dsh-custom-mode

Usage

The settings page (Settings → "Custom mode") is an assistant manager: the top of the page lists every custom mode you have — create, switch, delete — and the four blocks below (name, base mode, plugin switches, system prompt) edit whichever one is selected.

• Ordering — "Move up / Move down" writes the order into each assistant's preset.yml (order, the roster's own sort key), so it survives a restart and the new-session picker follows it.
• Import / export a prompt — "Export prompt" saves the current text as a .md; "Import prompt" reads a file into the editor (nothing is written until you save), so an import goes through the same {{…}} validation as anything typed.
• Asking the agent to change its own prompt requires your approval. The in-session custom_prompt tool goes through the platform's approval seam (tools/pre-execute returning ask), so the request waits for an explicit「允许一次」and shows what would be written and where. Measured: with the ask approval policy the panel appears and approving really writes; with never (full access) nothing prompts and the call is denied. The worst case is therefore "the change does not happen", never "it happened quietly".
• 配置了却不生效会被点名 — the page warns when a setting cannot take effect: the「身份（系统提示词）」 row is off while prompt.md still has content (so your prompt is silently ignored), the custom_prompt tool row is off, the assistant has no name or no description (the picker shows the bare id /「暂无描述」).
• The agent can change its own prompt, with your approval — the in-session custom_prompt tool reads the prompt, replaces it, or appends to it. Appending matters because it never has to reproduce the whole prompt: an agent that wants to remember one rule cannot lose existing content on the way (measured: it may still read first to see what it is adding to). Both writing actions go through the platform's approval panel first.
• Change history — every save, and any change made outside this page (the in-session custom_prompt tool, a hand edit of prompt.md), leaves a version in the history list under the prompt box, labelled with when and where it came from. Loading one only edits the draft: nothing is written until you save, so browsing old versions cannot destroy the current one. Before this, a prompt changed from inside a session was invisible — the page only ever showed "the current text".
• Reset to the factory prompt — one click puts the shipped template (the text a new assistant starts from) back into the editor. It is draft-only like every other edit: nothing is written until you save, and Reload discards it. Before this existed, a prompt you had edited into a corner could only be recovered by deleting the assistant and creating it again.
• New assistant — type a name and click "New assistant". It is seeded from the packaged template: the full Standard row set plus a starter prompt, selectable in a new session as soon as you save it — in an already-open page the picker's list is a load-time snapshot, so refresh (F5) once to see a new assistant there (measured; the roster itself is up to date).
• Duplicate — copies the selected assistant's prompt, base mode and row switches into a new one; the two are independent afterwards.
• Each assistant is independent — its prompt, base mode and row switches are its own; changing one leaves the others alone.
• Base mode is the row set, not the prompt — it decides which rows exist and which tools the mode has; this plugin always replaces the base's persona row with its own reader (complete: false), so the base's prompt semantics are not inherited. Minimal is the visible case: you get minimal's tool set, not minimal's prompt.
• Switching assistants never discards drafts — each keeps its own unsaved edits, marked "Unsaved" in the list; the only path that throws edits away is the reload button, which renames itself to say so.
• Delete — the shell's own risk-confirmation dialog, which requires ticking an acknowledgement. Deletion only removes the mode directory from disk: sessions already using it keep running (their composition was read when they started), and new sessions no longer offer it.
• Ask the agent — every assistant ships a custom_prompt tool, so a session can read or rewrite its own prompt.
• Edit the file — $DSH_HOME/.agent-presets//prompt.md is that assistant's single source of truth.

Only {{model}}, {{cwd}} and {{provider}} are interpolated. An unknown {{…}} is rejected when saved: the renderer throws on it, which would fail every request in that mode.

Every control (buttons, inputs, switches, tags, the confirmation dialog, icons) comes from the shell's own @deepseek-ai/dsh-client-ui-primitives, so theme, light/dark and future restyling reach this page automatically; a shell that does not provide those atoms falls back to built-in plain controls with the same behaviour.

An "assistant" is one directory under the user preset root (default $DSH_HOME/.agent-presets/), and its directory name is its internal id. The page manages only presets this tool created — the test is that the directory carries prompt.md and that its composition injects identity through prompt-reader.mjs. Any other hand-authored preset is neither listed nor touched: the page regenerates a composition from a base mode, and doing that to a hand-written one would destroy it.

How this differs from the built-in Plugins page

From dsh 0.1.6-alpha.2 the harness ships a Plugins page that can enable and disable plugins live. It and this mode's per-row switches act at different levels:

	Built-in Plugins page	This mode's per-row switches
Scope	The whole profile — what this machine has installed	One agent mode — which rows its composition mounts
Typical use	Turn a plugin off globally	Keep Standard fully loaded and trim this mode to what it needs

They coexist: the harness decides what the machine has, this mode decides which of it the mode uses.

The boundary is drawn by upstream: the Plugins page documents that it manages "the profile's bundles and their uniquely addressable rows", and states plainly that agent-preset rows remain read-only. The preset layer is therefore out of its reach — and that is exactly the layer this mode covers.

A demonstrable example: tool-plugin-manager (the agent-facing install/toggle tool) ships off in Standard and PTC — only Creator enables it. The official modes give you no way to change that; here you flip one switch.