Google Pay launches protocol to let AI agents make purchases

Google announced updates to Google Pay that include a Universal Commerce Protocol and a new Merchant Commerce Platform to let AI agents initiate and complete purchases via APIs, along with Android dynamic callbacks and expanded WebView payment support.

The Universal Commerce Protocol is a specification that standardizes how automated agents request inventory, pricing, order initiation and fulfillment details. The protocol defines common formats for these requests so developers do not need to build a custom integration for every merchant or payment provider an agent might contact.

The Merchant Commerce Platform is a server that will sit between merchants and agents. The MCP manages merchant integrations, handles payment flows and collects transaction data generated by agent-driven activity. Google said the platform aims to simplify backend work for developers while centralizing commerce signals for analysis.

To support multi-step checkouts, Google added dynamic callbacks to the Android Pay API. These callbacks allow an app or agent to update parts of an order in real time-for example, recalculating shipping or tax when a delivery address changes-without restarting the entire flow.

Expanded WebView payment support lets transactions complete inside third-party apps. Agents embedded in social platforms or other native apps can finalize purchases without sending users to external web pages.

Google outlined a human-in-the-loop security model to address authorization risks tied to autonomous agents. Cross-device biometric authentication will let an agent request human verification and prompt a user on their phone to approve a purchase an agent initiated on another device. Policies encoded in agent behavior will determine when user approval is required.

Merchants will need to provide machine-readable product data, pricing and availability so agents can find and buy items. If an agent cannot parse a seller’s inventory data, that seller may be skipped by automated buyers.

Routing agent transactions through a centralized platform gives Google broader visibility into commerce patterns. Information security, data governance and the long-term implications of relying on a proprietary protocol are factors that technology and procurement teams will evaluate when integrating the platform.

The updates shift transactional work from visually oriented checkout pages to standardized APIs, intermediary services and cross-device authentication for purchases initiated by automated software.