# Connecting to Amazon Neptune databases using IAM authentication with Gremlin JavaScript
<a name="gremlin-javascript-iam-auth"></a>

## Overview
<a name="gremlin-javascript-iam-auth-overview"></a>

 This guide demonstrates how to connect to an Amazon Neptune database with IAM authentication enabled using the Gremlin JavaScript driver, with Signature Version 4 authentication and the AWS SDK for Javascript v3. 

## Prerequisites
<a name="gremlin-javascript-iam-auth-prereqs"></a>
+  An Amazon Neptune cluster with IAM authentication enabled. 
+  Node 13 or later (refer to minimal versions for Gremlin JavaScript and [AWS SDK for Javascript v3](https://docs.aws.amazon.com//AWSJavaScriptSDK/v3/latest/introduction/#release-cadence)). 
+  AWS credentials configured (via environment variables, shared credentials file, or IAM role). 

## Create a basic connection
<a name="gremlin-javascript-iam-auth-basic-connection"></a>

 Use the following code example as guidance on how to establish a basic connection with IAM authentication using the Gremlin JavaScript driver. 

```
const { fromNodeProviderChain } = require('@aws-sdk/credential-providers');
const { getUrlAndHeaders } = require('gremlin-aws-sigv4/lib/utils');
const { loadConfig } = require("@smithy/node-config-provider");
const { NODE_REGION_CONFIG_FILE_OPTIONS, NODE_REGION_CONFIG_OPTIONS } = require("@smithy/config-resolver");

const gremlin = require('gremlin');
const DriverRemoteConnection = gremlin.driver.DriverRemoteConnection;
const traversal = gremlin.process.AnonymousTraversalSource.traversal;

const DEFAULT_REGION = 'us-east-1';

const getCredentials = async () => {
    try {
        // Loads the default credential provider chain
        return await fromNodeProviderChain();
    } catch (e) {
        console.error("No credentials found", e);
        throw e;
    }
};

(main = async () => {
    console.log('Starting');

    const credentials = await getCredentials();
    try {
        // region set inside config profile or via AWS_REGION environment variable will be loaded
        credentials['region'] = await loadConfig(NODE_REGION_CONFIG_OPTIONS, NODE_REGION_CONFIG_FILE_OPTIONS)();
    } catch (e) {
        credentials['region'] = DEFAULT_REGION
    }

    const connInfo = getUrlAndHeaders(
        'you.cluster.endpoint.neptune.amazonaws.com',
        '8182',
        credentials,
        '/gremlin',
        'wss');

    const dc = new DriverRemoteConnection(connInfo['url'], {headers: connInfo['headers']});
    const g = traversal().withRemote(dc);

    const query = g.V().limit(5).count();
    const count = await query.next();
    console.log("Vertex count: " + count.value);

    await dc.close();
})

main();
```