Tools overview - Browspark

Individual tool pages are generated from the companion’s registrations by bun run docs:tools, so parameter names, types, enums and defaults match the running code. Each example is validated against the tool’s schema when the docs are generated. Chrome, Brave, Firefox and Zen expose the same 45 tool names. Firefox and Zen provide an extension for existing tabs and developer sessions through BiDi, each with documented exceptions; identical names do not mean that every Chromium action is available. Conventions shared by all tools:

Page tools accept a tabId from browser_tabs or browser_status, unique across connected browsers. Without it the companion uses the calling agent’s own tab or the only usable tab; see Tabs and sharing.
For new tabs and browser_fetch, use browserId to select an extension profile or context to select a developer browser. See Using multiple browsers.
ref values come from browser_snapshot or devtools_elements search; see Snapshots and refs.
Search tools take query with optional regex: true, and paginate with offset and limit (default 50).
Long results are clipped; ask for a narrower query, a specific id, or a higher limit.
Files are written to ~/.browspark/artifacts unless a path is given.

Browser automation

Tool	Purpose
browser_status	Connection state, pairing instructions, usable tabs, open dialogs
browser_session	Launch, close, list and delete developer-browser contexts
browser_tabs	List, open, close, activate tabs across all windows
browser_navigate	Go to a URL, reload, back, forward
browser_snapshot	Accessible tree with refs, optionally as a diff
browser_read	Text, markdown, links, tables or HTML of the page or a ref
browser_fetch	Load a URL in a temporary tab and return its main content
browser_extract	Structured records from repeated elements
browser_click	Click, hover, drag
browser_fill	Replace the text of an input, textarea or contenteditable
browser_select	Choose options in a select
browser_upload	Set files on a file input
browser_key	Press keys or type text
browser_scroll	Scroll the page or a ref’s container
browser_screenshot	Viewport, full page or element image
browser_wait	Wait for text, URL or element state
browser_dialog	Accept or dismiss JavaScript dialogs
browser_batch	Several calls in one round trip
browser_policy	Allow or block domains per tab or by default
browser_download	List downloads or wait for one
browser_pdf	Print to PDF
browser_webmcp	List and invoke WebMCP tools a page exposes

Developer tools

The mode column below describes Chromium: “both” means extension and developer mode. On Firefox and Zen, consult their coverage or devtools_capabilities on the target tab before choosing an action.

Tool	Purpose	Mode
devtools_session	Start, stop, clear an inspection session	both
devtools_events	Read or wait for collected events	both
devtools_capabilities	Probe which protocol domains work for a tab	both
devtools_cdp	Raw DevTools Protocol command	developer
devtools_console	Search, inspect and wait on console output	both
devtools_evaluate	Run JavaScript in the page, a frame or a paused call frame	both
devtools_network	Search requests, bodies, frames, HAR, throttle, block, mock, replay	both
devtools_sources	Scripts, stylesheets, source maps, overrides	both
devtools_debugger	Breakpoints, stepping, scopes, watches	both
devtools_elements	DOM search, HTML and attribute edits, styles, box model, listeners, overlays	both
devtools_performance	Traces, Web Vitals, runtime metrics	both
devtools_profile	CPU sampling profiles	both
devtools_memory	Heap usage and growth (both); snapshots, diffs, retainers, allocation sampling (developer)	mixed
devtools_coverage	JavaScript and CSS coverage	both
devtools_storage	Cookies, web storage, IndexedDB, Cache Storage, quota, clearing	both
devtools_workers	Service workers and the web app manifest	mostly both
devtools_emulation	Devices, throttling, geolocation, media, locale, vision, animations	both
devtools_accessibility	Accessibility tree, audit, browser-reported issues	both
devtools_security	Connection state, certificate, mixed content	both
devtools_lighthouse	Lighthouse audit with reports	developer
devtools_recorder	Record, parameterise, replay, export to Playwright	both

The per-domain Chromium picture is in the capability matrix. Firefox and Zen return explicit errors for unsupported actions, including raw CDP and Lighthouse.

​Browser automation

​Developer tools

Browser automation

Developer tools