Set Up Metrics

With Sentry Metrics, you can send counters, gauges, distributions, and sets from your applications to Sentry. Once in Sentry, these metrics can be viewed alongside relevant errors, and searched using their individual attributes.

Requirements

Metrics are supported in all Sentry JavaScript SDKs version 10.22.0 and above.

Setup

Metrics are gated by an experimental option, _experiments.enableMetrics (this will not be required in future versions of the SDK).

Sentry.init({
  dsn: "https://examplePublicKey@o0.ingest.sentry.io/0",
  _experiments: {
    enableMetrics: true,
  },
});

Usage

Once the feature is enabled and the SDK is initialized, you can send metrics using the Sentry.metrics APIs.

The metrics namespace exposes three methods that you can use to capture different types of metric information: count, gauge and distribution.

Counter

Use count to track an incrementing value, such as the number of times a button was clicked or a function was called.

Sentry.metrics.count("button_click", 1);

Gauge

Use gauge to track a value that can go up and down, such as the current memory usage or the number of items in a queue.

Sentry.metrics.gauge("queue_depth", 42);

Distribution

Use distribution to track the distribution of a value, such as the response time of a request.

Sentry.metrics.distribution("response_time", 187.5);

Adding Attributes

You can also pass additional attributes to any of the metric methods via the attributes option. Attributes allow you to filter and group metrics.

Sentry.metrics.count("button_click", 1, {
  tags: {
    browser: "Firefox",
    app_version: "1.0.0",
  },
});

Specifying Units

For gauge and distribution metrics, you can specify a unit using the unit option. This helps Sentry display the metric value in a human-readable format.

Sentry.metrics.distribution("response_time", 187.5, {
  unit: "millisecond",
});

Sentry.metrics.gauge("memory_usage", 1024, {
  unit: "byte",
});

Options

The Sentry JavaScript SDK provides several options to configure how metrics are captured and sent to Sentry.

Filtering and Modifying Metrics

Use the beforeSendMetric callback to filter or modify metrics before they're sent to Sentry. This is useful for:

• Removing sensitive data from metric attributes
• Dropping metrics you don't want to send
• Adding or modifying attributes

The callback receives a metric object and must return either a modified metric or null to drop it.

Sentry.init({
  // ...
  beforeSendMetric: (metric) => {
    // Drop metrics with specific attributes
    if (metric.attributes?.dropMe === true) {
      return null;
    }

    // Modify metric attributes
    metric.attributes = {
      ...metric.attributes,
      processed: true,
    };

    return metric;
  },
});

Disabling Metrics

If you want to disable metrics collection entirely, you can do so by disabling the _experimental.enableMetrics flag:

Sentry.init({
  dsn: "https://examplePublicKey@o0.ingest.sentry.io/0",
  _experiments: {
    enableMetrics: false,
  },
});

Flushing Metrics

By default, metrics are buffered and flushed depending on buffer size and time. If you need to manually flush metrics before the automatic interval, you can use the flush method:

await Sentry.flush();

This will flush all pending metrics and events to Sentry.

Default Attributes

By default the SDK will attach the following attributes to a metric:

1. sentry.environment: The environment set in the SDK if defined.
2. sentry.release: The release set in the SDK if defined.
3. sentry.sdk.name: The name of the SDK that sent the metric.
4. sentry.sdk.version: The version of the SDK that sent the metric.

User Attributes

The SDK will optionally attach user information as attributes (guarded by sendDefaultPii):

1. user.id
2. user.name
3. user.email

Browser Attributes

The SDK will optionally attach browser information as attributes:

1. browser.name (added during ingestion, guarded by sendDefaultPii)
2. browser.version (added during ingestion, guarded by sendDefaultPii)
3. sentry.replay_id: The replay id of the replay that was active when the metric was collected. (added during ingestion by Relay)