Sierra announces Personal Agent Protocol, an open standard for personal AI agents

Sierra and Meta are developing Personal Agent Protocol, an open standard defining how personal AI agents authenticate with businesses and what those businesses let them do, with Genesys, Instinct, Rocket, Shopify, Stripe and Walmart. A v0.1 specification is due this month, and payments are listed as a future extension rather than part of it.

Meta and Sierra are writing a standard for how personal AI agents talk to businesses. Stripe and Shopify are among the partners. Both have already joined a rival protocol run by Visa.

Personal Agent Protocol is meant to handle authentication and show companies what agents are doing on their sites, Sierra said in a post by Bret Taylor and Clay Bavor. The other partners named are Genesys, Instinct, Rocket and Walmart. A v0.1 specification is due later this month.

Sessions are built on OAuth. An agent can start as a guest to check stock or a returns policy, and once a customer signs in they decide whether it gets read-only or write access. The session carries across channels, so a question asked before signing in and an order changed afterwards belong to one visit.

The company chooses whether the agent works through its website, through its APIs using standards such as MCP and OpenAPI, or through an agent of its own.