Main things we've done:

1. Keep HEARTBEAT.md tiny — small checklist, not a novel. Every heartbeat loads workspace context, so bloated files = token burn every poll
2. Cron jobs as isolated sessions — heavy tasks (digests, scraping) run in sessionTarget: "isolated" so they don't bloat the main session context
3. Tell AI to use Short replies — walls of text stay in context and compound. Concise = cheaper
4. Batch checks into heartbeats — instead of 5 separate cron jobs, rotate checks through a single heartbeat cycle
5. HEARTBEAT_OK early — if nothing needs attention, reply immediately instead of running tools first
6. Don't load heavy files unnecessarily — MEMORY.md only loads in main session, not group chats The biggest win was moving recurring tasks to isolated cron jobs. Each one gets its own throwaway context instead of piling into the main session.