---
id: class-cdpsession
title: "CDPSession"
---

* extends: [EventEmitter](https://nodejs.org/api/events.html#events_class_eventemitter)

The `CDPSession` instances are used to talk raw Chrome Devtools Protocol:
* protocol methods can be called with `session.send` method.
* protocol events can be subscribed to with `session.on` method.

Useful links:
* Documentation on DevTools Protocol can be found here: [DevTools Protocol Viewer](https://chromedevtools.github.io/devtools-protocol/).
* Getting Started with DevTools Protocol: https://github.com/aslushnikov/getting-started-with-cdp/blob/master/README.md

```js
const client = await page.context().newCDPSession(page);
await client.send('Animation.enable');
client.on('Animation.animationCreated', () => console.log('Animation created!'));
const response = await client.send('Animation.getPlaybackRate');
console.log('playback rate is ' + response.playbackRate);
await client.send('Animation.setPlaybackRate', {
  playbackRate: response.playbackRate / 2
});
```


- [cdpSession.detach()](api/class-cdpsession.md#cdpsessiondetach)
- [cdpSession.send(method[, params])](api/class-cdpsession.md#cdpsessionsendmethod-params)

## cdpSession.detach()
- returns: <[Promise]>

Detaches the CDPSession from the target. Once detached, the CDPSession object won't emit any events and can't be used to send messages.

## cdpSession.send(method[, params])
- `method` <[string]> protocol method name
- `params` <[Object]> Optional method parameters
- returns: <[Promise]<[Object]>>

[Playwright]: api/class-playwright.md "Playwright"
[Browser]: api/class-browser.md "Browser"
[BrowserContext]: api/class-browsercontext.md "BrowserContext"
[Page]: api/class-page.md "Page"
[Frame]: api/class-frame.md "Frame"
[ElementHandle]: api/class-elementhandle.md "ElementHandle"
[JSHandle]: api/class-jshandle.md "JSHandle"
[ConsoleMessage]: api/class-consolemessage.md "ConsoleMessage"
[Dialog]: api/class-dialog.md "Dialog"
[Download]: api/class-download.md "Download"
[Video]: api/class-video.md "Video"
[FileChooser]: api/class-filechooser.md "FileChooser"
[Keyboard]: api/class-keyboard.md "Keyboard"
[Mouse]: api/class-mouse.md "Mouse"
[Touchscreen]: api/class-touchscreen.md "Touchscreen"
[Request]: api/class-request.md "Request"
[Response]: api/class-response.md "Response"
[Selectors]: api/class-selectors.md "Selectors"
[Route]: api/class-route.md "Route"
[WebSocket]: api/class-websocket.md "WebSocket"
[TimeoutError]: api/class-timeouterror.md "TimeoutError"
[Accessibility]: api/class-accessibility.md "Accessibility"
[Worker]: api/class-worker.md "Worker"
[BrowserServer]: api/class-browserserver.md "BrowserServer"
[BrowserType]: api/class-browsertype.md "BrowserType"
[Logger]: api/class-logger.md "Logger"
[ChromiumBrowser]: api/class-chromiumbrowser.md "ChromiumBrowser"
[ChromiumBrowserContext]: api/class-chromiumbrowsercontext.md "ChromiumBrowserContext"
[ChromiumCoverage]: api/class-chromiumcoverage.md "ChromiumCoverage"
[CDPSession]: api/class-cdpsession.md "CDPSession"
[FirefoxBrowser]: api/class-firefoxbrowser.md "FirefoxBrowser"
[WebKitBrowser]: api/class-webkitbrowser.md "WebKitBrowser"
[Array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array "Array"
[Buffer]: https://nodejs.org/api/buffer.html#buffer_class_buffer "Buffer"
[ChildProcess]: https://nodejs.org/api/child_process.html "ChildProcess"
[Element]: https://developer.mozilla.org/en-US/docs/Web/API/element "Element"
[Error]: https://nodejs.org/api/errors.html#errors_class_error "Error"
[Evaluation Argument]: ./core-concepts.md#evaluationargument "Evaluation Argument"
[Map]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map "Map"
[Object]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object "Object"
[Promise]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise "Promise"
[RegExp]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp "RegExp"
[Serializable]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify#Description "Serializable"
[UIEvent.detail]: https://developer.mozilla.org/en-US/docs/Web/API/UIEvent/detail "UIEvent.detail"
[URL]: https://nodejs.org/api/url.html "URL"
[USKeyboardLayout]: ../src/usKeyboardLayout.ts "USKeyboardLayout"
[UnixTime]: https://en.wikipedia.org/wiki/Unix_time "Unix Time"
[boolean]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type "Boolean"
[function]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function "Function"
[iterator]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration_protocols "Iterator"
[null]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/null "null"
[number]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type "Number"
[origin]: https://developer.mozilla.org/en-US/docs/Glossary/Origin "Origin"
[selector]: https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Selectors "selector"
[Readable]: https://nodejs.org/api/stream.html#stream_class_stream_readable "Readable"
[string]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type "string"
[xpath]: https://developer.mozilla.org/en-US/docs/Web/XPath "xpath"