Part IV — Runtime behaviour

This part covers Chapters 15–20: work modes, the plan / todo state machines, history compaction, subtasks and background execution, status indicators and error messages.

15. Work modes

[!ref] Full details in the User Manual, "The five work modes".

15.1 Modes at a glance

Mode	Name	Default persona	Write files	Edit	Shell exec	Network
auto	Auto	Built-in · Auto	Allow	Allow	Allow	Allow
plan	Plan	Built-in · Plan	Deny	Deny	Deny	Allow
prepare	Prepare	Built-in · Prepare	Allow	Allow	Allow	Allow
execute	Execute	Built-in · Execute	Allow	Allow	Allow	Allow
assess	Assess	Built-in · Assess	Deny	Deny	Deny	Allow

plan is strictly read-only: only read-oriented tools are allowed (read files / read code / read git / security analysis / network / skills / todos and planning itself), and no fs.exec.* at all (fs.exec.tail and fs.exec.list are unavailable in plan mode too). The restriction intersects with the tools declared by the bound persona — a persona can only narrow it, never widen it, and the Settings panel can't loosen it.

assess is read-only, just like plan: writing files, editing, shell execution and running tests are all denied (mode-level defence in depth — rebinding to a different persona doesn't loosen it); read-only check tools such as lint, SAST, SBOM, security analysis (sec.*) and threat intelligence (vt.*) remain allowed. Note the distinction between the mode and the persona: the built-in "assess" persona (assess / reviewer) declares fs.exec.* in its tool list, and when dispatched as a subagent it is not clamped by the main session's work mode — with the parent session in an executable mode, a review subagent can run tests and linters to reproduce findings. The read-only constraint above applies only when the persona is bound as the main-session persona of assess mode.

15.2 Side effects of mode switch

When you switch	Behaviour
Load the mode's persona	Persona SOUL injected into the next turn
Apply mode's tool set	Tool list re-evaluated
Insert a divider in the stream	A "mode switch" event card
Plan and todo	Not reset; carry over from the previous mode
Model and parameters	Apply the mode's overrides; otherwise inherit workspace defaults

15.3 Recommended workflow

plan → prepare → execute → assess

The "exit" banner between modes appears at the top of the conversation; clicking auto-loads the next mode and injects the confirmed artefacts (plan / checklist / changes) into the next turn.