diff --git a/cli/types/cypress.d.ts b/cli/types/cypress.d.ts
index cf0604f27902..f4c69ec165cf 100644
--- a/cli/types/cypress.d.ts
+++ b/cli/types/cypress.d.ts
@@ -6009,7 +6009,11 @@ declare namespace Cypress {
     (fn: (currentSubject: Subject) => void): Chainable<Subject>
   }
 
-  interface BrowserLaunchOptions {
+  interface AfterBrowserLaunchDetails {
+    webSocketDebuggerUrl: string
+  }
+
+  interface BeforeBrowserLaunchOptions {
     extensions: string[]
     preferences: { [key: string]: any }
     args: string[]
@@ -6090,12 +6094,13 @@ declare namespace Cypress {
   }
 
   interface PluginEvents {
+    (action: 'after:browser:launch', fn: (browser: Browser, browserLaunchDetails: AfterBrowserLaunchDetails) => void | Promise<void>): void
     (action: 'after:run', fn: (results: CypressCommandLine.CypressRunResult | CypressCommandLine.CypressFailedRunResult) => void | Promise<void>): void
     (action: 'after:screenshot', fn: (details: ScreenshotDetails) => void | AfterScreenshotReturnObject | Promise<AfterScreenshotReturnObject>): void
     (action: 'after:spec', fn: (spec: Spec, results: CypressCommandLine.RunResult) => void | Promise<void>): void
     (action: 'before:run', fn: (runDetails: BeforeRunDetails) => void | Promise<void>): void
     (action: 'before:spec', fn: (spec: Spec) => void | Promise<void>): void
-    (action: 'before:browser:launch', fn: (browser: Browser, browserLaunchOptions: BrowserLaunchOptions) => void | BrowserLaunchOptions | Promise<BrowserLaunchOptions>): void
+    (action: 'before:browser:launch', fn: (browser: Browser, afterBrowserLaunchOptions: BeforeBrowserLaunchOptions) => void | Promise<void> | BeforeBrowserLaunchOptions | Promise<BeforeBrowserLaunchOptions>): void
     (action: 'file:preprocessor', fn: (file: FileObject) => string | Promise<string>): void
     (action: 'dev-server:start', fn: (file: DevServerConfig) => Promise<ResolvedDevServerConfig>): void
     (action: 'task', tasks: Tasks): void
diff --git a/packages/server/lib/browsers/browser-cri-client.ts b/packages/server/lib/browsers/browser-cri-client.ts
index c7f0964231ca..8d11b913afed 100644
--- a/packages/server/lib/browsers/browser-cri-client.ts
+++ b/packages/server/lib/browsers/browser-cri-client.ts
@@ -574,6 +574,13 @@ export class BrowserCriClient {
     this.extraTargetClients.delete(targetId)
   }
 
+  /**
+   * @returns the websocket debugger URL for the currently connected browser
+   */
+  getWebSocketDebuggerUrl () {
+    return this.versionInfo.webSocketDebuggerUrl
+  }
+
   /**
    * Closes the browser client socket as well as the socket for the currently attached page target
    */
diff --git a/packages/server/lib/browsers/chrome.ts b/packages/server/lib/browsers/chrome.ts
index 8ff81eab95cd..62026997c306 100644
--- a/packages/server/lib/browsers/chrome.ts
+++ b/packages/server/lib/browsers/chrome.ts
@@ -645,6 +645,10 @@ export = {
 
     await this.attachListeners(url, pageCriClient, automation, options, browser)
 
+    await utils.executeAfterBrowserLaunch(browser, {
+      webSocketDebuggerUrl: browserCriClient.getWebSocketDebuggerUrl(),
+    })
+
     // return the launched browser process
     // with additional method to close the remote connection
     return launchedBrowser
diff --git a/packages/server/lib/browsers/cri-client.ts b/packages/server/lib/browsers/cri-client.ts
index 97325b755cac..a578592a4a53 100644
--- a/packages/server/lib/browsers/cri-client.ts
+++ b/packages/server/lib/browsers/cri-client.ts
@@ -265,15 +265,26 @@ export const create = async ({
 
     maybeDebugCdpMessages(cri)
 
-    // Only reconnect when we're not running cypress in cypress. There are a lot of disconnects that happen that we don't want to reconnect on
-    if (!process.env.CYPRESS_INTERNAL_E2E_TESTING_SELF) {
+    // Having a host set indicates that this is the child cri target, a.k.a.
+    // the main Cypress tab (as opposed to the root browser cri target)
+    const isChildTarget = !!host
+
+    // don't reconnect in these circumstances
+    if (
+      // is a child target. we only need to reconnect the root browser target
+      !isChildTarget
+      // running cypress in cypress - there are a lot of disconnects that happen
+      // that we don't want to reconnect on
+      && !process.env.CYPRESS_INTERNAL_E2E_TESTING_SELF
+    ) {
       cri.on('disconnect', retryReconnect)
     }
 
-    // We only want to try and add child target traffic if we have a host set. This indicates that this is the child cri client.
-    // Browser cri traffic is handled in browser-cri-client.ts. The basic approach here is we attach to targets and enable network traffic
-    // We must attach in a paused state so that we can enable network traffic before the target starts running.
-    if (host) {
+    // We're only interested in child target traffic. Browser cri traffic is
+    // handled in browser-cri-client.ts. The basic approach here is we attach
+    // to targets and enable network traffic. We must attach in a paused state
+    // so that we can enable network traffic before the target starts running.
+    if (isChildTarget) {
       cri.on('Target.targetCrashed', async (event) => {
         if (event.targetId !== target) {
           return
diff --git a/packages/server/lib/browsers/electron.ts b/packages/server/lib/browsers/electron.ts
index fd4f819b4c8c..fb9ebf451564 100644
--- a/packages/server/lib/browsers/electron.ts
+++ b/packages/server/lib/browsers/electron.ts
@@ -539,6 +539,10 @@ export = {
       },
     }) as BrowserInstance
 
+    await utils.executeAfterBrowserLaunch(browser, {
+      webSocketDebuggerUrl: browserCriClient!.getWebSocketDebuggerUrl(),
+    })
+
     return instance
   },
 }
diff --git a/packages/server/lib/browsers/firefox.ts b/packages/server/lib/browsers/firefox.ts
index 4fbbc2c9297d..e7ae8e63ecd7 100644
--- a/packages/server/lib/browsers/firefox.ts
+++ b/packages/server/lib/browsers/firefox.ts
@@ -347,7 +347,7 @@ toolbar {
 
 `
 
-let browserCriClient
+let browserCriClient: BrowserCriClient | undefined
 
 export function _createDetachedInstance (browserInstance: BrowserInstance, browserCriClient?: BrowserCriClient): BrowserInstance {
   const detachedInstance: BrowserInstance = new EventEmitter() as BrowserInstance
@@ -382,7 +382,7 @@ export function clearInstanceState (options: GracefulShutdownOptions = {}) {
 }
 
 export async function connectToNewSpec (browser: Browser, options: BrowserNewTabOpts, automation: Automation) {
-  await firefoxUtil.connectToNewSpec(options, automation, browserCriClient)
+  await firefoxUtil.connectToNewSpec(options, automation, browserCriClient!)
 }
 
 export function connectToExisting () {
@@ -573,6 +573,10 @@ export async function open (browser: Browser, url: string, options: BrowserLaunc
 
       return originalBrowserKill.apply(browserInstance, args)
     }
+
+    await utils.executeAfterBrowserLaunch(browser, {
+      webSocketDebuggerUrl: browserCriClient.getWebSocketDebuggerUrl(),
+    })
   } catch (err) {
     errors.throwErr('FIREFOX_COULD_NOT_CONNECT', err)
   }
diff --git a/packages/server/lib/browsers/utils.ts b/packages/server/lib/browsers/utils.ts
index b6f246b28ff9..deed00e225cc 100644
--- a/packages/server/lib/browsers/utils.ts
+++ b/packages/server/lib/browsers/utils.ts
@@ -7,6 +7,7 @@ import * as plugins from '../plugins'
 import { getError } from '@packages/errors'
 import * as launcher from '@packages/launcher'
 import type { Automation } from '../automation'
+import type { Browser } from './types'
 import type { CriClient } from './cri-client'
 
 declare global {
@@ -157,6 +158,27 @@ async function executeBeforeBrowserLaunch (browser, launchOptions: typeof defaul
   return launchOptions
 }
 
+interface AfterBrowserLaunchDetails {
+  webSocketDebuggerUrl: string | never
+}
+
+async function executeAfterBrowserLaunch (browser: Browser, options: AfterBrowserLaunchDetails) {
+  if (plugins.has('after:browser:launch')) {
+    const span = telemetry.startSpan({ name: 'lifecycle:after:browser:launch' })
+
+    span?.setAttribute({
+      name: browser.name,
+      channel: browser.channel,
+      version: browser.version,
+      isHeadless: browser.isHeadless,
+    })
+
+    await plugins.execute('after:browser:launch', browser, options)
+
+    span?.end()
+  }
+}
+
 function extendLaunchOptionsFromPlugins (launchOptions, pluginConfigResult, options: BrowserLaunchOpts) {
   // if we returned an array from the plugin
   // then we know the user is using the deprecated
@@ -423,6 +445,8 @@ export = {
 
   extendLaunchOptionsFromPlugins,
 
+  executeAfterBrowserLaunch,
+
   executeBeforeBrowserLaunch,
 
   defaultLaunchOptions,
diff --git a/packages/server/lib/browsers/webkit.ts b/packages/server/lib/browsers/webkit.ts
index a02540daba39..26955261f4e5 100644
--- a/packages/server/lib/browsers/webkit.ts
+++ b/packages/server/lib/browsers/webkit.ts
@@ -101,7 +101,8 @@ export async function open (browser: Browser, url: string, options: BrowserLaunc
 
   removeBadExitListener()
 
-  const pwBrowser = await pw.webkit.connect(pwServer.wsEndpoint())
+  const websocketUrl = pwServer.wsEndpoint()
+  const pwBrowser = await pw.webkit.connect(websocketUrl)
 
   wkAutomation = await WebKitAutomation.create({
     automation,
@@ -147,5 +148,9 @@ export async function open (browser: Browser, url: string, options: BrowserLaunc
     }
   }
 
+  await utils.executeAfterBrowserLaunch(browser, {
+    webSocketDebuggerUrl: websocketUrl,
+  })
+
   return new WkInstance()
 }
diff --git a/packages/server/lib/plugins/child/browser_launch.js b/packages/server/lib/plugins/child/browser_launch.js
index c5680961e3d8..54b777d384e3 100644
--- a/packages/server/lib/plugins/child/browser_launch.js
+++ b/packages/server/lib/plugins/child/browser_launch.js
@@ -3,7 +3,7 @@ const util = require('../util')
 const ARRAY_METHODS = ['concat', 'push', 'unshift', 'slice', 'pop', 'shift', 'slice', 'splice', 'filter', 'map', 'forEach', 'reduce', 'reverse', 'splice', 'includes']
 
 module.exports = {
-  wrap (ipc, invoke, ids, args) {
+  wrapBefore (ipc, invoke, ids, args) {
     // TODO: remove in next breaking release
     // This will send a warning message when a deprecated API is used
     // define array-like functions on this object so we can warn about using deprecated array API
diff --git a/packages/server/lib/plugins/child/run_plugins.js b/packages/server/lib/plugins/child/run_plugins.js
index f86a35d5cdf9..0e439519860b 100644
--- a/packages/server/lib/plugins/child/run_plugins.js
+++ b/packages/server/lib/plugins/child/run_plugins.js
@@ -169,7 +169,9 @@ class RunPlugins {
       case '_get:task:body':
         return this.taskGetBody(ids, args)
       case 'before:browser:launch':
-        return browserLaunch.wrap(this.ipc, this.invoke, ids, args)
+        return browserLaunch.wrapBefore(this.ipc, this.invoke, ids, args)
+      case 'after:browser:launch':
+        return util.wrapChildPromise(this.ipc, this.invoke, ids, args)
       default:
         debug('unexpected execute message:', event, args)
 
diff --git a/packages/server/lib/plugins/child/validate_event.js b/packages/server/lib/plugins/child/validate_event.js
index 0a82f902d7d8..2c8832682552 100644
--- a/packages/server/lib/plugins/child/validate_event.js
+++ b/packages/server/lib/plugins/child/validate_event.js
@@ -27,6 +27,7 @@ const eventValidators = {
   '_get:task:body': isFunction,
   '_get:task:keys': isFunction,
   '_process:cross:origin:callback': isFunction,
+  'after:browser:launch': isFunction,
   'after:run': isFunction,
   'after:screenshot': isFunction,
   'after:spec': isFunction,
@@ -42,7 +43,11 @@ const validateEvent = (event, handler, config, errConstructorFn) => {
   const validator = eventValidators[event]
 
   if (!validator) {
-    const userEvents = _.reject(_.keys(eventValidators), (event) => event.startsWith('_'))
+    const userEvents = _.reject(_.keys(eventValidators), (event) => {
+      // we're currently not documenting after:browser:launch, so it shouldn't
+      // appear in the list of valid events
+      return event.startsWith('_') || event === 'after:browser:launch'
+    })
 
     const error = new Error(`invalid event name registered: ${event}`)
 
diff --git a/packages/server/test/integration/cypress_spec.js b/packages/server/test/integration/cypress_spec.js
index ca48af7aae03..f7957c35a0cf 100644
--- a/packages/server/test/integration/cypress_spec.js
+++ b/packages/server/test/integration/cypress_spec.js
@@ -1006,6 +1006,7 @@ describe('lib/cypress', () => {
             ensureMinimumProtocolVersion: sinon.stub().resolves(),
             attachToTargetUrl: sinon.stub().resolves(criClient),
             close: sinon.stub().resolves(),
+            getWebSocketDebuggerUrl: sinon.stub().returns('ws://debugger'),
           }
 
           const cdpAutomation = {
@@ -1076,6 +1077,7 @@ describe('lib/cypress', () => {
             attachToTargetUrl: sinon.stub().resolves(criClient),
             currentlyAttachedTarget: criClient,
             close: sinon.stub().resolves(),
+            getWebSocketDebuggerUrl: sinon.stub().returns('ws://debugger'),
           }
 
           sinon.stub(BrowserCriClient, 'create').resolves(browserCriClient)
diff --git a/packages/server/test/unit/browsers/chrome_spec.js b/packages/server/test/unit/browsers/chrome_spec.js
index 20dc11dfe6d7..5f8f5286c436 100644
--- a/packages/server/test/unit/browsers/chrome_spec.js
+++ b/packages/server/test/unit/browsers/chrome_spec.js
@@ -33,6 +33,7 @@ describe('lib/browsers/chrome', () => {
         attachToTargetUrl: sinon.stub().resolves(this.pageCriClient),
         close: sinon.stub().resolves(),
         ensureMinimumProtocolVersion: sinon.stub().withArgs('1.3').resolves(),
+        getWebSocketDebuggerUrl: sinon.stub().returns('ws://debugger'),
       }
 
       this.automation = {
@@ -93,14 +94,14 @@ describe('lib/browsers/chrome', () => {
       })
     })
 
-    it('is noop without before:browser:launch', function () {
+    it('executeBeforeBrowserLaunch is noop if before:browser:launch is not registered', function () {
       return chrome.open({ isHeadless: true }, 'http://', openOpts, this.automation)
       .then(() => {
-        expect(plugins.execute).not.to.be.called
+        expect(plugins.execute).not.to.be.calledWith('before:browser:launch')
       })
     })
 
-    it('is noop if newArgs are not returned', function () {
+    it('uses default args if new args are not returned from before:browser:launch', function () {
       const args = []
 
       sinon.stub(chrome, '_getArgs').returns(args)
@@ -304,6 +305,30 @@ describe('lib/browsers/chrome', () => {
       return expect(chrome.open({ isHeadless: true }, 'http://', openOpts, this.automation)).to.be.rejectedWith('Cypress requires at least Chrome 64.')
     })
 
+    it('sends after:browser:launch with debugger url', function () {
+      const args = []
+      const browser = { isHeadless: true }
+
+      sinon.stub(chrome, '_getArgs').returns(args)
+      sinon.stub(plugins, 'has').returns(true)
+
+      plugins.execute.resolves(null)
+
+      return chrome.open(browser, 'http://', openOpts, this.automation)
+      .then(() => {
+        expect(plugins.execute).to.be.calledWith('after:browser:launch', browser, {
+          webSocketDebuggerUrl: 'ws://debugger',
+        })
+      })
+    })
+
+    it('executeAfterBrowserLaunch is noop if after:browser:launch is not registered', function () {
+      return chrome.open({ isHeadless: true }, 'http://', openOpts, this.automation)
+      .then(() => {
+        expect(plugins.execute).not.to.be.calledWith('after:browser:launch')
+      })
+    })
+
     describe('downloads', function () {
       it('pushes create:download after download begins', function () {
         const downloadData = {
diff --git a/packages/server/test/unit/browsers/electron_spec.js b/packages/server/test/unit/browsers/electron_spec.js
index ecb0101d2f16..194e1414e076 100644
--- a/packages/server/test/unit/browsers/electron_spec.js
+++ b/packages/server/test/unit/browsers/electron_spec.js
@@ -80,6 +80,7 @@ describe('lib/browsers/electron', () => {
       attachToTargetUrl: sinon.stub().resolves(this.pageCriClient),
       currentlyAttachedTarget: this.pageCriClient,
       close: sinon.stub().resolves(),
+      getWebSocketDebuggerUrl: sinon.stub().returns('ws://debugger'),
     }
 
     sinon.stub(BrowserCriClient, 'create').resolves(this.browserCriClient)
@@ -111,8 +112,11 @@ describe('lib/browsers/electron', () => {
   })
 
   context('.open', () => {
-    beforeEach(function () {
-      return this.stubForOpen()
+    beforeEach(async function () {
+      // shortcut to set the browserCriClient singleton variable
+      await electron._getAutomation({}, { onError: () => {} }, {})
+
+      await this.stubForOpen()
     })
 
     it('calls render with url, state, and options', function () {
@@ -152,7 +156,7 @@ describe('lib/browsers/electron', () => {
       })
     })
 
-    it('is noop when before:browser:launch yields null', function () {
+    it('executeBeforeBrowserLaunch is noop when before:browser:launch yields null', function () {
       plugins.has.returns(true)
       plugins.execute.resolves(null)
 
@@ -207,6 +211,25 @@ describe('lib/browsers/electron', () => {
         expect(Windows.removeAllExtensions).to.be.calledTwice
       })
     })
+
+    it('sends after:browser:launch with debugger url', function () {
+      plugins.has.returns(true)
+      plugins.execute.resolves(null)
+
+      return electron.open('electron', this.url, this.options, this.automation)
+      .then(() => {
+        expect(plugins.execute).to.be.calledWith('after:browser:launch', 'electron', {
+          webSocketDebuggerUrl: 'ws://debugger',
+        })
+      })
+    })
+
+    it('executeAfterBrowserLaunch is noop if after:browser:launch is not registered', function () {
+      return electron.open('electron', this.url, this.options, this.automation)
+      .then(() => {
+        expect(plugins.execute).not.to.be.calledWith('after:browser:launch')
+      })
+    })
   })
 
   context('.connectProtocolToBrowser', () => {
@@ -821,7 +844,10 @@ describe('lib/browsers/electron', () => {
         expect(electron._launchChild).to.be.calledWith(this.url, parentWindow, this.options.projectRoot, this.state, this.options, this.automation)
       })
 
-      it('adds pid of new BrowserWindow to allPids list', function () {
+      it('adds pid of new BrowserWindow to allPids list', async function () {
+        // shortcut to set the browserCriClient singleton variable
+        await electron._getAutomation({}, { onError: () => {} }, {})
+
         const opts = electron._defaultOptions(this.options.projectRoot, this.state, this.options)
 
         const NEW_WINDOW_PID = ELECTRON_PID * 2
diff --git a/packages/server/test/unit/browsers/firefox_spec.ts b/packages/server/test/unit/browsers/firefox_spec.ts
index b0ab02ffacd3..6827d10f0fca 100644
--- a/packages/server/test/unit/browsers/firefox_spec.ts
+++ b/packages/server/test/unit/browsers/firefox_spec.ts
@@ -126,7 +126,9 @@ describe('lib/browsers/firefox', () => {
 
   context('#open', () => {
     beforeEach(function () {
-      this.browser = { name: 'firefox', channel: 'stable' }
+      // majorVersion >= 86 indicates CDP support for Firefox, which provides
+      // the CDP debugger URL for the after:browser:launch tests
+      this.browser = { name: 'firefox', channel: 'stable', majorVersion: 100 }
       this.automation = {
         use: sinon.stub().returns({}),
       }
@@ -150,31 +152,40 @@ describe('lib/browsers/firefox', () => {
       sinon.stub(plugins, 'execute')
       sinon.stub(launch, 'launch').returns(this.browserInstance)
       sinon.stub(utils, 'writeExtension').resolves('/path/to/ext')
+      sinon.stub(utils, 'getPort').resolves(1234)
       sinon.spy(FirefoxProfile.prototype, 'setPreference')
       sinon.spy(FirefoxProfile.prototype, 'updatePreferences')
+      sinon.spy(FirefoxProfile.prototype, 'path')
+
+      const browserCriClient: BrowserCriClient = sinon.createStubInstance(BrowserCriClient)
 
-      return sinon.spy(FirefoxProfile.prototype, 'path')
+      browserCriClient.attachToTargetUrl = sinon.stub().resolves({})
+      browserCriClient.getWebSocketDebuggerUrl = sinon.stub().returns('ws://debugger')
+      browserCriClient.close = sinon.stub().resolves()
+
+      sinon.stub(BrowserCriClient, 'create').resolves(browserCriClient)
+      sinon.stub(CdpAutomation, 'create').resolves()
     })
 
     it('executes before:browser:launch if registered', function () {
-      plugins.has.returns(true)
+      plugins.has.withArgs('before:browser:launch').returns(true)
       plugins.execute.resolves(null)
 
       return firefox.open(this.browser, 'http://', this.options, this.automation).then(() => {
-        expect(plugins.execute).to.be.called
+        expect(plugins.execute).to.be.calledWith('before:browser:launch')
       })
     })
 
     it('does not execute before:browser:launch if not registered', function () {
-      plugins.has.returns(false)
+      plugins.has.withArgs('before:browser:launch').returns(false)
 
       return firefox.open(this.browser, 'http://', this.options, this.automation).then(() => {
-        expect(plugins.execute).not.to.be.called
+        expect(plugins.execute).not.to.be.calledWith('before:browser:launch')
       })
     })
 
     it('uses default preferences if before:browser:launch returns falsy value', function () {
-      plugins.has.returns(true)
+      plugins.has.withArgs('before:browser:launch').returns(true)
       plugins.execute.resolves(null)
 
       return firefox.open(this.browser, 'http://', this.options, this.automation).then(() => {
@@ -183,7 +194,7 @@ describe('lib/browsers/firefox', () => {
     })
 
     it('uses default preferences if before:browser:launch returns object with non-object preferences', function () {
-      plugins.has.returns(true)
+      plugins.has.withArgs('before:browser:launch').returns(true)
       plugins.execute.resolves({
         preferences: [],
       })
@@ -194,7 +205,7 @@ describe('lib/browsers/firefox', () => {
     })
 
     it('sets preferences if returned by before:browser:launch', function () {
-      plugins.has.returns(true)
+      plugins.has.withArgs('before:browser:launch').returns(true)
       plugins.execute.resolves({
         preferences: { 'foo': 'bar' },
       })
@@ -205,7 +216,7 @@ describe('lib/browsers/firefox', () => {
     })
 
     it('adds extensions returned by before:browser:launch, along with cypress extension', function () {
-      plugins.has.returns(true)
+      plugins.has.withArgs('before:browser:launch').returns(true)
       plugins.execute.resolves({
         extensions: ['/path/to/user/ext'],
       })
@@ -218,7 +229,7 @@ describe('lib/browsers/firefox', () => {
     })
 
     it('adds only cypress extension if before:browser:launch returns object with non-array extensions', function () {
-      plugins.has.returns(true)
+      plugins.has.withArgs('before:browser:launch').returns(true)
       plugins.execute.resolves({
         extensions: 'not-an-array',
       })
@@ -331,12 +342,13 @@ describe('lib/browsers/firefox', () => {
 
     it('launches with the url and args', function () {
       return firefox.open(this.browser, 'http://', this.options, this.automation).then(() => {
-        expect(launch.launch).to.be.calledWith(this.browser, 'about:blank', undefined, [
+        expect(launch.launch).to.be.calledWith(this.browser, 'about:blank', 1234, [
           '-marionette',
           '-new-instance',
           '-foreground',
           '-start-debugger-server',
           '-no-remote',
+          '--remote-debugging-port=1234',
           '-profile',
           '/path/to/appData/firefox-stable/interactive',
         ])
@@ -410,6 +422,25 @@ describe('lib/browsers/firefox', () => {
       })
     })
 
+    it('executes after:browser:launch if registered', function () {
+      plugins.has.withArgs('after:browser:launch').returns(true)
+      plugins.execute.resolves(null)
+
+      return firefox.open(this.browser, 'http://', this.options, this.automation).then(() => {
+        expect(plugins.execute).to.be.calledWith('after:browser:launch', this.browser, {
+          webSocketDebuggerUrl: 'ws://debugger',
+        })
+      })
+    })
+
+    it('does not execute after:browser:launch if not registered', function () {
+      plugins.has.withArgs('after:browser:launch').returns(false)
+
+      return firefox.open(this.browser, 'http://', this.options, this.automation).then(() => {
+        expect(plugins.execute).not.to.be.calledWith('after:browser:launch')
+      })
+    })
+
     context('returns BrowserInstance', function () {
       it('from browsers.launch', async function () {
         const instance = await firefox.open(this.browser, 'http://', this.options, this.automation)
diff --git a/packages/server/test/unit/browsers/webkit_spec.ts b/packages/server/test/unit/browsers/webkit_spec.ts
index 9906936c98a8..708224b6ecd7 100644
--- a/packages/server/test/unit/browsers/webkit_spec.ts
+++ b/packages/server/test/unit/browsers/webkit_spec.ts
@@ -1,12 +1,79 @@
-require('../../spec_helper')
-
+import { proxyquire } from '../../spec_helper'
 import { expect } from 'chai'
+import utils from '../../../lib/browsers/utils'
+import * as plugins from '../../../lib/plugins'
 
-import * as webkit from '../../../lib/browsers/webkit'
+function getWebkit (dependencies = {}) {
+  return proxyquire('../lib/browsers/webkit', dependencies) as typeof import('../../../lib/browsers/webkit')
+}
 
 describe('lib/browsers/webkit', () => {
+  context('#open', () => {
+    let browser
+    let options
+    let automation
+    let webkit
+
+    beforeEach(async () => {
+      browser = {}
+      options = { experimentalWebKitSupport: true }
+      automation = { use: sinon.stub() }
+
+      const launchOptions = {
+        extensions: [],
+        args: [],
+        preferences: { },
+      }
+      const pwWebkit = {
+        webkit: {
+          connect: sinon.stub().resolves({
+            on: sinon.stub(),
+          }),
+          launchServer: sinon.stub().resolves({
+            wsEndpoint: sinon.stub().returns('ws://debugger'),
+            process: sinon.stub().returns({ pid: 'pid' }),
+          }),
+        },
+      }
+      const wkAutomation = {
+        WebKitAutomation: {
+          create: sinon.stub().resolves({}),
+        },
+      }
+
+      sinon.stub(utils, 'executeBeforeBrowserLaunch').resolves(launchOptions as any)
+      sinon.stub(plugins, 'execute').resolves()
+      sinon.stub(plugins, 'has')
+
+      webkit = getWebkit({
+        'playwright-webkit': pwWebkit,
+        './webkit-automation': wkAutomation,
+      })
+    })
+
+    it('sends after:browser:launch with debugger url', async () => {
+      (plugins.has as any).returns(true)
+
+      await webkit.open(browser as any, 'http://the.url', options as any, automation as any)
+
+      expect(plugins.execute).to.be.calledWith('after:browser:launch', browser, {
+        webSocketDebuggerUrl: 'ws://debugger',
+      })
+    })
+
+    it('executeAfterBrowserLaunch is noop if after:browser:launch is not registered', async () => {
+      (plugins.has as any).returns(false)
+
+      await webkit.open(browser as any, 'http://the.url', options as any, automation as any)
+
+      expect(plugins.execute).not.to.be.calledWith('after:browser:launch')
+    })
+  })
+
   context('#connectProtocolToBrowser', () => {
     it('throws error', () => {
+      const webkit = getWebkit()
+
       expect(webkit.connectProtocolToBrowser).to.throw('Protocol is not yet supported in WebKit.')
     })
   })
diff --git a/packages/server/test/unit/plugins/child/run_plugins_spec.js b/packages/server/test/unit/plugins/child/run_plugins_spec.js
index f87555f27c0f..7b89e2ec7fa6 100644
--- a/packages/server/test/unit/plugins/child/run_plugins_spec.js
+++ b/packages/server/test/unit/plugins/child/run_plugins_spec.js
@@ -141,6 +141,7 @@ describe('lib/plugins/child/run_plugins', () => {
 
     describe(`on 'execute:plugins' message`, () => {
       let onFilePreprocessor
+      let afterBrowserLaunch
       let beforeBrowserLaunch
       let taskRequested
       let setupNodeEventsFn
@@ -149,11 +150,13 @@ describe('lib/plugins/child/run_plugins', () => {
         sinon.stub(preprocessor, 'wrap')
 
         onFilePreprocessor = sinon.stub().resolves()
+        afterBrowserLaunch = sinon.stub().resolves()
         beforeBrowserLaunch = sinon.stub().resolves()
         taskRequested = sinon.stub().resolves('foo')
 
         setupNodeEventsFn = (on) => {
           on('file:preprocessor', onFilePreprocessor)
+          on('after:browser:launch', afterBrowserLaunch)
           on('before:browser:launch', beforeBrowserLaunch)
           on('task', taskRequested)
         }
@@ -201,6 +204,35 @@ describe('lib/plugins/child/run_plugins', () => {
           ipc.on.withArgs('execute:plugins').yield('before:browser:launch', ids, args)
         })
 
+        it('wraps child promise', () => {
+          expect(util.wrapChildPromise).to.be.calledWith(ipc, sinon.match.func, ids, args)
+        })
+
+        it('invokes registered function when invoked by handler', () => {
+          // console.log(util.wrapChildPromise.withArgs(ipc, sinon.match.func, ids, args).args)
+          util.wrapChildPromise.withArgs(ipc, sinon.match.func, ids, args).args[0][1](5, args)
+
+          expect(beforeBrowserLaunch).to.be.calledWith(...args)
+        })
+      })
+
+      context('after:browser:launch', () => {
+        let args
+        const ids = { eventId: 2, invocationId: '00' }
+
+        beforeEach(async () => {
+          sinon.stub(util, 'wrapChildPromise')
+
+          await runPlugins.runSetupNodeEvents(config, setupNodeEventsFn)
+
+          const browser = {}
+          const launchOptions = browserUtils.getDefaultLaunchOptions({})
+
+          args = [browser, launchOptions]
+
+          ipc.on.withArgs('execute:plugins').yield('after:browser:launch', ids, args)
+        })
+
         it('wraps child promise', () => {
           expect(util.wrapChildPromise).to.be.called
           expect(util.wrapChildPromise.lastCall.args[0]).to.equal(ipc)
@@ -212,7 +244,7 @@ describe('lib/plugins/child/run_plugins', () => {
         it('invokes registered function when invoked by handler', () => {
           util.wrapChildPromise.lastCall.args[1](4, args)
 
-          expect(beforeBrowserLaunch).to.be.calledWith(...args)
+          expect(afterBrowserLaunch).to.be.calledWith(...args)
         })
       })
 
diff --git a/packages/server/test/unit/plugins/child/validate_event_spec.js b/packages/server/test/unit/plugins/child/validate_event_spec.js
index dee6e85a0727..f024ee79cbbb 100644
--- a/packages/server/test/unit/plugins/child/validate_event_spec.js
+++ b/packages/server/test/unit/plugins/child/validate_event_spec.js
@@ -4,6 +4,7 @@ const _ = require('lodash')
 const validateEvent = require('../../../../lib/plugins/child/validate_event')
 
 const events = [
+  ['after:browser:launch', 'a function', () => {}],
   ['after:run', 'a function', () => {}],
   ['after:screenshot', 'a function', () => {}],
   ['after:spec', 'a function', () => {}],
diff --git a/packages/server/test/unit/util/args_spec.js b/packages/server/test/unit/util/args_spec.js
index 05ddb06210ec..ff7e1ba4af00 100644
--- a/packages/server/test/unit/util/args_spec.js
+++ b/packages/server/test/unit/util/args_spec.js
@@ -8,7 +8,7 @@ const minimist = require('minimist')
 const argsUtil = require(`../../../lib/util/args`)
 const getWindowsProxyUtil = require(`../../../lib/util/get-windows-proxy`)
 
-const cwd = process.cwd()
+const getCwd = () => process.cwd()
 
 describe('lib/util/args', () => {
   beforeEach(function () {
@@ -92,7 +92,7 @@ describe('lib/util/args', () => {
 
   context('--project', () => {
     it('sets projectRoot', function () {
-      const projectRoot = path.resolve(cwd, './foo/bar')
+      const projectRoot = path.resolve(getCwd(), './foo/bar')
       const options = this.setup('--project', './foo/bar')
 
       expect(options.projectRoot).to.eq(projectRoot)
@@ -113,7 +113,7 @@ describe('lib/util/args', () => {
 
   context('--run-project', () => {
     it('sets projectRoot', function () {
-      const projectRoot = path.resolve(cwd, '/baz')
+      const projectRoot = path.resolve(getCwd(), '/baz')
       const options = this.setup('--run-project', '/baz')
 
       expect(options.projectRoot).to.eq(projectRoot)
@@ -138,16 +138,16 @@ describe('lib/util/args', () => {
     it('converts to array', function () {
       const options = this.setup('--run-project', 'foo', '--spec', 'cypress/integration/a.js,cypress/integration/b.js,cypress/integration/c.js')
 
-      expect(options.spec[0]).to.eq(`${cwd}/cypress/integration/a.js`)
-      expect(options.spec[1]).to.eq(`${cwd}/cypress/integration/b.js`)
+      expect(options.spec[0]).to.eq(`${getCwd()}/cypress/integration/a.js`)
+      expect(options.spec[1]).to.eq(`${getCwd()}/cypress/integration/b.js`)
 
-      expect(options.spec[2]).to.eq(`${cwd}/cypress/integration/c.js`)
+      expect(options.spec[2]).to.eq(`${getCwd()}/cypress/integration/c.js`)
     })
 
     it('discards wrapping single quotes', function () {
       const options = this.setup('--run-project', 'foo', '--spec', '\'cypress/integration/foo_spec.js\'')
 
-      expect(options.spec[0]).to.eq(`${cwd}/cypress/integration/foo_spec.js`)
+      expect(options.spec[0]).to.eq(`${getCwd()}/cypress/integration/foo_spec.js`)
     })
 
     it('throws if argument cannot be parsed', function () {
@@ -165,56 +165,56 @@ describe('lib/util/args', () => {
     it('should be correctly parsing globs with lists & ranges', function () {
       const options = this.setup('--spec', 'cypress/integration/{[!a]*.spec.js,sub1,{sub2,sub3/sub4}}/*.js')
 
-      expect(options.spec[0]).to.eq(`${cwd}/cypress/integration/{[!a]*.spec.js,sub1,{sub2,sub3/sub4}}/*.js`)
+      expect(options.spec[0]).to.eq(`${getCwd()}/cypress/integration/{[!a]*.spec.js,sub1,{sub2,sub3/sub4}}/*.js`)
     })
 
     it('should be correctly parsing globs with a mix of lists, ranges & regular paths', function () {
       const options = this.setup('--spec', 'cypress/integration/{[!a]*.spec.js,sub1,{sub2,sub3/sub4}}/*.js,cypress/integration/foo.spec.js')
 
-      expect(options.spec[0]).to.eq(`${cwd}/cypress/integration/{[!a]*.spec.js,sub1,{sub2,sub3/sub4}}/*.js`)
-      expect(options.spec[1]).to.eq(`${cwd}/cypress/integration/foo.spec.js`)
+      expect(options.spec[0]).to.eq(`${getCwd()}/cypress/integration/{[!a]*.spec.js,sub1,{sub2,sub3/sub4}}/*.js`)
+      expect(options.spec[1]).to.eq(`${getCwd()}/cypress/integration/foo.spec.js`)
     })
 
     it('should be correctly parsing single glob with range', function () {
       const options = this.setup('--spec', 'cypress/integration/[a-c]*/**')
 
-      expect(options.spec[0]).to.eq(`${cwd}/cypress/integration/[a-c]*/**`)
+      expect(options.spec[0]).to.eq(`${getCwd()}/cypress/integration/[a-c]*/**`)
     })
 
     it('should be correctly parsing single glob with list', function () {
       const options = this.setup('--spec', 'cypress/integration/{a,b,c}/*.js')
 
-      expect(options.spec[0]).to.eq(`${cwd}/cypress/integration/{a,b,c}/*.js`)
+      expect(options.spec[0]).to.eq(`${getCwd()}/cypress/integration/{a,b,c}/*.js`)
     })
 
     // https://github.com/cypress-io/cypress/issues/20794
     it('does not split at filename with glob pattern', function () {
       const options = this.setup('--spec', 'cypress/integration/foo/bar/[baz]/test.ts,cypress/integration/foo1/bar/[baz]/test.ts,cypress/integration/foo2/bar/baz/test.ts,cypress/integration/foo3/bar/baz/foo4.ts')
 
-      expect(options.spec[0]).to.eq(`${cwd}/cypress/integration/foo/bar/[baz]/test.ts`)
-      expect(options.spec[1]).to.eq(`${cwd}/cypress/integration/foo1/bar/[baz]/test.ts`)
-      expect(options.spec[2]).to.eq(`${cwd}/cypress/integration/foo2/bar/baz/test.ts`)
-      expect(options.spec[3]).to.eq(`${cwd}/cypress/integration/foo3/bar/baz/foo4.ts`)
+      expect(options.spec[0]).to.eq(`${getCwd()}/cypress/integration/foo/bar/[baz]/test.ts`)
+      expect(options.spec[1]).to.eq(`${getCwd()}/cypress/integration/foo1/bar/[baz]/test.ts`)
+      expect(options.spec[2]).to.eq(`${getCwd()}/cypress/integration/foo2/bar/baz/test.ts`)
+      expect(options.spec[3]).to.eq(`${getCwd()}/cypress/integration/foo3/bar/baz/foo4.ts`)
     })
 
     // https://github.com/cypress-io/cypress/issues/20794
     it('correctly splits at comma with glob pattern', function () {
       const options = this.setup('--spec', 'cypress/integration/foo/bar/baz/test.ts,cypress/integration/foo1/bar/[baz]/test.ts,cypress/integration/foo2/bar/baz/test.ts,cypress/integration/foo3/bar/baz/foo4.ts')
 
-      expect(options.spec[0]).to.eq(`${cwd}/cypress/integration/foo/bar/baz/test.ts`)
-      expect(options.spec[1]).to.eq(`${cwd}/cypress/integration/foo1/bar/[baz]/test.ts`)
-      expect(options.spec[2]).to.eq(`${cwd}/cypress/integration/foo2/bar/baz/test.ts`)
-      expect(options.spec[3]).to.eq(`${cwd}/cypress/integration/foo3/bar/baz/foo4.ts`)
+      expect(options.spec[0]).to.eq(`${getCwd()}/cypress/integration/foo/bar/baz/test.ts`)
+      expect(options.spec[1]).to.eq(`${getCwd()}/cypress/integration/foo1/bar/[baz]/test.ts`)
+      expect(options.spec[2]).to.eq(`${getCwd()}/cypress/integration/foo2/bar/baz/test.ts`)
+      expect(options.spec[3]).to.eq(`${getCwd()}/cypress/integration/foo3/bar/baz/foo4.ts`)
     })
 
     // https://github.com/cypress-io/cypress/issues/20794
     it('correctly splits at comma with escaped glob pattern', function () {
       const options = this.setup('--spec', 'cypress/integration/foo/bar/\[baz\]/test.ts,cypress/integration/foo1/bar/\[baz1\]/test.ts,cypress/integration/foo2/bar/baz/test.ts,cypress/integration/foo3/bar/baz/foo4.ts')
 
-      expect(options.spec[0]).to.eq(`${cwd}/cypress/integration/foo/bar/\[baz\]/test.ts`)
-      expect(options.spec[1]).to.eq(`${cwd}/cypress/integration/foo1/bar/\[baz1\]/test.ts`)
-      expect(options.spec[2]).to.eq(`${cwd}/cypress/integration/foo2/bar/baz/test.ts`)
-      expect(options.spec[3]).to.eq(`${cwd}/cypress/integration/foo3/bar/baz/foo4.ts`)
+      expect(options.spec[0]).to.eq(`${getCwd()}/cypress/integration/foo/bar/\[baz\]/test.ts`)
+      expect(options.spec[1]).to.eq(`${getCwd()}/cypress/integration/foo1/bar/\[baz1\]/test.ts`)
+      expect(options.spec[2]).to.eq(`${getCwd()}/cypress/integration/foo2/bar/baz/test.ts`)
+      expect(options.spec[3]).to.eq(`${getCwd()}/cypress/integration/foo3/bar/baz/foo4.ts`)
     })
   })
 
@@ -600,9 +600,9 @@ describe('lib/util/args', () => {
       this.hosts = { a: 'b', b: 'c' }
       this.blockHosts = ['a.com', 'b.com']
       this.specs = [
-        path.join(cwd, 'foo'),
-        path.join(cwd, 'bar'),
-        path.join(cwd, 'baz'),
+        path.join(getCwd(), 'foo'),
+        path.join(getCwd(), 'bar'),
+        path.join(getCwd(), 'baz'),
       ]
 
       this.env = {
@@ -643,7 +643,7 @@ describe('lib/util/args', () => {
 
     it('backs up env, config, reporterOptions, spec', function () {
       expect(this.obj).to.deep.eq({
-        cwd,
+        cwd: getCwd(),
         _: [],
         config: this.config,
         invokedFromCli: false,
@@ -666,12 +666,12 @@ describe('lib/util/args', () => {
 
       expect(args).to.deep.eq([
         `--config=${mergedConfig}`,
-        `--cwd=${cwd}`,
+        `--cwd=${getCwd()}`,
         `--spec=${JSON.stringify(this.specs)}`,
       ])
 
       expect(argsUtil.toObject(args)).to.deep.eq({
-        cwd,
+        cwd: getCwd(),
         _: [],
         invokedFromCli: true,
         config: this.config,
@@ -684,7 +684,7 @@ describe('lib/util/args', () => {
 
       expect(result).to.deep.equal({
         ciBuildId: '1e100',
-        cwd,
+        cwd: getCwd(),
         _: [],
         invokedFromCli: false,
         config: {},
@@ -695,7 +695,7 @@ describe('lib/util/args', () => {
       const result = argsUtil.toObject(['--config', '{"baseUrl": "http://foobar.com", "specPattern":"**/*.test.js"}'])
 
       expect(result).to.deep.equal({
-        cwd,
+        cwd: getCwd(),
         _: [],
         invokedFromCli: false,
         config: {
@@ -718,7 +718,7 @@ describe('lib/util/args', () => {
       ]
 
       expect(argsUtil.toObject(argv)).to.deep.eq({
-        cwd,
+        cwd: getCwd(),
         _: [
           '/private/var/folders/wr/3xdzqnq16lz5r1j_xtl443580000gn/T/cypress/Cypress.app/Contents/MacOS/Cypress',
           '/Applications/Cypress.app',
@@ -743,7 +743,7 @@ describe('lib/util/args', () => {
       ]
 
       expect(argsUtil.toObject(argv)).to.deep.eq({
-        cwd,
+        cwd: getCwd(),
         _: [
           '/private/var/folders/wr/3xdzqnq16lz5r1j_xtl443580000gn/T/cypress/Cypress.app/Contents/MacOS/Cypress',
           '/Applications/Cypress.app1',