Session Persistence

Logician stores all session data in SQLite, providing fast queries and reliable recovery.

Database schema

Recovery

Sessions survive crashes and restarts:

1. Auto-save — messages are saved after each LLM response
2. Checkpoint — manual save points for rewind
3. Bookmark — named save points with labels
4. Compaction — automatic when context nears limit

Compaction

When the context window approaches its limit:

{
  "compaction": {
    "enabled": true,
    "triggerFraction": 0.75,
    "strategy": "summarize",
    "keepToolResults": true,
    "keepFinalAnswers": true
  }
}

Compaction preserves:

• Tool results and their outcomes
• Final answers to user questions
• Critical decisions and conclusions
• Error messages and their context

Session lifecycle