Using environment variables in an Amplify application

Environment variables are key-value pairs that you can add to your application's settings to make them available to Amplify Hosting. As a best practice, you can use environment variables to expose application configuration data. All environment variables that you add are encrypted to prevent rogue access.

Amplify enforces the following constraints on the environment variables that you create.

• Amplify doesn't allow you to create environment variable names with an AWS prefix. This prefix is reserved for Amplify internal use only.

• The value of an environment variable can't exceed 5500 characters.

Important

Don't use environment variables to store secrets. For a Gen 2 app, use the Secret management feature in the Amplify console. For more information, see Secrets and environment vars in the Amplify Documentation. For a Gen 1 app, store secrets in an environment secret created using the AWS Systems Manager Parameter Store. For more information, see Managing environment secrets.

Amplify environment variable reference

The following environment variables are accessible by default within the Amplify console.

Variable name	Description	Example value
_BUILD_TIMEOUT	The build timeout duration in minutes. The minimum value is 5. The maximum value is 120.	30
_LIVE_UPDATES	The tool will be upgraded to the latest version.	[{"name":"Amplify CLI","pkg":"@aws-amplify/cli","type":"npm","version":"latest"}]
USER_DISABLE_TESTS	The test step is skipped during a build. You can disable tests for all branches or specific branches in an app. This environment variable is used for apps that perform tests during the build phase. For more information about setting this variable, see Turning off tests for an Amplify application or branch.	true
AWS_APP_ID	The app ID of the current build	abcd1234
AWS_BRANCH	The branch name of the current build	main, develop, beta, v2.0
AWS_BRANCH_ARN	The branch Amazon Resource Name (ARN) of the current build	aws:arn:amplify:us-west-2:123456789012:appname/branch/...
AWS_CLONE_URL	The clone URL used to fetch the git repository contents	[e-mail]:<user-name>/<repo-name>.git
AWS_COMMIT_ID	The commit ID of the current build “HEAD” for rebuilds	abcd1234
AWS_JOB_ID	The job ID of the current build. This includes some padding of ‘0’ so it always has the same length.	0000000001
AWS_PULL_REQUEST_ID	The pull request ID of pull request web preview build. This environment variable is not available when using AWS CodeCommit as your repository provider.	1
AWS_PULL_REQUEST_SOURCE_BRANCH	The name of the feature branch for a pull request preview being submitted to an application branch in the Amplify console.	featureA
AWS_PULL_REQUEST_DESTINATION_BRANCH	The name of the application branch in the Amplify console that a feature branch pull request is being submitted to.	main
AMPLIFY_AMAZON_CLIENT_ID	The Amazon client ID	123456
AMPLIFY_AMAZON_CLIENT_SECRET	The Amazon client secret	example123456
AMPLIFY_FACEBOOK_CLIENT_ID	The Facebook client ID	123456
AMPLIFY_FACEBOOK_CLIENT_SECRET	The Facebook client secret	example123456
AMPLIFY_GOOGLE_CLIENT_ID	The Google client ID	123456
AMPLIFY_GOOGLE_CLIENT_SECRET	The Google client secret	example123456
AMPLIFY_DIFF_DEPLOY	Enable or disable diff based frontend deployment. For more information, see Configuring diff based frontend build and deploy.	true
AMPLIFY_DIFF_DEPLOY_ROOT	The path to use for diff based frontend deployment comparisons, relative to the root of your repository.	dist
AMPLIFY_DIFF_BACKEND	Enable or disable diff based backend builds. This applies to Gen 1 apps only. For more information, see Configuring diff based backend builds for a Gen 1 app	true
AMPLIFY_BACKEND_PULL_ONLY	Amplify manages this environment variable. This applies to Gen 1 apps only. For more information, see Edit an existing frontend to point to a different backend	true
AMPLIFY_BACKEND_APP_ID	Amplify manages this environment variable. This applies to Gen 1 apps only. For more information, see Edit an existing frontend to point to a different backend	abcd1234
AMPLIFY_SKIP_BACKEND_BUILD	If you do not have a backend section in your build specification and want to disable backend builds, set this environment variable to true. This applies to Gen 1 apps only.	true
AMPLIFY_ENABLE_DEBUG_OUTPUT	Set this variable to true to print a stack trace in the logs. This is helpful for debugging backend build errors.	true
AMPLIFY_MONOREPO_APP_ROOT	The path to use to specify the app root of a monorepo app, relative to the root of your repository.	apps/react-app
AMPLIFY_USERPOOL_ID	The ID for the Amazon Cognito user pool imported for auth	us-west-2_example
AMPLIFY_WEBCLIENT_ID	The ID for the app client to be used by web applications The app client must be configured with access to the Amazon Cognito user pool specified by the AMPLIFY_USERPOOL_ID environment variable.	123456
AMPLIFY_NATIVECLIENT_ID	The ID for the app client to be used by native applications The app client must be configured with access to the Amazon Cognito user pool specified by the AMPLIFY_USERPOOL_ID environment variable.	123456
AMPLIFY_IDENTITYPOOL_ID	The ID for the Amazon Cognito identity pool	example-identitypool-id
AMPLIFY_PERMISSIONS_BOUNDARY_ARN	The ARN for the IAM policy to use as a permissions boundary that applies to all IAM roles created by Amplify.	arn:aws:iam::123456789012:policy/example-policy
AMPLIFY_DESTRUCTIVE_UPDATES	Set this environment variable to true to allow a GraphQL API to be updated with schema operations that can potentially cause data loss.	true

Note

The AMPLIFY_AMAZON_CLIENT_ID and AMPLIFY_AMAZON_CLIENT_SECRET environment variables are OAuth tokens, not an AWS access key and secret key.

Frontend framework environment variables

If you are developing your app with a frontend framework that supports its own environment variables, it is important to understand that these are not the same as the environment variables you configure in the Amplify console. For example, React (prefixed REACT_APP) and Gatsby (prefixed GATSBY), enable you to create runtime environment variables that those frameworks automatically bundle into your frontend production build. To understand the effects of using these environment variables to store values, refer to the documentation for the frontend framework you are using.

Storing sensitive values, such as API keys, inside these frontend framework prefixed environment variables is not a best practice and is highly discouraged.