getsentry/sentry

Sentry is an open-source error tracking and application performance monitoring platform that helps development teams detect, investigate, and fix problems in their software in production. The core problem it solves is the gap between what developers see in development and what actually breaks for users in the real world: bugs often only appear under specific conditions, with specific data, on specific devices. Without a tool like Sentry, developers rely on user reports ("it just crashed") or scattered log files to diagnose these issues. When you add a Sentry SDK to your application, it automatically intercepts unhandled exceptions and errors and sends them to the Sentry server along with rich contextual information: the full stack trace, the values of local variables at each frame, the user's browser or device, the recent sequence of events leading up to the crash ("breadcrumbs"), and the exact URL or action that triggered it. All of this is displayed in a clean interface grouped by error type so you can prioritize by impact, seeing, for example, that a specific crash is affecting 12% of your users. Beyond error tracking, Sentry provides performance monitoring through distributed tracing. You can trace a single user request as it flows through multiple services, a frontend, an API server, a database query, see where the bottlenecks are, and understand the performance impact of code changes over time. It also offers session replays (recording exactly what a user was doing when an error occurred), uptime monitoring, and structured log aggregation. Sentry is available as a hosted cloud service or as a self-hosted installation of this open-source repository. The server is built with Python and Django. SDKs exist for virtually every major language and platform, including JavaScript, Python, Ruby, Go, Rust, Java, Swift, Dart, C++, and more. Teams at any scale, from solo developers to large enterprises, use Sentry to maintain visibility into what's breaking in production.