Current agent harnesses fall short for true autonomous operation; persistent runtime environments with continuous heartbeats are needed for long-term always-on AI agents.

Agent harnesses (prompt + tools + memory setups) are insufficient for agents that need to run autonomously for weeks or months without constant human triggering

Critical distinction exists between Agent Execution Runtime (secure sandboxes for code) and Agent Runtime Environment (persistent world where agents continuously operate)

True always-on autonomy requires environments with continuous heartbeat, sleep/wake cycle management, crash-resistant state persistence, and proactive action capabilities

Most developers are currently using cron jobs to trigger LangGraph workflows as a workaround rather than building genuine persistent agent runtime environments