Session modes

Mayfly keeps planning and permissions independent. With the editor focused, Shift+Tab toggles only:

normal ↔ plan

YOLO is selected separately through /permission and can remain active alongside plan mode. The first status row shows both plan in the accent color and yolo in the warning color; a pending plan transition displays plan.... These states come from dsh: plan uses the native plan projection, and yolo labels a danger-full-access + never permission preset.

normal

Plan mode is off. Default permissions are workspace-write + ask: workspace operations follow native tool policy, and actions requiring approval display the four-option panel (see Approvals & questionnaires). Returning from plan to normal preserves current permissions, including YOLO.

plan — plan first, act later

Plan mode gives the agent guidance to plan before acting without changing tool permissions or the filesystem sandbox. This is soft guidance, so combining plan with YOLO does not impose a read-only boundary. When the plan is final, the harness's exit_plan_mode request surfaces as the plan review panel (editor-slot replacement, mounted like the approval panel):

• the full plan renders as Markdown inside a bordered plan box;
• beneath it a numbered decision list — number keys pick directly, or ←→ + Enter; ↑↓ / PageUp / PageDown scroll only the plan body:

Option	Effect
1. Approve	Approve the plan, exit plan mode, start executing with current permissions
2. Reject	Reject — the model hears "the user chose to keep planning" and reacts in the same turn
3. Revise <text>	Inline revision: keep polishing the plan with your feedback

yolo — full access

Enter YOLO with /permission danger-full-access and restore default permissions with /permission workspace-write. /permissions opens Mayfly's permission picker. Mayfly does not register extra /yolo or /yes commands.

YOLO disables the filesystem sandbox and applies the never approval policy: actions that require approval are rejected without displaying an approval panel, while actions that do not require approval can run directly. User questions and plan reviews still appear, because the permission policy does not answer questions or approve plans for you.

Shift+Tab executes only /plan or /plan off, preserving YOLO. Likewise, /permission preserves plan state. For example, pressing Shift+Tab after entering YOLO shows plan yolo in the status bar; pressing it again ends planning and leaves yolo active. If the Agent preset does not provide plan mode, the shortcut reports that it is unavailable.

Relation to /preset

Plan mode is supplied by the harness's plan-mode plugin, composed through Agent presets (/preset, see the slash commands reference). Agent presets select capabilities, /plan controls planning collaboration, and /permission controls sandbox and approval policy.