core

Core agent-browser usage guide. Read this before running any agent-browser commands. Covers the snapshot-and-ref workflow, navigating pages, interacting with elements (click, fill, type, select), extracting text and data, taking screenshots, managing tabs, handling forms and auth, waiting for content, running multiple browser sessions in parallel, and troubleshooting common failures. Use when the user asks to interact with a website, fill a form, click something, extract data, take a screenshot, log into a site, test a web app, or automate any browser task.

Install
npx skills add 'https://github.com/vercel-labs/agent-browser/tree/main/skill-data/core'
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main · aff6125Scanned 2026-09-17

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GitHub-linked commit authors for this SKILL.md at the saved revision. Co-authors and history before file renames are not included.

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Command Reference

Complete reference for all agent-browser commands. For quick start and common patterns, see SKILL.md.

agent-browser open            # Launch browser (no navigation); stays on about:blank.
                              # Pair with `network route`, `cookies set --curl`, or
                              # `addinitscript` to stage state before the first navigation.
agent-browser open <url>      # Launch + navigate (aliases: goto, navigate)
                              # Supports: https://, http://, file://, about:, data://
                              # Auto-prepends https:// if no protocol given
agent-browser read [url]      # Fetch agent-readable text, or read rendered active-tab DOM
                              # Explicit URLs send Accept: text/markdown, then try .md if needed
                              # Walks ancestor paths for llms.txt before HTML fallback
                              # --llms and --require-md without URL use the active tab URL
                              # --filter narrows page content to matching heading sections
                              # Honors --allowed-domains, --content-boundaries, and --max-output
                              # Options: --raw, --require-md, --outline, --llms <index|full>, --filter, --timeout <ms>
agent-browser back            # Go back
agent-browser forward         # Go forward
agent-browser reload          # Reload page
agent-browser pushstate <url> # SPA client-side navigation. Auto-detects
                              # window.next.router.push (triggers RSC fetch on Next.js);
                              # falls back to history.pushState + popstate/navigate events.
agent-browser close           # Close browser (aliases: quit, exit)
agent-browser connect 9222    # Connect to browser via CDP port

Pre-navigation setup (one-turn batch)

agent-browser batch \
  '["open"]' \
  '["network","route","*","--abort","--resource-type","script"]' \
  '["cookies","set","--curl","cookies.curl","--domain","localhost"]' \
  '["navigate","http://localhost:3000/target"]'

open with no URL gives you a clean launch so any interception, cookies, or init scripts you register take effect on the first real navigation. Use for SSR-only debug (--resource-type script), protected-origin auth, or capturing fresh react suspense/vitals state without noise from a prior page.

Snapshot (page analysis)

agent-browser snapshot            # Full accessibility tree
agent-browser snapshot -i         # Interactive elements only (recommended)
agent-browser snapshot -c         # Compact output
agent-browser snapshot -d 3       # Limit depth to 3
agent-browser snapshot -s "#main" # Scope to CSS selector
agent-browser snapshot --delta     # Full state once, then bounded structural deltas
agent-browser snapshot --delta --full # Force full state and refresh baseline

Delta history is per tab and option set. Responses are full, unchanged, or delta; URL changes or large deltas return full state. For a delta, apply changes (add, remove, replace) to ref metadata. Split the previous tree on newlines, splice treeChange.lines at zero-based startLine, replacing deleteCount lines, then join with newlines. Apply both parts to baseRevision before advancing to revision; use --full if the baseline is unavailable.

Interactions (use @refs from snapshot)

agent-browser click @e1           # Click
agent-browser click @e1 --new-tab # Click and open in new tab
agent-browser dblclick @e1        # Double-click
agent-browser focus @e1           # Focus element
agent-browser fill @e2 "text"     # Clear and type
agent-browser type @e2 "text"     # Type without clearing
agent-browser press Enter         # Press key (alias: key)
agent-browser press Control+a     # Key combination
agent-browser keydown Shift       # Hold key down
agent-browser keyup Shift         # Release key
agent-browser hover @e1           # Hover
agent-browser check @e1           # Check checkbox
agent-browser uncheck @e1         # Uncheck checkbox
agent-browser select @e1 "value"  # Select by value or visible label
agent-browser select @e1 "a" "b"  # Select multiple options
agent-browser scroll down 500     # Scroll page (default: down 300px)
agent-browser scrollintoview @e1  # Scroll element into view (alias: scrollinto)
agent-browser drag @e1 @e2        # Drag and drop
agent-browser upload @e1 file.pdf # Upload files

Visible-label matching treats non-breaking and ordinary spaces equivalently.

Clicks fail before dispatch when another element covers the target's click point. The error names the covering element, for example covered by <div#consent-banner>. Dismiss or interact with that element, run a fresh snapshot, then retry the original action.

Get Information

agent-browser get text @e1        # Get element text
agent-browser get html @e1        # Get innerHTML
agent-browser get value @e1       # Get input value
agent-browser get attr @e1 href   # Get attribute
agent-browser get title           # Get page title
agent-browser get url             # Get current URL
agent-browser get cdp-url         # Get CDP WebSocket URL
agent-browser get count ".item"   # Count matching elements
agent-browser get box @e1         # Get bounding box
agent-browser get styles @e1      # Get computed styles (font, color, bg, etc.)

Check State

agent-browser is visible @e1      # Check if visible
agent-browser is enabled @e1      # Check if enabled
agent-browser is checked @e1      # Check if checked

Screenshots and PDF

agent-browser screenshot          # Save to temporary directory
agent-browser screenshot path.png # Save to specific path
agent-browser screenshot --full   # Full page
agent-browser screenshot --if-changed # Recommended: skip unchanged images to save tokens
agent-browser screenshot --threshold 0.01 # Ignore changes affecting at most 1% of pixels
agent-browser pdf output.pdf      # Save as PDF

--threshold <0-1> implies --if-changed. Conditional history is isolated by tab and capture scope. JSON responses include changed, revision, pixelChangeRatio, and threshold; path is present only when the change exceeds the threshold. The first capture for a scope is always changed.

Headless Chromium screenshots hide native scrollbars for consistent image output. Pass --hide-scrollbars false when launching to keep native scrollbars visible.

Video Recording

agent-browser open https://example.com     # Launch a browser session first
agent-browser record start ./demo.webm    # Start recording the current page at 30 fps
agent-browser click @e1                   # Perform actions
agent-browser record stop                 # Stop and save video
agent-browser record restart ./take2.webm # Stop current + start new

agent-browser record start ./scroll.webm --fps 60  # 60 fps for motion-heavy takes
agent-browser record start ./soak.webm --fps 10    # Lower rate for long sessions
agent-browser tab new https://example.com          # Open a separate tab first if you want the recording there
agent-browser record start ./demo.webm --cursor    # Add an animated mouse pointer
agent-browser record start ./demo.webm --contact-sheet # Save a timestamped PNG summary

Needs ffmpeg on PATH; use a path with an extension. --fps accepts 1 to 60 and defaults to 30. --contact-sheet-threshold <0-1> adjusts keyframe sensitivity and implies --contact-sheet.

Wait

agent-browser wait @e1                     # Wait for element
agent-browser wait 2000                    # Wait milliseconds
agent-browser wait --text "Success"        # Wait for text (or -t)
agent-browser wait --url "**/dashboard"    # Wait for URL pattern (or -u)
agent-browser wait --load domcontentloaded # Wait for DOMContentLoaded (or -l)
agent-browser wait --load load             # Wait for the load event
agent-browser wait --load networkidle      # Wait for network idle on known-quiet pages
agent-browser wait --fn "window.ready"     # Wait for JS condition (or -f)

After a page-changing action, prefer the selector, text, URL, or JavaScript condition that represents the result you need. Use a lifecycle wait when the lifecycle event is the milestone. networkidle is also supported, but use it only for pages known to become quiet because SSE, WebSockets, polling, and long-polling can keep it from resolving.

Mouse Control

agent-browser mouse move 100 200      # Move mouse instantly
agent-browser mouse move 600 400 --duration 250 --steps 24
agent-browser mouse move 600 400 --human --seed 42
agent-browser mouse down left         # Press button
agent-browser mouse up left           # Release button
agent-browser mouse wheel 100         # Scroll wheel

Use --human with click or drag when pointer-path events matter. Movement starts at the current cursor position and ends at the target; mouse move --seed makes the path reproducible. --duration is the target total duration, including browser response time; a slow browser can still extend it.

Semantic Locators (alternative to refs)

agent-browser find role button click --name "Submit"
agent-browser find role heading text --name "Skills"     # implicit roles work: <h2>=heading, <ul>=list, top-level <header>=banner
agent-browser find text "Sign In" click
agent-browser find text "Sign In" click --exact      # Exact match only
agent-browser find label "Email" fill "user@test.com"
agent-browser find placeholder "Search" fill "query"
agent-browser find alt "Logo" click
agent-browser find title "Close" click
agent-browser find testid "submit-btn" click
agent-browser find first ".item" click
agent-browser find last ".item" click
agent-browser find nth 2 "a" hover

Browser Settings

agent-browser set viewport 1920 1080          # Set viewport size
agent-browser set viewport 1920 1080 2        # 2x retina (same CSS size, higher res screenshots)
agent-browser set device "iPhone 14"          # Emulate device
agent-browser set geo 37.7749 -122.4194       # Set geolocation (alias: geolocation)
agent-browser set offline on                  # Toggle offline mode
agent-browser set headers '{"X-Key":"v"}'     # Extra HTTP headers
agent-browser set credentials user pass       # HTTP basic auth for current and future tabs (alias: auth)
agent-browser set media dark                  # Emulate color scheme
agent-browser set media light reduced-motion  # Light mode + reduced motion

Cookies and Storage

agent-browser cookies                     # Get all cookies
agent-browser cookies set name value      # Set cookie
agent-browser cookies clear               # Clear cookies
agent-browser storage local               # Get all localStorage
agent-browser storage local key           # Get specific key
agent-browser storage local set k v       # Set value
agent-browser storage local clear         # Clear all

Network

agent-browser network route <url>              # Intercept requests
agent-browser network route <url> --abort      # Block requests
agent-browser network route <url> --body '{}'  # Mock response
agent-browser network unroute [url]            # Remove routes
agent-browser network requests                 # View tracked requests
agent-browser network requests --filter api    # Filter requests
agent-browser network request <requestId>      # Full request/response detail incl. body
agent-browser network har start                # Record traffic (embeds text response bodies)
agent-browser network har start --content all  # Embed all bodies (binary as base64)
agent-browser network har start --content none # Sizes and headers only
agent-browser network har stop [output.har]    # Stop and save HAR

Tabs and Windows

agent-browser tab                              # List tabs with tabId and label
agent-browser tab new [url]                    # New tab
agent-browser tab new --label docs [url]       # New tab with a memorable label
agent-browser tab t2                           # Switch to tab by id
agent-browser tab docs                         # Switch to tab by label
agent-browser tab close                        # Close current tab
agent-browser tab close t2                     # Close tab by id
agent-browser tab close docs                   # Close tab by label
agent-browser window new                       # New window

Tab ids are stable strings of the form t1, t2, t3. They're never reused within a session, so the same id keeps referring to the same tab across commands. Positional integers are not accepted — tab 2 errors with a teaching message; use t2.

User-assigned labels (docs, app, admin) are interchangeable with ids everywhere a tab ref is accepted. Labels are the agent-friendly way to write multi-tab workflows:

agent-browser tab new --label docs https://docs.example.com
agent-browser tab new --label app  https://app.example.com
agent-browser tab docs                   # switch to docs
agent-browser snapshot                   # populate refs for docs
agent-browser click @e1                  # ref click on docs
agent-browser tab app                    # switch to app
agent-browser tab close docs             # close by label

Labels are never auto-generated, never rewritten on navigation, and must be unique within a session. To interact with another tab, switch to it first: the daemon maintains a single active tab, so refs (@eN) belong to the tab that was active when the snapshot ran.

Tabs opened through tab new or click --new-tab inherit the session's setup before their first document loads: user agent, set headers, set credentials, origin-scoped --headers, init scripts, route rules, and emulation overrides (color scheme, timezone, locale, geolocation, offline). Turning offline mode off or setting headers to {} restores the default setup for future tabs.

tab list --json also reports each tab's CDP targetId, accepted anywhere a tab ref is accepted (tab <targetId>, tab close <targetId>). Target ids stay stable across daemon restarts, unlike t<N> ids, which are per-daemon counters. With --pin-tab the session is pinned to its bound tab: if that tab is closed, commands fail with a tab_gone error instead of falling back to another tab, and tab new or tab list recover. JSON errors include code: "tab_gone" and a recovery object with data.targetId plus optional sanitized data.lastUrl; batch uses result for the same object.

Switching to a tab that the browser discarded to save memory reactivates it, since a discarded tab has no renderer to drive. Reactivation reloads the page and resets its unsaved state, and the switch result adds "revived": true so the reload is not silent. A tab whose page is paused by a JavaScript dialog is alive rather than discarded: the switch leaves it untouched and adds "dialogBlocked": true. Resolve the dialog with dialog accept/dialog dismiss and its state is preserved. Closing the active tab onto a discarded successor revives it the same way and reports "activeTabRevived": true.

Frames

agent-browser frame "#iframe"     # Switch to iframe by CSS selector
agent-browser frame @e3           # Switch to iframe by element ref
agent-browser frame main          # Back to main frame

Iframe support

Iframes are detected automatically during snapshots. When the main-frame snapshot runs, Iframe nodes are resolved and their content is inlined beneath the iframe element in the output (one level of nesting; iframes within iframes are not expanded).

agent-browser snapshot -i
# @e3 [Iframe] "payment-frame"
#   @e4 [input] "Card number"
#   @e5 [button] "Pay"

# Interact directly — refs inside iframes already work
agent-browser fill @e4 "4111111111111111"
agent-browser click @e5

# Or switch frame context for scoped snapshots
agent-browser frame @e3               # Switch using element ref
agent-browser snapshot -i             # Snapshot scoped to that iframe
agent-browser frame main              # Return to main frame

The frame command accepts:

  • Element refsframe @e3 resolves the ref to an iframe element
  • CSS selectorsframe "#payment-iframe" finds the iframe by selector
  • Frame name/URL — matches against the browser's frame tree

Dialogs

By default, alert and beforeunload dialogs are automatically accepted so they never block the agent. confirm and prompt dialogs still require explicit handling. Use --no-auto-dialog to disable this behavior.

agent-browser dialog accept [text]  # Accept dialog
agent-browser dialog dismiss        # Dismiss dialog
agent-browser dialog status         # Check if a dialog is currently open

JavaScript

agent-browser eval "document.title"          # Simple expressions only
agent-browser eval -b "<base64>"             # Any JavaScript (base64 encoded)
agent-browser eval --stdin                   # Read script from stdin

Use -b/--base64 or --stdin for reliable execution. Shell escaping with nested quotes and special characters is error-prone.

# Base64 encode your script, then:
agent-browser eval -b "ZG9jdW1lbnQucXVlcnlTZWxlY3RvcignW3NyYyo9Il9uZXh0Il0nKQ=="

# Or use stdin with heredoc for multiline scripts:
cat <<'EOF' | agent-browser eval --stdin
const links = document.querySelectorAll('a');
Array.from(links).map(a => a.href);
EOF

Authentication and Plugins

agent-browser auth save <name> --url <url> --username <user> --password-stdin
agent-browser auth login <name>          # Login using saved credentials
agent-browser auth login <name> --no-navigate
                                          # Use active page after same-origin validation
agent-browser auth login <name> --credential-provider <plugin> [--item <ref>] [--url <url>]
agent-browser auth login <name> --username-selector <s> --password-selector <s> [--submit-selector <s>]
agent-browser auth list                  # List saved auth profiles
agent-browser auth show <name>           # Show profile metadata, no passwords
agent-browser auth delete <name>         # Delete a saved profile
agent-browser plugin add <ref>           # Add a plugin from npm or GitHub
agent-browser plugin list                # List configured plugins
agent-browser plugin show <name>         # Show one configured plugin
agent-browser plugin run <name> <type> --payload <json>
                                          # Run an arbitrary plugin request

auth login normally navigates to the effective credential URL. --no-navigate requires an existing active top-level HTTP(S) page, checks that its scheme, host, and effective port match the effective credential URL, then uses the normal selector waits, fills, and submit click without replacing the document. Paths, queries, and fragments may differ, and submit-triggered navigation remains enabled. Command-level --url takes precedence over stored or provider metadata and becomes the expected-origin constraint in this mode.

Credential provider plugins run out-of-process over the agent-browser.plugin.v1 stdio JSON protocol and must declare credential.read. Use --confirm-actions plugin:<name>:credential.read to require explicit approval before a plugin resolves secrets.

Other capabilities use the same protocol:

  • browser.provider: agent-browser --provider <name> open <url>
  • launch.mutate: append local launch args, extensions, or init scripts
  • command.run: agent-browser plugin run <name> <type> --payload <json>

plugin run is for command.run and custom capabilities. Core capabilities and protocol request types use their dedicated command paths.

State Management

agent-browser state save auth.json    # Save cookies, storage, auth state
agent-browser state load auth.json    # Restore saved state

Live Streaming

agent-browser stream status --json    # Enabled state, port, client count
agent-browser stream enable           # Start the WebSocket stream server
agent-browser stream enable --port 9223

# Experimental WebMCP page tools
# Browser results announce brief summaries only when the catalog changes.
# Choose a relevant tool, fetch its schema, then invoke within the user task.
agent-browser webmcp list <tool> --frame <frame-id> --json
agent-browser webmcp list --json  # Full catalog or context recovery
agent-browser webmcp invoke <tool> --params '{"key":"value"}'
agent-browser webmcp invoke <tool> --params @input.json --detach
agent-browser webmcp result <invocation-id>
agent-browser webmcp cancel <invocation-id>
agent-browser stream disable          # Stop it

Clients connect to ws://127.0.0.1:<port> and receive frame, status, tabs, url, and console messages. They send input_mouse, input_keyboard, and input_touch to drive the page, {"type":"config","maxFps":N} (1 to 120, 0 = uncapped) to cap their own frame rate, and {"type":"config","pacing":"ack"} to receive one frame at a time, acknowledged with {"type":"ack","seq":N}. Both settings can be declared on the URL instead (ws://127.0.0.1:<port>/?pacing=ack&maxFps=10). See streaming.md.

Observability Dashboard

agent-browser dashboard start
agent-browser dashboard start --port 8080
agent-browser dashboard start --allowed-origins https://dashboard.example.com
agent-browser dashboard stop

Loopback origins are allowed by default over IPv4 and IPv6 without an access token. Set --allowed-origins or AGENT_BROWSER_DASHBOARD_ALLOWED_ORIGINS to a comma-separated list of exact HTTPS reverse-proxied origins. Every origin must be valid, and custom ports must be integers from 1 to 65535. Unknown options, missing values, invalid ports, and malformed origins fail without starting the server. The command prints private tokenized access URLs only for external origins; open the matching URL once to establish the browser session and do not share it. Open http://localhost:<port> directly for local access. Repeated starts reuse the running dashboard only when the port and allowed origins match; stop it before changing either setting.

MCP Server

agent-browser mcp
agent-browser mcp --tools all
agent-browser mcp --tools core,network,react

Starts a stdio Model Context Protocol server. MCP clients should configure the server command as agent-browser with args ["mcp"]. The server defaults to MCP protocol 2025-11-25 and accepts older supported client protocol versions during initialization.

The default tools profile is core, which keeps MCP context small for everyday browser automation. Use --tools all for the full typed CLI parity surface, or combine profiles with commas, such as --tools core,network,react.

Profiles:

  • core - Default. Navigation, snapshots, interaction, waits, reads, screenshots, JavaScript eval, close, tab basics, and profile discovery
  • network - Network routes, request inspection, HAR, headers, credentials, offline
  • state - Cookies, storage, auth, saved state, sessions, profiles, skills
  • debug - Console/errors, tracing, profiling, recording, a11y audit, clipboard, plugins, doctor, dashboard, install, upgrade, chat, diff, batch, confirm/deny
  • tabs - Back/forward/reload, tabs, windows, frames, dialogs
  • react - React tree/inspect/renders/suspense, vitals, pushstate
  • mobile - Viewport/device/geolocation/media, touch, swipe, mouse, keyboard
  • all - Every MCP tool, including the full typed CLI parity surface

Common tools include:

  • agent_browser_tools_profiles
  • agent_browser_open
  • agent_browser_snapshot
  • agent_browser_click
  • agent_browser_fill
  • agent_browser_type
  • agent_browser_press
  • agent_browser_wait_for_selector
  • agent_browser_screenshot
  • agent_browser_get_url
  • agent_browser_eval
  • agent_browser_close

Tool calls use the same config files and environment variables as the CLI. Each tool accepts typed arguments plus extraArgs for advanced CLI flags and exact CLI parity. The common allowedDomains array maps to --allowed-domains and activates the same WebRTC containment and launch-mode restrictions. Tool discovery is paginated and includes read-only/open-world annotations so modern MCP clients can load the large typed surface incrementally. Use the session tool argument or AGENT_BROWSER_SESSION to isolate browser state.

Global Options

agent-browser --session <name> ...    # Isolated browser session
agent-browser --json ...              # JSON output for parsing
agent-browser --headed ...            # Show browser window (not headless; on displayless Linux an Xvfb display starts automatically)
agent-browser --webgpu ...            # Enable WebGPU (SwiftShader software Vulkan on Linux, no GPU needed)
agent-browser --no-webmcp ...         # Disable default experimental WebMCP Chrome features (or AGENT_BROWSER_NO_WEBMCP env)
agent-browser --cdp <port|url> ...    # Connect via CDP; root query slash is optional
agent-browser --pin-tab ...           # Pin the session to its bound tab (strict tab binding)
agent-browser --no-pin-tab ...        # Disable a sticky pin previously enabled with --pin-tab
agent-browser -p <provider> ...       # Browser provider or configured provider plugin
agent-browser --proxy <url> ...       # Use proxy server
agent-browser --proxy-bypass <hosts>  # Hosts to bypass proxy
agent-browser --headers <json> ...    # HTTP headers scoped to URL's origin
agent-browser --executable-path <p>   # Custom browser executable
agent-browser --extension <path> ...  # Load browser extension (repeatable)
agent-browser --ignore-https-errors   # Ignore SSL certificate errors
agent-browser --ca-cert <path>        # Trust a CA in local Chromium on Linux (install --with-deps provides certutil)
agent-browser --no-ca-cert            # Clear CA trust retained by the running session
agent-browser --hide-scrollbars false # Keep native scrollbars visible in headless Chromium screenshots
agent-browser --help                  # Show help (-h)
agent-browser --version               # Show version (-V)
agent-browser <command> --help        # Show detailed help for a command

Debugging

On Windows, owned headless Chrome runs on a private desktop so hidden windows cannot draw stray rectangles over the user's desktop. This applies to custom Chrome executables and windows created later through CDP. Headed and extension sessions use the interactive desktop. Owned Chrome trees are terminated when their daemon exits, including forced termination; attaching to an external browser does not take ownership of it.

agent-browser --headed open example.com   # Show browser window
agent-browser --cdp 9222 snapshot         # Connect via CDP port
agent-browser connect 9222                # Alternative: connect command
agent-browser console                     # View console messages
agent-browser console --clear             # Clear console
agent-browser errors                      # View page errors
agent-browser errors --clear              # Clear errors
agent-browser highlight @e1               # Highlight element
agent-browser inspect                     # Open Chrome DevTools for this session
agent-browser trace start                 # Start recording trace
agent-browser trace stop trace.json       # Stop and save trace
agent-browser profiler start              # Start Chrome DevTools profiling
agent-browser profiler stop trace.json    # Stop and save profile

React / Web Vitals

Requires --enable react-devtools at launch for the react ... commands. vitals and pushstate are framework-agnostic.

agent-browser open --enable react-devtools <url>    # Launch with React hook installed
agent-browser react tree                            # Full component tree
agent-browser react inspect <fiberId>               # Props, hooks, state, source
agent-browser react renders start                   # Begin re-render recording
agent-browser react renders stop [--json]           # Stop and print render profile
agent-browser react suspense [--only-dynamic] [--json]  # Suspense boundaries + classifier
                                                         # --only-dynamic hides the "static" list
agent-browser vitals [url] [--json]                 # LCP/CLS/TTFB/FCP/INP + hydration
agent-browser pushstate <url>                       # SPA client-side nav (auto-detects Next router)

vitals prints a summary by default and uses the same fields as the structured --json response.

Accessibility audit

Runs an embedded axe-core audit with no CDN fetch. The vendored engine runs private partial audits through CDP across the page's frame tree and merges serialized results without page messaging, so page CSP does not block it, page-provided window.axe values remain intact, and iframe violations retain their frame selector paths. Accessibility audits require a CDP browser and are not available with Safari or iOS WebDriver sessions. Reports WCAG violations with impact, rule id, fix guidance URL, and failing-node selectors.

agent-browser a11y                                  # Audit the current page
agent-browser a11y <url>                            # Navigate, then audit
agent-browser a11y --tags wcag2a,wcag2aa            # Only rules with these axe tags
agent-browser a11y --selector "#main"               # Scope audit to a subtree
agent-browser a11y <url> --json                     # Structured results for automation

--json returns counts plus violations/incomplete arrays; each entry has id, impact, help, helpUrl, tags, nodeCount, and up to 10 nodes (target selector path arrays, html snippet, failureSummary). Nested target arrays preserve shadow DOM boundaries. incomplete lists rules axe could not evaluate automatically — review those manually.

Init scripts

agent-browser open --init-script <path>             # Register before first navigation (repeatable)
agent-browser addinitscript <js>                    # Register at runtime (returns identifier)
agent-browser removeinitscript <identifier>         # Remove from every tab in the session

Runtime init-script identifiers are session-wide. Removing one clears it from every open tab where it was registered and from the setup replayed into future tabs.

agent-browser cookies set --curl <file>                             # Auto-detects JSON/cURL/Cookie-header
agent-browser cookies set --curl <file> --domain example.com        # Scope to a domain

Supported formats: JSON array of {name, value}, a cURL dump from DevTools -> Network -> Copy as cURL, or a bare Cookie header. Errors never echo cookie values.

Network route by resource type

agent-browser network route '*' --abort --resource-type script       # Block scripts only (SSR-lock pattern)
agent-browser network route '*' --resource-type image,font --body '' # Stub images and fonts

Environment Variables

AGENT_BROWSER_SESSION="mysession"            # Default session name
AGENT_BROWSER_EXECUTABLE_PATH="/path/chrome" # Custom browser path
AGENT_BROWSER_EXTENSIONS="/ext1,/ext2"       # Comma-separated extension paths
AGENT_BROWSER_INIT_SCRIPTS="/a.js,/b.js"     # Comma-separated init script paths
AGENT_BROWSER_ENABLE="react-devtools"        # Comma-separated built-in init script features
AGENT_BROWSER_HIDE_SCROLLBARS="false"        # Keep native scrollbars visible in headless Chromium screenshots
AGENT_BROWSER_WEBGPU="1"                     # Enable the WebGPU launch preset (see references/webgpu.md)
AGENT_BROWSER_NO_XVFB="1"                    # Disable automatic Xvfb for headed mode on displayless Linux
AGENT_BROWSER_PROVIDER="browserbase"         # Browser provider or configured provider plugin
AGENT_BROWSER_STREAM_PORT="9223"             # Override WebSocket streaming port (default: OS-assigned)
AGENT_BROWSER_DASHBOARD_ALLOWED_ORIGINS="https://dashboard.example.com" # Trusted HTTPS reverse-proxied dashboard origins
AGENT_BROWSER_CONFIG="./agent-browser.json"  # Custom config file
AGENT_BROWSER_CDP="9222"                     # Connect daemon to CDP port or WebSocket URL
AGENT_BROWSER_ALLOWED_DOMAINS="example.com"  # Restrict network domains; requires a fresh controllable browser context without profile/session startup args, restore/state replay, or direct-page provider plugins
AGENT_BROWSER_PLUGINS='[{"name":"vault","command":"agent-browser-plugin-vault","capabilities":["credential.read"]},{"name":"stealth","command":"agent-browser-plugin-stealth","capabilities":["launch.mutate"]}]'
Referenced from SKILL.md