Azure Cosmos DB Node.js SDK for API for NoSQL: Release notes and resources


Resource Link
Download SDK @azure/cosmos
API Documentation JavaScript SDK reference documentation
SDK installation instructions npm install @azure/cosmos
Contribute to SDK Contributing guide for azure-sdk-for-js repo
Samples Node.js code samples
Getting started tutorial Get started with the JavaScript SDK
Web app tutorial Build a Node.js web application using Azure Cosmos DB
Current supported Node.js platforms LTS versions of Node.js

Release notes

Release history is maintained in the azure-sdk-for-js repo, for detailed list of releases, see the changelog file.

Migration guide for breaking changes

If you are on an older version of the SDK, it's recommended to migrate to the 3.0 version. This section details the improvements you would get with this version and the bug fixes made in the 3.0 version.

Improved client constructor options

Constructor options have been simplified:

  • masterKey was renamed key and moved to the top level
  • Properties previously under options.auth have moved to the top level
// v2
const client = new CosmosClient({
    endpoint: "",
    auth: {
        masterKey: "your-primary-key"

// v3
const client = new CosmosClient({
    endpoint: "",
    key: "your-primary-key"

Simplified query iterator API

In v2, there were many different ways to iterate or retrieve results from a query. We have attempted to simplify the v3 API and remove similar or duplicate APIs:

  • Remove and iterator.current(). Use fetchNext() to get pages of results.
  • Remove iterator.forEach(). Use async iterators instead.
  • iterator.executeNext() renamed to iterator.fetchNext()
  • iterator.toArray() renamed to iterator.fetchAll()
  • Pages are now proper Response objects instead of plain JS objects
  • const container = client.database(dbId).container(containerId)
// v2
container.items.query('SELECT * from c').toArray()
container.items.query('SELECT * from c').executeNext()
container.items.query('SELECT * from c').forEach(({ body: item }) => { console.log( })

// v3
container.items.query('SELECT * from c').fetchAll()
container.items.query('SELECT * from c').fetchNext()
for await(const { result: item } in client.databases.readAll().getAsyncIterator()) {

Fixed containers are now partitioned

The Azure Cosmos DB service now supports partition keys on all containers, including those that were previously created as fixed containers. The v3 SDK updates to the latest API version that implements this change, but it isn't breaking. If you don't supply a partition key for operations, we'll default to a system key that works with all your existing containers and documents.

Upsert removed for stored procedures

Previously upsert was allowed for non-partitioned collections, but with the API version update, all collections are partitioned so we removed it entirely.

Item reads won't throw on 404

const container = client.database(dbId).container(containerId)

// v2
try {, undefined)
} catch (e) {
    if (e.code === 404) { console.log('item not found') }

// v3
const { result: item }  =, undefined)
if (item === undefined) { console.log('item not found') }

Default multi-region writes

The SDK will now write to multiple regions by default if your Azure Cosmos DB configuration supports it. This was previously opt-in behavior.

Proper error objects

Failed requests now throw proper Error or subclasses of Error. Previously they threw plain JS objects.

New features

User-cancelable requests

The move to fetch internally allows us to use the browser AbortController API to support user-cancelable operations. In the case of operations where multiple requests are potentially in progress (like cross-partition queries), all requests for the operation will be canceled. Modern browser users will already have AbortController. Node.js users will need to use a Polyfill library

 const controller = new AbortController()
 const {result: item} = await items.query('SELECT * from c', { abortSignal: controller.signal});

Set throughput as part of db/container create operation

const { database }  = client.databases.create({ id: 'my-database', throughput: 10000 })
database.containers.create({ id: 'my-container', throughput: 10000 })


Header token generation was split out into a new library, @azure/cosmos-sign. Anyone calling the Azure Cosmos DB REST API directly can use this to sign headers using the same code we call inside @azure/cosmos.

UUID for generated IDs

v2 had custom code to generate item IDs. We have switched to the well known and maintained community library uuid.

Connection strings

It's now possible to pass a connection string copied from the Azure portal:

const client = new CosmosClient("AccountEndpoint=;AccountKey=c213asdasdefgdfgrtweaYPpgoeCsHbpRTHhxuMsTaw==;")
Add DISTINCT and LIMIT/OFFSET queries (#306)
 const { results } = await items.query('SELECT DISTINCT VALUE FROM ROOT').fetchAll()
 const { results } = await items.query('SELECT * FROM root r OFFSET 1 LIMIT 2').fetchAll()

Improved browser experience

While it was possible to use the v2 SDK in the browser, it wasn't an ideal experience. You needed to Polyfill several Node.js built-in libraries and use a bundler like webpack or Parcel. The v3 SDK makes the out of the box experience much better for browser users.

  • Replace request internals with fetch (#245)
  • Remove usage of Buffer (#330)
  • Remove node builtin usage in favor of universal packages/APIs (#328)
  • Switch to node-abort-controller (#294)

Bug fixes

  • Fix offer read and bring back offer tests (#224)
  • Fix EnableEndpointDiscovery (#207)
  • Fix missing RUs on paginated results (#360)
  • Expand SQL query parameter type (#346)
  • Add ttl to ItemDefinition (#341)
  • Fix CP query metrics (#311)
  • Add activityId to FeedResponse (#293)
  • Switch _ts type from string to number (#252)(#295)
  • Fix Request Charge Aggregation (#289)
  • Allow blank string partition keys (#277)
  • Add string to conflict query type (#237)
  • Add uniqueKeyPolicy to container (#234)

Engineering systems

Not always the most visible changes, but they help our team ship better code, faster.

  • Use rollup for production builds (#104)
  • Update to TypeScript 3.5 (#327)
  • Convert to TS project references. Extract test folder (#270)
  • Enable noUnusedLocals and noUnusedParameters (#275)
  • Azure Pipelines YAML for CI builds (#298)

Release & Retirement Dates

Microsoft provides notification at least 12 months in advance of retiring an SDK in order to smooth the transition to a newer/supported version. New features and functionality and optimizations are only added to the current SDK, as such it's recommended that you always upgrade to the latest SDK version as early as possible. Read the Microsoft Support Policy for SDKs for more details.

Version Release Date Retirement Date
v3 June 28, 2019 ---
v2 September 24, 2018 September 24, 2021
v1 April 08, 2015 August 30, 2020


How will I be notified of the retiring SDK?

Microsoft will provide 12 month's advance notice before the end of support of the retiring SDK to facilitate a smooth transition to a supported SDK. We'll notify you through various communication channels: the Azure portal, Azure updates, and direct communication to assigned service administrators.

Can I author applications by using a to-be-retired Azure Cosmos DB SDK during the 12-month period?

Yes, you'll be able to author, deploy, and modify applications by using the to-be-retired Azure Cosmos DB SDK during the 12-month notice period. We recommend that you migrate to a newer supported version of the Azure Cosmos DB SDK during the 12-month notice period, as appropriate.

After the retirement date, what happens to applications that use the unsupported Azure Cosmos DB SDK?

After the retirement date, Azure Cosmos DB will no longer make bug fixes, add new features, or provide support to the retired SDK versions. If you prefer not to upgrade, requests sent from the retired versions of the SDK will continue to be served by the Azure Cosmos DB service.

Which SDK versions will have the latest features and updates?

New features and updates will be added only to the latest minor version of the latest supported major SDK version. We recommend that you always use the latest version to take advantage of new features, performance improvements, and bug fixes. If you're using an old, non-retired version of the SDK, your requests to Azure Cosmos DB will still function, but you won't have access to any new capabilities.

What should I do if I can't update my application before a cutoff date?

We recommend that you upgrade to the latest SDK as early as possible. After an SDK is tagged for retirement, you'll have 12 months to update your application. If you're not able to update by the retirement date, requests sent from the retired versions of the SDK will continue to be served by Azure Cosmos DB, so your running applications will continue to function. But Azure Cosmos DB will no longer make bug fixes, add new features, or provide support to the retired SDK versions.

If you have a support plan and require technical support, contact us by filing a support ticket.

How can I request features be added to an SDK or connector?

New features are not always added to every SDK or connector immediately. If there is a feature not supported that you would like added, please add feedback to our community forum.

See also

To learn more about Azure Cosmos DB, see Microsoft Azure Cosmos DB service page.