Personal AI agents, assistants that act on your behalf rather than just chat, are arriving fast. OpenAI launched always-on "Dots" at DevDay, and Meta's Muse agent can already pay with saved cards. But when your agent visits a shop or a bank, how does the business know who it is, what it is allowed to do, and that you approved it? On 6 October, Sierra and Meta proposed an answer: the Personal Agent Protocol, an open standard built on OAuth and backed by Walmart, Shopify, Stripe and others.
How it works
PAP describes the conversation between a customer's agent and a business, from an anonymous first question to an authorised action:
- Guest access
- An agent can ask public questions, such as stock levels or a returns policy, before anyone signs in.
- Scoped permissions
- After the customer signs in, they choose whether the agent gets read-only or write access.
- One session across channels
- Questions asked before sign-in and actions taken after belong to the same visit.
- Business choice of interface
- A company can let agents in through its website, its APIs (for example via MCP or OpenAPI), or its own customer-service agent.
- Visibility
- Businesses can see what agents are doing on their sites, rather than guessing from unusual traffic.
PAP, MCP, A2A: which protocol does what?
A year ago "agent protocol" mostly meant MCP. There are now several, and they solve different problems:
MCP
Agent ↔ tools- Started by
- Anthropic, 2024
- Connects
- an AI app to tools and data
- The standard way to plug databases, files and APIs into AI assistants
- Supported by every major AI platform
Use it to give an agent access to your data.
A2A
Agent ↔ agent- Started by
- Google, 2025
- Connects
- agents to other agents
- Lets agents from different vendors delegate tasks
- Discovery through published agent cards
Use it when your agents need to work with someone else's.
PAP
Personal agent ↔ business- Started by
- Sierra and Meta, 2026
- Connects
- a customer's agent to a company
- Identity and permissions for consumer agents, built on OAuth
- Version 0.1; payments not included yet
The one that matters for customer-facing businesses.
The payments question
Payments are listed as a future extension of PAP. In the meantime, card networks and payment companies have their own standards. Visa runs the Trusted Agent Protocol, which Stripe, Shopify, Microsoft and Worldpay have joined, so some of the same companies back both. Expect the two to meet: PAP for identity and permissions, a payment protocol for the money.
Who is behind it
- Sierra
- Co-author. Builds customer-service agents for large companies; announced the protocol.
- Meta
- Co-author. Its Muse personal agent is one of the first consumer agents that will use it.
- Walmart and Shopify
- Retail partners: one of the largest retailers and the platform behind millions of online shops.
- Stripe
- Payments partner, also a member of Visa's Trusted Agent Protocol.
- Genesys
- Contact-centre software, where agent-to-agent customer service will happen.
- Rocket and Instinct
- Further launch partners named in the announcement.
What it means for data and analytics teams
When agents shop, book and complain on customers' behalf, a growing share of "customer" activity comes from software. On this site, analytics already flag visits from AI assistants such as Google's NotebookLM reading articles. For businesses, that shift has practical consequences:
- 1
Identify agent traffic
Tag sessions that arrive through PAP, MCP or known agent user agents so they do not distort conversion rates, funnels and A/B tests.
- 2
Measure agents as a channel
Report agent-led orders, changes and support contacts separately, just like mobile or email.
- 3
Expose clean data
Agents work best with clear APIs and well-described data: product catalogues, stock, order status and policies. The same semantic clarity helps internal AI too.
- 4
Log permissions
Record which agent acted, under which scope and with whose approval. It is the audit trail compliance teams will ask for.
Check your understanding
1/3What is the main job of the Personal Agent Protocol?
MCP connects agents to tools and data; PAP covers identity and permissions between a personal agent and a business.
2/3Which technology is PAP built on?
OAuth is the widely used standard behind "Sign in with..." buttons.
3/3Are payments part of PAP version 0.1?
Payments are listed for later; Visa's Trusted Agent Protocol is a separate standard for agent payments.
You got 0 out of 3.
Agents are only as good as the context you give them. See how the data platforms are preparing in Databricks: October 2026 update, and which models power these agents in The best AI models in October 2026.
Sources: The Next Web on the Personal Agent Protocol (6 October 2026) and Sierra's announcement by Bret Taylor and Clay Bavor; AI Weekly; reporting on Visa's Trusted Agent Protocol. The specification is at version 0.1 and may change.
Alessandro Ecclesie AgazziWritten by Alessandro Ecclesie Agazzi, analytics engineer in London. Updated 21 October 2026. About me