A reactive agent maps the current observation directly to the next action with no explicit internal model of the future. It is fast and robust in familiar environments and brittle whenever success depends on a commitment made several steps earlier.

Reactive Architecture

A deliberative agent builds an explicit plan over an internal model of the world, then executes it. Planning buys coherence over long horizons at the cost of latency, and of plans that go stale the moment the environment surprises the agent.

Deliberative Architecture

A topic of the Building AI Agents course. Planned for 2 hours at Medium difficulty.

University of Michigan - Ann Arbor

A category of the Building AI Agents course, covering 4 topics.

Foundations of Agentic Systems

A topic of the Building AI Agents course. Planned for 1.5 hours at Easy difficulty.

What Makes a System an Agent

The Perception, Reasoning and Action Loop

Agent Architectures: Reactive, Deliberative, Hybrid

Choosing a Model for an Agent

For agents, the deciding capability is rarely raw knowledge; it is whether the model reliably respects tool schemas, stop conditions and formatting contracts across dozens of turns. A model that drifts from its contract at turn fifteen cannot be deployed unsupervised.

Learn Before

Related

Learn After