@lexmount/dsh-browser

Lexmount cloud browser tools for DeepSeek Harness. This package is a lightweight DSH Bundle: it registers native model tools and invokes the Rust browser-cli, but it does not contain a native executable, run an MCP server, or depend on the Lexmount Node.js SDK.

Status: preview releases are published on npm under the next tag. Windows x64 and macOS Apple Silicon validation is complete; use next for preview installations.

Current platform support: Windows x64 and macOS Apple Silicon only. macOS Intel is not supported by this pre-release.

Runtime architecture

DSH Web / Headless
  → @lexmount/dsh-browser (Bundle and Node adapter only)
  → pinned browser-cli download and user cache
  → browser-cli child process
  → Lexmount API / CDP / cloud browser

The Bundle registers tools without accessing the network. On the first tool call it selects the current OS/CPU asset, downloads the pinned browser-cli release and SHA256SUMS from Lexmount's versioned Tencent COS path, verifies the digest, executable format/architecture, and CLI version, then installs it atomically in a user cache. Later calls and restarts reuse the verified cache, so an already populated cache works offline.

The npm tarball contains no browser-cli or browser-cli.exe file. End users do not need Rust, Python, a browser driver, or an npm lifecycle script.

Platform status

native-source.json pins browser-cli v1.1.13 at commit 3af544780365309feae97d51b631070e7ca73762. The Windows asset in this release statically links the C runtime. This pre-release intentionally uses the two assets published by that immutable release. Adding macOS Intel requires a new browser-cli version and a new npm package version with fresh validation; it will not mutate this release in place.

Install

The current pre-release requires Node.js >=22.14.0, DSH 0.1.0-rc.6, and a pnpm executable on PATH. The commands below use npx, so a global DSH installation is not required. Keep @next in preview installations; do not rely on npm's implicit latest tag until this release line is formally promoted.

Windows x64

Open a normal, non-administrator PowerShell in the directory that should become the DSH workspace, then run:

node --version
corepack --version
corepack install --global pnpm@11.22.0
corepack enable pnpm
pnpm --version

npx --yes @deepseek-ai/dsh@0.1.0-rc.6 plugin --profile web add @lexmount/dsh-browser@next
npx --yes @deepseek-ai/dsh@0.1.0-rc.6 web

If corepack enable pnpm reports an access error under C:\Program Files\nodejs, run only the Corepack setup commands once from an administrator PowerShell, close it, and run DSH itself as the normal user. If port 3080 is already occupied, start DSH on an OS-assigned free port and open the URL it prints:

npx --yes @deepseek-ai/dsh@0.1.0-rc.6 web --port 0

macOS Apple Silicon

This pre-release supports Apple Silicon only. Confirm that the machine reports arm64; x86_64 means an Intel Mac and is not currently supported. In Terminal, change to the directory that should become the DSH workspace, then run:

uname -m
node --version
corepack --version
corepack install --global pnpm@11.22.0
corepack enable pnpm
pnpm --version

npx --yes @deepseek-ai/dsh@0.1.0-rc.6 plugin --profile web add @lexmount/dsh-browser@next
npx --yes @deepseek-ai/dsh@0.1.0-rc.6 web

If port 3080 is already occupied, use an OS-assigned free port and open the printed URL:

npx --yes @deepseek-ai/dsh@0.1.0-rc.6 web --port 0

DSH RC.6 delegates plugin installation to a pnpm executable on PATH; it does not bundle that executable. If Corepack cannot create the shim, install pnpm through the normal Node package-manager setup and verify pnpm --version first.

If DSH was already running while the Bundle was installed or updated, stop and restart it before testing. Package installation does not hot-load a new Bundle into an existing Web process.

For unattended use, install the same Bundle into the Headless profile:

npx --yes @deepseek-ai/dsh@0.1.0-rc.6 plugin --profile headless add @lexmount/dsh-browser@next

The supported Harness range is >=0.1.0-rc.6 <0.2.0. DSH remains a release candidate, so each DSH upgrade requires installation and tool-registration regression testing.

First use and cache

1. Run lexmount_doctor. The first call may download the current platform executable.
2. If credentials are missing, run lexmount_auth_login from the interactive Web profile and approve access in the system browser.
3. Create a temporary Session, or select/create a persistent Context when login state must be reused.
4. Navigate, inspect with lexmount_browser_snapshot, then use typed wait/click/fill tools.
5. Close temporary Sessions when finished.

Default cache locations are:

Set LEXMOUNT_BROWSER_CLI_CACHE_DIR to choose another cache root. LEXMOUNT_BROWSER_CLI_PATH is an explicit administrator/developer override for a preinstalled CLI; that path is still checked for format and version, but its trust is controlled by whoever sets the environment variable.

The login flow stores credentials at the existing browser-cli location and never asks the user to paste an API key into chat. Headless runs must authenticate beforehand because the PKCE flow requires an interactive system browser.

Tool surface

The Bundle registers 31 native tools:

• diagnostics and authentication: version, doctor, auth status/login/logout;
• Sessions: create/get/list/close/keepalive/targets;
• downloads: list/get/archive/delete;
• Contexts: create/get/list/fork/delete/force-release;
• browser actions: open URL, wait selector/text, click, fill, snapshot, screenshot, PDF;
• escape hatches: arbitrary page JavaScript and raw CDP.

Screenshot results are persisted through the DSH image attachment service. PDF and download tools write to the requested host path and return that path because DSH 0.1.0-rc.6 has no generic binary attachment content block.

Security and behavior

• Downloads use a fixed HTTPS origin and version path. The matching SHA256SUMS entry, executable format, platform architecture, expected CLI version, and cache metadata are verified before execution.
• A cancelled first call cancels its download when no other call is waiting. Plugin disposal cancels downloads and terminates owned child processes.
• Model input is passed as a child-process argument array with shell: false; it is never concatenated into a shell command.
• API keys, Authorization fields, ws, and Chrome DevTools WebSocket URLs are removed from returned data and diagnostics.
• Tool guidance tells the model to obtain user confirmation before purchases, publication, destructive remote actions, and account/security changes.
• JavaScript evaluation and raw CDP remain model-visible for advanced browser automation.

DSH RC.6 does not expose MCP-style side-effect annotations on native tools. UI presentation categories are not permission enforcement.

Known browser-cli limitations

The first release intentionally retains behavior already shipped through WorkBuddy:

• URL, form value, JavaScript, metadata, and raw CDP params are visible in local process argv;
• each action connects independently and selects the first page target;
• ordinary interaction is limited to wait, click, and fill; there is no ACE, hover, press, select, check, drag, or file upload;
• CDP commands do not have complete internal deadlines or reconnect/replay behavior;
• snapshot returns complete page text and HTML;
• credential writes and Windows ACL behavior are unchanged;
• Windows binaries are not Authenticode-signed in the first release;
• output paths are not restricted by an additional plugin sandbox.

Development

npm install
npm run check
npm run package:verify

On a currently supported host, test a locally built v1.1.13 CLI without changing the package:

LEXMOUNT_BROWSER_CLI_PATH=/absolute/path/to/browser-cli npm run test:native

Verify the pinned remote assets, then run the real current-platform integration test on Windows x64 or macOS Apple Silicon:

npm run native:assets
npm run test:native

The browser-cli-rs repository owns native builds, macOS signing/notarization, checksums, and COS publication. This repository verifies those immutable inputs and publishes only the lightweight npm wrapper.