---
name: applicationinsights-web-ts
description: Instrument browser/web apps with the Application Insights JavaScript SDK (@microsoft/applicationinsights-web). Use for Real User Monitoring (RUM) — page views,…
---

# applicationinsights-web-ts

Instrument browser/web apps with the Application Insights JavaScript SDK (@microsoft/applicationinsights-web). Use for Real User Monitoring (RUM) — page views,…

# applicationinsights-web-tsby microsoft
Instrument browser/web apps with the Application Insights JavaScript SDK (@microsoft/applicationinsights-web). Use for Real User Monitoring (RUM) — page views,…

`npx skills add https://github.com/microsoft/agent-skills --skill applicationinsights-web-ts`Download ZIPGitHub

## Application Insights JavaScript SDK (Web) for TypeScript

Real User Monitoring (RUM) for browser apps with `@microsoft/applicationinsights-web`. Auto-collects page views, AJAX/fetch dependencies, unhandled exceptions, and (with the Click Analytics plugin) clicks. Supports custom events, metrics, and GenAI agent traces that follow OpenTelemetry GenAI semantic conventions and correlate to backend spans via W3C Trace Context.

Distinct from `azure-monitor-opentelemetry-ts`, which is for Node.js server apps. This skill is for browser/web code (and React Native).

## Before Implementation

Search `microsoft-docs` MCP for current API patterns:

* Query: "Application Insights JavaScript SDK setup"

* Query: "Application Insights JavaScript SDK configuration"

* Query: "Application Insights JavaScript framework extensions React Angular"

* Verify package version: `npm view @microsoft/applicationinsights-web version`

## Packages

PackagePurpose`@microsoft/applicationinsights-web`Core RUM SDK (page views, AJAX, exceptions).`@microsoft/applicationinsights-clickanalytics-js`Auto-collect click telemetry.`@microsoft/applicationinsights-react-js`React plugin (router instrumentation, hooks, HOC, ErrorBoundary).`@microsoft/applicationinsights-react-native`React Native plugin (native crashes, sessions).`@microsoft/applicationinsights-angularplugin-js`Angular plugin (router events, ErrorHandler).`@microsoft/applicationinsights-debugplugin-js`Dev-only telemetry inspector.`@microsoft/applicationinsights-perfmarkmeasure-js`User Timing (`performance.mark/measure`) integration.

## Installation

```
`npm i --save @microsoft/applicationinsights-web
# Optional plugins (install only what you use):
npm i --save @microsoft/applicationinsights-clickanalytics-js
npm i --save @microsoft/applicationinsights-react-js @microsoft/applicationinsights-react-native @microsoft/applicationinsights-angularplugin-js
`
```

Typings ship with the package — no separate `@types/...` install needed.

## Connection String

The browser SDK requires a connection string at init time. It ships in plaintext to clients — Microsoft Entra ID auth is not supported for browser telemetry. Use a separate App Insights resource with local auth enabled for browser RUM if you need to isolate it from backend telemetry.

```
`# Vite / CRA / Next.js — expose to client via the public env prefix
VITE_APPINSIGHTS_CONNECTION_STRING="InstrumentationKey=...;IngestionEndpoint=https://...;LiveEndpoint=https://..."
NEXT_PUBLIC_APPINSIGHTS_CONNECTION_STRING="InstrumentationKey=..."
`
```

## Quick Start (npm)

```
`import { ApplicationInsights } from "@microsoft/applicationinsights-web";

export const appInsights = new ApplicationInsights({
config: {
connectionString: import.meta.env.VITE_APPINSIGHTS_CONNECTION_STRING,
enableAutoRouteTracking: true, // SPA route changes -> page views
enableCorsCorrelation: true, // propagate Request-Id / traceparent to cross-origin AJAX
enableRequestHeaderTracking: true,
enableResponseHeaderTracking: true,
distributedTracingMode: 2, // DistributedTracingModes.AI_AND_W3C — emit traceparent for backend correlation
autoTrackPageVisitTime: true,
disableFetchTracking: false, // fetch() is auto-instrumented by default
excludeRequestFromAutoTrackingPatterns: [/livemetrics\.azure\.com/i]
}
});

appInsights.loadAppInsights();
appInsights.trackPageView();
`
```

Call `loadAppInsights()` exactly once, as early as possible (before user interactions you want tracked). Then `trackPageView()` for the initial load — when `enableAutoRouteTracking` is on, subsequent route changes are automatic.

## Quick Start (SDK Loader Script)

Recommended when you want auto-updating SDK and zero build pipeline. Paste this as the first `<script>` in `<head>`:

```
`<script type="text/javascript" src="https://js.monitor.azure.com/scripts/b/ai.3.gbl.min.js" crossorigin="anonymous"></script>
<script type="text/javascript">
var appInsights = window.appInsights || function (cfg) {
/* See: https://learn.microsoft.com/azure/azure-monitor/app/javascript-sdk
Use the latest snippet from the Microsoft Learn page above — it includes
backup-CDN failover (cr), SDK-load-failure reporting, and the queue shim
so calls before SDK ready are not lost. */
}({ src: "https://js.monitor.azure.com/scripts/b/ai.3.gbl.min.js",
crossOrigin: "anonymous",
cfg: { connectionString: "YOUR_CONNECTION_STRING" } });
</script>
`
```

Loader-only API (queued until SDK loads): `trackEvent`, `trackPageView`, `trackException`, `trackTrace`, `trackDependencyData`, `trackMetric`, `trackPageViewPerformance`, `startTrackPage`, `stopTrackPage`, `startTrackEvent`, `stopTrackEvent`, `addTelemetryInitializer`, `setAuthenticatedUserContext`, `clearAuthenticatedUserContext`, `flush`.

## Core Tracking APIs

```
`// Page views (SPAs that disable enableAutoRouteTracking)
appInsights.trackPageView({ name: "Checkout", uri: "/checkout", properties: { cartSize: 3 } });

// Custom events (user actions, business events)
appInsights.trackEvent({ name: "PurchaseCompleted" }, { orderId: "ord_123", amountUsd: 49.95 });

// Exceptions (caught errors)
try {
await pay(order);
} catch (err) {
appInsights.trackException({ exception: err as Error, severityLevel: 3, properties: { orderId: order.id } });
}

// Traces (logs, severity 0=Verbose, 1=Info, 2=Warning, 3=Error, 4=Critical)
appInsights.trackTrace({ message: "Cart hydrated from local storage", severityLevel: 1 });

// Custom metrics (numeric)
appInsights.trackMetric({ name: "checkout.duration_ms", average: 1234 });

// Dependencies (manually-tracked outbound calls — fetch/XHR are auto-tracked)
appInsights.trackDependencyData({
id: crypto.randomUUID(),
name: "GET /api/orders",
duration: 87, success: true, responseCode: 200,
data: "https://api.example.com/api/orders", target: "api.example.com", type: "Fetch"
});

// User identity (set ONCE per authenticated session — values are PII; do not pass emails)
appInsights.setAuthenticatedUserContext("user-id-123", "tenant-456", /*storeInCookie*/ true);
appInsights.clearAuthenticatedUserContext(); // on logout

// Force send before unload
appInsights.flush();
`
```

## Telemetry Initializers (enrichment & filtering)

Run for every envelope before send. Return `false` to drop.

```
`import type { ITelemetryItem } from "@microsoft/applicationinsights-web";

appInsights.addTelemetryInitializer((item: ITelemetryItem) => {
item.tags ??= {};
item.tags["ai.cloud.role"] = "web-shop";
item.tags["ai.cloud.roleInstance"] = window.location.hostname;
item.data ??= {};
item.data["app.version"] = import.meta.env.VITE_APP_VERSION;
item.data["app.build"] = import.meta.env.VITE_BUILD_SHA;

// Drop noisy health-check page views
if (item.baseType === "PageviewData" && item.baseData?.uri?.endsWith("/healthz")) return false;

// Scrub query-string secrets
if (item.baseData?.uri) {
item.baseData.uri = item.baseData.uri.replace(/([?&](token|sig|key)=)[^&]+/gi, "$1REDACTED");
}
});
`
```

## Click Analytics

```
`import { ClickAnalyticsPlugin } from "@microsoft/applicationinsights-clickanalytics-js";

const clickPlugin = new ClickAnalyticsPlugin();
const appInsights = new ApplicationInsights({
config: {
connectionString: import.meta.env.VITE_APPINSIGHTS_CONNECTION_STRING,
extensions: [clickPlugin],
extensionConfig: {
[clickPlugin.identifier]: {
autoCapture: true,
dataTags: { useDefaultContentNameOrId: true, customDataPrefix: "data-ai-" },
urlCollectHash: false,
behaviorValidator: (b: string) => /^[a-z0-9_]+$/.test(b) ? b : ""
}
}
}
});
appInsights.loadAppInsights();
`
```

Mark elements with `data-ai-*` attributes; clicks are emitted as Custom Events with parent-content metadata.

## SPA Route Tracking

* Built-in: set `enableAutoRouteTracking: true`. Hooks `history.pushState/replaceState` and `popstate`.

* React Router: use `@microsoft/applicationinsights-react-js` `withAITracking` HOC (see references/framework-extensions.md).

* Manual: call `appInsights.trackPageView({ name, uri })` in your router's `useEffect` on route change. Disable `enableAutoRouteTracking` to avoid double counting.

## Distributed Tracing (correlate to backend)

Set `distributedTracingMode: 2` (`DistributedTracingModes.AI_AND_W3C`). The SDK adds `traceparent` (and legacy `Request-Id`) to outbound `fetch`/`XHR`. Backends instrumented with OpenTelemetry (e.g. `@azure/monitor-opentelemetry`) auto-link to the browser's operation_Id.

For cross-origin calls, also set `enableCorsCorrelation: true` and add the calling origin to the CORS exposed headers on the API.

## GenAI Agent Traces (OTel semantic conventions)

When the browser invokes an AI agent (function-calling, tool-use, model calls direct from the client), emit App Insights Dependency telemetry whose attributes follow the OpenTelemetry GenAI semantic conventions so they are queryable alongside backend agent spans in App Insights / Log Analytics.

Set the opt-in env first so backend instrumentations agree on the same schema version:

```
`OTEL_SEMCONV_STABILITY_OPT_IN=gen_ai_latest_experimental
`
```

### Required attribute keys (use the OTel names verbatim)

Span / opRequired attributes`invoke_agent {agent.name}``gen_ai.operation.name=invoke_agent`, `gen_ai.provider.name`, `gen_ai.agent.name`, `gen_ai.agent.id` (when known)`create_agent {agent.name}``gen_ai.operation.name=create_agent`, `gen_ai.provider.name`, `gen_ai.agent.name`, `gen_ai.request.model``chat {model}``gen_ai.operation.name=chat`, `gen_ai.provider.name`, `gen_ai.request.model`, `gen_ai.response.model`, `gen_ai.usage.input_tokens`, `gen_ai.usage.output_tokens``execute_tool {tool.name}``gen_ai.operation.name=execute_tool`, `gen_ai.tool.name`, `gen_ai.tool.type` (`function` | `extension` | `datastore`), `gen_ai.tool.call.id`
`gen_ai.provider.name` well-known values: `openai`, `azure.ai.openai`, `azure.ai.inference`, `anthropic`, `aws.bedrock`, `gcp.gemini`, `gcp.vertex_ai`, `cohere`, `mistral_ai`, `groq`, `deepseek`, `perplexity`, `x_ai`, `ibm.watsonx.ai`.

Sensitive content opt-in. `gen_ai.system_instructions`, `gen_ai.input.messages`, `gen_ai.output.messages`, `gen_ai.tool.call.arguments`, `gen_ai.tool.call.result` are Opt-In by default. Gate them behind a runtime flag and avoid them in production unless you have approved data handling.

### Pattern: invoke_agent + nested tool/model spans

```
`import { ApplicationInsights, SeverityLevel } from "@microsoft/applicationinsights-web";

type GenAiAttrs = Record<string, string | number | boolean | undefined>;

function startGenAiSpan(name: string, attrs: GenAiAttrs) {
const id = crypto.randomUUID();
const start = performance.now();
const baseProps: GenAiAttrs = { "gen_ai.span.id": id, ...attrs };
return {
end(success: boolean, extra: GenAiAttrs = {}, error?: Error) {
const duration = Math.round(performance.now() - start);
const properties = { ...baseProps, ...extra };
appInsights.trackDependencyData({
id, name, duration, success,
responseCode: error ? 500 : 200,
type: "GenAI",
target: String(attrs["gen_ai.provider.name"] ?? "genai"),
properties: properties as Record<string, string>
});
if (error) {
appInsights.trackException({
exception: error,
severityLevel: SeverityLevel.Error,
properties: { ...properties, "error.type": error.name } as Record<string, string>
});
}
}
};
}

// Agent invocation
const agentSpan = startGenAiSpan("invoke_agent ResearchAssistant", {
"gen_ai.operation.name": "invoke_agent",
"gen_ai.provider.name": "azure.ai.openai",
"gen_ai.agent.name": "ResearchAssistant",
"gen_ai.agent.id": "asst_5j66UpCpwteGg4YSxUnt7lPY",
"gen_ai.request.model": "gpt-4o-mini",
"server.address": "myresource.openai.azure.com"
});

try {
// Nested chat completion span
const chat = startGenAiSpan("chat gpt-4o-mini", {
"gen_ai.operation.name": "chat",
"gen_ai.provider.name": "azure.ai.openai",
"gen_ai.request.model": "gpt-4o-mini"
});
const res = await callAzureOpenAi(/* ... */);
chat.end(true, {
"gen_ai.response.model": res.model,
"gen_ai.response.id": res.id,
"gen_ai.response.finish_reasons": JSON.stringify(res.choices.map(c => c.finish_reason)),
"gen_ai.usage.input_tokens": res.usage.prompt_tokens,
"gen_ai.usage.output_tokens": res.usage.completion_tokens,
"gen_ai.output.type": "text"
});

// Nested tool execution span
const tool = startGenAiSpan("execute_tool getWeather", {
"gen_ai.operation.name": "execute_tool",
"gen_ai.tool.name": "getWeather",
"gen_ai.tool.type": "function",
"gen_ai.tool.call.id": "call_abc123"
});
const toolResult = await runGetWeather({ location: "SF" });
tool.end(true);

agentSpan.end(true, {
"gen_ai.usage.input_tokens": res.usage.prompt_tokens,
"gen_ai.usage.output_tokens": res.usage.completion_tokens
});
} catch (err) {
agentSpan.end(false, { "error.type": (err as Error).name }, err as Error);
}
`
```

The browser's `traceparent` is automatically attached to outbound `fetch` (when `distributedTracingMode: 2`), so downstream Azure OpenAI / agent backend spans hang under the same operation_Id in App Insights.

For the full attribute reference, well-known values, and content-capture guidance, see references/agent-traces.md.

### KQL: query GenAI traces in App Insights

```
`dependencies
| where type == "GenAI"
| extend op = tostring(customDimensions["gen_ai.operation.name"]),
agent = tostring(customDimensions["gen_ai.agent.name"]),
model = tostring(customDimensions["gen_ai.request.model"]),
tin = toint(customDimensions["gen_ai.usage.input_tokens"]),
tout = toint(customDimensions["gen_ai.usage.output_tokens"])
| summarize calls=count(), p95_ms=percentile(duration, 95),
avg_in=avg(tin), avg_out=avg(tout) by op, agent, model, bin(timestamp, 5m)
`
```

## React (TypeScript)

See references/framework-extensions.md for full React, React Native, Angular, Next.js, and Vite recipes.

```
`import { ApplicationInsights } from "@microsoft/applicationinsights-web";
import { ReactPlugin, withAITracking } from "@microsoft/applicationinsights-react-js";
import { createBrowserHistory } from "history";

const reactPlugin = new ReactPlugin();
const browserHistory = createBrowserHistory();

export const appInsights = new ApplicationInsights({
config: {
connectionString: import.meta.env.VITE_APPINSIGHTS_CONNECTION_STRING,
extensions: [reactPlugin],
extensionConfig: { [reactPlugin.identifier]: { history: browserHistory } }
}
});
appInsights.loadAppInsights();

export const TrackedCheckout = withAITracking(reactPlugin, Checkout, "Checkout");
`
```

## React Native

```
`import { ApplicationInsights } from "@microsoft/applicationinsights-web";
import { ReactNativePlugin } from "@microsoft/applicationinsights-react-native";

const rnPlugin = new ReactNativePlugin();
const appInsights = new ApplicationInsights({
config: {
connectionString: process.env.EXPO_PUBLIC_APPINSIGHTS_CONNECTION_STRING,
extensions: [rnPlugin],
disableFetchTracking: false
}
});
appInsights.loadAppInsights();
`
```

## Performance — Web Vitals

Auto-collected: page-load timings via `PerformanceTiming` / `PerformanceNavigationTiming`. To add Core Web Vitals:

```
`import { onCLS, onLCP, onINP, type Metric } from "web-vitals";

function send(m: Metric) {
appInsights.trackMetric(
{ name: `web_vitals.${m.name.toLowerCase()}`, average: m.value },
{ rating: m.rating, navigationType: m.navigationType, id: m.id }
);
}
onCLS(send); onLCP(send); onINP(send);
`
```

## Cookies & Privacy

```
`new ApplicationInsights({ config: {
connectionString,
isCookieUseDisabled: true, // hard-disable all cookies
cookieCfg: { enabled: true, domain: ".example.com", path: "/", expiry: 365 }
}});
`
```

To honor consent dynamically:

```
`appInsights.getCookieMgr().setEnabled(userGaveConsent);
appInsights.config.disableTelemetry = !userGaveConsent;
`
```

## Sampling

Server-side ingestion sampling (recommended) is configured on the App Insights resource. SDK-side sampling reduces network use:

```
`new ApplicationInsights({ config: { connectionString, samplingPercentage: 50 } });
`
```

Per-type sampling via telemetry initializer: drop with `return false` based on `item.baseType`.

## Offline / Send-on-Unload

The SDK uses `sendBeacon` (default `onunloadDisableBeacon: false`) to flush on `pagehide` / `unload`. For SPAs, also call `appInsights.flush()` before destructive transitions (logout, hard reload).

## Common Pitfalls

* Do not initialize twice. Re-importing the module under different bundles produces duplicate page views. Use a single shared module export.

* Initialize before first user input to avoid losing early clicks/exceptions.

* Connection string is public — never reuse the same App Insights resource for backend secrets.

* `enableAutoRouteTracking` + manual `trackPageView` = duplicates. Pick one.

* CORS distributed tracing requires the API to allow `Request-Id`, `Request-Context`, `traceparent`, `tracestate` request headers and expose `Request-Context` response header.

* GenAI sensitive content (`gen_ai.input.messages` etc.) is Opt-In — never log without an explicit runtime flag and approved data handling.

* Agent token usage is on `chat` spans, not `invoke_agent` — copy aggregated usage to the parent agent span only if you know it.

* React StrictMode double-invokes effects in dev — guard `loadAppInsights()` with a module-level singleton.

## Bundle Size

The full web SDK is ~110 KB minified (~36 KB gzipped). For aggressive budgets, use the Loader Script path so the SDK loads asynchronously off the critical path, or tree-shake unused plugins.

## Key Types

```
`import {
ApplicationInsights,
SeverityLevel,
DistributedTracingModes,
type IConfiguration,
type IConfig,
type ITelemetryItem,
type ITelemetryPlugin,
type ICustomProperties,
type IPageViewTelemetry,
type IEventTelemetry,
type IExceptionTelemetry,
type ITraceTelemetry,
type IMetricTelemetry,
type IDependencyTelemetry
} from "@microsoft/applicationinsights-web";
`
```

## Best Practices

* One singleton instance exported from a single module.

* Initialize early in the app entrypoint, before router setup.

* Use telemetry initializers to attach `app.version`, `tenantId`, and to scrub PII / query-string secrets.

* Set `distributedTracingMode: 2` and ensure your APIs accept/expose W3C trace context headers.

* For GenAI, follow OTel `gen_ai.*` attribute names verbatim — they are queryable across browser and backend telemetry uniformly.

* Gate sensitive content capture (`gen_ai.input.messages` / `gen_ai.output.messages`) behind a build-time or runtime opt-in.

* Flush on logout / sensitive navigation so in-flight telemetry isn't dropped.

## References

* references/agent-traces.md — Full OTel GenAI semconv distilled (agent / model / tool spans, attributes, content capture).

* references/framework-extensions.md — React, React Native, Angular, Next.js, Vite recipes.

* references/configuration.md — Full `IConfiguration` reference and tuning guide.

* Microsoft Learn: https://learn.microsoft.com/azure/azure-monitor/app/javascript-sdk

* ApplicationInsights-JS source: https://github.com/microsoft/ApplicationInsights-JS

* OTel GenAI semantic conventions: https://opentelemetry.io/docs/specs/semconv/gen-ai/

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---

**Source**: https://github.com/microsoft/agent-skills/tree/HEAD/.github/skills/applicationinsights-web-ts
**Author**: microsoft
**Discovered via**: mcpservers.org