dsh-sidebar-vscode

中文 · npm · GitHub

A dsh-better-sidebar sidebar tab for DeepSeek Harness (DSH) that embeds the VS Code web workbench, and turns editor selections / explorer files into atomic reference chips in the conversation composer — expanded by the host half into model context right after the citing message on submit.

Screenshot

editor selection                    explorer
  right-click / Ctrl+Alt+C          right-click file / folder
        │                                  │
        └──────────► atomic chip ◄─────────┘
                  @src/main.ts L10-L12   @src/main.ts   @src
        │                                  │
        ▼ on submit                        ▼
<text-selection path line …>    <file-selection path/> / <folder-selection path/>
  (carries the capture snapshot      (path only, no content)
   and freshness flags)

• Package: dsh-sidebar-vscode on npm
• Source: chendefine/dsh-sidebar-vscode on GitHub
• Version: 0.2.8
• License: MIT
• Platform: web (the DSH Web GUI)
• Tests: 467 passing (19 spec files)

Features

The tab

• Registers a VSCode tab (id dsh-sidebar-vscode:vscode) in the better-sidebar sidebar, embedding the code serve-web workbench in a same-origin iframe opened at the current session's workspace (<base>/?folder=<mapped path>); switching tabs never destroys the iframe, so the VS Code session survives.
• The toolbar shows the workspace path with reload / open-in-new-window actions; all chrome follows the DSH appearance (light / dark / system); copy is bilingual (zh/en).

Reference injection

• Selection references: select code inside the embedded VS Code, right-click "DSH: Send Selection to Session" (中文界面：「DSH: 发送选中代码到会话」) or press Ctrl/Cmd+Alt+C — the selection lands in the composer at the current caret as one atomic chip (@src/main.ts L10-L12; one backspace deletes it whole; a composer selection is replaced); multi-cursor selections produce one chip each in editor order. On submit the host half expands it at agent/pre-step into a standalone context message right after the citing one:

  <!-- User-captured VS Code selection (capture-time snapshot); re-read the
       file before editing. -->
  <text-selection path="src/main.ts" line="L10-L12" lang="typescript">
  const a = 1
  const b = 2
  const c = 3
  </text-selection>
  

• Explorer file/folder references: right-click files/folders in the explorer ("DSH: Send File/Folder to Session"; multi-select aware, the file vs. folder entry is picked by the right-clicked item) — each item lands at the composer's current caret as one atomic chip: @src/main.ts for a file, @src for a folder. Resource references carry no content: on submit they expand into content-less, guidance-free markers — the tag name itself expresses the file/folder kind, and the model reads the bytes only when it needs them:

  <file-selection path="src/main.ts"/>
  <folder-selection path="src"/>
  

• Reference management: a rail above the composer groups every chip by reference (truncated / folder badges, occurrence counts); its × removes all chips of that reference through one draft write. A chip's serialized form is a self-contained canonical mention — the draft text is the single store of truth; delete it all and nothing is injected, with no leftover state.

• Fallbacks & recovery: with a cross-origin serverUrl the same-origin bridge is unavailable — the envelope lands on the real clipboard and pasting it into the composer still recognizes it as chips, landing them at the paste caret; when the input machine refuses a chip insert (mid-submit transient) the mention degrades to plain text (the host parses it identically, only the chip affordance is lost); copying a rendered reference and pasting it back — even as whitespace-mangled sigil text (@ [ label ]( dsh-vscode: … )) or a truncation that lost the closing paren — is re-validated canonically and rebuilt as atomic chips at the caret with the surrounding prose kept verbatim (fail-soft, never throws).

• Default tab: an optional switch makes brand-new sessions open the VSCode tab by default (replacing better-sidebar's hardcoded seeded Files tab); used sessions keep their own layouts, and turning it off only affects future sessions.

• Chat file-click takeover (gated by the same switch; research options II + III): clicking produced-file chips (the per-turn changed-files row), tool-row path links, or prose file mentions in the conversation no longer opens better-sidebar's built-in Files tab — it focuses this VSCode tab (the panel auto-expands) and opens the file inside the embedded VS Code, with no workbench reload. File-type blocklist (openBlocklist): a file whose extension is on the list (by default pdf/docx/xlsx/pptx/png/jpeg/jpg; editable in the gear settings) is NOT taken over into VS Code — it opens in better-sidebar's built-in Files tab instead (its file viewers are the sidebar's own surface for images, PDFs, and Office documents; the type is still routed through the sidebar takeover, never the Host opener). Option III's wrapper reroutes that path into the Files tab and resolves the stock success receipt (the Host opener only takes it when the Files tab type is disabled in the side card settings); option II's chips follow the same reroute, degrading to the render site's stock openFile when it refuses; non-listed paths behave exactly as before, and settings are read per click. Two takeover seams: option II — register the conversation.chat.turnTail slot at priority -2 (before better-sidebar's own -1 entry), claim the produced-files row with the same derivation (reading the engine Turn data's deliverables record first, the node replica as fallback; the matched value also carries the owner's openFile for the blocklist fallback), and render its chips as a visual twin whose clicks reroute here; option III — wrap the runtime's chat file-open funnel, whichever era provides it: the gateway-era remote.session.openWorkspacePath Host Remote (ui-chat's injected openFile — the tool-row path links and prose mentions — is its only production caller; the namespace method is a getter-only own property, so the wrapper redefines it with a getter that re-reads the stock method per access, installed through a nested optional inject that parks until the remote.session service exists), or the legacy workspaces.openPath client service (ui-conversation's apply.ts) — exactly one of the two ever installs. Interop with dsh-better-sidebar ≥ 0.18.0: the peer now shadows the SAME gateway-era method with a value-property wrapper of its own (captured original closure, installed before this plugin by batch module order), so the redefinition chains onto BOTH shapes — the stock getter mount and the peer's value shadow — with the later install sitting outermost and seeing each call first (this plugin loads after the peer, so the takeover claims the open; the peer's closure stays as the decline-time fallback). A one-shot re-assert a few seconds after install repairs the remaining window where a peer disable/enable cycle re-runs its shadow above ours. Option III also repairs a headless-container hole: better-sidebar declines its own takeover whenever its built-in Files tab is disabled, letting opens fall through to the Host OS opener (spawn xdg-open ENOENT); this wrapper keeps them landing in the VSCode tab regardless of that setting. After the click: the tab's meta carries an openRequest → this plugin's host half writes /tmp/dsh-sidebar-vscode/<slug(workspace)>/cmd.json → the extension (≥ 0.1.2) polls every 500ms and consumes it via showTextDocument; a cap.json liveness marker plus a capability probe gate the channel, and any miss degrades to a one-shot URL-payload workbench reload. Boot-tagged delivery (extension ≥ 0.1.3): serve-web keeps a previous extension host (and its 500ms spool poll) alive for a while after the tab's iframe went away, so the click that re-creates a closed tab raced that lingering host — it consumed the command, opened into a dying window, and the fresh host's ledger reconcile closed the file as a ghost (the open silently lost). The client now defers the send until this boot's nonce is parked and tags the command with it (cmd.json {boot}); only the host that activated with the same nonce consumes a tagged command. Switch off = the feature is entirely disabled (chat behavior unchanged).

• Settings "open configuration file" takeover (option IV, same switch): the settings page's「打开配置文件」button stock-behavior hands $DSH_HOME/settings.yaml to the Host OS opener — dead on headless containers (xdg-open missing); on the current runtime the click drives the remote.settings.openSettingsDocument Host Remote (SettingsDocumentStore.open is its only production caller; the wrapper redefines the namespace method's getter-only own property, installed through a nested optional inject that parks until the remote.settings service exists), and on pre-gateway runtimes the legacy /api/settings.openDocument member — exactly one of the two ever intercepts. With the switch on, this plugin instead resolves the document path through its own fenced node-half route (POST /sidebar-vscode/api/settings.document → prepareDocument()), then reroutes it through the very same openRequest channel as the chat clicks — the file opens inside the embedded VS Code (the absolute path needs no pathMap rule since mapPathForOpen passes unmatched paths through). A landed reroute also closes the settings dialog itself: its open state is component-local (no service exposes a close), so the close rides the panel's own document-level Escape listener — mounted exactly while the dialog is open — via one synthetic Escape keydown, leaving the workbench in view. Fail-soft: an absent settings provider, an un-reloaded host half, or any transport error falls back to the stock open (dialog stays open), so the button never breaks.

Installation

Prerequisites

• A DSH host (Web GUI) with dsh-better-sidebar ≥ 0.12 installed (an optional peer: without it tab registration silently skips while the paste fallbacks keep working; the dev baseline is 0.16);
• A code serve-web instance reachable from the browser — pick a wiring shape:
  1. Built-in proxy (the default; the choice for gateway-less deployments: Windows, LAN dsh web) — an EMPTY serverUrl defaults to http://127.0.0.1:8000 (a bare local code serve-web — the CLI's own defaults), or paste any full address it prints (base path and ?tkn= token included). The address is pushed via /sidebar-vscode/api/proxy.config and mounted as the same-origin /sidebar/vscode/ on the very port dsh web listens on (transparent HTTP forwarding, WebSocket upgrade pipe, token auto-append) — zero nginx, zero start flags:

     code serve-web            # zero-config: port 8000, root path
     

     Routing self-corrects to the serverBasePath baked in the index HTML, so --server-base-path is optional (non-mount bases get an identity mirror; root upstreams a <quality>-<commit> shim). When the host cannot reach the address yet, the tab falls back to the direct iframe with a notice and switches to the mount automatically once the proxy serves. Tip: run serve-web with --server-base-path /sidebar/vscode to gather every request under the single mount prefix (identity mount, no mirror/shim). Pre-configure without settings via DSH_SIDEBAR_VSCODE_UPSTREAM (full URLs; default http://127.0.0.1:8000; off disables). If /sidebar/vscode is owned by another plugin the feature backs off with a warning;
  2. Gateway same-origin subpath (the reference topology) — serve-web runs inside the dsh-runtime container behind the gateway's /vscode reverse proxy (see deployment topology); same-host deployments may leave serverUrl empty (the built-in proxy takes over). Only when serve-web is NOT reachable from the DSH host (a split gateway) configure it explicitly (serverUrl = /vscode, or the env var pointing at the real address);
  3. Cross-origin direct URL (automatic fallback shape) — appears only when the host half cannot proxy: the clipboard signal bridge is off (paste fallback keeps working), selections degrade to copy → paste;
• The companion VS Code extension dsh.selection-reference installed into that serve-web instance (it provides the context-menu commands and the keybinding; the chat file-open channel needs ≥ 0.1.2 — see below).

The plugin itself

Channel A — the bundle channel (standard, recommended for clean profiles)

The package ships a dsh.bundle.patch (cordis.patch.yml: one insert row mounting the host-half entry). From the npm registry (prebuilt — no build permission needed):

dsh plugin --profile web add dsh-sidebar-vscode

From the GitHub repository (source — pnpm runs the prepare build; the repo also carries the committed lib/ artifacts as a fallback):

dsh plugin --profile web add github:chendefine/dsh-sidebar-vscode

Or through the DSH plugin marketplace (设置 → DSH插件市场) — tag the repo with the dsh-plugin topic and it is indexed automatically.

After a bundle plugin is added to the profile layer stack, restart dsh web for it to load; uninstall with dsh plugin --profile web remove dsh-sidebar-vscode and restart again.

Channel B — link + a manual mount row (the hot channel of this deployment, no restart)

# 1. Install the plugin as a link: dependency of the web profile
#    (repo checkout path, e.g. /opt/dsh/plugins/dsh-sidebar-vscode; this
#     deployment's profile dir: /data/dsh-home/profiles/web)
pnpm -C <profile-dir> add link:<repo-checkout>

# 2. Append the mount row to the profile's own cordis.patch.yml
#    - insert:
#        - id: dsh-sidebar-vscode
#          name: dsh-sidebar-vscode

watchUserPatches hot-mounts the node half, the client boot graph recomputes live, and /plugins/dsh-sidebar-vscode/client.js is served immediately — a hard refresh (Cmd/Ctrl+Shift+R) reveals the new tab.

⚠️ The two channels are mutually exclusive: the package's bundle row and the profile's manual row share the entry id dsh-sidebar-vscode — having both fails at startup with a duplicate entry. Remove the other channel's row (and the link dependency) before switching. The in-package double-mount guard (disabled: !!js …) is left commented out by default.

Note: client-half changes apply on a hard refresh; host-half changes (src/index.ts / src/mention.ts) need a dsh web restart (or a hot re-mount of the entry through the profile channel) before the new bundle loads.

The VS Code extension

The send commands and the chat file-click polling channel come from the dsh.selection-reference extension (sources in extension/), which must be installed into the serve-web instance. The file-open channel needs ≥ 0.1.2 (0.1.1 replays consumed commands on every workbench reboot — see the replay guards below; its capability marker fails the version probe, so open clicks safely degrade to the URL-payload reload):

scripts/install-extension.sh                  # package VSIX → install → register manifest → restart → health-check
scripts/install-extension.sh --skip-build     # reuse the built VSIX
scripts/install-extension.sh --vsix <path>    # use a given VSIX

The local code binary is the standalone CLI (no desktop install), so code --install-extension does not work; the script installs via four steps: package with vsce → drop files → register the extensions.json manifest → restart serve-web with its exact previous argv. Step-by-step details and troubleshooting: scripts/install-extension.md (中文).

Replay guards (≥ 0.1.2) — closing the sidebar's VSCode tab tears the workbench iframe out of the DOM and reopening it boots a fresh extension host; a spool command that survives consumption re-opens its file on every such reboot (the "closed file reopens on next VS Code start" bug). Three independent guards: the extension deletes cmd.json the moment it acts on it (or skips it as garbage/TTL-expired — commands older than 10 minutes are never opened), a consumed-nonce watermark persists in last.json for delete-failed corners, and the versioned cap.json marker ({v:2,at}) makes the client's capability probe refuse the replaying 0.1.1 outright.

Clean embedded boots: ledger + reconcile + hidden reveal (≥ 0.1.2) — the iframe teardown also skips VS Code's unload lifecycle, so its editor-state restore can replay a file the user closed seconds before closing the tab (VS Code flushes workspace editor state only periodically). The model restores exactly what was open at teardown and shows nothing in between:

• Editor ledger (editors.json) — the extension records the window's open file-tabs (order + active editor) into the spool synchronously on every tab change, so the teardown race cannot lose it; whatever is on disk at the next activation is the previous session's final state.
• Boot reconcile — at activation the extension waits for VS Code's own restore to settle, then makes the window match the ledger: restored tabs the ledger does not list (files closed before the teardown) are closed — dirty tabs survive, data wins —, ledger files the restore lost are reopened, and the active editor is restored. A boot with no ledger (first ever boot in a workspace, or a degraded URL-payload open) keeps VS Code's own behavior untouched.
• Hidden reveal (boot.begin / boot.status) — before mounting the iframe the tab parks a boot nonce (bootreq.json); the extension echoes it in its post-reconcile boot.json receipt, and the client keeps the frame at opacity 0 behind the loading overlay until the echo lands (or a bounded timeout gives up). The first visible frame already shows the reconciled editor area — nothing ever visibly opens just to be closed again. Fail-soft everywhere: on an older host half (boot routes not reloaded yet) the gate falls back to a DOM-quiet watcher (same-origin peek at the workbench's editor tab strip — reveal when it holds still), and a cross-origin direct iframe boots ungated with stock behavior.
• Ledger ownership fence + boot rotation (extension ≥ 0.1.3) — serve-web also keeps extension hosts alive for a while after their renderer went away, and such a lingering host keeps its armed ledger handlers: it writes its own (invisible) window's tab set into the shared editors.json, and the reconcile's reopen loop re-opens ledger files into that window, whose tab events then re-write the ledger again — poisoning it with files the visible workbench never showed, which every later boot faithfully restores (closed files coming "back"). The ledger is now owned by the boot: every ledger write, the reconcile itself, and the ghost passes re-check that the parked boot nonce is still the one the host activated with. The client rotates that nonce whenever the frame reloads in place (the pane DOM is detached on a panel collapse or a workspace switch and re-inserted later, which the browser treats as a reload — a fresh renderer whose host would otherwise activate against the previous boot's nonce) and as the tab unmounts, retiring every host that still holds the old nonce.
• Late-ghost passes (extension ≥ 0.1.3) — VS Code's own restore can still be landing tabs after the reconcile's settle budget ran out (a slow first boot of a heavy workspace), and those late arrivals are exactly the closed-file ghosts nobody else will close. A few close-only diff passes run after the arming, spaced across the restore tail: each closes background tabs the boot ledger does not list, sparing dirty tabs and the ACTIVE editor (seconds after a remount the only deliberate opens are user ones, and a user open becomes the active editor). No pass ever opens anything.

Usage

Opening the tab

Pick VSCode from the sidebar「+」menu; or turn on the openAsDefault setting so brand-new sessions open it by default (a collapsed panel stays collapsed — the tab is simply what the next expansion shows). The toolbar shows the workspace path;「⧉ open in new window」pops a standalone one.

Sending a selection

1. Select code in the embedded editor (multi-cursor = one chip each);
2. Right-click → "DSH: Send Selection to Session", or press Ctrl/Cmd+Alt+C;
3. The atomic chip @src/main.ts L10-L12 appears in the composer — success is silent (the chip is the feedback); only degradations/failures flash an amber notice in the toolbar;
4. Type and submit as usual. The chip is rewritten to the readable @path L10-L12, and the <text-selection> context is injected right after the message.

Selection reference details:

• Dedup: within one step by (path, start, end) — sending the same selection twice injects one context; the same range with different content (file changed) keeps the newest capture;
• Freshness: at submit the disk range is re-read confined to the session cwd and hash-compared — a mismatch marks stale="true"; a truncated snapshot instead verifies its kept head/tail halves (truncation alone never marks stale); an unsaved buffer marks dirty="true"; the snapshot text is always injected (no filesystem dependency), and the leading comment tells the model to re-read before editing;
• Truncation: beyond maxLines (default 200) / maxBytes (default 20000, guards minified single-line files) the head and tail halves are kept with the middle omitted inline as ... (N lines omitted, L51-L150) ..., the tag carries truncated="true", and the real line range is preserved;
• The context message source is { kind: 'vscode-mention', form: 'notice', version: 1, path, startLine, endLine, language?, contentHash, bytes, truncated, dirty, stale }.

Sending files / folders

Select files/folders in the explorer (multi- and mixed-select work), right-click → Send File/Folder to Session (the entry sits near "Copy Path"). One chip per item: @src/main.ts (file icon) or @src (folder icon); the kind comes from the extension's workspace.fs.stat (symlinks classify by target). On submit each expands to <file-selection path/> / <folder-selection path/> with source { kind: 'vscode-resource', form: 'notice', version: 1, path, type }. Resource references do no freshness check and ignore the truncation caps; within one step they dedupe by (path, kind), and a selection reference and a resource reference on the same path stay independent.

Managing references

• The rail above the composer lists every VS Code reference (truncated … badge, folder icon, ×N count); a tag's × removes all chips of that reference at once;
• One backspace deletes a whole chip; once no mention of a reference remains in the draft, submit injects nothing for it;
• Copying a (rendered) chip and pasting it back rebuilds atomic chips.

Settings

Settings live under "side card → VSCode → 功能设置" (the tab card's gear popup); the five panel rows render through this plugin's own settings UI and persist in better-sidebar's pluginSettings['dsh-sidebar-vscode:vscode'] — not in cordis.patch.yml (pathMap below is read from the same blob but deliberately has no panel row):

Key	Default	Description
openAsDefault	false	Brand-new sessions open this tab by default (replacing the seeded Files tab); used sessions keep their layouts. The switch also gates the chat file-click takeover and the settings「打开配置文件」takeover
openBlocklist	(unset = pdf, docx, xlsx, pptx, png, jpeg, jpg)	"File types never opened in VS Code": an array of extensions rendered as a tag editor (tags carry a × remove button; a free-form input adds entries on Enter/comma, with a dropdown suggesting common binary types). A chat click on a matching file opens it in better-sidebar's built-in Files tab instead (its file viewers render images, PDFs, and Office documents); only when that tab type is disabled in the side card settings does the open fall back to the system's default opener (a matching produced chip degrades to the render site's stock openFile on the same refusal). Unset = the seven defaults; an emptied list stores [], letting VS Code open everything (distinct meanings). Matching is case-insensitive, by "base name ends with .<ext>" (a.notpdf does not match pdf; entries may contain inner dots, e.g. tar.gz; extension-less files never match); settings are read per click, so edits apply immediately. The settings「打开配置文件」takeover is deliberately not affected
serverUrl	(empty = http://127.0.0.1:8000)	The full address code serve-web prints (base path and ?tkn= token included); empty = the default http://127.0.0.1:8000 (a bare local server). Whenever the proxy is reachable the workbench opens at the same-origin /sidebar/vscode/; a host-unreachable full URL falls back to a direct connection (same-origin bridge degrades); an explicit relative subpath (e.g. /vscode) is used with gateway semantics when the proxy is off
pathMap	(empty = no mapping)	Config-file only — no settings-panel row (rare, split-container deployments only). DSH prefix → VS Code container prefix as src=dst pairs joined by ;; longest source prefix wins; a path already under a destination passes through unchanged. When empty, no mapping is applied at all — the session cwd and clicked files open at their raw absolute paths (the same-container default). Rules are prefix rewriters, not a whitelist: absolute paths no rule matches pass through as-is (VS Code itself reports a genuinely missing file)
maxLines	200 (range 1–2000)	Max rendered code lines per reference; overflow keeps head+tail halves and marks the omitted middle inline
maxBytes	20000 (range 1000–200000)	UTF-8 byte cap per reference (guards minified single-line files)

(Selection injection itself is always on — no switch.) Number rows enforce their range as you type (red field + inline hint; out-of-range edits snap to the nearest bound on commit); text rows stack description-over-input; the openBlocklist row is tags + an inline input (junk flags a red hint, duplicate adds are silent no-ops).

Troubleshooting

Symptom	Fix
The tab stays blank / the loading hint never clears	Check serverUrl reachability; diagnose via "open in new window"; with a cross-origin URL the bridge is off by design (paste fallback still works). On the built-in proxy, confirm serve-web answers at the configured upstream (default http://127.0.0.1:8000; any base path works)
A file matching openBlocklist opens in the built-in Files tab (or errors on click)	A blocklist hit reroutes the open into better-sidebar's built-in Files tab (its viewers render the type); only when that tab type is disabled in the side card settings does the open fall back to the Host OS opener, which headless containers may not have. Remove the extension from the list if you want VS Code to open that type
"Workspace path is not absolute…" notice	Fires only when the session cwd is not an absolute path (the workbench then opened its default view); healthy deployments never trigger it — no mapping needed
No DSH command in the context menu / palette	Extension not installed, serve-web not restarted (the manifest is scanned at startup only), or the workspace is untrusted (restricted mode) — see the FAQ in scripts/install-extension.md
No chip after sending; a code snippet appears on the clipboard	Landing failed and the readable fallback reached the clipboard (no composer / cross-origin); paste it into the composer to recover chips
"Injected as a text reference…" notice	The composer was mid-submit so the chip degraded to a plain-text mention — submitting works the same
Caret vanishes from the composer ~1s after creating a session, or focus jumps into the sidebar's open file after switching back from another workspace's session (older-version symptoms)	The booted workbench focuses itself (Getting Started page on render, a restored editor on workspace restore): a boot behind a collapsed panel stole the caret invisibly, and the re-insertion reload a workspace switch-back triggers landed focus in the restored file right after the composer was autofocused. Current versions guard it generically — the first load is deferred until the tab has been seen, and every boot of the frame gets a focus fence that bounces uninvited grabs back unless the user actually clicks into the workbench (see "Focus guards" below); the first workbench load on expansion arrives slightly later by design

Architecture

The two halves

A DSH plugin has a host (node) half and a browser half; this plugin's split:

┌─ host half (node) ─────────────────────────────────────────────┐
│ src/index.ts    agent/created → mount agent/pre-step per agent │
│ src/mention.ts  the boundary core: parse/rewrite, dedup,       │
│                 freshness, context injection                   │
└────────────────────────────────────────────────────────────────┘
┌─ browser half (web) ───────────────────────────────────────────┐
│ src/client/index.tsx        register tab + dock + @ source     │
│ src/client/VscodeView.tsx   cwd → path mapping → iframe+bridge │
│ src/client/references.ts    payload→chips, insert, rail, paste │
│ src/client/composer.tsx     the dock: reference rail + pastes  │
│ … (full listing under Repository layout below)                 │
└────────────────────────────────────────────────────────────────┘

• The host half owns the model-facing seam: per live agent it listens at agent/pre-step, parses canonical mentions in the claimed user messages (markdown and bare URIs, both schemes, strict canonical validation), rewrites them to readable labels (freezeMessage keeps message ids), dedupes by reference identity, and injects each context (createUserMessage) right after the first message citing it. The filesystem is consulted only for freshness marks — snapshot content rides inside the mention, so injection never depends on disk state;
• The browser half owns all UI: the tab, chips, the rail, the settings panel, dictionaries; without better-sidebar, tab registration silently skips.

The four-stage chain

Both reference kinds share one chain:

1. VS Code extension (extension/): the selection command packs { path, relative?, language?, dirty?, spans[] }; the resource commands workspace.fs.stat each URI and pack { kind: 'resource', resources: [{ path, relative?, type }] } (no content), handed to vscode.env.clipboard.writeText inside the envelope @@DSH_REF::<base64url(json)>::\n<readable fallback>;
2. Clipboard signal bridge (src/client/clipboardBridge.ts): same-origin iframe privilege — the parent page patches navigator.clipboard.writeText on the workbench window, intercepting the extension host's clipboard chain (ext host → MainThreadClipboard → BrowserClipboardService → the late-bound navigator.clipboard.writeText); a successful landing never touches the real clipboard, a failed one writes the readable fallback for manual paste; on cross-origin URLs the bridge no-ops;
3. Composer chips (src/client/references.ts + composer.tsx): the payload is reverse-mapped through pathMap back into DSH space (relativized under cwd), truncated (head+tail halves), hashed via crypto.subtle into the sha-256 prefix, and formatted as the canonical mention, then landed as an atomic occurrence chip through the conversation.input service's insertReference — at the composer's current caret: the addressed session's live editor selection via the input resolver's keyboard face (caretSpan() — the Lexical-era composer's own projection), falling back to the displayed composer's DOM selection mapped through the detect projection (composerDom.ts — chips count as one atomic char), whenever the surface belongs to the addressed session (a selected range is replaced, a batch splices in order); when no caret is addressable (session mismatch, no live composer) the landing keeps the historical end-of-draft zero-width span CAS. Spans are detect-projection offsets on Lexical hosts (DSH ≥ 0.1.2-alpha.2, where the draft is the clipboard projection and each chip expands to its full clipboardText there but to a single  in span coordinates) and draft offsets on the older textarea-era machine — one structural probe (editor on the input facade) picks the plane; the plain-text degradation rides the scoped 'slash/input-insert-text' event so every other chip in the draft survives the landing; this plugin registers the @ trigger source vscode-reference (candidates always empty — it exists purely so submit serialization routes through its codec); the conversation.input.dock component renders the rail (its close button removes one reference's chips through the scoped 'slash/input-consume-token' event — chip-preserving on Lexical hosts, where a whole-draft setDraft write would flatten every remaining chip to raw mention text) and intercepts pastes at the document capture phase, addressing both the contenteditable composer and the old textarea (envelopes go to the injection lander at the paste caret; recovered mention copies land as chips — preventDefault alone does not stop the composer's own paste handling, so stopPropagation rides along);
4. Host boundary (src/mention.ts): after the strict parse, one fail-soft recovery scan catches whitespace-mangled copies; closing-tag collisions are salted with the content hash so the body cannot forge a terminator.

The mention codec

• Canonical form: @[<escaped label>](dsh-vscode:<base64url(json)>) (selections) / dsh-vscode-res: (resources); the payload is self-contained (path / lines / snapshot / hash / flags), so the draft text is the single store; the two scheme prefixes are mutually exclusive — neither can over-match the other;
• Decoding must re-encode to the identical URI (the canonical discipline shared with dsh-session: references): an explicit markdown mention with a malformed URI fails loudly; bare text counts as a reference only when a base64url shape follows the scheme, and it must still pass canonical validation;
• The recovery layer (scanRecoveredMentions) recognizes whitespace-drifted copies and truncations that lost the closing paren; projections are rebuilt only from payloads that fully validate — a copied label is never trusted (it is display residue);
• The shared pure module src/mentionCodec.ts has no Node builtins and no @deepseek-ai/* value imports, so both the host and browser bundles reuse it verbatim (it passes the client purity gate).

Truncation & freshness

• At capture (truncateSnapshot): LF-normalize → line cap (whole head/tail half-lines) → byte cap (head shrunk from its end, tail from its start, multi-byte safe); the payload records headLen / omitLines / omitBytes and the host renders the inline omission marker, which the counters exclude;
• At submit (freshnessOf): the disk range is re-read confined to the session cwd (escapes / files over 8 MiB / read failures all yield unknown), hash-compared into fresh / stale; a truncated snapshot verifies that the disk range starts with the kept head, ends with the kept tail, and holds at least one char between them (edits inside the omitted middle are undetectable; truncation alone never marks stale).

The default-tab swap

better-sidebar hardcodes the fresh-session seed (upstream makeDefaultState('editor-home') — a path-less Files editor tab) — there is no "default tab" preference. This plugin implements the companion approach the upstream service suggests (src/client/defaultTab.ts, no upstream changes): it watches the sidebar store, and while the switch is on and the active session still carries its pristine seed (single pane, at most the one path-less Files tab, no minted counters, no expansions, no bottom tabs, no floats), it openTab({ type })s the VSCode tab and closeTabs the seed — a replacement, not an addition; a type-only open never expands a collapsed panel. The swap runs once per session (a localStorage marker — without it, closing the tab would let the next store notification re-open it forever); a disabled tab type or a refused open never costs the sidebar its seed.

Focus guards (the workbench must earn focus)

When the VS Code workbench boots it programmatically focuses its own content — the Getting Started page calls focus() on itself when it renders, and a restored workspace focuses the editor it restored — roughly 0.5–4s after the iframe loads, with zero user interaction. Whenever that boot lands at a moment the user did not aim at the workbench, the grab rips the caret out from under them: a new conversation's default tab behind a collapsed panel loses the caret invisibly (two blinks), and switching back to a session in another workspace re-boots the workbench (the pane survives at the React level, but its iframe is torn out of the document on the way out and re-inserted on the way back, which the browser reloads) and lands focus in the restored file right after the composer was autofocused. src/client/VscodeView.tsx guards with two mechanisms:

• Deferred first load: the iframe is held back until this tab has been visible at least once (active tab AND open panel). The default-tab swap usually lands with the panel collapsed — a hidden boot buys nothing the user can see and only invites the grab; deferring it moves any boot-time focus event to the first real expansion, where the user is looking AT the workbench. Once loaded, the frame is never keyed away again (the keep-alive contract stands). visible === undefined (a better-sidebar peer too old to pass the flag) fails OPEN — load as before, never defer on a guess.
• Focus fence (src/client/focusGuard.ts): a focus entry into the frame is handed straight back to the element that last held focus outside it — budgeted per sliding window (default 5 restores per 10s) so a re-grabbing workbench cannot livelock the focus chain — in exactly two armed situations:
  • Hidden (visible === false, explicit only): the frame cannot receive user clicks, so every entry is a steal. A collapsed panel or a non-current tab cannot legitimize a grab.
  • Boot: for a window (default 6s) after EVERY load of the frame, because every load is a workbench boot and every boot self-focuses — page reloads and the workspace switch-back re-insertion included. Entries bounce UNLESS the user gestured inside the frame (same-origin pointerdown/keydown trackers, re-attached on every load — clicking into a freshly booted workbench works immediately) or a parent Tab keypress handed focus over. The one sanctioned boot is the deferred first load above: the user revealed the tab to release it, so its focus grab is welcome. A cross-origin frame (the direct-iframe fallback) cannot report in-frame gestures, so the boot fence stands down rather than bounce real clicks.
  • Detection rides focusout, not focusin (a crossing INTO the iframe fires focusout in the parent but never focusin — the focusin lands inside the frame's own document).

Deployment topology (why the defaults)

The VS Code server (code serve-web) runs inside the dsh-runtime container:

code serve-web --host 0.0.0.0 --port 8000 --server-base-path /vscode \
  --server-data-dir /data/workspace/.vscode --without-connection-token \
  --default-folder /data/workspace

nginx: location /vscode/ → 127.0.0.1:8000 (with WebSocket upgrade)
      the gateway merely proxies user → instance; /vscode is no special
      case, so adding/removing users needs zero gateway sync

Deployments without a gateway tier (Windows, a bare LAN dsh web) need no self-managed nginx either: the plugin's host half registers the equivalent reverse proxy on the port dsh web itself listens on (src/vscodeProxy.ts, mounted at /sidebar/vscode). HTTP prefix routes forward transparently and keep the browser's Host (serve-web bakes remoteAuthority pointing at the DSH port, so every workbench URL stays same-origin); the WebSocket upgrade registers at the exact path <upstream-base-path>/<quality>-<commit> — the only path the browser socket factory ever connects to (serve-web's handleUpgrade ignores the path). The routing base follows the serverBasePath baked in the index HTML, not the probe URL: non-mount bases get an identity mirror at their own path, root upstreams a discovered <quality>-<commit> shim. The index probe follows up to three redirects and adopts the final origin, so an upstream behind a redirecting reverse proxy (e.g. an enforced http→https hop) still discovers — and forwards — correctly. The upstream comes from a full-URL serverUrl (pushed via proxy.config) or DSH_SIDEBAR_VSCODE_UPSTREAM (default http://127.0.0.1:8000, off to disable).

The DSH session and the embedded workbench see the same filesystem under the same paths, so pathMap defaults to empty = no mapping: the session cwd and chat-clicked files are handed to the workbench at their raw absolute paths, untouched (the previous default was the identity pair /data/workspace=/data/workspace;/opt=/opt, which covered only those two roots and flagged everything else as unmappable). The rules are prefix rewriters, not a whitelist: even with rules configured, unmatched paths pass through unchanged (existence is the open channel's call), and no blocking notice ever appears. Move the workbench to another container/mount and configure real prefix rewrites via pathMap (in the settings document — it has no panel row).

Repository layout

src/index.ts                  # host-half entry: agent/created → pre-step boundary + fenced /sidebar-vscode/api routes (inject: agents, webServer, webRuntime)
src/vscodeProxy.ts            # host half: same-origin /sidebar/vscode reverse proxy (HTTP + WS pipe + path/token rewrite + configure channel + trust fence) (41 tests)
src/mention.ts                # host-half core: parse/rewrite/dedup/freshness/<text-selection> etc. (38 tests)
src/mentionCodec.ts           # shared pure logic: canonical URI codecs (2 schemes)/truncation/hashing (42 tests)
src/openChannel.ts            # host half: /tmp command-channel spool the workbench extension polls (slug spec, capability freshness, atomic writes) (11 tests)
src/trust-fence.ts            # host half: browser-trust fence for this plugin's routes (loopback/trustedHosts + same-origin markers)
src/client/index.tsx          # browser-half entry: tab + dock + @ source + dicts (ctx.effect, HMR-safe)
src/client/VscodeView.tsx     # tab component: cwd → path mapping → iframe + toolbar/notices + bridge + focus guards
src/client/focusGuard.ts     # hidden-frame focus fence: sliding-window restore budget
src/client/clipboardBridge.ts # same-origin iframe navigator.clipboard.writeText signal patch (10 tests; no-ops on the cross-origin SecurityError throw)
src/client/composer.tsx       # dock component: reference rail (self-adopted styles) + paste fallbacks
src/client/composerDom.ts     # detect-projection walk over the Lexical composer DOM (DOM selection ⇄ detect offsets) (11 tests)
src/client/references.ts      # payload→chips (selection/resources)/insert at the caret/rail projection/paste recovery (69 tests)
src/client/selection.ts       # clipboard envelope codecs (selection + resource payloads) (16 tests)
src/client/paths.ts           # pathMap parse/map/reverse-map, URL building (34 tests)
src/client/settings.ts        # pluginSettings reads + capture-cap contract (defaults/bounds/commit) (14 tests)
src/client/settingsRows.tsx   # settings panel: switch row + blocklist tag row + stacked text rows + cap rows (self-adopted styles)
src/client/settingsTakeover.ts # settings「open configuration file」takeover: wraps settings.openDocument + dialog close behind the same switch (17 tests)
src/client/openIntercept.ts   # chat-open takeover plumbing: reroute driver + openRequest vehicle + the openPath/openWorkspacePath wrappers (48 tests)
src/client/openBlocklist.ts   # "never open in VS Code" extension list: defaults / normalization / base-name suffix matching (24 tests)
src/client/openChannelApi.ts  # client half of the open channel: fenced /sidebar-vscode/api probes and commands (11 tests)
src/client/defaultTab.ts      # "open VSCode by default": pristine-seed detection + swap rails + watcher (22 tests)
src/client/i18n.ts            # locale service wiring + t()
src/client/locales.ts         # zh/en dictionaries
src/client/icons.tsx          # VS Code mark + chip file/folder/close icons (currentColor SVG)
extension/                    # the VS Code extension dsh.selection-reference (commands + menus + keybinding + nls + the file-open polling channel)
 ├ extension.js / harness.js / package.json / package.nls*.json / .vscodeignore / vsix/*.vsix
scripts/install-extension.sh  # one-command extension install (vsce package → files → manifest → restart → health)
scripts/install-extension.md  # step-by-step install doc + troubleshooting (Chinese)
README.md / README.zh-CN.md   # this doc (English) / the Chinese doc
screenshot.png                # product usage screenshot (see [Screenshot](#screenshot))
tests/*.spec.ts               # vitest specs — 380 tests / 15 files (per-file counts noted above)
cordis.patch.yml              # the bundle channel's host-half insert row (mount declaration)
tsdown.config.ts              # dual-bundle build (host ESM + client ModuleLoader format + purity gate)
vitest.config.ts              # test-time dsh-llm alias (harness checkout preferred, installed package fallback)
lib/                          # build outputs (committed: the link: deployment serves lib/client.js directly)
.github/workflows/ci.yml      # CI: typecheck / test / build / package verification on Node 22 & 24

Build outputs: the host half is a plain ESM bundle (@deepseek-ai/dsh-llm stays external, resolved by the DSH host loader); the browser half is a window.__ModuleLoader__.load({ id, factory }) registration bundle (the official external client-plugin delivery format) with React / cordis external and a purity gate that rejects Node builtins and @deepseek-ai/* value imports.

Development

Build & test

git clone https://github.com/chendefine/dsh-sidebar-vscode && cd dsh-sidebar-vscode
pnpm build        # tsc declarations + tsdown dual bundle → lib/
pnpm typecheck    # tsc --noEmit
pnpm test         # vitest run (380 tests)

Rebuild, then hard-refresh the browser (the link: dependency plus content-rev query params bust caches); host-half changes need a dsh web restart.

Environment notes

• pnpm ≥ 11: pnpm-specific settings are read only from pnpm-workspace.yaml (same-named .npmrc keys are silently ignored). This repo pins autoInstallPeers: false (internal @deepseek-ai/* packages are not on the public registry) and verifyDepsBeforeRun: false (node_modules + lockfile are a frozen baseline; skip the pre-run check) there, plus allowBuilds.node-pty: false (types-only dependency; its native build never runs);
• Type & runtime mapping: the @deepseek-ai/* build-time packages (dsh-llm, dsh-agent, and dsh-llm's runtime peers) are devDependencies resolved from the npm registry, so plain clones and CI work out of the box; tsconfig paths and the vitest alias prefer a sibling harness checkout (/app/dsh) when one exists — its built artifacts are fresher than the published rc's — and fall back to the installed packages otherwise;
• CI: GitHub Actions (.github/workflows/ci.yml) runs typecheck / test / build / package-content verification on Node 22 and 24 — the matrix mirrors DSH's own support range (^22.19.0 || >=24.0.0, which the published engines field matches);
• devDependencies baseline: dsh-better-sidebar@^0.16 and the @deepseek-ai/* devDependencies exist for types, tests, and dev-time alignment only — at runtime they are all optional peers resolved by the DSH host;
• Extension manual harness: node extension/harness.js extension/extension.js (stubs the injected vscode module, runs all three commands, prints each envelope + decoded payload).

Publishing

The npm package is dsh-sidebar-vscode (repo: chendefine/dsh-sidebar-vscode):

# 1. bump package.json version (and extension/package.json when extension/ changed)
# 2. build + test, then publish (prepublishOnly re-runs the build)
pnpm test && pnpm publish --access public
# 3. tag & push the release
git tag v<version> && git push origin main --tags

extension/ (the VS Code extension) rides along in the npm tarball but is never loaded by DSH itself — it installs into a serve-web instance via scripts/install-extension.sh (see Installation). After changing it, bump extension/package.json's version and re-run the script so the committed VSIX stays in sync.

Known limits

• In the direct-connection fallback (host cannot proxy) the same-origin clipboard bridge is unavailable (browser same-origin policy) — only the paste fallback remains; when it is merely boot timing (serve-web becoming ready after dsh web), the client polls proxy.status's serving every 5s and switches back to the mount automatically — no manual refresh needed;
• The built-in proxy targets a single upstream (the last-pushed serverUrl wins — multiple sessions pushing different addresses share one globally); upstreams must be directly reachable over http(s) (self-signed TLS needs system trust; embedded credentials in the URL are unsupported); the proxy does no auth stripping — tokens are appended as-is. The mount inherits the dsh web port's exposure: every client that can reach the port may use the proxied workbench (the ?tkn= token gates the upstream, not the mount — the proxy appends it transparently), so keep the port behind the same trust boundary as the GUI itself (loopback / trusted gateway);
• Selection injection is always on; there is no switch;
• Host-half changes take effect only after a dsh web restart;
• tsdown emits deprecation warnings for external / noExternal (output is correct; migration to deps.* is future work).

License

MIT (see LICENSE).