dsh-plan-build-mode

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A Plan / Build mode switcher for DeepSeek Harness (dsh), shaped like opencode's Build/Plan selector.

Two things it adds:

1. A dropdown in the composer, sitting immediately to the right of the permission control (完全权限 / Full access). It is always visible and switches the current session both ways.
2. A "Default mode" row in Settings → General, directly under the permission row. It decides which mode newly created sessions start in.

Why it exists

DSH 0.2.0-rc.2 already ships Plan mode (@deepseek-ai/dsh-plan-mode), but the official composer chip PlanChip is exit-only:

if (!(plan.pending ? !plan.active : plan.active)) return null;

When the session is not in Plan mode the chip renders nothing at all, so the only way into Plan mode is typing /plan by hand — there is no discoverable entry point. This plugin takes the same seat (conversation.input.plan) and supplies a two-way dropdown instead.

Features

• Always-visible dropdown showing the current mode (Build or Plan) with a chevron.
• Two menu items with a check mark:
  • Build — implement directly (/plan off)
  • Plan — plan only, no changes executed (/plan)
• Blue highlight while in Plan mode (uses the official --dsw-alias-state-business-* tokens).
• Optimistic display — while a switch is in flight (pending), the button already shows the target mode.
• Default mode row — pick Build / Plan as the starting mode for new sessions. The current session is unaffected; use the composer control for that.

Install

Pin the version, so pnpm's release cooldown cannot hand you an older build:

dsh plugin --profile web add dsh-plan-build-mode@1.1.0

Straight from GitHub (no npm publish needed):

dsh plugin --profile web add github:yzhclcl/dsh-plan-build-mode

Desktop app: install from the in-app Plugins page. The CLI cannot modify profiles/desktop.

Then fully quit and restart the process serving the profile. The client bundle revision is derived from file metadata (mtime/ctime/size), so a page refresh alone is not enough — a stale revision makes the browser request a URL the server now 404s, which surfaces as client-modules: bundle script ... failed to load.

Use

Composer dropdown — click it, pick Build or Plan. It maps to the shipped /plan and /plan off commands, so nothing about the plan-mode machinery changes.

Default mode — Settings → General → Default mode, under the permission row.

Note: the first time you save this row, ~/.dsh/profiles/<profile>/cordis.patch.yml gains a top-level entry at the end:

- id: plan-build-mode
  name: dsh-plan-build-mode
  config:
    defaultMode: plan

That is the normal config-editor write path. Delete the entry (or set build) to go back to the default.

How it works

Concern	Approach
Composer seat	conversation.input.plan — the modes row of the input bar, adjacent to conversation.input.permission
Shadowing the official chip	register({ priority: -1 }) — a single slot only rejects equal priority; the lowest priority renders
Reading state	useProjection("plan") → { active, pending }
Switching	ctx.remote.commands.execute(sessionId, "/plan" | "/plan off", [])
Styles	deduplicated injection via style[data-plugin-css="dsh-plan-build-mode"], reusing official size/colour tokens
Settings row seat	settings.general.item list slot, id: "default-mode", order: -10 (permission is -20, language is 0)
Settings read/write	ctx.configForms.get("plan-build-mode") → remote.settings.mutate(ns, [{op:"set",path:["defaultMode"],value}], revision)
Config field	z.union([z.const("build"), z.const("plan")]).default("build").volatile() — only entries carrying volatile fields reach the settings surface
Suppressing the auto form	ctx.inject(["settings"], (child) => child.effect(() => child.settings.configure({ auto: false }, ctx.fiber)))
Pinning new sessions	On session/created, if the session is brand new (seq === 0, not seeded, no parentSession) and the default is plan, append plan/mode { active: true } — the same first-party event @deepseek-ai/dsh-plan-mode writes, and one of the names on the persisted event allowlist

What "Plan mode" actually is

Plan mode is a soft, prompt-level guide, not a sandbox. All tools stay available in both modes; the harness injects a plan:policy prompt section that tells the model to explore and plan rather than execute. Real restriction comes from the permission presets (sandbox mode + approval policy), which are independent and read no plan state. If you want a hard read-only guarantee, switch the permission preset to Read Only.

Switching mid-turn is supported: the intent is queued and applied at the next turn boundary, while the button immediately reflects the target.

Compatibility

dsh	Status
0.2.0-rc.2	Verified on Windows, web profile — dropdown, settings row, persistence, and new-session pinning all exercised

Declared range: >=0.2.0-0 <0.3.0-0. The plugin targets the 0.2.x seat layout (conversation.input.plan, settings.general.item) and the plan/mode event, so older 0.1.x hosts are out of scope.

Uninstall

dsh plugin --profile web remove dsh-plan-build-mode

Restart afterwards. The official PlanChip returns to its original behaviour immediately — this plugin modifies no official file.

License

MIT