Trajectory-level monitoring – Definition & Meaning

Definition of trajectory-level monitoring

: the practice of evaluating an AI agent's full sequence of observations, reasoning, tool calls, and actions so that a harmful overall plan can be detected even when each individual step appears acceptable
- Trajectory-level monitoring caught the agent assembling a blocked credential from pieces across several tool calls.
- The company added trajectory monitoring because reviewing each action separately did not reveal what the agent was trying to accomplish.

Origin & history

first known use2026

OpenAI publicly highlighted trajectory-level monitoring in July 2026 while describing safeguards for long-running models. The approach extends familiar monitoring methods from reinforcement learning and security to the complete behavior of tool-using agents.

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Related terms

long-horizon model an AI model designed to work autonomously on a goal through many steps and repeated attempts… agent loop the repeating cycle at the heart of an agent: the model decides on an action, a tool carries… AI safety the field concerned with making AI systems behave as intended and avoid causing harm, from… eval a set of test cases used to measure how well a model or AI feature performs on the tasks you… agent containment the use of enforced technical boundaries to limit what an AI agent can read, change, execute… human-in-the-loop describing a system in which a person reviews, approves, or corrects an AI's work at key…

Cite this entry

"Trajectory-level monitoring." AI Dictionary, Dadgogo, https://dadgogo.com/dictionary/trajectory-level-monitoring/. Accessed 4 Oct. 2026.