Quickstart: Build a Node.js application by using Azure Cosmos DB Gremlin API account


In this quickstart, you create and manage an Azure Cosmos DB Gremlin (graph) API account from the Azure portal, and add data by using a Node.js app cloned from GitHub. Azure Cosmos DB is a multi-model database service that lets you quickly create and query document, table, key-value, and graph databases with global distribution and horizontal scale capabilities.


Create a database account

  1. In a new browser window, sign in to the Azure portal.

  2. In the left menu, select Create a resource.

    Create a resource in the Azure portal

  3. On the New page, select Databases > Azure Cosmos DB.

    The Azure portal Databases pane

  4. On the Create Azure Cosmos DB Account page, enter the settings for the new Azure Cosmos DB account.

    Setting Value Description
    Subscription Subscription name Select the Azure subscription that you want to use for this Azure Cosmos account.
    Resource Group Resource group name Select a resource group, or select Create new, then enter a unique name for the new resource group.
    Account Name Enter a unique name Enter a unique name to identify your Azure Cosmos DB account. Your account URI will be gremlin.azure.com appended to your unique account name.

    The account name can use only lowercase letters, numbers, and hyphens (-), and must be between 3 and 44 characters long.
    API Gremlin (graph) The API determines the type of account to create. Azure Cosmos DB provides five APIs: Core (SQL) for document databases, Gremlin for graph databases, MongoDB for document databases, Azure Table, and Cassandra. You must create a separate account for each API.

    Select Gremlin (graph), because in this quickstart you are creating a table that works with the Gremlin API.

    Learn more about the Gremlin API.
    Location The region closest to your users Select a geographic location to host your Azure Cosmos DB account. Use the location that is closest to your users to give them the fastest access to the data.
    Capacity mode Provisioned throughput or Serverless Select Provisioned throughput to create an account in provisioned throughput mode. Select Serverless to create an account in serverless mode.
    Apply Azure Cosmos DB free tier discount Apply or Do not apply With Azure Cosmos DB free tier, you will get the first 1000 RU/s and 25 GB of storage for free in an account. Learn more about free tier.


    You can have up to one free tier Azure Cosmos DB account per Azure subscription and must opt-in when creating the account. If you do not see the option to apply the free tier discount, this means another account in the subscription has already been enabled with free tier.

    The new account page for Azure Cosmos DB

  5. In the Global Distribution tab, configure the following details. You can leave the default values for the purpose of this quickstart:

    Setting Value Description
    Geo-Redundancy Disable Enable or disable global distribution on your account by pairing your region with a pair region. You can add more regions to your account later.
    Multi-region Writes Disable Multi-region writes capability allows you to take advantage of the provisioned throughput for your databases and containers across the globe.


    The following options are not available if you select Serverless as the Capacity mode:

    • Apply Free Tier Discount
    • Geo-redundancy
    • Multi-region Writes
  6. Optionally you can configure additional details in the following tabs:

    • Networking - Configure access from a virtual network.
    • Backup Policy - Configure either periodic or continuous backup policy.
    • Encryption - Use either service-managed key or a customer-managed key.
    • Tags - Tags are name/value pairs that enable you to categorize resources and view consolidated billing by applying the same tag to multiple resources and resource groups.
  7. Select Review + create.

  8. The account creation takes a few minutes. Wait for the portal to display the Congratulations! Your Azure Cosmos DB account was created page.

    Azure Cosmos DB account created page

Add a graph

You can now use the Data Explorer tool in the Azure portal to create a graph database.

  1. Select Data Explorer > New Graph.

    The Add Graph area is displayed on the far right, you may need to scroll right to see it.

    The Azure portal Data Explorer, Add Graph page

  2. In the Add graph page, enter the settings for the new graph.

    Setting Suggested value Description
    Database ID sample-database Enter sample-database as the name for the new database. Database names must be between 1 and 255 characters, and cannot contain / \ # ? or a trailing space.
    Throughput 400 RUs Change the throughput to 400 request units per second (RU/s). If you want to reduce latency, you can scale up the throughput later.
    Graph ID sample-graph Enter sample-graph as the name for your new collection. Graph names have the same character requirements as database IDs.
    Partition Key /pk All Cosmos DB accounts need a partition key to horizontally scale. Learn how to select an appropriate partition key in the Graph Data Partitioning article.
  3. Once the form is filled out, select OK.

Clone the sample application

Now let's clone a Gremlin API app from GitHub, set the connection string, and run it. You'll see how easy it is to work with data programmatically.

  1. Open a command prompt, create a new folder named git-samples, then close the command prompt.

    md "C:\git-samples"
  2. Open a git terminal window, such as git bash, and use the cd command to change to the new folder to install the sample app.

    cd "C:\git-samples"
  3. Run the following command to clone the sample repository. This command creates a copy of the sample app on your computer.

    git clone https://github.com/Azure-Samples/azure-cosmos-db-graph-nodejs-getting-started.git
  4. Open the solution file in Visual Studio.

Review the code

This step is optional. If you're interested in learning how the database resources are created in the code, you can review the following snippets. Otherwise, you can skip ahead to Update your connection string.

The following snippets are all taken from the app.js file.

This console app uses the open-source Gremlin Node.js driver.

  • The Gremlin client is created.

    const authenticator = new Gremlin.driver.auth.PlainTextSaslAuthenticator(
    const client = new Gremlin.driver.Client(
            traversalsource : "g",
            rejectUnauthorized : true,
            mimeType : "application/vnd.gremlin-v2.0+json"

    The configurations are all in config.js, which we edit in the following section.

  • A series of functions are defined to execute different Gremlin operations. This is one of them:

    function addVertex1()
        console.log('Running Add Vertex1'); 
        return client.submit("g.addV(label).property('id', id).property('firstName', firstName).property('age', age).property('userid', userid).property('pk', 'pk')", {
                age:44, userid: 1
            }).then(function (result) {
                    console.log("Result: %s\n", JSON.stringify(result));
  • Each function executes a client.execute method with a Gremlin query string parameter. Here is an example of how g.V().count() is executed:

    function countVertices()
        console.log('Running Count');
        return client.submit("g.V().count()", { }).then(function (result) {
            console.log("Result: %s\n", JSON.stringify(result));
  • At the end of the file, all methods are then invoked. This will execute them one after the other:

    .catch((err) => {
        console.error("Error running query...");
    }).then((res) => {
    }).catch((err) => 
        console.error("Fatal error:", err)

Update your connection string

  1. Open the config.js file.

  2. In config.js, fill in the config.endpoint key with the Gremlin Endpoint value from the Overview page of your Cosmos DB account in the Azure portal.

    config.endpoint = "https://<your_Gremlin_account_name>.gremlin.cosmosdb.azure.com:443/";

    View and copy an access key in the Azure portal, Overview page

  3. In config.js, fill in the config.primaryKey value with the Primary Key value from the Keys page of your Cosmos DB account in the Azure portal.

    config.primaryKey = "PRIMARYKEY";

    Azure portal keys blade

  4. Enter the database name, and graph (container) name for the value of config.database and config.collection.

Here's an example of what your completed config.js file should look like:

var config = {}

// Note that this must include the protocol (HTTPS:// for .NET SDK URI or wss:// for Gremlin Endpoint) and the port number
config.endpoint = "https://testgraphacct.gremlin.cosmosdb.azure.com:443/"; 
config.primaryKey = "Pams6e7LEUS7LJ2Qk0fjZf3eGo65JdMWHmyn65i52w8ozPX2oxY3iP0yu05t9v1WymAHNcMwPIqNAEv3XDFsEg==";
config.database = "graphdb"
config.collection = "Persons"

module.exports = config;

Run the console app

  1. Open a terminal window and change (via cd command) to the installation directory for the package.json file that's included in the project.

  2. Run npm install to install the required npm modules, including gremlin.

  3. Run node app.js in a terminal to start your node application.

Browse with Data Explorer

You can now go back to Data Explorer in the Azure portal to view, query, modify, and work with your new graph data.

In Data Explorer, the new database appears in the Graphs pane. Expand the database, followed by the container, and then select Graph.

The data generated by the sample app is displayed in the next pane within the Graph tab when you select Apply Filter.

Try completing g.V() with .has('firstName', 'Thomas') to test the filter. Note that the value is case sensitive.

Review SLAs in the Azure portal

The Azure portal monitors your Cosmos DB account throughput, storage, availability, latency, and consistency. Charts for metrics associated with an Azure Cosmos DB Service Level Agreement (SLA) show the SLA value compared to actual performance. This suite of metrics makes monitoring your SLAs transparent.

To review metrics and SLAs:

  1. Select Metrics in your Cosmos DB account's navigation menu.

  2. Select a tab such as Latency, and select a timeframe on the right. Compare the Actual and SLA lines on the charts.

    Azure Cosmos DB metrics suite

  3. Review the metrics on the other tabs.

Clean up your resources

When you're done with your app and Azure Cosmos DB account, you can delete the Azure resources you created so you don't incur more charges. To delete the resources:

  1. In the Azure portal Search bar, search for and select Resource groups.

  2. From the list, select the resource group you created for this quickstart.

    Select the resource group to delete

  3. On the resource group Overview page, select Delete resource group.

    Delete the resource group

  4. In the next window, enter the name of the resource group to delete, and then select Delete.

Next steps

In this article, you learned how to create an Azure Cosmos DB account, create a graph by using Data Explorer, and run a Node.js app to add data to the graph. You can now build more complex queries and implement powerful graph traversal logic by using Gremlin.