An agent protocol is a set of conventions a personal agent follows before acting on your behalf with a business: it introduces itself and asks what it is allowed to do. Its leading example is Poppy, short for Personal Agent Protocol, developed under the leadership of Sierra and Meta, with v1.0 released on November 13, 2026. The protocol itself makes no decisions for you; it solves just one problem: when your agent arrives at a business, how does it say who it is, what it can do for you, and what it must not touch.
What problem does it actually solve?
A business publishes a Poppy file under its own domain, at the fixed path /.well-known/poppy.json, and an agent reads it first when it visits. The file states whether the business accepts personal agents, how an agent identifies itself, and what it is allowed to do. Authentication runs over OAuth, and you can adjust at any time what your agent may and may not do. Technically it reuses existing standards such as MCP, OpenAPI, and UCP.
It is not the same thing as MCP or A2A
The three sit at different layers and complement each other:
| Protocol | The two sides it connects | The problem it solves |
|---|---|---|
| MCP | Agents with tools and data | How an agent calls tools and reads data |
| A2A | Agent to agent | How agents work together |
| Poppy | Personal agent to business | How an agent connects with a business while acting for you |
The split with UCP is equally clear: Poppy handles what happens before the visit, namely identifying itself and learning its permissions; UCP handles the shopping itself, namely finding products, filling the cart, and checking out.
What it can do now, and what not to expect from it
The fastest rollout is Shopify: it automatically publishes a Poppy file for every merchant on its platform, covering merchants in more than 175 countries, with no extra work required from merchants. Meta's Muse agent is available to all users and looks for Poppy first whenever it visits a website. Live examples include Mercury: an agent can check balances, review recent transactions, and categorize spending, while initiating a payment or transfer first has to pass an account approval step; Turkish Airlines lets an agent check fares and flight status and retrieve an order with a booking reference, and upgrades and payments require the user's approval.
But three things should not be expected: if a business has not published a Poppy file, an agent has nothing to connect to, so coverage depends on whether businesses adopt it; v1.0 does not mean every capability has landed, so judge it only by what the released version actually says; and it is not an all-access pass — sensitive actions always need your go-ahead, and you can withdraw authorization at any time. It suits tasks like checking a bill, checking an order, or comparing trips — 'ask first, then act' scenarios; anything that needs you to approve a payment on the spot or sort out a complicated dispute still needs you in person.
