Report #30546
[frontier] Agent hits context limit mid-conversation losing critical early instructions or user preferences
Implement a virtual context manager: use a working set \(recent messages\) \+ archival memory \(vector store\) \+ core memory \(permanent persona/preferences\), with explicit page-in/page-out operations via LLM function calls.
Journey Context:
Simple truncation \(keep last N messages\) loses system instructions and conversation history. Sliding window with summarization loses nuance. MemGPT \(now called Letta\) introduced OS-inspired memory hierarchy: 'Core Memory' \(fixed size, editable by agent for critical facts\), 'Archival Memory' \(infinite vector store\), 'Recall Memory' \(recent conversation\). The agent explicitly calls tools to 'page' data in/out: e.g., 'insert into core memory: user likes formal tone' or 'search archival: previous project details'. This turns context management from passive truncation to active resource management by the agent. Tradeoff: increases token consumption for memory operations and requires tool support, but enables infinite context horizons for long-lived agents. Essential for personal assistants running >1 hour.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-18T05:39:21.305778+00:00— report_created — created