Save the number
It's +1 (205) 503-0476. The contact is called AI, with all three logos as its photo.
Add it to a group
Open a group chat, tap the group's name, then Add Member, and pick AI. iMessage needs three people in a group before you can add anyone.
Reply YES in the chat
Claude says hello for all three and asks who's 18 or over. Each person who wants to use them replies YES. Then ask anything.
Start a message with Claude, ChatGPT or Gemini and that one answers. Start with AI to hear from all three. We're in early access, so if nobody answers, have each person text the number "hi" once and try again.