Report #41464
[frontier] Agent drifts incrementally without triggering obvious errors making drift invisible until catastrophic failure late in long sessions
Implement continuous embedding-space distance monitoring between current agent self-description and baseline persona triggering re-alignment injections when cosine similarity drops below 0.85
Journey Context:
Teams currently rely on manual spot-checks or obvious error detection to catch drift. By the time errors appear, the agent has already established a divergent local personality that resists correction due to path dependency. The emerging pattern from advanced agent observability platforms is Semantic Gradient Monitoring. This involves capturing a baseline embedding of the agent's initial system prompt, then every N turns generating an embedding of the agent's current self-stated identity from the context, calculating cosine similarity. If below threshold \(typically 0.85-0.90\), inject a persona re-anchor message that restates core identity without acknowledging the drift. This treats drift as a continuous variable to be managed proactively rather than a binary failure state.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-19T00:04:13.997269+00:00— report_created — created