AI Agent
An AI system that takes multi-step actions to accomplish goals — browsing the web, running code, editing files — rather than just responding to single prompts.
An AI agent is a system built on an LLM that can autonomously take multiple actions to accomplish a goal. Unlike chat assistants that respond once per prompt, agents loop: observe state → reason about next step → take action (via tools like web browsing, code execution, API calls) → observe results → continue until done.
Examples include Claude Code (coding agent), ChatGPT Operator (web automation), Cursor's Composer (multi-file editing), and Devin (autonomous software engineer). The "agent" pattern is the major 2024-2026 push in AI products.
Current limitations: agents fail on tasks requiring sustained multi-step reasoning over many actions. They're reliable for narrow, well-scoped tasks (refactor this code, fill this form) but unreliable for open-ended autonomy. Improving agent reliability is one of the major research frontiers.