✨ Add AI agent detection context with Tier 1 & Tier 2 signals

Detect AI agents and automation frameworks visiting instrumented pages.

Tier 1 (zero false positives): cooperative window global, cooperative
cookie, navigator.webdriver, user-agent pattern matching, and
automation framework globals (Playwright, Puppeteer, Selenium).

Tier 2 (low false positives): WebGL software renderer detection,
headless environment heuristics, and CDP connection probing.

Detection is gated behind the ai_agent_detection experimental feature
flag. When an agent is detected, isAgentSession and aiAgentContext are
added to the event context via the Assemble hook.

Author: nguyexua

packages/core/src/tools/experimentalFeatures.ts

@@ -19,6 +19,7 @@ export enum ExperimentalFeature {
   START_STOP_ACTION = 'start_stop_action',
   START_STOP_RESOURCE = 'start_stop_resource',
   TOO_MANY_REQUESTS_INVESTIGATION = 'too_many_requests_investigation',
+  AI_AGENT_DETECTION = 'ai_agent_detection',
   SESSION_RENEWAL_DEBUG_CONTEXT = 'session_renewal_debug_context',
 }
 

packages/rum-core/src/boot/startRum.ts

@@ -17,6 +17,8 @@ import {
   startGlobalContext,
   startUserContext,
   startTabContext,
+  isExperimentalFeatureEnabled,
+  ExperimentalFeature,
 } from '@datadog/browser-core'
 import { createDOMMutationObservable } from '../browser/domMutationObservable'
 import { createWindowOpenObservable } from '../browser/windowOpenObservable'
@@ -39,6 +41,7 @@ import { startCustomerDataTelemetry } from '../domain/startCustomerDataTelemetry
 import { startPageStateHistory } from '../domain/contexts/pageStateHistory'
 import { startDisplayContext } from '../domain/contexts/displayContext'
 import { startVitalCollection } from '../domain/vital/vitalCollection'
+import { startAiAgentContext } from '../domain/contexts/aiAgentContext'
 import { startCiVisibilityContext } from '../domain/contexts/ciVisibilityContext'
 import { startLongTaskCollection } from '../domain/longTask/longTaskCollection'
 import { startSyntheticsContext } from '../domain/contexts/syntheticsContext'
@@ -186,6 +189,9 @@ export function startRumEventCollection(
 
   const displayContext = startDisplayContext(hooks, configuration)
   cleanupTasks.push(displayContext.stop)
+  if (isExperimentalFeatureEnabled(ExperimentalFeature.AI_AGENT_DETECTION)) {
+    startAiAgentContext(hooks)
+  }
   const ciVisibilityContext = startCiVisibilityContext(configuration, hooks)
   cleanupTasks.push(ciVisibilityContext.stop)
   startSyntheticsContext(hooks)