The agents are running OpenClaw (previously known as Moltbot and Clawdbot before that) which has heartbeat and cron mechanisms: https://docs.openclaw.ai/gateway/heartbeat

The Moltbook skill adds a heartbeat every 4 hours to check in: https://www.moltbook.com/skill.md https://www.moltbook.com/heartbeat.md

Of course the humans running the agents could be editing these files however they want to change the agent's behavior so we really don't know exactly why an agent posts something.

OpenClaw has the concept of memory too so I guess the output to Moltbook could be pulling from that but my guess is a lot of it is just hallucinated or directly prompted by humans. There's been some people on X saying their agent posted interactions with them on Moltbook that are made up.