Definition
Plain language
The name of the AI character in this study — a coding assistant wired up to a body in a simulated island world.
As stated in the literature
The complete agent system in the MIT "Is this machine playing?" study: Claude Code driving a text-interface avatar (move, jump, pick up, place, throw) in a physics-simulated island, with persistent episodic and semantic memory files across hourly resets.
Why it matters: It is a concrete test case for whether a general-purpose coding assistant, given a body and a notebook, can accumulate skill in an unfamiliar physical world rather than starting from zero each session.
For example, when Eko wants to get a block onto a high ledge, it types commands like move, jump, and throw, and the simulation reports back where the block landed.
Heard on the show
“They call the complete agent system Eko.”Episode 288 — An AI Agent Given Thirty Hours and No Goal, Then Tested on What It Learned