Send real, physical greeting cards through the mail. Design custom cards with the user, print on premium cardstock, and mail with a first-class stamp. Use when the user wants to send a card, mentions a birthday or occasion, or asks about greeting cards. Requires a free API registration (POST /v1/auth/register returns a Bearer token). Works via API — no browser needed. Homepage https://indexcards.com — privacy policy at https://indexcards.com/privacy.