline'
       end
       post ':id/pipeline' do
         Gitlab::QueryLimiting.whitelist('https://gitlab.com/gitlab-org/gitlab-ce/issues/42124')
@@ -50,7 +50,7 @@ module API
 
         new_pipeline = Ci::CreatePipelineService.new(user_project,
                                                      current_user,
-                                                     declared_params(include_missing: false))
+                                                     declared_params(include_missing: false).merge(variables_attributes: params[:variables]))
                            .execute(:api, ignore_skip_ci: true, save_on_errors: false)
 
         if new_pipeline.persisted?
diff --git a/spec/requests/api/pipelines_spec.rb b/spec/requests/api/pipelines_spec.rb
index f20c2275152..0c6bb56e11d 100644
--- a/spec/requests/api/pipelines_spec.rb
+++ b/spec/requests/api/pipelines_spec.rb
@@ -302,17 +302,32 @@ describe API::Pipelines do
         end
 
         context 'variables given' do
-          let(:variables_attributes) { [{ 'key' => 'UPLOAD_TO_S3', 'value' => 'true' }] }
+          let(:variables) { [{ 'key' => 'UPLOAD_TO_S3', 'value' => 'true' }] }
 
           it 'creates and returns a new pipeline using the given variables' do
             expect do
-              post api("/projects/#{project.id}/pipeline", user), ref: project.default_branch, variables_attributes: variables_attributes
+              post api("/projects/#{project.id}/pipeline", user), ref: project.default_branch, variables: variables
             end.to change { project.pipelines.count }.by(1)
 
             expect(response).to have_gitlab_http_status(201)
             expect(json_response).to be_a Hash
             expect(json_response['sha']).to eq project.commit.id
-            expect(json_response['variables']).to eq variables_attributes
+            expect(json_response['variables']).to eq variables
+          end
+        end
+
+        context 'when excluding a ref' do
+          before do
+            config = YAML.dump(test: { script: 'test', except: [project.default_branch] })
+            stub_ci_pipeline_yaml_file(config)
+          end
+
+          it "doesn't not create a job for the exluded ref" do
+            expect do
+              post api("/projects/#{project.id}/pipeline", user), ref: project.default_branch
+            end.not_to change { project.pipelines.count }
+
+            expect(response).to have_gitlab_http_status(400)
           end
         end