sentry

Sentry Skill

Comprehensive guide for error monitoring, performance tracking, and application observability using Sentry.

Quick Reference

DSN (Data Source Name)

The DSN is the unique identifier for your Sentry project:

https://<PUBLIC_KEY>@<HOST>/<PROJECT_ID>

Example: https://[email protected]/1234567

Core Concepts

Concept	Description
Event	Single instance of data sent to Sentry (error, transaction, etc.)
Issue	Group of similar events deduplicated by fingerprint
Transaction	Performance monitoring span representing a unit of work
Span	Individual operation within a transaction (DB query, HTTP call)
Trace	Connected series of transactions across services
Release	Version of your code deployed to an environment
Environment	Deployment target (production, staging, development)

SDK Installation & Configuration

JavaScript/Node.js

npm install @sentry/node @sentry/profiling-node

const Sentry = require("@sentry/node");
const { nodeProfilingIntegration } = require("@sentry/profiling-node");

Sentry.init({
  dsn: "https://[email protected]/1",
  release: process.env.RELEASE_VERSION || "1.0.0",
  environment: process.env.NODE_ENV || "development",

  // Error sampling (1.0 = 100% of errors)
  sampleRate: 1.0,

  // Performance monitoring (0.1 = 10% of transactions)
  tracesSampleRate: 0.1,

  // OR use dynamic sampling
  tracesSampler: (samplingContext) => {
    if (samplingContext.transactionContext.name === "/health") {
      return 0; // Don't sample health checks
    }
    if (samplingContext.parentSampled !== undefined) {
      return samplingContext.parentSampled; // Inherit parent decision
    }
    return 0.1; // Default 10%
  },

  // Profiling
  profilesSampleRate: 0.1,
  integrations: [nodeProfilingIntegration()],

  // Data scrubbing
  beforeSend(event) {
    if (event.request?.headers) {
      delete event.request.headers["Authorization"];
    }
    return event;
  },
});