A program that continuously perceives and acts on its environment, without human intervention.

Once a software agent is started up, it keeps executing autonomously to perform its task.

Agent architecture diagram

Agents come in all forms, from simple to complex. These are the main levels of complexity:

  • A simple reflexive agent follows simple rules to determine its next action
  • A state based agent keeps a representation of the environment to better inform its decision
  • A goal based agent has goals to achieve, and creates plans or searches for ways to decide what to do next
  • A utility based agent distinguishes between possible actions by choosing the one that best matches a utility function


  • Vacuum-cleaning robot
  • Chatbot

When should you use it?

  • If the task requires an autonomous program that is permanently active and runs without human intervention
  1. Wikipedia