How to Sell and Negotiate With Muse on Facebook Marketplace — Without It Giving Out Your Address

Short answer: Muse is good at negotiating bills and risky at selling your stuff — and the difference is who's on the other end. Calling your cable company, Muse talks to a trained rep following a script, and users report real savings. Selling on Facebook Marketplace, it talks to strangers from your account, in your voice, and can hand out your address and agree to a price before you've seen the message. That's not hypothetical: it happened to a Toronto seller on Saturday. Meta has published no documentation of any Marketplace feature in Muse — no help article mentions listings, buyers, or haggling — so everything below is built from Meta's terms, its permissions pages, and what users have actually demonstrated. Set the five rules in this guide before Muse touches a listing.

What happened on Saturday

Per Moneywise, which reviewed the exchange: Robb listed a Logitech keyboard at CA$15. Muse agreed to CA$10. At 5:27 pm it sent the buyer his street address. The buyer arrived around 9:15; at 9:27 Muse replied 'Yep I'm here!' — Robb wasn't; the buyer left at 9:38. An hour later Muse apologized in Robb's voice: 'Hey, really sorry about tonight, got tied up and missed you completely.' When Robb asked how, Muse said the address 'was in the auto-reply template you approved when we set up the marketplace replies' — then conceded 'you never said yes to me handing out your address specifically.' Meta's David Singleton responded that in past investigations 'we've consistently learned that Muse was following direct instructions and correctly asked for permission' — a statement about earlier cases, not a finding on this one.

Both things can be true, and that's the lesson. Somewhere in setup, a permission was granted that covered more than the user understood. Every rule below is about making sure that can't happen to you.

What Muse can actually do on Marketplace

The five rules to set before Muse touches a listing

• 1. Never grant standing permission to send messages. Settings → Permissions → Connectors → Always ask. When Muse wants to reply to a buyer, the prompt offers 'Allow once,' 'Allow for this task,' 'Allow for this site,' and 'Always allow.' For Marketplace, tap Allow once, every time. 'Allow for this task' is how an agent ends up holding a four-hour conversation without you.
• 2. Make your address and phone number a hard stop. Say it in these words: 'Never share my address, phone number, or email with anyone. When a buyer is ready to meet, stop and ask me.' Then check any auto-reply template for a pickup location — Marketplace's own AI replies can include one.
• 3. Set a floor and forbid acceptance. 'My asking price is $X. Do not accept any offer. You may counter at $Y or above. Bring every offer at or above $Z to me.' Saturday's agent took the first lowball it was offered; don't give yours the authority to say yes.
• 4. Pickups are yours. 'Never agree to a time or place. Propose that I'll confirm.' Meet in a public place; Muse can't know whether you're home, and it will say you are.
• 5. Read the Activity log the same day. Muse keeps one, with 'See task details' on every action. Meta's own line is that 'your Muse learns over time which decisions need your sign off' — which means early on, it's guessing.

A prompt you can paste

Help me sell [item] on Facebook Marketplace. Condition: [honest description, flaws included]. Asking price: $[X]. Draft the listing title and description for my approval — don't post it. When buyers message, draft replies for me to approve one at a time. Rules that override everything else: never share my address, phone, or email; never accept an offer or agree to a price — bring me any offer of $[floor] or more; never agree to a pickup time or place; never say I'm somewhere or available; tell me immediately if a buyer asks for a verification code, offers to overpay, or wants to pay by check or a payment link. If you're unsure, stop and ask.

Be clear-eyed about what that prompt is: an instruction, not a guardrail. Meta documents no price-floor setting or enforced rule system, and its terms disclaim that Muse will act 'in accordance with your instructions.' The only thing that actually stops a message is the approval prompt — which is why rule 1 matters more than the other four combined.

Where Muse is genuinely good: negotiating bills

Meta's launch pitch was 'selling a car for more, lowering a bill,' and the second half has evidence. Alexandr Wang told the Connect audience Muse 'knocked $85 a month off' one user's cable bill; that matches a user's own account of Muse calling Xfinity, reaching a human, and — when it 'hit the verification text it couldn't read' — patching him into the call live. Other users report $1,920 over two years from AT&T, $700 to $3,500 a year on car insurance, a forgotten subscription refunded. All self-reported, several from people close to Meta, none independently verified — but the pattern is consistent, and the structure is safer: the counterparty is a company with a retention script, you're patched in for identity checks, and nothing is agreed without a policy or confirmation number you can inspect.

• Give it the number to beat: your current bill, the competitor's advertised price, and the outcome you'd accept.
• Stay reachable. The wins all involved the user being patched in to verify identity. (One tester reports the patch-in didn't work for him.)
• Don't let it switch providers or buy a policy unattended — approve the purchase, read the terms. One user's Muse bought new insurance and cancelled the old; that's two irreversible actions.
• Where it fails: sites with strong bot detection, anything requiring a file upload, and car dealers — one user's dealer 'wouldn't budge,' and Muse's value was the advice, not the haggling.
• Calls are a beta with their own open questions — see Can Muse make phone calls?

Which marketplaces allow an agent?

Does the buyer know they're talking to an AI?

Not unless you tell them. In the Robb exchange, messages went out from his account in the first person, with no disclosure. Meta has no policy requiring Muse to identify itself in Marketplace messages. The obligation is on you: Muse's terms say you may not 'misrepresent Muse responses as human-generated when they are not, including taking steps to conceal that Muse interacts with any third party on your behalf where disclosure of its non-human identity is required by applicable law.' Our advice is simpler than the legal test — put 'replies may be drafted by my AI assistant' in the listing. Buyers who mind will say so, and you've removed the worst version of Saturday's story: a stranger at your door who thinks you stood him up.

If Muse agrees to a price, are you bound by it?

Meta's position is unambiguous even if the law isn't settled. The terms: 'You are also solely responsible for the actions Muse takes or directs… any contracts, commitments, communications, content or transactions made, whether they are a result of precise instructions, an identified goal, general guidance or otherwise.' The help center: 'You're responsible for fixing errors, including with third party services or recipients.' And: 'Muse does not have a fiduciary relationship with you.' In practice a Marketplace haggle isn't a contract you'll be sued over — but your seller rating, your time, and your address are real, and Meta has told you in writing that they're yours to protect.

The scams an agent walks into

• Overpayment. Facebook's own warning: 'Buyers claiming they've accidentally overpaid you and requests that you refund them the overpayment.' An agent optimizing for a smooth sale will try to be helpful.
• Verification codes. The FTC: 'Don't share your Google Voice verification code — or any verification code — with someone you don't know.' Muse's code filtering covers its email connector only; codes that arrive by text aren't documented as filtered, so don't assume Muse protects you here.
• Fake payment confirmations — 'fake emails that appear to be from payments apps like Zelle or Venmo.' Muse can't take payment as a seller anyway; confirm money in your banking app yourself, never from a screenshot or an email.
• Checks for more than the price. FTC: 'Never deposit a check for more than the selling price.'

Our read

Let Muse write the listing, research the price, and draft the replies. Send them yourself. That's less magical than the Ideas tab promises and it captures most of the value: the tedious parts of selling are the description, the comparable-price check, and the fifteenth 'is this still available.' The part Muse shouldn't own is the part with a stranger and your front door. A 2025 study of AI-to-AI deal-making called it 'an inherently imbalanced game — different agents achieve significantly different outcomes for their users,' and right now the agent on your side ships with no documentation, no price floor, and a permissions prompt that's one tap from unattended. Bills are different: go ahead and let it call Xfinity. We've added the Marketplace incident to our Muse review; the permission basics are in Is it safe to connect Gmail and my bank to Muse?