Building Physical AI agents with MCP and MQTT on AWS IoT Core

This article explains how to build Physical AI agents that combine cloud intelligence with edge device control using MQTT and the Model Context Protocol (MCP) on AWS IoT Core.

• Physical AI systems need cloud reasoning plus edge execution capabilities working in real time
• MQTT reduces message overhead by 85-90% compared to HTTP for constrained devices
• MCP gives cloud AI structured access to tools: recipes, inventory, customer preferences, device status
• AWS IoT Core MQTT broker bridges robot commands with cloud AI agent reasoning
• Lambda translates between MQTT and MCP formats without maintaining session state
• Standardized topic hierarchy enables targeted messaging and scope-based security policies
• QoS 1 delivery guarantees ensure physical commands survive network interruptions
• Robots cache popular recipes locally and operate safely offline until connectivity restores
• Pattern extends to delivery robots, medical robots, manufacturing cobots needing cloud context

The architecture solves Physical AI's core challenge: connecting onboard execution intelligence with cloud reasoning intelligence reliably over constrained networks.