Create and manage contacts in Messages on Mac
You can create and manage your contacts right from Messages.
If you set communication limits, you may not be able to add contacts.
Create a new contact
You can create a contact card for the person you’re texting if they’re not already in your Contacts.
Go to the Messages app
on your Mac.Select a conversation.
In the menu bar, choose Conversation > Add to Contacts.
If you see Show Contact Card instead of Add to Contacts, you already have a card for that person.
Fill in the fields in the contact card.
In macOS Tahoe or later, you can add new contacts who are introduced to a group conversation. Control-click a message from that new contact, then choose Add to Contacts.
Change how a contact appears in the sidebar
If you only see an email address or phone number in the sidebar when you’re texting someone, you can open their contact card from the conversation and add their name, so you see that in the sidebar instead.
Go to the Messages app
on your Mac.Double-click a conversation in the sidebar to open it in its own window.
At the top of the conversation, click
next to the email address or phone number, then choose Create New Contact or Add to Existing Contact.When you finish filling in the fields, click
.
If someone shares their name and photo with you in Messages, you can update that person’s name or photo (or both) in the Contacts app 
—just choose an option from the Update Contact pop-up menu at the top of the conversation.