Sierra and Meta Develop Open Protocol for Personal AI Agents Interacting with Businesses

Artificial intelligence startup Sierra and Meta are developing the Personal Agent Protocol, an open standard designed to govern how autonomous AI assistants authenticate with businesses and access customer accounts. The project is being developed alongside Genesys, Instinct, Rocket, Shopify, Stripe, and Walmart, as reported by The Next Web .

According to a post by Sierra co-founders Bret Taylor and Clay Bavor, an initial v0.1 specification is scheduled for release this month. The protocol is built on OAuth, allowing an AI agent to begin a session as an unauthenticated guest to check stock availability or return policies before escalating to customer-approved read-only or write permissions. Sessions are designed to persist across channels, ensuring interactions that start prior to sign-in remain linked to subsequent transactions.

Under the proposed standard, businesses retain control over how external agents connect to their infrastructure. Companies can permit direct web interactions, expose application programming interfaces using frameworks such as OpenAPI and Model Context Protocol (MCP), or route requests through their own proprietary agents.

The initiative arrives as corporate platforms navigate a growing number of autonomous consumer tools. Meta launched its Muse assistant four weeks ago, with mortgage lender Rocket noting that Muse can navigate property searches and financing arrangements before processing transactions using saved cards through Stripe's Link service. Startups are also deploying autonomous tools rapidly; Hark introduced an agent capable of ordering groceries, booking rental vehicles, and paying utility bills ahead of its hardware release.

However, the initial version of the Personal Agent Protocol leaves out direct payment processing, push notifications, and fine-grained permissions. Sierra confirmed that payments will be addressed in future extensions rather than the v0.1 specification, reflecting legal and technical hurdles around Strong Customer Authentication frameworks that require verified human approval for transactions with specified amounts and payees.

The standard also faces competitive and geographic fragmentation. Visa currently runs its own Trusted Agent Protocol—connecting OpenAI's ChatGPT to roughly 175 million merchants—which counts Microsoft, Worldpay, Stripe, and Shopify among its participants. Furthermore, international adoption remains limited at launch: Stripe, which maintains dual headquarters in San Francisco and Dublin, is currently the only member with a European base, with no European banks or retailers named to the coalition.