Sierra's Poppy Agent Protocol Hits 1.0, On by Default in Meta's Muse and Every Shopify Store
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TL;DR
Sierra shipped version 1.0 of the Personal Agent Protocol, nicknamed Poppy, on Nov 13, and it arrived with distribution attached: every Shopify store across the 175+ countries the platform serves now publishes a poppy.json file automatically, and Muse, Meta's personal agent, checks for Poppy first on every site it visits. The protocol tells a visiting agent who it is talking to, which doors exist, and what sign-in and approval each one requires. More than 100 companies have signed on as design partners, and Mercury, Synchrony and Turkish Airlines are live with it today.
The handshake that was missing
Agent-to-business traffic today is binary. The company either blocks anything that looks automated, or the agent logs in as the customer with stored credentials and can do everything the customer can. The spec's own framing is "all or nothing," with companies playing detection games and agents playing evasion games, and nobody wins that loop.
Poppy replaces the loop with a file. A document at /.well-known/poppy.json names the organization, lists the interfaces it offers (website, MCP server, OpenAPI APIs, or a company agent of its own), and states what access agents may request, with standard OAuth metadata saying where sign-in happens. The customer signs in on the company's own page, picks the scopes to grant, and can revoke them later. Think robots.txt with permissions: robots.txt told crawlers what they could read, while poppy.json hands an agent a visitor badge and a list of doors, and the locked ones require a signature.
Access is granular rather than all-or-nothing. The spec sketches five levels for a hotel example: no agents at all, any agent may search rooms, signed-in users can see reservations, a booking goes through only with the customer's approval, or the agent acts as the user in full. A company publishes which level each capability sits at, and can move them independently.
One session across web, API and conversation
Under the hood, one session covers all three interfaces. The agent signs a header on every API and conversation request with a short-lived key, naming the session and a user ID that differs at each company. Web browsing joins the same session through a one-time code the agent authorizes, and browsing signed in takes its own scope; a company can tell agents not to browse at all. In conversations, both sides declare whether a human or an AI is speaking. Extensions add behaviors without touching the core: one approves exact terms before an action, and the commerce extension handles checkout through UCP.
None of this is a new stack. Poppy composes MCP, OpenAPI, OAuth and the Universal Commerce Protocol, which is why a team can implement it with libraries it already has.
Every Shopify store, by default
Protocols usually die waiting for somebody to go first; this one showed up pre-installed. Shopify already ran the Universal Commerce Protocol on every store for carts and checkout, so it now auto-publishes each store's Poppy file too, and merchants implement nothing. The split is clean: UCP handles the shopping, Poppy handles the moment an agent arrives, says who it is, and finds out what it may do. Shopify co-authored the commerce extension linking the two, which lets an agent shop as a guest or with the customer's account, and makes the agent ask the customer before certain actions.
Sierra counts 60 new design partners this week for a total above 100, including Affirm, Cisco, Delta Air Lines, GoFundMe, HelloFresh, Intuit, Lemonade, Manus, Salesforce (Fin, Commerce Cloud and Agentforce), SoFi, The Knot, Twilio, Wayfair, Wix and Zoom. Meta's post adds BYLT and Hertz on the agent side, the latter through a Decagon Personal Agent Gateway pilot.
Who is actually live
The partner list is the promise; the production list is shorter, and worth reading closely because each deployment shows a different depth of integration.
- Mercury (via Sierra): agents can check balances, review recent transactions, categorize spending, and request a payment or transfer, with the request routed through the account's existing approval policy before anything moves. Mercury is not a bank; its banking services run through FDIC-insured partner banks.
- Synchrony: financing and rewards surfaced inside agent-led shopping, aimed at a network of more than 500,000 merchant locations.
- Turkish Airlines: fares, flight status and stopovers without signing in, plus booking lookup with a reference number and surname, and business-class upgrades the customer approves before paying. End-to-end purchase inside the conversation is in progress.
Depth varies by orders of magnitude here: read-only public data at one end, money movement through approval chains at the other, all inside the same protocol because capabilities are declared per company.
Read the fine print
Version 1.0 is out, but The Next Web notes the specification is still labeled a draft, and changes could break existing setups. Muse is so far the only personal agent shipping support; the protocol is open to any taker, but the installed base on the consumer side is currently one agent with, per TNW, more than 10 million setups. Meta also reviews "verified connectors" for functional, security and legal requirements, so "any business can implement Poppy" comes with a queue for the Meta-side distribution.
The field is not unified either. Visa and Mastercard are building identity checks for agents, and Amazon would rather shoppers use its own agent than Muse. And in October, Schwab and JPMorgan went the other way entirely, blocking outside agents from customer accounts. Mercury saying yes to agent-initiated payments is the counter-signal worth watching.
If you sell or build online
The implementation kit walks a company through setup in stages and ships a validator to check the work, so the cheapest credible move this week is a website-only file plus a test pass. If you build agents instead of stores, the short version is that your scraper's ghost town just got zoning: discovery, identity and permissions now have a published shape, and Muse will ask for it at every domain it visits.
Key Takeaways
- Sierra shipped Personal Agent Protocol (Poppy) v1.0 on Nov 13, five weeks after the Oct 9 draft. The spec and a company implementation kit with a validator are public.
- Every Shopify store in 175+ countries now auto-publishes poppy.json with zero merchant work. UCP handles carts and checkout; Poppy handles arrival, identity and permissions; Shopify co-authored the commerce extension linking them.
- Meta's Muse checks for Poppy first on every site it visits and is the only personal agent shipping support so far. TNW puts Muse at more than 10 million setups.
- Design partners passed 100 after 60 joined this week (Affirm, Cisco, Delta, Intuit, Salesforce, Twilio, Wayfair, Wix, Zoom). Live in production: Mercury, Synchrony and Turkish Airlines, plus BYLT and a Hertz pilot on the Muse side.
- Mechanics: discovery via /.well-known/poppy.json, OAuth sign-in on the company's own page, one signed session across API, web and conversation, per-company pseudonymous user IDs, and extensions for approvals and UCP checkout.
- Caveats: the 1.0 spec is still labeled a draft and may break setups; Visa, Mastercard and Amazon are pursuing rival approaches; most of the 100+ partners are commitments rather than deployments.
Sources: Sierra, Releasing Personal Agent Protocol 1.0, Nov 13, 2026, Muse (Meta), More Ways for Muse to Work With Businesses, Nov 13, 2026, Personal Agent Protocol 1.0 specification, Personal Agent Protocol implementation kit, The Next Web, Nov 13, 2026.