OAuth

Social login is configured in packages/auth/src/index.ts. Enabled providers are listed by getEnabledSocialProviders() in packages/auth/src/social-providers.ts.

Redirect URIs use the SaaS origin that mounts /api/auth:

{SAAS_URL}/api/auth/callback/{provider}

Google (required)

Set in the root .env:

GOOGLE_CLIENT_ID=…
GOOGLE_CLIENT_SECRET=…

Redirect URI: {SAAS_URL}/api/auth/callback/google.

GitHub (optional)

GITHUB_CLIENT_ID=…
GITHUB_CLIENT_SECRET=…

Include user:email scope / email read permission. Redirect URI: {SAAS_URL}/api/auth/callback/github.

When unset, isGithubOAuthConfigured() is false and the GitHub button stays hidden on the SaaS UI.

Apple (optional)

APPLE_CLIENT_ID=…
APPLE_TEAM_ID=…
APPLE_KEY_ID=…
APPLE_PRIVATE_KEY=… # .p8 contents; use \n for newlines

The client secret JWT is generated at runtime with jose (generateAppleClientSecret).

Apple does not support http://localhost return URLs — use HTTPS (tunnel) in development. Redirect URI: {SAAS_URL}/api/auth/callback/apple.

When unset, the Apple button is hidden.

trustedOrigins / allowedDevOrigins already include https://appleid.apple.com.

Which providers are enabled?

export function getEnabledSocialProviders(): SocialProviderId[] {
	const providers: SocialProviderId[] = ["google"];
	if (isGithubOAuthConfigured()) providers.push("github");
	if (isAppleOAuthConfigured()) providers.push("apple");
	return providers;
}

Adding another provider

Example: Facebook.

1. Create an app in the Facebook developer console and copy the client ID and secret.
2. Add env vars (and wire them through @repo/env the same way GitHub/Apple are gated).
3. Register the provider on the Better Auth instance:

socialProviders.facebook = {
	clientId: env.FACEBOOK_CLIENT_ID,
	clientSecret: env.FACEBOOK_CLIENT_SECRET,
};

4. On the SaaS auth UI in the full TurboJet monorepo, add the provider to the OAuth providers map (icon + label) so the login page shows a button.

Learn more in the Better Auth Facebook docs.

Related

• User and session
• Environment
• Authentication overview