The [Amazon SDK for JavaScript V3 API Reference Guide](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/) describes in detail all the API operations for the Amazon SDK for JavaScript version 3 (V3). 

# Set credentials in Node.js
<a name="setting-credentials-node"></a>

We recommend that new users who are developing locally and are not given a method of authentication by their employer to set up Amazon IAM Identity Center. For more information, see [SDK authentication with Amazon](getting-your-credentials.md).

There are several ways in Node.js to supply your credentials to the SDK. Some of these are more secure and others afford greater convenience while developing an application. When obtaining credentials in Node.js, be careful about relying on more than one source, such as an environment variable and a JSON file you load. You can change the permissions under which your code runs without realizing the change has happened.

Amazon SDK for JavaScript V3 provides a default credential provider chain in Node.js, so you are not required to supply a credential provider explicitly. The default [credential provider chain](https://docs.amazonaws.cn/sdkref/latest/guide/standardized-credentials.html#credentialProviderChain) attempts to resolve the credentials from a variety of different sources in a given precedence, until a credential is returned from the one of the sources. You can find the credential provider chain for SDK for JavaScript V3 [here](https://docs.amazonaws.cn/AWSJavaScriptSDK/v3/latest/Package/-aws-sdk-credential-providers/#fromnodeproviderchain).

## Credential provider chain
<a name="credchain"></a>

All SDKs have a series of places (or sources) that they check in order to get valid credentials to use to make a request to an Amazon Web Services service. After valid credentials are found, the search is stopped. This systematic search is called the default credential provider chain. 

For each step in the chain, there are different ways to set the values. Setting values directly in code always takes precedence, followed by setting as environment variables, and then in the shared Amazon `config` file. For more information, see [Precedence of settings](https://docs.amazonaws.cn/sdkref/latest/guide/settings-reference.html#precedenceOfSettings) in the *Amazon SDKs and Tools Reference Guide*. 

The *Amazon SDKs and Tools Reference Guide* has information on SDK configuration settings used by all Amazon SDKs and the Amazon CLI. To learn more about how to configure the SDK through the shared Amazon `config` file, see [Shared config and credentials files](https://docs.amazonaws.cn/sdkref/latest/guide/file-format.html). To learn more about how to configure the SDK through setting environment variables, see [Environment variables support](https://docs.amazonaws.cn/sdkref/latest/guide/environment-variables.html).

To authenticate with Amazon, the Amazon SDK for JavaScript checks the credential providers in the order listed in the following table.

[\[See the AWS documentation website for more details\]](http://docs.amazonaws.cn/en_us/sdk-for-javascript/v3/developer-guide/setting-credentials-node.html)

If you followed the recommended approach for new users to get started, you set up Amazon IAM Identity Center authentication during [SDK authentication with Amazon](getting-your-credentials.md) of the Getting started topic. Other authentication methods are useful for different situations. To avoid security risks, we recommend always using short-term credentials. For other authentication method procedures, see [Authentication and access](https://docs.amazonaws.cn/sdkref/latest/guide/access.html) in the *Amazon SDKs and Tools Reference Guide*.

The topics in this section describe how to load credentials into Node.js.

**Topics**
+ [Credential provider chain](#credchain)
+ [Load credentials in Node.js from IAM roles for Amazon EC2](loading-node-credentials-iam.md)
+ [Load credentials for a Node.js Lambda function](loading-node-credentials-lambda.md)