start_url
Open this page at launch so the session can be driven in live view with no client connected.
Use it for: A person logs in or passes a check by hand in live view first; then your code connects and carries on in the same page.
Browsers: Google Chrome, Microsoft Edge, Brave, Opera, Naver Whale, Yandex Browser, Chromium, Patchright, Camoufox, Firefox, WebKit.
Details
- Type:
string (http/https URL) - Default: none
- Example:
{"start_url":"https://example.com"}
The server opens the page itself and the session doesn't wait for your code to connect: open a live link in control mode (POST /admin/session/live) and use it like a local browser. Mouse and keyboard input in control mode count as activity, so the session ends after inactivity_timeout without input. Your code can still connect later — browser.contexts()[0].pages() holds the page. This is what the dashboard's Launch interactive does.
http or https, at most 2,048 characters (400 invalid_start_url). Headless needs "live_view": true on a Chromium-based browser; Firefox, Camoufox and WebKit only headful (400 start_url_not_viewable). Without keep_alive, a client that connects and then disconnects ends the session. See Launch interactive.
Used in
- Case 82: Kept downloads in practice: a person in Launch interactive and an AI agent over MCP
- Case 58: Do it by hand in live view, then let your code finish in the same browser
- Open a page on the server, take over in live view, then join from code
All options: launch options.