Files
BrowserSkill/packages/dsh-plugin-browserskill/README.md
T
BB-fat 3d050e0f26 feat(dsh-plugin-browserskill): strict ownership boundary — foreign sessions are invisible
Tighten the shared-daemon boundary from 'cleanup only touches owned
sessions' to 'the plugin only ever sees and operates on sessions it
created':

- browser_session_list no longer queries the daemon at all; it returns
  the plugin's own session table (with the current marker), so foreign
  sessions cannot even be enumerated through the plugin.
- Every tool's optional session argument must name a plugin-created
  session; foreign/unknown ids are rejected with a clear error before
  any command reaches the daemon (the reference-adoption channel is
  gone).
- Unchanged: dispose stops exactly the owned set, stop requires
  ownership, the start reservation protocol, and handle-precise child
  kills.

Tests updated (59): explicit-foreign rejection without daemon contact,
registry-only listing, reservation race, stale-handle-tolerant dispose.
e2e: a manually started foreign session was rejected on reference,
absent from session_list, refused on stop, and survived dispose while
both plugin sessions were cleaned up.
2026-08-14 04:12:38 +00:00

5.6 KiB

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. Only plugin-created sessions can be stopped.
browser_session_list — (registry only) List the sessions this plugin created, marking the current one. Foreign daemon sessions are never shown.
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.

Ownership boundary: the bsk daemon may be shared with other agents, terminals, or dsh instances. The plugin therefore only ever sees and operates on sessions it created itself — an explicit session argument naming a foreign or unknown id is rejected, browser_session_list shows plugin-created sessions only (no daemon-wide view), and stop/unload cleanup can never touch a session owned by another program.

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