Meta and Sierra Announce Work on Personal Agent Protocol

Meta and Sierra are developing an open Personal Agent Protocol with Genesys, Instinct, Rocket, Shopify, Stripe and Walmart. The proposed standard would govern how personal AI agents interact with businesses, but its first specification remains unpublished.

Sierra plans to publish a version 0.1 specification later in October 2026, then hold design workshops and release a reference implementation. The announcement presents the specification, workshops and reference implementation as future work; it does not identify a production deployment or completed interoperability test.

Under the proposal, consumers would control the access they grant to their agents, while each business would set parameters for what those agents may do. An agent could start as a guest to check product availability or a return policy. Account-level tasks would require the customer to sign in on the company’s page or use credentials already configured with the personal agent. The customer could then grant read-only or write access.

Sierra said protocol sessions would be built on OAuth 2.0, an authorization framework for limited third-party access. The announcement does not yet provide a complete protocol-level account of how a personal agent would be authenticated or bound to a particular user.

Under the proposed cross-channel model, a session would persist before and after sign-in as part of the same visit. A business could choose whether the agent interacts through its website, through APIs using standards such as MCP or OpenAPI, or through the business’s own agent.

The focus on business-controlled access comes as personal agents test existing platform boundaries. In September, Amazon blocked Meta’s Muse agent from shopping on Amazon.com. That episode is separate from the Personal Agent Protocol announcement.

Sierra also listed more granular permissions, push notifications and payment extensions as possible future capabilities, not features available in a published specification.