dsh-liangshen — LiangShen Mode (two-phase anchored-standard agent preset)

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Ships the "Anchored Standard" preset as a one-command plugin of the dsh-web-ui family: on host startup it syncs the bundled preset into ~/.dsh/.agent-presets, so new sessions can pick "梁神模式" from the preset picker. The first model request sees only the builtin Minimal preset's exact two tools — persistent bash plus str_replace_editor — only the one-line persona prompt section, no runtime contexts, and no injected instructions; after the anchor is established the wire switches to Code Mode (PTC) and the ordinary injections open. Built entirely on the official NPM SDK — no dsh source changes.

Why

DeepSeek V4 Pro conditions strongly on the API tool catalog visible in the FIRST request when choosing its execution trajectory. In the community eval (xiaobright/modeltest), Standard / PTC scored 91/92 while Minimal reached 99/96 — but Minimal keeps only two tools. This two-phase approach separates the first-trajectory choice from full later capability:

1. The first model request exposes only the builtin Minimal preset's exact two tools (persistent bash plus str_replace_editor), keeps only the deployment:persona prompt section, empties runtime contexts, and passes only the user's own messages;
2. After the session's first durable tool/call, promotion waits until the first reasoning block is minimal-like (contains we and no let me), with a four-step fallback; the wire then switches to Code Mode (PTC) — a single run_code tool backed by the full tool registry SDK — and every assembled prompt section plus the ordinary workspace-instruction, skill-catalog, and runtime-context injections return;
3. The phase derives from persisted session events, so resume / reload never lose state.

Measured on native Windows (DeepSeek V4 Pro, max, V4.1b task): 98 / 99, mean 98.5, zero let me traces in the second run — reproducible, not a lucky draw, and no tool capability sacrificed. Original experiment: xiaobright/dsh-anchored-standard.

Stabilization controls

The preset ships with extra safeguards on top of the reference mechanism, all configured in agent.cordis.yml under tool-bootstrap:

• anchorGate — after the first tool/call, the catalog stays two-tool until the first reasoning block classifies minimal-like, so a Let me first block does not immediately earn the full catalog;
• maxBootstrapSteps — fallback promotion after N steps when no anchored block appeared;
• promoteAfterFirstResponse — a tool-less first response promotes once it has responded; an anchor-gated session also releases when its first turn ends (turn/end), so the next user turn already sees the promoted catalog;
• promotedPresentation: code — after promotion the wire is Code Mode (PTC): one run_code tool with the full registry available through the generated SDK, switched at the step boundary so the current step's native calls are never interrupted;
• deferredSources + deferredGraceSteps — workspace instructions and the skill catalog wait one extra step after promotion, so the tool-catalog switch and the injection shock do not land in the same step.

Plan mode is supported: phase 1 filters the assembled prompt sections down to the one-line deployment:persona, and promotion restores all sections and appends the session's working directory to the persona, so the agent knows its workspace and the plan-mode plan:policy section takes effect for every step after promotion.

Install

# Option 1: family bundle (recommended)
dsh plugin --profile web add @linxin666/dsh-web-ui-all

# Option 2: standalone
dsh plugin --profile web add @linxin666/dsh-liangshen

# Pick ONE of the two: the bundle and the standalone @linxin666/dsh-liangshen
# both mount this preset. If you switch between them, remove the other first:
dsh plugin --profile web remove @linxin666/dsh-liangshen

Fully restart dsh web, open a NEW empty session, and pick "梁神模式" as the preset. The plugin syncs the presets into ~/.dsh/.agent-presets at startup (upgrades refresh them automatically on next restart).

Verify

Export the session JSONL and inspect request/header:

• The first header should carry only bash/str_replace_editor (the persistent shell plus the sandboxed editor);
• The first turn should contain only the user's own messages — no workspace-instruction baseline, no runtime snapshot, no skill-catalog message — and only the deployment:persona prompt section;
• After the first tool call, the next changed header should carry exactly run_code (PTC); the runtime snapshot and all prompt sections arrive with that step (including plan mode's plan:policy, and the persona now ends with the selected workspace path), and the workspace instructions and skill catalog arrive one step later;
• Phase-1 editor writes obey the host file sandbox policy — there is no bare local-filesystem bypass;
• Later requests keep run_code.

Trajectory drift can be measured without reading raw reasoning:

node tools/analyze-session.mjs ~/.dsh/sessions///session.jsonl

Behavior and limits

• A first model response that calls no tool promotes once it has responded; an anchor-gated session also releases when its first turn ends (turn/end). The release is decided during prompt assembly, so the new user turn already gets the promoted PTC catalog and its messages are not stripped;
• After the first tool call, promotion waits for the first minimal-like reasoning block or the maxBootstrapSteps fallback, whichever comes first;
• A tool call that fails still counts toward promotion as long as tool/call was persisted;
• Phase 1 keeps only the deployment:persona prompt section; promotion restores every assembled section and appends the session's working directory (Your working directory is .) to the persona, so the agent works in the selected workspace and plan mode's plan:policy is enforced after phase 1;
• Workspace instructions, the skill catalog, and the runtime snapshot stay out of phase 1; the snapshot returns with the catalog and the other two arrive one step later;
• Phase-1 file tools inherit the host file sandbox (no bare dsh-fs-local filesystem);
• The phase-1 persistent bash replaces the Standard ephemeral shell for the whole session (both tools register the name bash);
• The catalog changes exactly once, so a prefix-cache change happens between the first and second request;
• The preset carries the same trust level as shell access — review presets/liangshen/ before installing;
• The plugin makes no network requests and adds no telemetry;
• Do not switch presets mid-conversation;
• Requires DSH 0.1.0-rc.5+ (preset mechanism and the system-prompt/assemble hook).

License

Plugin body Apache-2.0 (zhu1090093659). presets/liangshen/agent.cordis.yml derives from the DeepSeek Harness builtin Minimal and Standard presets, and tool-bootstrap.mjs comes from xiaobright/dsh-anchored-standard — all MIT, with copyright and license notices kept in the preset's NOTICE.