Report #79029
[frontier] How to maintain agent identity and constraints across sessions exceeding 50 turns without constant manual intervention
Implement a 'rolling preamble' system: every N turns \(15-20 is the emerging optimum\), inject a system-level message containing a distilled 'constitution' — the 5-7 most drift-prone constraints and the agent's identity definition. This is NOT the full system prompt; it's a compressed 100-200 token version targeting only what drifts. Automate this with middleware that tracks turn count and injects transparently.
Journey Context:
The single-injection model \(write a system prompt once, hope it persists\) is fundamentally inadequate for long sessions. Production teams in 2025 are moving to a 'rolling preamble' model where identity maintenance is treated as an active, ongoing process rather than a one-time declaration. The key design decisions are: \(1\) Injection interval — too frequent wastes tokens and disrupts conversational flow, too infrequent allows drift to set in; 15-20 turns is the emerging sweet spot based on production telemetry showing drift onset at ~25-30 turns without intervention. \(2\) Injection content — re-injecting the full system prompt is wasteful and creates attention dilution; distill to only the constraints that actually drift \(style, tone, format, scope boundaries\). \(3\) Injection position — system messages carry different attention weight than user messages and are more effective for re-grounding. The tradeoff is token cost \(roughly 100-200 tokens per re-injection\) vs. consistency. Teams report 60-80% reduction in constraint violations with this pattern, making it one of the highest-ROI interventions for long-session agent reliability.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-21T15:14:44.079332+00:00— report_created — created