browser_session

Developer-mode browsers: launch Chrome, Brave, Firefox, or Zen without the user’s logins. Only launch when the user explicitly asks (pass userRequested: true, never on your own initiative), or a tool reported it needs developer mode. For everyday work use shared tabs. Each named context has its own persistent profile; use different context names to run browsers simultaneously. chromium preserves automatic Chrome/Chromium discovery. Firefox and Zen use WebDriver BiDi with documented exceptions; Firefox/Zen extension sharing uses its own package and has additional documented exceptions. launch/close take a context (default “default”); status lists running browsers; contexts lists saved profiles; delete removes a stopped profile.

The tool names stay the same across browsers. See browser selection and Firefox and Zen exceptions before choosing an operation.

Use a different context name for each running browser. Connected dashboards apply the most restrictive developer-browser setting: Never, then Only when needed, then Always. An explicit user request satisfies Only when needed.

Parameters

enum

required

One of: launch, status, close, contexts, delete.

string

Context name, e.g. “work” or “personal” (default “default”)

boolean

close: close every running context

string

Initial URL for launch

boolean

launch: the user explicitly asked for a developer browser in their own words. Satisfies the “Only when needed” dashboard setting. Never set it on your own initiative.

boolean

Launch without a window; screenshots work in either browser, live view is Chromium-only

enum

launch/delete: browser brand (default chromium for a new context). One of: chromium, chrome, brave, firefox, zen.

string

Executable for the selected browser; overrides automatic discovery.

string

Legacy executable override for Chromium browsers

string

Legacy executable override for Firefox browsers

string[]

Extra browser switches

boolean

Chromium only: open DevTools for every tab (default true unless headless); Firefox rejects true

string

Proxy server for this browser, e.g. “http://proxy:8080” or “socks5://127.0.0.1:1080”

string[]

Chromium only: unpacked extension directories to load

string

Where downloads land (default ~/.browspark/downloads/<browser>/<context>; legacy chromium omits the browser directory)

Example

Launch the default context

{
  "action": "launch"
}

Launch because the user asked for a developer browser

{
  "action": "launch",
  "userRequested": true
}

Launch Firefox in an isolated profile

{
  "action": "launch",
  "browser": "firefox",
  "context": "firefox",
  "userRequested": true
}

Launch Chrome in a named context

{
  "action": "launch",
  "browser": "chrome",
  "context": "chrome-work",
  "userRequested": true
}

Run Brave alongside the other contexts

{
  "action": "launch",
  "browser": "brave",
  "context": "brave-work",
  "userRequested": true
}

Run Zen in its own profile

{
  "action": "launch",
  "browser": "zen",
  "context": "zen-work",
  "userRequested": true
}

Launch a named, headless context behind a proxy

{
  "action": "launch",
  "context": "scraper",
  "headless": true,
  "proxy": "socks5://127.0.0.1:1080",
  "url": "https://example.com"
}

Close everything

{
  "action": "close",
  "all": true
}

Browser automation

Developer tools

Parameters

Example

​Parameters

​Example

Parameters

Example