diff --git a/_extension/package.json b/_extension/package.json
index a8e30975c5d..4ca8b08a0ea 100644
--- a/_extension/package.json
+++ b/_extension/package.json
@@ -223,7 +223,8 @@
     },
     "dependencies": {
         "@vscode/extension-telemetry": "^1.5.1",
-        "vscode-languageclient": "^10.0.0-next.21"
+        "vscode-languageclient": "^10.0.0-next.21",
+        "vscode-tas-client": "0.1.84"
     },
     "devDependencies": {
         "@types/vscode": "~1.110.0",
diff --git a/_extension/src/commands.ts b/_extension/src/commands.ts
index 1a9079deb81..4a20e567cff 100644
--- a/_extension/src/commands.ts
+++ b/_extension/src/commands.ts
@@ -6,7 +6,6 @@ import type {
     Position,
 } from "vscode-languageclient";
 
-import { Client } from "./client";
 import type * as tr from "./telemetryReporting";
 import { restartExtHostOnChangeIfNeeded } from "./util";
 
diff --git a/_extension/src/experimentationService.ts b/_extension/src/experimentationService.ts
new file mode 100644
index 00000000000..ac47ae2bca1
--- /dev/null
+++ b/_extension/src/experimentationService.ts
@@ -0,0 +1,57 @@
+import * as vscode from "vscode";
+import * as tas from "vscode-tas-client";
+
+interface ExperimentTypes {
+    // Experiment variables go here.
+    suggestNativePreview: boolean;
+}
+
+export class ExperimentationService {
+    private readonly _experimentationService: tas.IExperimentationService;
+    private readonly _telemetryReporter: tas.IExperimentationTelemetry;
+
+    constructor(telemetryReporter: tas.IExperimentationTelemetry, id: string, version: string, globalState: vscode.Memento) {
+        this._telemetryReporter = telemetryReporter;
+        this._experimentationService = createTasExperimentationService(this._telemetryReporter, id, version, globalState);
+    }
+
+    public async getTreatmentVariable<K extends keyof ExperimentTypes>(name: K, defaultValue: ExperimentTypes[K]): Promise<ExperimentTypes[K]> {
+        const experimentationService = this._experimentationService;
+        try {
+            const treatmentVariable = await experimentationService.getTreatmentVariableAsync("vscode", name, /*checkCache*/ true) as ExperimentTypes[K];
+            return treatmentVariable ?? defaultValue;
+        }
+        catch {
+            return defaultValue;
+        }
+    }
+}
+
+function createTasExperimentationService(
+    reporter: tas.IExperimentationTelemetry,
+    id: string,
+    version: string,
+    globalState: vscode.Memento,
+): tas.IExperimentationService {
+    let targetPopulation: tas.TargetPopulation;
+    switch (vscode.env.uriScheme) {
+        case "vscode":
+            targetPopulation = tas.TargetPopulation.Public;
+            break;
+        case "vscode-insiders":
+            targetPopulation = tas.TargetPopulation.Insiders;
+            break;
+        case "vscode-exploration":
+            targetPopulation = tas.TargetPopulation.Internal;
+            break;
+        case "code-oss":
+            targetPopulation = tas.TargetPopulation.Team;
+            break;
+        default:
+            targetPopulation = tas.TargetPopulation.Public;
+            break;
+    }
+
+    const experimentationService = tas.getExperimentationService(id, version, targetPopulation, reporter, globalState);
+    return experimentationService;
+}
diff --git a/_extension/src/extension.ts b/_extension/src/extension.ts
index ff18f533766..9b2c28ffa8f 100644
--- a/_extension/src/extension.ts
+++ b/_extension/src/extension.ts
@@ -16,8 +16,12 @@ import {
     promptUseWorkspaceVersion,
     SessionManager,
 } from "./session";
+
+import { ExperimentationService } from "./experimentationService";
 import { createTelemetryReporter } from "./telemetryReporting";
 
+import assert from "node:assert";
+
 export interface ExtensionAPI {
     onLanguageServerInitialized: vscode.Event<void>;
     initializeAPIConnection(pipe?: string): Promise<string>;
@@ -29,6 +33,14 @@ export async function activate(context: vscode.ExtensionContext): Promise<Extens
     const telemetryReporter = createTelemetryReporter(new VSCodeTelemetryReporter(aiConnectionString));
     context.subscriptions.push(telemetryReporter);
 
+    const version = context.extension.packageJSON.version;
+    assert(typeof version === "string");
+    // Constructing the experimentation service actually sets shared properties
+    // so that events include context on treatments/flights.
+    // If we actually need to read treatment variables we would hold onto this instance,
+    // but for now we just construct it to ensure shared properties are set for telemetry.
+    void new ExperimentationService(telemetryReporter, context.extension.id, version, context.globalState);
+
     registerEnablementCommands(context, telemetryReporter);
 
     const output = vscode.window.createOutputChannel("typescript-native-preview", { log: true });
diff --git a/_extension/src/telemetryReporting.ts b/_extension/src/telemetryReporting.ts
index 86d16ac6061..1fcd165205e 100644
--- a/_extension/src/telemetryReporting.ts
+++ b/_extension/src/telemetryReporting.ts
@@ -1,4 +1,5 @@
 import type { TelemetryReporter as VSCodeTelemetryReporter } from "@vscode/extension-telemetry";
+import type { IExperimentationTelemetry } from "vscode-tas-client";
 
 // As new events are added, update the TelemetryReporter interface below.
 // This helps ensure that the telemetry events used in the codebase are
@@ -27,21 +28,45 @@ export interface TelemetryReporter {
     dispose(): void;
 }
 
-export function createTelemetryReporter(vscReporter: VSCodeTelemetryReporter): TelemetryReporter {
+export interface ExperimentationTelemetryReporter extends TelemetryReporter, IExperimentationTelemetry {}
+
+// Note:
+// This reporter *supports* experimentation telemetry,
+// but will only do so when passed to an `ExperimentationService` which
+// will set shared properties on this reporter.
+export function createTelemetryReporter(vscReporter: VSCodeTelemetryReporter): ExperimentationTelemetryReporter {
+    let sharedProperties: Record<string, string> = Object.create(null);
+
     return {
+        // Primary reporting methods for the extension.
         sendTelemetryEvent,
         sendTelemetryErrorEvent,
         sendTelemetryEventUntyped: sendTelemetryEvent,
         sendTelemetryErrorEventUntyped: sendTelemetryErrorEvent,
 
+        // Required for the experimentation telemetry service interface.
+        setSharedProperty,
+        postEvent,
+
         dispose: () => vscReporter.dispose(),
     };
 
+    function setSharedProperty(key: string, value: string): void {
+        sharedProperties[key] = value;
+    }
+
+    function postEvent(eventName: string, props: Map<string, string>): void {
+        const propsAsObj = { ...sharedProperties, ...Object.fromEntries(props) };
+        vscReporter.sendTelemetryEvent(eventName, propsAsObj);
+    }
+
     function sendTelemetryEvent(eventName: string, data?: Record<string, string>, measurements?: Record<string, number>): void {
+        data = { ...sharedProperties, ...data };
         vscReporter.sendTelemetryEvent(eventName, data, measurements);
     }
 
     function sendTelemetryErrorEvent(eventName: string, data?: Record<string, string>, measurements?: Record<string, number>): void {
+        data = { ...sharedProperties, ...data };
         vscReporter.sendTelemetryErrorEvent(eventName, data, measurements);
     }
 }
diff --git a/_extension/src/util.ts b/_extension/src/util.ts
index 1d8d3cfca17..da25eb2946a 100644
--- a/_extension/src/util.ts
+++ b/_extension/src/util.ts
@@ -1,5 +1,3 @@
-import { exec } from "child_process";
-import { get } from "http";
 import * as path from "path";
 import * as vscode from "vscode";
 
@@ -222,3 +220,8 @@ export function readUnifiedConfig<T>(
     if (explicit !== undefined) return explicit;
     return vscode.workspace.getConfiguration(fallbackSection, scope).get<T>(fallbackKey, defaultValue);
 }
+
+export interface PackageInfo {
+    name: string;
+    version: string;
+}
diff --git a/_extension/tsconfig.json b/_extension/tsconfig.json
index 6c645c7a449..1dbb37fcc55 100644
--- a/_extension/tsconfig.json
+++ b/_extension/tsconfig.json
@@ -1,16 +1,16 @@
 {
     "compilerOptions": {
-        "target": "es2023",
-        "module": "NodeNext",
         "rootDir": "./src",
         "outDir": "./dist",
-        "esModuleInterop": true,
-        "strict": true,
-        "skipLibCheck": true,
-        "resolveJsonModule": true,
-        "sourceMap": true,
         "noEmit": true,
-        "types": ["node"]
+
+        "target": "es2023",
+        "module": "preserve",
+        "moduleResolution": "bundler",
+        "types": ["node"],
+
+        "strict": true,
+        "noImplicitOverride": true
     },
     "include": ["./src/**/*"]
 }
diff --git a/package-lock.json b/package-lock.json
index c017687f1dc..6476a399d43 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -38,7 +38,8 @@
             "version": "0.0.0",
             "dependencies": {
                 "@vscode/extension-telemetry": "^1.5.1",
-                "vscode-languageclient": "^10.0.0-next.21"
+                "vscode-languageclient": "^10.0.0-next.21",
+                "vscode-tas-client": "0.1.84"
             },
             "devDependencies": {
                 "@types/vscode": "~1.110.0",
@@ -49,6 +50,24 @@
                 "vscode": "^1.110.0"
             }
         },
+        "_extension/node_modules/tas-client": {
+            "version": "0.2.33",
+            "resolved": "https://registry.npmjs.org/tas-client/-/tas-client-0.2.33.tgz",
+            "integrity": "sha512-V+uqV66BOQnWxvI6HjDnE4VkInmYZUQ4dgB7gzaDyFyFSK1i1nF/j7DpS9UbQAgV9NaF1XpcyuavnM1qOeiEIg==",
+            "license": "MIT"
+        },
+        "_extension/node_modules/vscode-tas-client": {
+            "version": "0.1.84",
+            "resolved": "https://registry.npmjs.org/vscode-tas-client/-/vscode-tas-client-0.1.84.tgz",
+            "integrity": "sha512-rUTrUopV+70hvx1hW5ebdw1nd6djxubkLvVxjGdyD/r5v/wcVF41LIfiAtbm5qLZDtQdsMH1IaCuDoluoIa88w==",
+            "license": "MIT",
+            "dependencies": {
+                "tas-client": "0.2.33"
+            },
+            "engines": {
+                "vscode": "^1.85.0"
+            }
+        },
         "_packages/api": {
             "name": "@typescript/api",
             "version": "1.0.0",