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Kernel

Kernel provides cloud browsers, computer controls, Playwright execution, session replays, and persistent browser profiles for building browser-based agents and automations.

Connect Kernel in Definable

What agents can do

Actions35

  • Batch computer actions

    Execute 1-100 computer actions sequentially in a Kernel browser, stopping on the first error.

  • Browser curl

    Send a read-only GET, HEAD, or OPTIONS request through a Kernel browser's network stack, inheriting its cookies, TLS fingerprint, proxy settings, and default headers.

  • Browser http request

    Send a state-changing POST, PUT, PATCH, or DELETE request through a Kernel browser's network stack, inheriting its cookies, TLS fingerprint, proxy settings, and default headers.

  • Click

    Click at browser viewport coordinates with an optional mouse button, click phase, modifiers, and repetition count.

  • Create browser

    Create a Kernel browser session; defaults to a headless browser with a 60-second inactivity timeout.

  • Create profile

    Create an empty persistent browser profile, optionally with a unique name, for reuse by later browser sessions.

  • Delete browser

    Permanently end and delete a Kernel browser session by ID or name.

  • Delete playwright executor

    Stop and permanently delete a named, non-default Playwright executor from a Kernel browser.

27 more

  • Delete profile

    Permanently delete a browser profile by ID or name.

  • Download profile

    Download a profile's stored browser state.

  • Drag mouse

    Drag a mouse button through an ordered path of browser viewport coordinates, with optional timing, linear-step, and modifier controls.

  • Execute playwright

    Execute arbitrary TypeScript or JavaScript with Playwright access to the browser; the code may navigate, mutate pages, submit forms, or cause irreversible external effects.

  • Get browser

    Get safe operational details for one browser session by ID or name, optionally including a deleted session.

  • Get mouse position

    Get the current mouse cursor coordinates in a Kernel browser session.

  • Get profile

    Get one browser profile by its ID or exact name.

  • Get replay

    Download a completed browser replay as MP4.

  • List browsers

    List browser sessions, optionally filtered by lifecycle state, search text, tags, or region, one offset page at a time.

  • List playwright executors

    List the default and named Playwright executors for a Kernel browser, including whether each is busy and its owned tab when available.

  • List profiles

    List browser profiles, optionally filtered by substring or exact name, one offset page at a time.

  • List replays

    List replay recordings for a headful browser session without returning signed viewer URLs.

  • Move mouse

    Move the cursor to browser viewport coordinates, optionally using a timed human-like path and held modifier keys.

  • Press key

    Press an ordered sequence of X11 keys or key chords in a browser, optionally holding modifiers or holding the sequence for a duration.

  • Read clipboard

    Read the current text from a Kernel browser session's clipboard.

  • Rename profile

    Rename a Kernel browser profile by ID or exact name.

  • Restart default playwright executor

    Restart a Kernel browser's reserved default Playwright executor.

  • Save browser profile

    Save a running browser's current state to exactly one destination profile ID or name, creating a named profile when needed and overwriting an existing destination.

  • Scroll

    Scroll horizontally or vertically at browser viewport coordinates, optionally while holding modifier keys.

  • Set cursor visibility

    Hide or show the cursor in a Kernel browser session.

  • Start replay

    Start recording a headful Kernel browser session and return its replay identifier and recording metadata without exposing its signed viewer URL.

  • Stop replay

    Stop an active replay recording for a Kernel browser identified by ID or name.

  • Take screenshot

    Capture the full browser viewport or a rectangular region as a PNG download.

  • Type text

    Type text into the currently focused browser element with an optional per-keystroke delay.

  • Update browser

    Update mutable settings on an existing Kernel browser session.

  • Upload browser extensions

    Upload and activate one or more unpacked Chromium extension ZIP archives in an existing running browser.

  • Write clipboard

    Write text to the system clipboard of a Kernel browser session.

How it connects

You paste an API key from Kernel on a page Composio hosts, so the key never passes through Definable.

Keep the connection to yourself or share it with your workspace. Any action that writes or sends can wait for your approval.

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