The short answer: the Personal Agent Protocol (PAP) is an open standard, announced on October 6, 2026 by Sierra and Meta, for how a shopper’s personal AI agent authenticates to a business. As of today it is an announcement, not a specification: Sierra says it plans to publish the v0.1 spec “later this month”. There is nothing for a merchant to implement yet.

What was announced

In Sierra’s announcement, PAP is described as an open standard that Meta and Sierra are developing with Genesys, Instinct, Rocket, Shopify, Stripe and Walmart. Its stated aim is to handle authentication, empower consumers and give companies visibility into what personal agents do through their websites, APIs or company agents.

The problem it names is familiar: most personal agents today use websites and apps the way people do, loading pages and clicking through forms, and when that fails they may call a support line or open web chat.

How a session works

According to the same post:

  • The protocol starts on the website, where an agent can discover what the company offers and how to reach it.
  • The agent begins a session on the user’s behalf. It can start as a guest, which may be enough to check product availability or ask about a returns policy.
  • When a task needs account access, the customer signs in on the company’s page or uses credentials already set up with their agent. The customer decides between read-only and write access.
  • The session is built on OAuth and carries across channels, so a question before sign-in and an order change afterward belong to the same visit.
  • The company chooses the route: its website, its APIs (Sierra names standards such as MCP and OpenAPI), or an agent of its own.

What is not in it yet

Sierra lists detailed permissions, push notifications and payments extensions as things that “could” come later. The payments idea it describes is letting an agent complete a purchase without sharing card details. In other words, PAP as announced is about who the agent is and what it may see or change. It is not a checkout protocol.

What a merchant can do now

  • Check that guest access works. PAP’s first rung is an anonymous agent reading stock and returns policy. If your product pages or policy pages need a script, a login or a challenge page to be read, that rung fails regardless of any standard.
  • Treat identity as a separate layer from checkout. Other identity efforts already exist, such as Web Bot Auth and Visa’s Trusted Agent Protocol. PAP is OAuth-scoped sessions; Web Bot Auth is signed requests. They answer “who is this agent” differently.
  • Wait for the spec before building. We could not find a published discovery file or header for PAP; if v0.1 defines one, it becomes something a scanner can test.

FAQ

What is the Personal Agent Protocol?

It is an open standard that Sierra and Meta are developing with partners including Shopify, Stripe and Walmart. It defines how a consumer’s personal AI agent authenticates to a business and what it is allowed to do there, using OAuth sessions.

Do I need to implement PAP on my store?

Not yet. The v0.1 specification had not been published at the time of writing; Sierra says it plans to publish it later in October 2026. Until then there is no format to implement or test against.

Does PAP handle checkout and payments?

Not in the announced design. Sierra describes payments as a possible future extension, alongside push notifications and finer-grained permissions. The announcement covers authentication and access.

Sources

Being let in as an agent is only the first step; AgentReady audits whether the agent can then read, choose and buy.