Personal Agent Protocol
What it is
An open standard, developed by Sierra and Meta with a growing list of industry partners, for how a consumer's personal AI agent identifies itself to a business, establishes who it represents, and is limited to only what that consumer has actually authorized. It builds on existing infrastructure rather than replacing it — OAuth for consent and session scoping, OpenAPI and MCP for the actual service calls — and lets a business decide whether an incoming personal agent talks to its website, its APIs, or to a business-side agent of its own.
Why it's emerging now
As personal AI agents (Meta's Muse being the flagship example) start acting on a user's behalf — booking a mortgage pre-approval, comparison-shopping insurance, managing a subscription — businesses have no shared way to tell a legitimate, user-authorized agent from a scraper or an impersonator, or to scope what it's allowed to touch. Sierra announced the protocol on October 6, 2026 with Meta and launch partners including Genesys, Rocket, Shopify, Stripe, and Walmart (reports vary on the exact partner list); within days, additional companies such as GEICO, Liberty Mutual, Insurify, and Cigna signed on as design partners, and a v0.1 specification was slated for later in October. The timing tracks the broader push toward agent-to-business commerce that MCP, A2A, and the Legal Context Protocol already serve — this is the piece aimed specifically at the "my agent talks to your business" leg of that triangle.
How it relates to what you know
It sits next to the Legal Context Protocol already on your ledger — both are consent/authorization layers for agentic commerce, but LCP is about the legal consent and dispute-resolution record for a transaction, while the Personal Agent Protocol is about identity and access scoping: who is this agent, whom does it represent, and what is it allowed to do. It's explicitly built as a layer on top of OAuth, OpenAPI, and MCP rather than a competitor to any of them, the same composable-standards pattern you've already seen with A2A and ACP.