Your AI agent is about to walk into a store. Meta and Sierra want to make sure it knows how to knock.
On October 6, at Sierra Summit in San Francisco, Sierra and Meta announced the Personal Agent Protocol — PAP, an open standard for how a person's AI agent signs in to a business and gets a task done there. Sierra co-founders Bret Taylor, the former Salesforce co-CEO, and Clay Bavor published the announcement with founding partners Walmart, Stripe, Shopify, Genesys, Rocket, and Instinct.
The problem it solves is real. Today, an agent typically acts like a human visitor: clicking through pages, hoping the form works. "It is kind of chaos until such a standard exists," Taylor told CNBC. PAP gives the agent a proper door: sessions built on OAuth, the web's common sign-in standard. An agent can start as a guest for light tasks like checking stock; for account tasks, the customer signs in and chooses read-only or write access. The business decides what agents are allowed to do, and picks one of three routes: its existing website set up to be read by agents, its APIs over standards like MCP or OpenAPI, or its own conversational agent for tasks like a warranty claim.
The spec itself is still cooking. Sierra plans to publish v0.1 later in October, with a reference implementation and design workshops to follow. On October 9, Sierra published a draft nicknamed Poppy — companies publish one file at /.well-known/poppy.json — and named 35 more design partners, OpenAI among them. That is a notable evolution: OpenAI and Anthropic were conspicuously absent from the original announcement.
Payments are explicitly a future extension, not part of v0.1. Agent checkout is being addressed separately — by OpenAI's Agentic Commerce Protocol and Visa's Trusted Agent Protocol, among others. PAP answers "who is this agent and what may it do here?" and leaves "how does the money move?" to someone else.
The field is crowded — PAP, UCP, ACP, and TAP all cover different slices of the transaction, and the same companies keep appearing on several of them. But PAP's positioning is clever: it is less a rival than a layer beneath the others. If it gains traction, it becomes the plumbing through which personal agents browse, book, and interact with services on a user's behalf.
Watch the spec drop later this month. Standards wars are won by whoever ships the boring, working file first.
