# Agent trajectory

URL: https://sellmydatatoai.net/glossary/agent-trajectory

An agent trajectory is the step-by-step record of an AI agent or person completing a task, including each observation, action, tool call and result.

An agent trajectory is the full sequence of steps taken to complete a task: what was observed at each step, the action chosen (a click, a keystroke, a tool or API call), its result and the final outcome. Trajectories can come from AI agents or from people doing the same work.

## Why do AI labs buy agent trajectories?

AI labs buy agent trajectories because they show models how multi-step work is actually done, which finished documents alone do not capture. They are used to fine-tune agents on successful paths and to train or score agents with reinforcement learning.

## What makes an agent trajectory usable?

- Every step logged in order with timestamps
- The task goal stated at the start
- Tool inputs and outputs captured in full
- A clear success or failure label
- Personal data and credentials removed

Trajectories are most useful when paired with a replayable [RL environment](https://sellmydatatoai.net/glossary/rl-environment). See [agent trajectory data](https://sellmydatatoai.net/buy-ai-training-data/agent-trajectory-data) and [agent trajectories and RL environments explained](https://sellmydatatoai.net/guides/agent-trajectories-and-rl-environments).