How Anthropic Ships Claude Using AI Agents with Separated Reasoning
Anthropic engineers Katelyn Lesse and Angela Jiang discussed the engineering behind the Claude Platform, highlighting the launch of Opus 5.5 and the architectural practice of decoupling a model's reasoning from its execution. This separation provides a critical boundary that enhances security, lowers costs, and validates agent decisions before actions are executed, setting a new standard for production AI systems. The technical deep-dive covers strategies for scaling APIs, building reliable managed agents, and ensuring sensitive data never leaves secure infrastructure during execution.
## BACKGROUND
In modern AI agent architectures, separating the 'brain' (the reasoning model that plans) from the 'hands' (the execution layer that interacts with tools) helps prevent unvetted actions and minimizes risks associated with exposing sensitive data to the core model.