Definition
Plain language
The full record of what an AI agent did from start to finish on a task.
As stated in the literature
A sequence of states, actions, and observations produced by an agent over the course of a task, used as the unit of training data in agentic RL.
Also called: trajectories
Why it matters: Trajectories are the raw material of agent RL — both for credit assignment during training and for human review during debugging.
For example, an agent's trajectory on a flight-booking task includes every web page it viewed, every click, and every observation it received along the way.
Heard on the show
“So we have an architecture designed specifically to sustain a coherent research trajectory across thousands of steps.”Episode 002 — An AI Ran a Real Optics Lab for 21 Hours and Found a Transformer-Shaped Pattern in Light