TL;DR: "Free VPS" for an always-on AI agent exists in exactly three honest flavors: always-free cloud tiers (real but small, scarce, and reclaimable — Oracle Cloud is the canonical example), trial credits (great for weeks, gone in months), and hardware you already own (a spare machine or Raspberry Pi — genuinely $0 forever). For an agent that must answer at 3am, the reliability ladder is: owned hardware < always-free tier < a $5 VPS < managed hosting. This guide maps each rung honestly.
What an agent actually needs from hosting
An OpenClaw-style agent is not demanding: the runtime is light when models run via API. The hard requirement is continuity — heartbeats, scheduled tasks, and inbound messages all die if the host sleeps. That single requirement is what disqualifies most "free hosting": platforms that suspend idle workloads (common in free web-app tiers) break agents by design.
Option 1: Always-free cloud tiers
The real thing exists — small always-free instances (Oracle Cloud's Always Free ARM tier is the one everyone cites) can run an agent runtime continuously. Honest constraints: regional capacity is scarce, specs are modest, terms evolve, and reclamation of idle-looking instances happens. Verify current terms directly, keep backups of your agent's memory, and treat it as a free tier — not an SLA.
Option 2: Trial credits
Cloud trials run a real VPS for weeks or months. The failure mode is silent: an always-on agent consumes credit 24/7, and expiry lands mid-month. Set a billing alert the hour you start, and export your agent state before the cliff, not after.
Option 3: The zero-cost path that usually wins
The genuinely free option is hardware you already own. A spare laptop, mini PC, or Pi at home runs the runtime fine, keeps your data at home, and never expires. The trade: your power and network are now the uptime story, and a laptop that sleeps takes your agent with it — the PC setup guide covers keeping a box awake responsibly.
When free stops being worth it
Price the alternative honestly: a small paid VPS is roughly $5/month (setup guide), and managed OneClaw hosting removes the ops entirely. If your agent handles anything you rely on — reminders, messages, schedules — the question is not whether you can host it free, but whether the hours spent babysitting free infrastructure cost more than a coffee per month. Start free, feel the friction, upgrade when the agent earns it.