Sierra published a draft of the Personal Agent Protocol on October 9, nicknamed Poppy, and announced 35 additional design partners the same day, bringing the named roster to 45. The protocol’s job is small and consequential: define how a personal AI agent discovers a business online, authenticates a session, and transacts without a human ever touching the website.

The whole thing hinges on a file at /.well-known/poppy.json. A business publishes it, declares what agents can read and what they can write, hands off session auth to OAuth, and is now legible to the agent layer. A business that doesn’t publish it’s, for this new class of traffic, invisible.

The roster matters because it tells you where the pipes are being laid. Shopify, Stripe, and Walmart are founding partners. The October 9 wave brought in OpenAI, Visa, Mastercard, PayPal, Bank of America, and Target. Anthropic is conspicuously not on the list. Meta’s David Singleton told CNBC that Muse, Meta’s personal agent, already has millions of U.S. users and is “growing rapidly”, booking kids into classes, buying gifts, scheduling dentist appointments. That volume is already running through Meta’s Muse checkout on every Shopify store, and it’s the demand side of the same equation as Meta’s live agentic ads manager.

Bret Taylor, chairman of both Sierra and OpenAI, framed the stakes bluntly: companies have a risk from random bots acting without a person behind them, and “it is kind of chaos until such a standard exists.” The cautionary tale is already visible. Amazon has blocked Meta’s agents over scraping concerns and sued Perplexity last November over its agent. Without a protocol, every agent-site interaction is a potential lawsuit.

PYMNTS reports that v0.1 and a reference implementation are set to land by the end of October. Sierra’s own draft post says design workshops will run over the following month.

For a 5-to-30-person business, the decision window is now. Publishing poppy.json the week the reference drops is the cheapest competitive edge on offer. The standards fights that reshape distribution rarely feel urgent until the file formats are already settled.

Sources