When a session is created for a conversation that already has messages in the DB, prior messages are loaded via ConversationsRepo.findMessages() and injected into the agent session as a system prompt addition so the agent has full context of the prior exchange. Context window management (M1-005): if the full history would exceed 80% of the model's context window (estimated at ~4 chars/token), older messages are summarized as a simple extractive summary and only the most recent messages are kept verbatim. Co-Authored-By: Claude Sonnet 4.6 <[email protected]>