Anthropic's Claude large language model is powering the majority of complex tasks for Amazon's new Alexa+, sources tell CNBC.

Some of the new abilities coming to Alexa Plus include the ability to do things for you — you’ll be able to ask it to order groceries for you or send event invites to your friends. Amazon says it will also be able to memorize personal details like your diet and movie preferences.

Alexa Plus will start rolling out next month in early access. It's an opt-in service and won't be available to everyone through an over-the-air update in March.