DSH plugin flags: npx @deepseek-ai/dsh web vs global install

npx @deepseek-ai/dsh web is the official command to start the DeepSeek Harness web UI: npx fetches the package on demand, @deepseek-ai/dsh is the package to run, and web is the subcommand to start (source). This guide takes the command apart, walks through startup flags such as --port, --host and --no-open one by one, and finally compares it with dsh web after a global install.

DSH plugin overview: the segments of one npx @deepseek-ai/dsh web command

npx @deepseek-ai/dsh web splits into three segments: the executor npx + the package name @deepseek-ai/dsh + the subcommand web. Each segment carries a clear responsibility:

By default it listens on 127.0.0.1:3080 and opens the browser automatically once startup finishes (source). To change the port, swap the binding address or stop it from opening the browser, you rely on the flags that follow.

DSH plugin startup flags, one by one: --port, --host and --no-open

The web app ships its own set of flags, written as dsh web --flag, and they override the defaults in the config file. The key question is who parses what: the launcher only parses its own flags, and after the first argument it recognizes, everything else is handed to the launched web app (source). So --port belongs to the web app, not the launcher.

The common flags, one by one:

1. --port <port> changes the listening port. It defaults to 3080; pass it explicitly to run the service on another port, for example dsh --profile web --port 8080; passing 0 hands the choice of a free port to the operating system. Expected: the address and port printed in the terminal change accordingly.
2. --host <address> changes the binding address. It only accepts an IPv4 / IPv6 literal for a specific local NIC; wildcard addresses are rejected. Expected: the service listens only on the address you specify, not the default 127.0.0.1.
3. --no-open stops the browser from opening automatically. Use it when the server is up but you do not want a browser popup (on a remote machine or started from a script). Expected: the terminal still prints the address, but no browser is launched.
4. --public-url <url> sets the access root to advertise. Behind a reverse proxy or tunnel, it makes the printed address, DSH_WEB_URL and so on point at this root for easy copying. Expected: the address you copy is the domain you expose publicly.
5. --trusted-host <authority> appends a trusted origin. The browser trust fence for /api only accepts authorities on the allowlist; pass this flag repeatedly when you need to allow more. Expected: requests from that origin are no longer blocked by the fence.
6. -h, --help shows help only. Running dsh web --help prints the web app's own flag reference, not the launcher's help, and does not actually start the service.

A minimal example of the command broken down:

# Switch to port 8080 and skip opening the browser, good for running on a remote machine
npx @deepseek-ai/dsh web --port 8080 --no-open

What happens if a flag is wrong? The parser rejects invalid values before startup, and the process prints an error and exits with a non-zero code rather than running with a broken config (source). For example, passing letters as the port makes the command error out immediately; to see every available flag, run dsh web --help first.

How the DSH plugin differs from dsh web after a global install

npx and a global install read the same data; the only differences are whether to fetch the package each time and how fast startup is. Comparison:

The choice is simple: for occasional use and a quick trial, take npx; if you use it daily and keep managing plugins with dsh plugin, install globally once. Once installed, the next step is to connect it to the plugin ecosystem:

1. Run dsh plugin --profile web add dsh-plugin to install DSH Plugin Hub into the web profile;
2. Restart dsh web and open Settings → Plugin Market;
3. Browse by category in the market and install community plugins with one click.

Rather than typing a long npx command by hand each time and remembering flags and ports yourself, install globally once and connect the plugin market, so installing, uninstalling and updating DeepSeek Harness plugins is one click in a visual interface.

DSH plugin caveats

These are the DSH plugin pitfalls that trip people up most when configuring web startup flags. One by one:

1. Whose flag is it: --port, --host and --no-open are web app flags; see the launcher's own flags with dsh --help — the two help screens are not the same.
2. Flags beat config: once a flag value is passed it overrides the config file's default, and it is only parsed once at startup, so no later config reload can quietly change it back.
3. Wildcard addresses are rejected: --host only accepts a specific local address literal; do not expect to use it for broad listening.
4. Do not close the terminal: an npx-launched service follows the terminal process, and closing the window stops it; for always-on use, install globally and run it in the background.
5. Check the default port first on conflict: before changing the port, make sure 3080 is not taken by another process; when you hit an error, check the --port spelling and the occupation first.

Sources: dsh CLI README, dsh-cmdline README, dshplugin/dsh-plugin-hub