Via Travelwithgrant, American Express has added a feature to their app which lets you split a charge in the Amex login. No, you can’t push part of the cost to someone else’s Amex card, it’s just a Paypal/Venmo payment request. The neat thing is that you can make the request from within the Amex app once your Amex account is linked to your Venmo or Paypal.
The feature was initially announced over a year ago, as part of a broader Amex-Paypal partnership; I haven’t heard of this feature going live until now. I don’t see the option on the Amex website, presumably it’s an app-only feature.
Nothing really groundbreaking, but certainly an interesting feature. You can read a full walk-through on how to link accounts in this Travelwithgrant post.