Metrics

Every Tracelit backend SDK ships a metrics API on top of OpenTelemetry. Create custom instruments in your code and the SDK collects automatic runtime metrics in the background — no separate metrics agent needed.

Instrument types

Type	Use when
Counter	A value that only goes up — requests served, orders placed, emails sent
Histogram	A distribution of values — request durations, payload sizes, queue wait time
Gauge	A value that can go up or down — active connections, queue depth, cache size

Custom metrics

import Tracelit from "@tracelit/sdk";

// Counter
const ordersPlaced = Tracelit.metrics.counter("orders.placed", {
  description: "Total orders placed",
  unit: "{orders}",
});
ordersPlaced?.add(1, { currency: "USD", channel: "web" });

// Histogram
const apiLatency = Tracelit.metrics.histogram("external.api.duration", {
  description: "External API call duration",
  unit: "ms",
});
const start = Date.now();
await callExternalApi();
apiLatency?.record(Date.now() - start, { service: "stripe" });

// Gauge
const queueDepth = Tracelit.metrics.gauge("job_queue.depth", {
  description: "Number of pending background jobs",
  unit: "{jobs}",
});
queueDepth?.record(await queue.pendingCount(), { queue: "default" });

import (
    "go.opentelemetry.io/otel/metric"
    "go.opentelemetry.io/otel/attribute"
)

// Counter
requests, _ := tracelit.Counter("http.server.requests",
    metric.WithDescription("Total HTTP requests"),
    metric.WithUnit("{request}"),
)
requests.Add(ctx, 1, metric.WithAttributes(
    attribute.String("method", r.Method),
    attribute.Int("status", statusCode),
))

// Histogram
latency, _ := tracelit.Histogram("http.server.duration",
    metric.WithUnit("ms"),
)
latency.Record(ctx, durationMs)

// Counter
var counter = TracelitClient.Metrics.Counter(
    "orders.placed",
    description: "Total orders placed",
    unit: "{orders}");

counter.Add(1,
    new KeyValuePair<string, object?>("currency", "USD"),
    new KeyValuePair<string, object?>("channel", "web"));

// Histogram
var histogram = TracelitClient.Metrics.Histogram(
    "external.api.duration",
    description: "External API call duration",
    unit: "ms");

var sw = Stopwatch.StartNew();
await CallExternalApiAsync();
histogram.Record(sw.Elapsed.TotalMilliseconds,
    new KeyValuePair<string, object?>("service", "stripe"));

// Gauge (callback-based)
var gauge = TracelitClient.Metrics.Gauge(
    "job_queue.depth",
    () => (double)JobQueue.PendingCount,
    description: "Number of pending background jobs",
    unit: "{jobs}");

Observable gauges

Use an observable gauge when the value is expensive to compute and should only be read on each export interval:

Node.js

const queueGauge = Tracelit.metrics.observableGauge("message.queue.size", {
  description: "Estimated message queue size",
  unit: "{messages}",
});

queueGauge?.addCallback((result) => {
  result.observe(getQueueSize(), { queue: "events" });
});

Automatic metrics

Once the SDK starts, the following metrics are collected with no extra code:

Node.js
Go
.NET

Metric	Type	Description	Interval
`process.memory.rss`	Gauge	Process RSS memory (MB)	60 s
`process.event_loop.lag`	Histogram	Node.js event loop lag (ms)	30 s
`http.server.request.count`	Counter	Total HTTP requests (with Express middleware)	—
`http.server.request.duration`	Histogram	Request duration (ms)	—
`http.server.error.count`	Counter	5xx responses	—

Add the Express middleware to enable HTTP metrics:

app.use(Tracelit.expressMetricsMiddleware()); // add before routes

Metric	Type	Description	Interval
Goroutine count	Gauge	Active goroutines	60 s
GC pause time	Histogram	Garbage collection pause durations	—
Heap allocation	Gauge	Current heap allocation in bytes	60 s

All runtime metrics are collected via the go.opentelemetry.io/contrib/instrumentation/runtime package, enabled automatically.

Metric	Type	Description
`http.server.request.duration`	Histogram	HTTP request duration
`http.server.active_requests`	UpDownCounter	In-flight requests
`http.client.request.duration`	Histogram	Outbound HTTP call duration
`dotnet.gc.*`	Various	GC collections, heap size, pause time
`dotnet.thread_pool.*`	Various	Thread pool queue length, worker threads
`process.memory.rss`	Gauge	Process working set in MB

Viewing metrics

All metrics are available in the Metrics tab of your service in the Tracelit dashboard. You can:

Plot any metric by name with custom time ranges and aggregations
Overlay metrics from multiple services on a single chart
Set alert thresholds on any metric — see Incidents

Learn more

Topic	Description	Guide
Distributed tracing	Traces and metrics share the same SDK — no extra setup.	Read
Incidents	Metric anomalies and thresholds can trigger incidents automatically.	Read

Getting Started

Core Features

Agentic Process

Integrations

Instrument types

Custom metrics

Observable gauges

Automatic metrics

Viewing metrics

Learn more

​Instrument types

​Custom metrics

​Observable gauges

​Automatic metrics

​Viewing metrics

​Learn more

Instrument types

Custom metrics

Observable gauges

Automatic metrics

Viewing metrics

Learn more