On October 9, Sierra released a draft specification for its Personal Agent Protocol, abbreviated Poppy, and announced 35 additional design partners. The most closely watched name on the list is OpenAI. When the protocol debuted three days earlier, the only model company among the participants was Meta, which co-developed it with Sierra.
What the draft says
Poppy addresses how a user's own AI agent should deal with businesses on that user's behalf. The draft lays out a flow in roughly four steps:
- Discovery: a business places a file at the fixed address /.well-known/poppy.json describing how an agent can connect, how users sign in, and what the agent can get done;
- Sessions: the agent opens a session on the user's behalf. It can enter as a guest first, but it must identify itself as an agent;
- Sign-in: when an account is needed, the user logs in through OAuth on the business's own page, and, if the business allows it, the agent continues with a session token that carries only the permissions the user granted;
- Channels for getting things done: a business can let agents work through its website, through an API (based on OpenAPI and MCP), or by handing off to the company's own customer-service agent. These options can coexist, and the same token works across all of them.
Everything underneath uses existing standards: OAuth, JWT, HTTPS, OpenAPI and MCP. Sierra positions the protocol as complementary to the Universal Commerce Protocol (UCP), which covers the shopping flow. The draft is hosted at personalagentprotocol.org, and Sierra says it will hold design workshops and release a reference implementation over the next month. The announcement does not mention licensing or governance.
From 8 partners to 43
The partners announced at launch were Meta, Genesys, Instinct, NiCE, Rocket, Shopify, Stripe and Walmart. Of the 35 new names, finance and payments make up the largest group: Bank of America, Wells Fargo, BBVA, Chime, Synchrony, Mastercard, Visa, PayPal, Venmo, Adyen and Plaid. Retail is represented by Target, Gap and Nordstrom, and insurance by GEICO, Liberty Mutual and Cigna. The list also includes industries under heavy customer-service pressure, such as United Airlines, Hertz, Comcast, DIRECTV and SiriusXM, along with infrastructure and tooling companies including Cloudflare, Okta, 1Password, Zapier, Notion, Zendesk and ElevenLabs.
The business side is covered broadly, but the agent side still has only two model companies. Google and Anthropic both offer consumer-facing assistants, and neither is on the list; neither has commented on that. OpenAI joined as a design partner. The announcement gives no timeline for when, or how, ChatGPT will call business services under this spec, and OpenAI has not issued a separate statement.
The view from China
No Chinese companies are on the list. Personal assistants in China generally connect to outside services one by one through each vendor's own open platform and plugin system, so a business that wants several assistants to handle its transactions has to build a separate adapter for each. Poppy's design has a business publish a single declaration file that any agent following the spec can read, with the same rules for all.
For Chinese companies doing business overseas, two parts of the draft are worth reading early: the fields in poppy.json, which determine how far an agent can go on a user's behalf, and the permission scope of the session token. With banks and payment companies crowding in, those rules are likely to be pushed toward fine granularity.
For Chinese assistant makers, the draft offers a ready-made reference. Whether to build a similar shared protocol or keep maintaining separate plugin ecosystems is a question none of the domestic companies has publicly addressed. The draft is still in its comment period, and both fields and flow could change, so building adapters now is premature, though reading the spec costs very little.
Sources: Sierra official blog, the draft spec at personalagentprotocol.org, CocoLoop; the new partner list and the draft's four-step flow were checked against the Sierra blog.