Added next js api route based newsletter implementation

[gabros20]

1. Environment Variables Check
We need to ensure all required env vars are set:

MAILCHIMP_API_KEY=your_api_key
MAILCHIMP_LIST_ID=your_list_id
MAILCHIMP_SERVER_PREFIX=your_server_prefix  # e.g., 'us1'
RECAPTCHA_SECRET_KEY=your_recaptcha_secret

2 .Dependencies Check
Added dependency:

npm install @mailchimp/mailchimp_marketing

3. Integration Flow
✅ Frontend:

• Collects email
• Validates reCAPTCHA
• Sends both to API
• Handles all response cases correctly
• Proper loading states
• Good error messaging

✅ API Route:

• Validates reCAPTCHA token
• Validates email format
• Checks for existing subscribers
• Proper error handling
• Secure error responses

4. Mailchimp Specific
✅ Integration Code:

• Using official SDK
• Proper member existence check
• Clean subscription flow
• Error handling matches Mailchimp's API responses

5. Security
✅ Good:

• All sensitive keys server-side only
• reCAPTCHA validation
• Email validation
• No sensitive data exposure

The integration looks solid and follows Mailchimp's best practices. The only thing to test in production would be:

1. The Mailchimp server prefix format (should be like 'us1', 'us2', etc.)
2. The List ID format (should be like 'abc123def')
3. The API key permissions (needs write access to the list)

Everything else is properly implemented and should work as expected in a dynamic Next.js environment.

[sysrex]

ulgtm