Dictionary entry
action space
also agent action space
Definition of action space
-
: the complete set of actions an AI system is able or permitted to choose in an environment, such as moving a robot, calling a tool, clicking an interface, sending a message, or changing a file
- Giving the coding agent a shell expanded its action space far beyond suggesting text.
- The safety layer reduced the payment agent's action space so it could prepare a transfer but not submit one without approval.
Two meanings, one word
In everyday English
The range of actions that are available to a person or system in a particular situation.
In AI
The complete set of actions an AI system is able or permitted to choose in an environment, such as moving a robot, calling a tool, clicking an interface, sending a…
Origin & history
Action space is a long-established term in control theory and reinforcement learning for the set of actions available to an agent. It became newly prominent in discussions of tool-using and computer-using AI because tools, permissions, and interfaces determine which real-world actions a model can attempt.
Test yourself
Which of these is the meaning of action space?
Cite this entry
"Action space." AI Dictionary, Dadgogo, https://dadgogo.com/dictionary/action-space/. Accessed 10 Oct. 2026.