Configuration

For both local development and deployment, the configuration of the GCN web application is controlled by the environment variables. You can adjust the environment variables in any one of three ways:

.env file: Create a file called .env in the base directory of your project formatted like this:
```
FOO=value_of_foo_for_local_testing
BAR=value_of_bar_for_local_testing
```

preferences.arc file: Create a file called .preferences.arc in the base directory of your project formatted like this:

@env
testing
  FOO=value_of_foo_for_local_testing
  BAR=value_of_bar_for_local_testing

production
  FOO=value_of_foo_for_deployment
  BAR=value_of_bar_for_deployment

arc env command: Adjust settings for production by running the following commands.

arc env -e production --add FOO value_of_foo_for_deployment
arc env -e production --add BAR value_of_bar_for_deployment

Supported environment variables

All environment variables are optional in local development. All environment variables with the exception of GCN_FEATURES are required in production deployment.

Key	Description	Default
`SESSION_SECRET`	Signing key for session cookies. Should be a long, random string	Hard-coded constant
`COGNITO_USER_POOL_ID`, `OIDC_CLIENT_ID`, `OIDC_CLIENT_SECRET`	OpenID Connect identity provider configuration for AWS Cognito	Sandbox identity provider
`RECAPTCHA_SITE_KEY`, `RECAPTCHA_SECRET_KEY`	Google ReCAPTCHA configuration	ReCAPTCHAs replaced with placeholder
`GITHUB_API_TOKEN`	GitHub API token for the schema browser. In GitHub settings, generate a Classic token with the expiration as long as possible and no scopes selected	Anonymous GitHub API requests with lower rate limits
`ORIGIN`	URL origin for external redirects, email From addresses, etc.	http://localhost:3333
`ZENDESK_EMAIL`	Email address for Zendesk forwarding	Forwarding disabled
`ZENDESK_TOKEN`, `ZENDESK_TOKEN_EMAIL`	Zendesk API token and user email address	Zendesk API disabled
`ADS_TOKEN`	Astrophysics Data System (ADS) API token	ADS disabled
`GCN_FEATURES`	Feature flags (for example, `ANTIGRAVITY,TIME_TRAVEL,PYROKINESIS`)	No features