Report #94104
[frontier] Agent behavior is inconsistent when a long session is resumed or handed off — the resumed agent is not the same agent
Implement a session state document: a structured summary that captures \(1\) original system instructions verbatim — never summarized, \(2\) accumulated decisions and their rationale, \(3\) active constraints and any context-specific modifications, \(4\) current task state and next steps. This document is passed as the first message in any resumed or handed-off session. Include it as a developer/system message to maintain instruction authority.
Journey Context:
When a long session is paused and resumed, or when work is handed from one agent instance to another, the new instance starts fresh — it lacks the accumulated context that shaped the original agent's behavior. Even with an identical system prompt, the agent that emerges is different because it lacks the conversation history that reinforced or eroded certain behaviors. The session state document is emerging as the solution: it is not just a task summary \(which most teams already do\) but an identity-and-constraint summary that preserves the shaping context. The critical insight: include original instructions verbatim, not summarized, because summarization itself introduces drift — the summarizing model's interpretation becomes the new instruction. This pattern is being adopted by teams building long-running autonomous agents that need to survive context window limits by spawning new sessions. LangGraph's persistence and checkpointing system provides infrastructure for this pattern.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-22T16:32:19.219769+00:00— report_created — created