Vol. X · Field Operations · X.3
Plan Mode and Act Mode
Long-horizon work has two speeds. Plan mode is a deny-writes session that produces a revisable document. Act mode is a budgeted loop against that document. Mixing them is how agents wander and how humans lose the veto.
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Doctrine
- Plan is a file (or a structured todo list) the human can edit. Thoughts are not a plan.
- Entering act is a permission change, not a vibe. Writes were denied; now some are allowed.
- Revise the plan as a tool call when reality disagrees. A 40-step plan generated once is a lie.
Two modes, one checkpoint
Cline named it. Codex, Goose, Deep Agents, and OpenHands all grew a version. The durable run stores both the plan and the mode. A crash mid-act resumes the plan, not the chat novel. Factor 6 (pause/resume) and Factor 8 (control flow) are the same feature from two sides.
Anti-patterns
- Acting while still 'planning' so files change before agreement.
- Planning forever without a first action.