The protocol Meta and Sierra are developing wants a personal AI agent to identify itself to a company, instead of signing in as the customer, with the customer's account. On 9 October Sierra released the draft, called Poppy. For now it is a design, not a working standard.
- 9 October 2026: Sierra published a draft of Personal Agent Protocol, known as Poppy, and announced 35 additional design partners, among them OpenAI, Visa, Mastercard, PayPal and Cloudflare. The protocol was announced on 6 October; Meta and Sierra are developing it.
- The principle, per Sierra: the customer decides what access to give their agent, the company decides what the agent can do. The agent identifies itself, so the company always knows it is dealing with an agent acting for a customer.
- The protocol is built on OAuth, JWT, HTTPS, OpenAPI and MCP. The partners will take part in the design with feedback, and over the next month Sierra promises workshops and a reference implementation.
Ask your personal AI agent today to return a jacket, and it often signs in to the store with your account and clicks through pages built for people. The company has no standard way to guide it. That is how Sierra itself describes the problem, and the draft it released on 9 October is its answer.
Sierra's example says more than the five blocks. The agent returns the jacket: it finds the store through the protocol, identifies itself, you sign in once. The store knows it is dealing with an agent for a signed-in customer, and lets it start the return but not change the payment details on file. Under the draft, the customer gives the agent access to view, to make changes, or both, and the company decides which action requires which access.
At the door of an event, the guest with a badge and the one who slipped in behind him look the same until someone checks the list. Poppy is an attempt to give the agent a badge.
The list of 35 is assembled to impress, and it does. Visa, Mastercard and PayPal, where the payments run. Bank of America and Wells Fargo. Target and United Airlines, where people buy. And OpenAI. A design partner, in Sierra's words, takes part in designing the draft with its feedback. That does not mean the protocol already runs at that company, or that it will adopt it.
The liveliest part is the demo from Sierra Summit on 6 October. Alex McGillis of Rocket asks Muse, Meta's personal agent, to get him pre-approved for a mortgage. Muse finds Rocket's agent through Poppy and asks for permission, Alex signs in and shares his credit and income details, the two agents work through the price, the down payment and the interest rate, and within moments the letter is ready. The demo ran on Sierra's own stage. On 6 October the company promised a v0.1 specification later this month. The specification on personalagentprotocol.org is now labelled draft 0.1, updated on 9 October, and warns that any part of it can change before a stable version.
The draft is public, and Sierra invites every company to read it and help shape it. The test will come with the first company that turns the protocol on for its real customers.