# Launch options

The JSON body of `POST https://starter.cdpfleet.com/<browser>/session` takes these options. Each has its own page with what it does, what it's for, which browsers take it and the cases and recipes that use it. Per browser, the same options are on its [browser page](https://cdpfleet.com/docs/browsers); the [code builder](https://cdpfleet.com/docs/builder) writes a program with any of them.

| Option | What it does | Browsers |
| --- | --- | --- |
| [`proxy`](https://cdpfleet.com/docs/options/proxy) | Upstream proxy for the browser. | All |
| [`proxy_rules`](https://cdpfleet.com/docs/options/proxy_rules) | Send specific destination hosts through specific proxies. | All |
| [`proxy_updatable`](https://cdpfleet.com/docs/options/proxy_updatable) | Kept for compatibility: every session's proxy can now be swapped without it. | All |
| [`inactivity_timeout`](https://cdpfleet.com/docs/options/inactivity_timeout) | End the session after this long with no traffic on its WebSocket. | All |
| [`overall_timeout`](https://cdpfleet.com/docs/options/overall_timeout) | Hard cap on the session's total lifetime, regardless of activity. | All |
| [`memory`](https://cdpfleet.com/docs/options/memory) | Give the session 2, 3 or 4 times your plan's memory; it counts as that many times the threads. | All |
| [`headless`](https://cdpfleet.com/docs/options/headless) | Run without a display. | All |
| [`channel`](https://cdpfleet.com/docs/options/channel) | Release channel of the browser build. | Google Chrome, Microsoft Edge, Brave, Opera, Naver Whale, Yandex Browser |
| [`version`](https://cdpfleet.com/docs/options/version) | Pin an older major version. | Google Chrome, Camoufox |
| [`os`](https://cdpfleet.com/docs/options/os) | Operating system of the generated fingerprint. | Camoufox |
| [`locale`](https://cdpfleet.com/docs/options/locale) | Browser locale(s). | Camoufox |
| [`geoip`](https://cdpfleet.com/docs/options/geoip) | Match timezone, locale, geolocation and WebRTC IP to the proxy's exit IP. | Camoufox |
| [`humanize`](https://cdpfleet.com/docs/options/humanize) | Human-like cursor movement. | Camoufox |
| [`block_images`](https://cdpfleet.com/docs/options/block_images) | Block all images. | Camoufox |
| [`block_webrtc`](https://cdpfleet.com/docs/options/block_webrtc) | Disable WebRTC entirely. | Camoufox |
| [`block_webgl`](https://cdpfleet.com/docs/options/block_webgl) | Disable WebGL. | Camoufox |
| [`disable_coop`](https://cdpfleet.com/docs/options/disable_coop) | Disable Cross-Origin-Opener-Policy. | Camoufox |
| [`screen`](https://cdpfleet.com/docs/options/screen) | Constrain the fingerprint's screen size. | Camoufox |
| [`window`](https://cdpfleet.com/docs/options/window) | Fixed outer window size. | Camoufox |
| [`fingerprint`](https://cdpfleet.com/docs/options/fingerprint) | Use a complete BrowserForge fingerprint. | Camoufox |
| [`config`](https://cdpfleet.com/docs/options/config) | Override individual fingerprint properties. | Camoufox |
| [`fonts`](https://cdpfleet.com/docs/options/fonts) | Extra font families to expose. | Camoufox |
| [`custom_fonts_only`](https://cdpfleet.com/docs/options/custom_fonts_only) | Expose only the fonts in `fonts`. | Camoufox |
| [`webgl_config`](https://cdpfleet.com/docs/options/webgl_config) | Force a specific WebGL vendor/renderer pair. | Camoufox |
| [`ff_version`](https://cdpfleet.com/docs/options/ff_version) | Firefox major version to claim in the fingerprint. | Camoufox |
| [`screencast`](https://cdpfleet.com/docs/options/screencast) | Stream the page to your code (Playwright page.screencast). | Google Chrome, Microsoft Edge, Brave, Opera, Naver Whale, Yandex Browser, Chromium, Patchright, Camoufox, Firefox, WebKit |
| [`keep_alive`](https://cdpfleet.com/docs/options/keep_alive) | Keep the session when your client disconnects (dedicated threads only). | Google Chrome, Microsoft Edge, Brave, Opera, Naver Whale, Yandex Browser, Chromium, Patchright, Camoufox, Firefox, WebKit |
| [`profile`](https://cdpfleet.com/docs/options/profile) | Restore a saved browser profile and save it again when the session ends. | Google Chrome, Microsoft Edge, Brave, Opera, Yandex Browser, Chromium, Patchright, Camoufox, Firefox, WebKit |
| [`record`](https://cdpfleet.com/docs/options/record) | Opt this session out of recording with false. | All |
| [`downloads`](https://cdpfleet.com/docs/options/downloads) | Keep every file the browser downloads, to fetch after the session. | All |
| [`live_view`](https://cdpfleet.com/docs/options/live_view) | Make a headless session watchable and controllable from outside. | Google Chrome, Microsoft Edge, Brave, Opera, Naver Whale, Yandex Browser, Chromium, Patchright, Rebrowser |
| [`start_url`](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. | Google Chrome, Microsoft Edge, Brave, Opera, Naver Whale, Yandex Browser, Chromium, Patchright, Camoufox, Firefox, WebKit |
| [`screen_size`](https://cdpfleet.com/docs/options/screen_size) | Resolution of the session's own display (headful only). | All |
| [`cdp`](https://cdpfleet.com/docs/options/cdp) | Also expose a Chrome DevTools Protocol endpoint (cdpUrl). | Google Chrome, Microsoft Edge, Brave, Opera, Yandex Browser, Chromium |
| [`vpn_tunnel`](https://cdpfleet.com/docs/options/vpn_tunnel) | VPN Tunnel: UDP/WebRTC full support — all of the browser's traffic, UDP included, goes through the residential exit. | All |
| [`vpn`](https://cdpfleet.com/docs/options/vpn) | Own network (dedicated plans): send all of the browser's traffic through your own VPN instead of a proxy. | All |
| [`main_world_eval`](https://cdpfleet.com/docs/options/main_world_eval) | Allow scripts in the page's main world. | Camoufox |

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