playwright/docs/src/api/class-cdpsession.md

class: CDPSession

• since: v1.8
• langs: js, python, csharp
• extends: [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.
• Getting Started with DevTools Protocol: https://github.com/aslushnikov/getting-started-with-cdp/blob/master/README.md

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
});

client = await page.context.new_cdp_session(page)
await client.send("Animation.enable")
client.on("Animation.animationCreated", lambda: print("animation created!"))
response = await client.send("Animation.getPlaybackRate")
print("playback rate is " + str(response["playbackRate"]))
await client.send("Animation.setPlaybackRate", {
    playbackRate: response["playbackRate"] / 2
})

client = page.context.new_cdp_session(page)
client.send("Animation.enable")
client.on("Animation.animationCreated", lambda: print("animation created!"))
response = client.send("Animation.getPlaybackRate")
print("playback rate is " + str(response["playbackRate"]))
client.send("Animation.setPlaybackRate", {
    playbackRate: response["playbackRate"] / 2
})

var client = await Page.Context.NewCDPSessionAsync(Page);
await client.SendAsync("Runtime.enable");
client.Event("Animation.animationCreated").OnEvent += (_, _) => Console.WriteLine("Animation created!");
var response = await client.SendAsync("Animation.getPlaybackRate");
var playbackRate = response.Value.GetProperty("playbackRate").GetDouble();
Console.WriteLine("playback rate is " + playbackRate);
await client.SendAsync("Animation.setPlaybackRate", new() { { "playbackRate", playbackRate / 2 } });

async method: CDPSession.detach

• since: v1.8

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

async method: CDPSession.send

• since: v1.8
• langs: js, python, csharp

• returns: <[Object]>

async method: CDPSession.send

• since: v1.30
• langs: csharp

• returns: <[JsonElement?]>

param: CDPSession.send.method

• since: v1.8
• langs: js, python, csharp

• method <[string]>

Protocol method name.

param: CDPSession.send.params

• since: v1.8
• langs: js, python

• params ?<[Object]>

Optional method parameters.

param: CDPSession.send.params

• since: v1.30
• langs: csharp
  • alias-csharp: args

• params ?<[Map<string, Object>]>

Optional method parameters.

method: CDPSession.event

• since: v.1.30
• langs: csharp

• returns: <[CDPSessionEvent]>

Returns an event emitter for the given CDP event name.

param: CDPSession.event.eventName

• since: v1.30
• langs: csharp

• eventName <[string]>

CDP event name.