Sierra publishes Poppy draft and names 35 additional design partners

Sierra has published a draft of its Personal Agent Protocol, which it calls Poppy, and says it is inviting additional companies to help shape the design. The company announced 35 new design partners, including Adyen, Cloudflare, OpenAI and Zapier. The partners are expected to contribute feedback from their business perspectives as the draft develops.

Poppy sets out a framework for personal agents and businesses to interact, with customers choosing what access to grant and companies defining what agents may do. Its five building blocks cover discovery, sessions, sign-in, continuity across channels and completing a task. For discovery, a business publishes a file at a standard location on its website to tell agents how to interact, how customers can sign in and which actions are supported. An agent can begin as a guest for tasks such as checking availability, then use customer-approved access if an account is needed. The protocol also aims to let a session continue across a company’s website, APIs and agent, rather than splitting the interaction into separate visits.

Businesses would choose which channels to support: their regular websites, APIs or an agent of their own. On a website, an agent would use the company’s existing pages while the company applies the customer’s permissions. For APIs, the protocol describes connections through standards such as OpenAPI and MCP, while a company agent could handle conversational tasks such as exchanges or warranty claims. Sierra says replies from a company agent can stream as they are written, and a request can remain open while awaiting an update. For AI builders, the proposed ability to connect once through Poppy, instead of creating a separate connection for each personal agent, is a central design goal.

The draft builds on OAuth, JSON Web Tokens, HTTPS, OpenAPI and MCP, which Sierra says teams can implement with existing libraries and tools. Developers can therefore start with standards and tools they already use, according to the company. Sierra describes Poppy as complementary to the Universal Commerce Protocol: while that protocol focuses on shopping, Poppy addresses agent identity, customer permission and business interactions across different kinds of tasks. Sierra says it plans design workshops and a reference implementation to help developers begin working with the draft.