diff --git a/lib/stack/bulkOperation/index.js b/lib/stack/bulkOperation/index.js
index 05621003..945f8dd9 100644
--- a/lib/stack/bulkOperation/index.js
+++ b/lib/stack/bulkOperation/index.js
@@ -9,6 +9,24 @@ export function BulkOperation (http, data = {}) {
   this.stackHeaders = data.stackHeaders
   this.urlPath = `/bulk`
 
+  this.addItems = async ({ data, bulk_version = "" }) => {
+    this.urlPath = `/bulk/release/items`;
+    const headers = {
+      headers: {
+        ...cloneDeep(this.stackHeaders),
+      },
+    };
+    if (bulk_version) headers.headers.bulk_version = bulk_version;
+    try {
+      const response = await http.post(this.urlPath, data, headers);
+      if (response.data) {
+        return response.data;
+      }
+    } catch (error) {
+      console.error(error);
+    }
+  };
+
   /**
    * The Publish entries and assets in bulk request allows you to publish multiple entries and assets at the same time.
    * @memberof BulkOperation
diff --git a/test/sanity-check/api/release-test.js b/test/sanity-check/api/release-test.js
index 20c9c822..8b4a1a7c 100644
--- a/test/sanity-check/api/release-test.js
+++ b/test/sanity-check/api/release-test.js
@@ -213,6 +213,38 @@ describe('Relases api Test', () => {
       .catch(done)
   })
 
+  it('Bulk Operation: should add items to a release', done => {
+    const items = {
+      release: releaseUID,
+      action: 'publish',
+      locale: ['en-us'],
+      reference: true,
+      items: [
+        {
+          version: entries[1]._version,
+          uid: entries[1].uid,
+          content_type_uid: multiPageCT.content_type.uid,
+          locale: 'en-us',
+          title: entries[1].title
+        },
+        {
+          version: entries[2]._version,
+          uid: entries[2].uid,
+          content_type_uid: multiPageCT.content_type.uid,
+          locale: 'en-us',
+          title: entries[2].title
+        },
+      ],
+    }
+    doBulkOperation().addItems({ data: items, bulk_version: '2.0' })
+    .then((response) => {
+      expect(response.notice).to.equal('Your add to release request is in progress.')
+      expect(response.job_id).to.not.equal(undefined)
+      done()
+    })
+    .catch(done)
+  })
+
   it('should delete specific Releases with Uid ', done => {
     makeRelease(releaseUID)
       .delete()
@@ -237,3 +269,7 @@ describe('Relases api Test', () => {
 function makeRelease (uid = null) {
   return client.stack({ api_key: process.env.API_KEY }).release(uid)
 }
+
+function doBulkOperation(uid = null) {
+  return client.stack({ api_key: process.env.API_KEY }).bulkOperation()
+}
\ No newline at end of file
diff --git a/test/unit/bulkOperation-test.js b/test/unit/bulkOperation-test.js
new file mode 100644
index 00000000..0f21f6fd
--- /dev/null
+++ b/test/unit/bulkOperation-test.js
@@ -0,0 +1,186 @@
+import Axios from 'axios';
+import { expect } from 'chai';
+import MockAdapter from 'axios-mock-adapter';
+import { describe, it } from 'mocha';
+import { BulkOperation } from '../../lib/stack/bulkOperation';
+import { stackHeadersMock } from './mock/objects';
+
+describe('Contentstack BulkOperation test', () => {
+  it('BulkOperation test without uid', done => {
+    const bulkOperation = makeBulkOperation();
+    expect(bulkOperation.urlPath).to.be.equal('/bulk');
+    expect(bulkOperation.stackHeaders).to.be.equal(undefined);
+    expect(bulkOperation.addItems).to.not.equal(undefined);
+    expect(bulkOperation.publish).to.not.equal(undefined);
+    expect(bulkOperation.unpublish).to.not.equal(undefined);
+    expect(bulkOperation.delete).to.not.equal(undefined);
+    done();
+  });
+
+  it('BulkOperation test with stackHeaders', done => {
+    const bulkOperation = makeBulkOperation({ stackHeaders: { ...stackHeadersMock } });
+    expect(bulkOperation.urlPath).to.be.equal('/bulk');
+    expect(bulkOperation.stackHeaders).to.not.equal(undefined);
+    expect(bulkOperation.stackHeaders.api_key).to.be.equal(stackHeadersMock.api_key);
+    expect(bulkOperation.addItems).to.not.equal(undefined);
+    expect(bulkOperation.publish).to.not.equal(undefined);
+    expect(bulkOperation.unpublish).to.not.equal(undefined);
+    expect(bulkOperation.delete).to.not.equal(undefined);
+    done();
+  });
+
+  it('should add items to a release', async () => {
+    const items = {
+      release: 'blt05e951e5f3a1d342',
+      action: 'publish',
+      locale: ['en-us'],
+      reference: true,
+      items: [
+        {
+          content_type_uid: 'ct_1',
+          uid: 'bltf6e197a18a11ec5f',
+          version: 2,
+          locale: 'en-us',
+          title: 'validation test',
+        },
+      ],
+    };
+
+    var mock = new MockAdapter(Axios);
+    mock.onPost('/bulk/release/items').reply(200, {
+      notice: 'Your add to release request is in progress.',
+      job_id: 'job_id',
+    });
+
+    const response = await makeBulkOperation().addItems({ data: items, bulk_version: '2.0' });
+    expect(response.notice).to.equal('Your add to release request is in progress.');
+    expect(response.job_id).to.not.equal(undefined);
+  });
+
+  it('should publish items in bulk', async () => {
+    const publishDetails = {
+      entries: [
+        {
+          uid: 'entry_uid',
+          content_type: 'content_type_uid',
+          version: 'version',
+          locale: 'entry_locale',
+        },
+      ],
+      assets: [{ uid: 'uid' }],
+      locales: ['en'],
+      environments: ['env_uid'],
+    };
+
+    var mock = new MockAdapter(Axios);
+    mock.onPost('/bulk/publish').reply(200, {
+      notice: 'Your publish request is in progress.',
+      job_id: 'job_id',
+    });
+
+    const response = await makeBulkOperation().publish({ details: publishDetails });
+    expect(response.notice).to.equal('Your publish request is in progress.');
+    expect(response.job_id).to.not.equal(undefined);
+  });
+
+  it('should unpublish items in bulk', async () => {
+    const unpublishDetails = {
+      entries: [
+        {
+          uid: 'entry_uid',
+          content_type: 'content_type_uid',
+          version: 'version',
+          locale: 'entry_locale',
+        },
+      ],
+      assets: [{ uid: 'uid' }],
+      locales: ['en'],
+      environments: ['env_uid'],
+    };
+
+    var mock = new MockAdapter(Axios);
+    mock.onPost('/bulk/unpublish').reply(200, {
+      notice: 'Your unpublish request is in progress.',
+      job_id: 'job_id',
+    });
+
+    const response = await makeBulkOperation().unpublish({ details: unpublishDetails });
+    expect(response.notice).to.equal('Your unpublish request is in progress.');
+    expect(response.job_id).to.not.equal(undefined);
+  });
+
+  it('should delete items in bulk', async () => {
+    const deleteDetails = {
+      entries: [
+        {
+          uid: 'entry_uid',
+          content_type: 'content_type_uid',
+          locale: 'entry_locale',
+        },
+      ],
+      assets: [{ uid: 'uid' }],
+    };
+
+    var mock = new MockAdapter(Axios);
+    mock.onPost('/bulk/delete').reply(200, {
+      notice: 'Your delete request is in progress.',
+      job_id: 'job_id',
+    });
+
+    const response = await makeBulkOperation().delete({ details: deleteDetails });
+    expect(response.notice).to.equal('Your delete request is in progress.');
+    expect(response.job_id).to.not.equal(undefined);
+  });
+
+  it('should update items in bulk', async () => {
+    const updateBody = {
+      entries: [
+        {
+          content_type: 'content_type_uid1',
+          uid: 'entry_uid',
+          locale: 'en-us',
+        },
+        {
+          content_type: 'content_type_uid2',
+          uid: 'entry_uid',
+          locale: 'en-us',
+        },
+      ],
+      workflow: {
+        workflow_stage: {
+          comment: 'Workflow-related Comments',
+          due_date: 'Thu Dec 01 2018',
+          notify: false,
+          uid: 'workflow_stage_uid',
+          assigned_to: [
+            {
+              uid: 'user_uid',
+              name: 'user_name',
+              email: 'user_email_id',
+            },
+          ],
+          assigned_by_roles: [
+            {
+              uid: 'role_uid',
+              name: 'role_name',
+            },
+          ],
+        },
+      },
+    };
+
+    var mock = new MockAdapter(Axios);
+    mock.onPost('/bulk/workflow').reply(200, {
+      notice: 'Your update request is in progress.',
+      job_id: 'job_id',
+    });
+
+    const response = await makeBulkOperation().update(updateBody);
+    expect(response.notice).to.equal('Your update request is in progress.');
+    expect(response.job_id).to.not.equal(undefined);
+  });
+});
+
+function makeBulkOperation(data) {
+  return new BulkOperation(Axios, data);
+}
\ No newline at end of file
diff --git a/test/unit/index.js b/test/unit/index.js
index cde49f51..a49ffca1 100644
--- a/test/unit/index.js
+++ b/test/unit/index.js
@@ -14,6 +14,7 @@ require('./extension-test')
 require('./branch-test')
 require('./branchAlias-test')
 require('./release-test')
+require('./bulkOperation-test')
 require('./asset-test')
 require('./webhook-test')
 require('./workflow-test')
diff --git a/types/stack/bulkOperation/index.d.ts b/types/stack/bulkOperation/index.d.ts
index 867345da..feb2160d 100644
--- a/types/stack/bulkOperation/index.d.ts
+++ b/types/stack/bulkOperation/index.d.ts
@@ -6,14 +6,15 @@ export interface BulkOperation extends SystemFields {
     publish(config: BulkOperationConfig): Promise<Response>
     unpublish(config: BulkOperationConfig): Promise<Response>
     delete(config: BulkDeleteConfig): Promise<Response>
+    addItems(config: AddItemsConfig): Promise<Response>
 }
-
 export interface BulkOperationConfig {
     details: PublishItems
     skip_workflow_stage?: boolean
     approvals?: boolean
     is_nested?: boolean
     api_version?: string
+    bulk_version?: string
 }
 
 export interface PublishItems extends PublishDetails {
@@ -44,4 +45,9 @@ export interface BulkDeleteAsset {
 export interface BranchData extends AnyProperty {
     name: string
     source: string
+}
+
+export interface BulkAddItemsConfig {
+    data: AnyProperty;
+    bulk_version?: string;
 }
\ No newline at end of file