AI Systems Atlas

H-09State Machine Agent

/harnesses/state-machine

The agent’s lifecycle is an explicit state machine; the model acts within states, the harness owns the transitions.

Step-by-step walkthrough6 steps
  1. Every transition is explicit — the harness, not the model, owns control flow. Click any state to inspect it.
  2. goal arrives → PLANNING
  3. PLANNING → ACTING → WAITING: side effects, then block on the world.
  4. VERIFYING gates completion.
  5. Fail loops back to PLANNING with the failure attached.
  6. Pass → COMPLETE. Legible, resumable, debuggable.
Key insight

Explicit states make agents debuggable, resumable and observable — you can always answer “what is it doing right now?”

Failure mode

States that don’t match reality: work that spans two states, or a “waiting” that never fires, forces the model to fight the harness.

Further reading
RelatedEvent-driven agentLong-running agent

Elsewhere in the atlas

Security →Evals →Context →Coding Agents →Tools →Ops →