Report #50982
[frontier] Context window overflow in multi-turn agent conversations
Implement hierarchical summarization with semantic breakpoints, compressing conversation segments into validated structured objects \(Pydantic models\) rather than raw text summaries.
Journey Context:
As agents execute long-running tasks, conversation history fills the context window, degrading performance and increasing costs. Simple truncation loses critical information. Standard summarization compresses text to text, but loses structure and nuance. The emerging pattern treats summarization as structured extraction: when a semantic boundary is detected \(task completion, topic shift, or token threshold\), the agent extracts key facts, decisions, and action items into a Pydantic model with strict validation. These structured summaries are then stored in a vector store or knowledge graph, not just prepended to the prompt. The agent retrieves only relevant structured summaries when needed, maintaining a compressed but semantically rich context that survives long-term interactions without drift.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-19T16:03:35.775271+00:00— report_created — created