[Launch options](https://cdpfleet.com/docs/options)

# `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](https://cdpfleet.com/docs/browsers/chrome#opt-start_url), [Microsoft Edge](https://cdpfleet.com/docs/browsers/edge#opt-start_url), [Brave](https://cdpfleet.com/docs/browsers/brave#opt-start_url), [Opera](https://cdpfleet.com/docs/browsers/opera#opt-start_url), [Naver Whale](https://cdpfleet.com/docs/browsers/whale#opt-start_url), [Yandex Browser](https://cdpfleet.com/docs/browsers/yandex#opt-start_url), [Chromium](https://cdpfleet.com/docs/browsers/chromium#opt-start_url), [Patchright](https://cdpfleet.com/docs/browsers/patchright#opt-start_url), [Camoufox](https://cdpfleet.com/docs/browsers/camoufox#opt-start_url), [Firefox](https://cdpfleet.com/docs/browsers/firefox#opt-start_url), [WebKit](https://cdpfleet.com/docs/browsers/webkit#opt-start_url).

## 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](https://cdpfleet.com/docs/live-view#launch-interactive).

## Used in

-   [Case 82: Kept downloads in practice: a person in Launch interactive and an AI agent over MCP](https://cdpfleet.com/docs/cases/downloads-in-practice)
-   [Case 58: Do it by hand in live view, then let your code finish in the same browser](https://cdpfleet.com/docs/cases/launch-interactive-to-code)
-   [Open a page on the server, take over in live view, then join from code](https://cdpfleet.com/docs/examples#start-url-live)

All options: [launch options](https://cdpfleet.com/docs/options).

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Source: https://cdpfleet.com/docs/options/start_url · Markdown: https://cdpfleet.com/docs/options/start_url.md · All docs for AI tools: https://cdpfleet.com/llms.txt