# Application Metrics — Trace-Connected and High-Cardinality

> Sentry's application metrics are trace-connected and high-cardinality. Tag any measurement with customer_id, route, or region — and drill from any spike into the trace and code behind it.

**URL:** https://sentry.io/product/metrics/

---

Track the signals that matter, slice by any attribute at query time, and jump straight to the trace when something spikes — without getting penalized for adding context.

## Features

### Every metric, linked to the trace it came from

A spike isn't a number on a graph — it's a clickable path to the exact request, span, and line of code.

Drill from a p95 outlier into the slow span that produced it

Jump from a counter increment to the issue and stack trace behind it

Correlate metric movements with releases, feature flags, and deploys automatically

### Instrument once. Ask anything.

Tag every measurement with the dimensions you actually debug with — customer_id, route, region, plan, build SHA. High cardinality is the default, not a limit. Emit raw measurements, then ask new questions later — without redeploying.

Counters, gauges, and distributions — first-class, with the tags you need

Slice and group after the fact — like grouping checkout.failed by customer_id

Filter with structured queries like route:"/checkout" AND region:"eu-west"

Alert on any structured dimension, not just pre-canned rollups

### Get the answer from your metrics

Calculate error rates and conversion ratios from the metrics you already emit.

Aggregate by sum, avg, count, or p50/p95/p99

Combine up to 26 queries with equations like A / B for ratios, or (A + (B / 2)) / C for Apdex

Use derived series in dashboards and alerts

## More Features

- **Equations**: Combine metrics with arithmetic to derive the number you actually care about — ratios, deltas, and composite scores like Apdex. Reference up to 26 metric queries (A, B, C…) in a single equation: A / B for a failure ratio, A - B against a baseline, or (A + (B / 2)) / C for a satisfaction score. — [Learn more](https://docs.sentry.io/product/metrics/#multiple-metrics-and-equations)

- **Metric-Based Alerts**: Alert on any structured dimension. Route to the on-call who owns that surface.

- **Metric Dashboards**: Compose error rates, latency, and throughput next to the issues and traces they describe.

- **Trace-connected**: Traditional metrics tools tell you if something changed. Trace-connected metrics tell you why. Metrics are automatically tagged with trace_id and span_id — so when checkout.failed spikes, you click into an exemplar and land in the exact trace, spans, logs, and errors that produced it. Debugging stops being speculation. — [Learn more](https://docs.sentry.io/platforms/javascript/metrics/#trace-context)

- **Metric aggregation**: View related metrics — error rates, latency, throughput — alongside the issues and traces they describe for one-pane root-cause analysis.

## FAQ

**How much do application metrics cost?**

All Sentry plans come with 5 GB. Additional usage beyond that costs $0.50/GB. Usage will be applied to your pay-as-you-go budget.

**Why metrics in Sentry?**

Traditional metrics tools punish you for the tags you actually need and live in a different tab from your errors and [traces](https://sentry.io/product/tracing/). Sentry treats high cardinality as the default for application-level signals, and links every emission to the trace and issue behind it.

The result: you go from a metric spike to the trace, span, and stack frame that caused it — without leaving Sentry.

**Can I send my OTel metrics?**

Not today — and it's a deliberate choice. OTLP metrics are pre-aggregated before they reach us, which strips out the high-cardinality detail that makes our query model useful. If you need OTel-style infra metrics, pair Sentry with your existing metrics backend.

**How to get started?**

If you already have the Sentry SDK installed, you're a few lines away from emitting metrics. Call `Sentry.metrics.count()`, `Sentry.metrics.gauge()`, or `Sentry.metrics.distribution()` directly from your code — no separate import, no extra service to wire up. Release, environment, and SDK context are attached automatically.

Check out our docs to [read more.](https://docs.sentry.io/product/metrics/getting-started/)

## Of course we have more metrics content

- [How to get started with metrics](https://www.youtube.com/watch?v=lDDj6ohKMoY): A walkthrough of getting started with application metrics in Sentry.

- [Why we killed our metrics product and rebuilt it](https://blog.sentry.io/the-metrics-product-we-built-worked-but-we-killed-it-and-started-over-anyway/): Two years ago, Sentry built a metrics product that worked great on paper. But when we dogfooded it, we realized it was not what our customers really needed.

- [Application Metrics caught my broken size estimator](https://blog.sentry.io/metrics-caught-ai-size-estimate/): Some numbers are too important to bury in a log or lose to sampling. A video converter became the clearest case for tracking KPIs with Application Metrics.

## Use Cases

- [Build custom metrics dashboard in Next.js](https://sentry.io/cookbook/custom-metrics-dashboard-alerts-nextjs/)

- [Monitor a Supabase log drain](https://sentry.io/cookbook/setup-supabase-log-drain-monitoring/)

- [Create dashboards with AI agents](https://sentry.io/cookbook/create-dashboards-with-ai-agent/)

- [Incident playbooks in dashboards](https://sentry.io/cookbook/playbooks-in-dashboard-markdown-widgets/)

## Testimonials

> With Metrics, we can have a more central location for all our error tracking and data analysis.

> I was able to get our first metrics in Sentry very quickly!

## Quick Start

### Python

Install the Sentry Python SDK with pip

```bash
pip install sentry-sdk
```

Configuration should happen as early as possible in your application's lifecycle.

```python
import sentry_sdk

sentry_sdk.init(
  dsn="https://examplePublicKey@o0.ingest.sentry.io/0",
  # Add data like request headers and IP for users, if applicable;
  # see https://docs.sentry.io/platforms/python/data-management/data-collected/ for more info
  send_default_pii=True,
  # Set traces_sample_rate to 1.0 to capture 100%
  # of transactions for tracing.
  traces_sample_rate=1.0,
  #Enable logs to be sent to Sentry
  enable_logs=True,
  # To collect profiles for all profile sessions,
  # set profile_session_sample_rate to 1.0.
  profile_session_sample_rate=1.0,
  # Profiles will be automatically collected while
  # there is an active span.
  profile_lifecycle="trace",
)
```

### JavaScript

Install the Sentry JavaScript SDK with npm

```bash
npm install @sentry/browser --save
```

Configuration should happen as early as possible in your application's lifecycle.

```javascript
import * as Sentry from "@sentry/browser";

Sentry.init({
  dsn: "https://examplePublicKey@o0.ingest.sentry.io/0",
  // Adds request headers and IP for users, for more info visit:
  // https://docs.sentry.io/platforms/javascript/configuration/options/#sendDefaultPii
  sendDefaultPii: true,
  // Set tracesSampleRate to 1.0 to capture 100%
  // of transactions for tracing.
  tracesSampleRate: 1.0,
  // Set tracePropagationTargets to control for which URLs trace propagation should be enabled
  tracePropagationTargets: ["localhost", /^https:\/\/yourserver\.io\/api/],
  // Enable logs to be sent to Sentry
  enableLogs: true,
  // Set profilesSampleRate to 1.0 to profile every transaction.
  // Since profilesSampleRate is relative to tracesSampleRate,
  // the final profiling rate can be computed as tracesSampleRate * profilesSampleRate
  // For example, a tracesSampleRate of 0.5 and profilesSampleRate of 0.5 would
  // result in 25% of transactions being profiled (0.5*0.5=0.25)
  profilesSampleRate: 1.0,
  integrations: [
    Sentry.browserTracingIntegration(),
    Sentry.browserProfilingIntegration(),
  ],
});
```

### React

Run the command for your preferred package manager to add the Sentry SDK to your application:

```bash
npm install @sentry/react --save
```

To import and initialize Sentry, create a file in your project's root directory, for example, `instrument.js`, and add the following code:

```javascript
import * as Sentry from "@sentry/react";

Sentry.init({
  dsn: "https://examplePublicKey@o0.ingest.sentry.io/0",
  // Adds request headers and IP for users, for more info visit:
  // https://docs.sentry.io/platforms/javascript/guides/react/configuration/options/#sendDefaultPii
  sendDefaultPii: true,
  // Set tracesSampleRate to 1.0 to capture 100%
  // of transactions for tracing.
  // Learn more at
  // https://docs.sentry.io/platforms/javascript/configuration/options/#traces-sample-rate
  tracesSampleRate: 1.0,
  // Set `tracePropagationTargets` to control for which URLs trace propagation should be enabled
  tracePropagationTargets: [/^//, /^https://yourserver.io/api/],
  // Enable logs to be sent to Sentry
  enableLogs: true,
  // Set profilesSampleRate to 1.0 to profile every transaction.
  // Since profilesSampleRate is relative to tracesSampleRate,
  // the final profiling rate can be computed as tracesSampleRate * profilesSampleRate
  // For example, a tracesSampleRate of 0.5 and profilesSampleRate of 0.5 would
  // result in 25% of transactions being profiled (0.5*0.5=0.25)
  profilesSampleRate: 1.0,
  integrations: [
    // If you're using react router, use the integration for your react router version instead.
    // Learn more at
    // https://docs.sentry.io/platforms/javascript/guides/react/features/react-router/
    Sentry.browserTracingIntegration(),
    Sentry.browserProfilingIntegration(),
  ],
});
```

Initialize Sentry as early as possible in your application. We recommend putting the import of your initialization code as the first import in your app's entry point:

```javascript
// Sentry initialization should be imported first!
import "./instrument";
import App from "./App";
import { createRoot } from "react-dom/client";

const container = document.getElementById("app");
const root = createRoot(container);
root.render(<App />);
```

To make sure Sentry captures all your app's errors, configure error handling based on your React version. 
 For React versions 19 and up:  

```javascript
import { createRoot } from "react-dom/client";
import * as Sentry from '@sentry/react';

const container = document.getElementById("app");
const root = createRoot(container, {
  // Callback called when an error is thrown and not caught by an ErrorBoundary.
  onUncaughtError: Sentry.reactErrorHandler((error, errorInfo) => {
    console.warn('Uncaught error', error, errorInfo.componentStack);
  }),
  // Callback called when React catches an error in an ErrorBoundary.
  onCaughtError: Sentry.reactErrorHandler(),
  // Callback called when React automatically recovers from errors.
  onRecoverableError: Sentry.reactErrorHandler(),
});
root.render();
```

For React versions 18 and below, use the ErrorBoundary component to automatically send errors from specific component trees to Sentry and provide a fallback UI:

```javascript
import React from "react";
import * as Sentry from "@sentry/react";

<Sentry.ErrorBoundary fallback={<p>An error has occurred</p>}>
  <Example />
</Sentry.ErrorBoundary>;
```

### Next.js

To install Sentry using the installation wizard, run thrun the following command and step through the prompts:

```bash
npx @sentry/wizard@latest -i nextjs
```

For manual installation run the following command and use the following configurations:

```bash
npm install @sentry/nextjs --save
```

Extend your app's default Next.js options by adding code with `withSentryConfig` into your `next.config.(js|mjs)` file:

```javascript
const { withSentryConfig } = require("@sentry/nextjs");
const nextConfig = {
  // Your existing Next.js configuration
};
// Make sure adding Sentry options is the last code to run before exporting
module.exports = withSentryConfig(nextConfig, {
  org: "example-org",
  project: "example-project",
  // Only print logs for uploading source maps in CI
  // Set to `true` to suppress logs
  silent: !process.env.CI,
  // Automatically tree-shake Sentry logger statements to reduce bundle size
  disableLogger: true,
});
```

#### Client-Side Configuration

```javascript
import * as Sentry from "@sentry/nextjs";
Sentry.init({
  dsn: "https://examplePublicKey@o0.ingest.sentry.io/0",
  // Adds request headers and IP for users, for more info visit:
  // https://docs.sentry.io/platforms/javascript/guides/nextjs/configuration/options/#sendDefaultPii
  sendDefaultPii: true,
  // Set tracesSampleRate to 1.0 to capture 100%
  // of transactions for tracing.
  // We recommend adjusting this value in production
  // Learn more at
  // https://docs.sentry.io/platforms/javascript/configuration/options/#traces-sample-rate
  tracesSampleRate: 1.0,
  // Enable logs to be sent to Sentry
  enableLogs: true,
  // Set profilesSampleRate to 1.0 to profile every transaction.
  // Since profilesSampleRate is relative to tracesSampleRate,
  // the final profiling rate can be computed as tracesSampleRate * profilesSampleRate
  // For example, a tracesSampleRate of 0.5 and profilesSampleRate of 0.5 would
  // result in 25% of transactions being profiled (0.5*0.5=0.25)
  profilesSampleRate: 1.0,
});

// This export will instrument router navigations, and is only relevant if you enable tracing.
// `captureRouterTransitionStart` is available from SDK version 9.12.0 onwards
export const onRouterTransitionStart = Sentry.captureRouterTransitionStart;
```

#### Server-Side Configuration

```javascript
import * as Sentry from "@sentry/nextjs";
Sentry.init({
  dsn: "https://examplePublicKey@o0.ingest.sentry.io/0",
  // Adds request headers and IP for users, for more info visit:
  // https://docs.sentry.io/platforms/javascript/guides/nextjs/configuration/options/#sendDefaultPii
  sendDefaultPii: true,
  // Set tracesSampleRate to 1.0 to capture 100%
  // of transactions for tracing.
  // We recommend adjusting this value in production
  // Learn more at
  // https://docs.sentry.io/platforms/javascript/configuration/options/#traces-sample-rate
  tracesSampleRate: 1.0,
  // Enable logs to be sent to Sentry
  enableLogs: true,
});
```

#### Register Sentry Server-Side SDK Initialization

Create a Next.js Instrumentation file named `instrumentation.(js|ts)` in your project root or inside the `src` folder if you have one. Import your server and edge configurations, making sure that the imports point to your specific files:

```javascript
export async function register() {
  if (process.env.NEXT_RUNTIME === "nodejs") {
    await import("./sentry.server.config");
  }
  if (process.env.NEXT_RUNTIME === "edge") {
    await import("./sentry.edge.config");
  }
}
```

### Go

Grab the Sentry Go SDK:

```bash
go get "github.com/getsentry/sentry-go"
```

Configuration should happen as early as possible in your application's lifecycle.

```text
err := sentry.Init(sentry.ClientOptions{
  Dsn: "https://examplePublicKey@o0.ingest.sentry.io/0",
  // Enable printing of SDK debug messages.
  // Useful when getting started or trying to figure something out.
  Debug: true,
  // Adds request headers and IP for users,
  // visit: https://docs.sentry.io/platforms/go/data-management/data-collected/ for more info
  SendDefaultPII: true,
  EnableTracing: true,
  // Set TracesSampleRate to 1.0 to capture 100%
  // of transactions for tracing.
  TracesSampleRate: 1.0,
})
if err != nil {
  log.Fatalf("sentry.Init: %s", err)
}
// Flush buffered events before the program terminates.
// Set the timeout to the maximum duration the program can afford to wait.
defer sentry.Flush(2 * time.Second)
```

### Ruby

Add the sentry-ruby gem to your Gemfile:

```ruby
gem "sentry-ruby"
```

Configuration should happen as early as possible in your application's lifecycle.

```ruby
require 'sentry-ruby'

Sentry.init do |config|
  config.dsn = 'https://examplePublicKey@o0.ingest.sentry.io/0'

  # get breadcrumbs from logs
  config.breadcrumbs_logger = [:sentry_logger, :http_logger]

  # Add data like request headers and IP for users, if applicable;
  # see https://docs.sentry.io/platforms/ruby/data-management/data-collected/ for more info
  config.send_default_pii = true
  # enable tracing
  # we recommend adjusting this value in production
  config.traces_sample_rate = 1.0
  # Enable logs to be sent to Sentry
  config.enable_logs = true
  # enable profiling
  # this is relative to traces_sample_rate
  config.profiles_sample_rate = 1.0
end
```

### PHP

Install the Sentry SDK using Composer:

```bash
composer require sentry/sentry
```

To use Profiling, you'll also need to install the Excimer extension via PECL:

```bash
pecl install excimer
```

To capture all errors, even the one during the startup of your application, you should initialize the Sentry PHP SDK as soon as possible.

```php
\Sentry\init([
  'dsn' => 'https://examplePublicKey@o0.ingest.sentry.io/0',
  // Add request headers, cookies and IP address,
  // see https://docs.sentry.io/platforms/php/data-management/data-collected/ for more info
  'send_default_pii' => true,
  // Specify a fixed sample rate
  'traces_sample_rate' => 1.0,
  // Enable logs to be sent to Sentry
  'enable_logs' => true,
  // Set a sampling rate for profiling - this is relative to traces_sample_rate
  'profiles_sample_rate' => 1.0,
]);
```

### .NET

Install the NuGet package to add the Sentry dependency:

```shell
dotnet add package Sentry -v 5.16.2
```

To use Profiling, you'll also need to install the Sentry.Profiling package:

```shell
dotnet add package Sentry.Profiling -v 5.16.2
```

To capture all errors, even the one during the startup of your application, you should initialize the Sentry .NET SDK as soon as possible.

```csharp
SentrySdk.Init(options =>
{
    options.Dsn = "https://examplePublicKey@o0.ingest.sentry.io/0";
    options.Debug = true;
    // Adds request URL and headers, IP and name for users, etc.
    options.SendDefaultPii = true;
    // A fixed sample rate of 1.0 - 100% of all transactions are getting sent
    options.TracesSampleRate = 1.0f;
    // A sample rate for profiling - this is relative to TracesSampleRate
    options.ProfilesSampleRate = 1.0f;
});
```

---

*Source: [sentry.io/product/metrics/](https://sentry.io/product/metrics/)*