Phone calls are the Muse feature people cannot stop talking about, partly because they work and partly because not everyone has them yet. Here is what the r/MetaAI threads say, kept to what people actually reported.
The calls that worked
The most detailed account: a user had Muse call AT&T to ask for a discount because the signal at their house is poor. The call ran 98 minutes across several transfers and departments, with the agent talking to real people throughout. Afterwards they had it call Verizon and T-Mobile at the same time to get each carrier's best deal, with Muse holding the context on their existing plans, payoff balances and bills. Then it rang three local companies for fence quotes.
A parent had Muse build a spreadsheet of daycares nearby and call each one about prices and waitlist places. Only two of ten answered, but the transcripts showed it getting through the phone menus and holding a normal conversation.
A beta tester said they used calling to get quotes from auto shops, that the voice sounds natural without delay, and that Muse hands you a recording and a transcript afterwards.
The limits people hit
Several replies said Muse told them it did not support calling, and the users who have it said it is being rolled out slowly. One person asked Muse to file a request with Meta for the feature and is waiting to see if that does anything.
It will only call numbers it judges to be businesses, not personal contacts. There is no voice mode for you, so you cannot join the call yourself; one user described a conference-call workaround but no official way. Muse told one person it would ring them if it hit a question it could not answer, which they declined.
The workaround
One power user gave Muse an ElevenLabs API key. ElevenLabs runs its own phone agents, so Muse could place calls through it before Meta's own calling reached their account. That is a paid third-party service and a fair amount of setup, so it suits people who already live in that toolbox.
Before you hand over a call
Give the agent everything it will need: account numbers, the outcome you want, your walk-away point, and what it is not allowed to agree to. Ask for the transcript. And treat a negotiated deal as a proposal until you have seen it in writing on your own account. The starter workflows below are written that way.