The bot freezes while doing heavy work How do I offload that

Use sub-agents for long or parallel tasks. Sub-agents run in their own session, return a summary, and keep your main chat responsive.
Ask your bot to “spawn a sub-agent for this task” or use /subagents. Use /status in chat to see what the Gateway is doing right now (and whether it is busy).
Token tip: long tasks and sub-agents both consume tokens. If cost is a concern, set a cheaper model for sub-agents via agents.defaults.subagents.model.
Docs: Sub-agents.