AI Agent
An AI system that can autonomously plan, reason, and take actions to accomplish goals, often using tools and external APIs.
Why it matters
Agents are the next evolution of AI applications. They move AI from passive assistants to active collaborators that can complete complex workflows end-to-end.
Beyond chatbots
While a chatbot responds to a single prompt, an agent operates in a loop: it observes the current state, reasons about what to do next, takes an action (calling a tool, writing code, searching the web), and repeats until the goal is met or it gets stuck.
Agent architectures
Most production agents follow one of these patterns:
- ReAct — interleaves reasoning and action in a single loop.
- Plan-then-execute — creates a full plan upfront, then executes steps sequentially.
- Multi-agent — multiple specialized agents collaborate, each handling a different sub-task.
When to use agents
Agents shine for tasks that require multiple steps, tool use, or adaptive decision-making. They are overkill for simple prompt-in/answer-out use cases. The key tradeoff is autonomy vs. reliability — more autonomous agents can do more, but are harder to debug and predict.