Files
BrowserSkill/packages/dsh-plugin-browserskill
BB-fat afdc398730 fix(dsh-plugin-browserskill): strict session ownership on a shared daemon
Review hardening for daemon-sharing deployments (other agents,
terminals, or dsh instances on the same bsk daemon):

- Ownership split: only sessions created by browser_session_start are
  'owned'. Explicitly referenced foreign sessions are still tracked for
  the current-session pointer, but browser_session_stop refuses them
  and unload cleanup stops exactly the owned set — no path can stop a
  session this plugin did not create.
- Start race: the capacity check is now a synchronous
  reserveStart/completeStart/abandonStart protocol, so two concurrent
  starts can never both pass the cap (check-and-reserve is atomic on
  the event loop); a rejected or failed start never leaks a session.
- Stale handles: dispose already swallowed per-stop errors; the owned
  set is computed at dispose time so an externally stopped session is a
  no-op, not a failure.

Tests (+7): reservation race (two concurrent starts, cap 1 -> exactly
one spawn), foreign-stop refusal (no stop command reaches the daemon),
reference adoption never becoming owned, resolveForStop pointer
stability, and an apply-level dispose test proving only owned sessions
are stopped while stale stops are tolerated. e2e: a manually started
foreign session survived the plugin's full lifecycle while both plugin
sessions were cleaned up.
2026-08-14 03:45:52 +00:00
..

dsh-plugin-browserskill

A DeepSeek Harness (dsh) tool plugin that exposes BrowserSkill (bsk) browser automation to the model.

Each tool maps to one bsk <cmd> --json invocation: the plugin spawns the bsk CLI, parses its structured JSON output, and returns a canonical typed value. The bsk daemon, browser, and Chrome extension keep owning the actual browser control — this package is a thin, well-typed bridge.

Tools

Tool bsk command Purpose
browser_session_start bsk session start Open an Agent Window session; optional initial URL, window size, and device emulation preset. Returns the session id and makes it the current session.
browser_session_stop bsk session stop Stop a session (the current one by default) and close its Agent Window.
browser_session_list bsk session list List daemon-side sessions, marking the plugin's current session.
browser_navigate bsk navigate Navigate the active tab, with waitUntil / timeout control.
browser_snapshot bsk snapshot Indented aria-tree snapshot with @eN refs for interaction tools.
browser_observe bsk observe Semantic VOM observation (read-only) with @eN refs.
browser_click bsk click Click a snapshot ref or CSS selector (button / click-count options).
browser_fill bsk fill Fill an input / textarea / contenteditable (clears first by default).
browser_press bsk press Dispatch a key or combo, optionally focusing a target first.
browser_screenshot bsk screenshot PNG capture of the tab or a ref-cropped element; inlines the image when the deployment supports image input, otherwise returns a file path.
browser_emulate bsk emulate Apply or clear mobile device emulation on the active tab.

Multi-session model

One agent conversation can drive several browser sessions at once:

  • browser_session_start returns the session id and makes it the current session.
  • Every operation tool accepts an optional session argument. When omitted, the call acts on the current session (the one most recently started or used); when given, that session becomes current.
  • Every tool result echoes the session it actually acted on, so the model never has to guess.
  • The number of concurrent sessions started through the plugin is capped (maxSessions, default 5).
  • Unloading the plugin stops every session it started and kills in-flight bsk processes.

Installation

The plugin follows the standard dsh bundle layout (dsh.bundle manifest + cordis.patch.yml):

dsh plugin --profile <name> add <path-or-spec-of-this-package>
dsh --profile <name>

Prerequisite: the bsk CLI must be installed and on PATH, and the BrowserSkill Chrome extension must be connected — see the BrowserSkill README. When bsk is missing, tool calls fail with install guidance instead of a bare spawn error.

Configuration

All fields are optional and validated through the plugin's Schemastery Config:

# cordis.patch.yml override example
- insert:
    - id: browserskill
      name: dsh-plugin-browserskill
      config:
        bskPath: bsk          # path to the bsk binary (default: resolve from PATH)
        defaultTimeoutMs: 120000
        maxSessions: 5

Behavior notes

  • Cancellation: aborting a tool call (exec.signal) kills the underlying bsk child process, matching BrowserSkill's cooperative tool-cancellation model.
  • UI cards: calls render as terminal cards (command line as title, output as the completed card). Screenshots additionally attach the image itself when the host mounts an attachment store and the active model route declares image input; otherwise the PNG path is returned.
  • Web UI toolview (browser half): the package is dual-face. dsh.client (platform web) ships lib/client.js, which registers a keyed tool.call.toolview view for browser_screenshot. The custom view keeps the terminal block (command + output) and, when the settled result carries an image block, resolves the durable attachment through the client session's authorized readAttachment RPC and renders it with the shared MessageImage thumbnail/lightbox atoms. Every other browser_* tool keeps the stock terminal card. The bundle follows the dsh client contract: a CJS closure factory handed to window.__ModuleLoader__.load, platform modules (react, dsh-client-ui-*) external, everything else inlined, CSS Modules compiled by lightningcss.
  • Errors: non-zero bsk exits surface the CLI's JSON error envelope (code, message, hint) so the model gets the daemon's actionable guidance.
  • Long-running work (e.g. bsk record) is not backgrounded via ctx.jobs yet — tracked as a follow-up.

Development

pnpm install
pnpm --filter dsh-plugin-browserskill typecheck
pnpm --filter dsh-plugin-browserskill test     # unit tests mock bsk; no browser needed
pnpm --filter dsh-plugin-browserskill build    # tsdown -> lib/

License

MIT