Google Pay launches Universal Commerce Protocol for AI agents

Google announced updates to Google Pay that introduce the Universal Commerce Protocol (UCP) and a Merchant Commerce Platform (MCP). The changes let AI agents query inventory, request quotes, confirm prices and shipping, and complete purchases through APIs. The system also supports cross-device biometric verification for human approval.

UCP is a specification that defines the messages and data formats agents use to interact with merchants and payment systems. It covers inventory checks, price and shipping confirmations, and fulfillment triggers. Google intends UCP to reduce the need for separate integrations with each merchant or payment provider.

The MCP server will act as an intermediary that manages merchant integrations, routes agent-driven commerce, and provides orchestration, analytics and transaction trends. For developers building agents, the MCP is designed to handle backend complexity so agents can focus on task logic rather than on individual merchant APIs.

Google is adding dynamic callbacks to the Android Pay API so apps and agents can update shipping costs, taxes or availability during checkout without restarting the flow. Expanded WebView support allows third-party apps to host native payments inside embedded browsers, enabling transactions inside social and messaging apps where conversational agents may operate.

Security and authorization use cross-device biometric verification. An agent can programmatically prompt a user’s phone to approve a transaction initiated elsewhere. That creates a human-in-the-loop control for high-value or sensitive purchases and produces an audit record for agent actions. Google also plans controls that require agents to seek human approval when transactions exceed permitted limits.

Merchants must provide machine-readable product data such as descriptions, pricing, inventory and fulfillment options. If an agent cannot parse a merchant’s catalog or availability, the merchant risks being bypassed by automated purchasing flows. Marketing and e-commerce teams will need to adjust content and data feeds so agents can discover and act on product information.

Routing agent transactions through the MCP centralizes commerce telemetry and gives Google visibility into agent-driven purchasing patterns. That consolidation can support fraud detection and analytics and raises questions about vendor dependency and data governance. Chief information officers and procurement teams should evaluate the implications of relying on a proprietary protocol and a centralized transaction hub.

Google described the updates as a way to provide a machine-facing commerce layer for conversational agents that book travel, order supplies or complete routine purchases on behalf of users.