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Sentry
Application monitoring platform for identifying, debugging, and resolving software errors and performance issues.
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How to structure a log
Logging arbitrary JSON objects often produces unstable messages and deeply nested data that complicate searching, aggregating, and debugging production incidents. Structured logging treats log output as real application data by establishing predictable, consistent schemas across services. Engineers should define stable event names using a domain.action pattern and capture dynamic dimensions with flattened, snake_case attributes formatted in dot notation. Attribute payloads must contain only primitive values or primitive arrays rather than arbitrary objects, utilizing low-cardinality result identifiers and explicit units for numeric measurements. Teams can enforce these structural conventions automatically with linting tools such as ESLint, while routing execution durations and timing measurements to tracing spans.
MongoDB Query Tracing in .NET with Sentry + OTLP
Measuring MongoDB performance in a .NET application requires command details, durations, and enough context to distinguish isolated spikes from recurring query patterns. The post presents an end-to-end setup that uses MongoDB’s built-in OpenTelemetry Activity instrumentation, the .NET OpenTelemetry SDK, Sentry.OpenTelemetry.Exporter, and OTLP ingestion rather than a dedicated Sentry.MongoDB integration. Configuration initializes Sentry with UseOtlp(), subscribes to MongoTelemetry.ActivitySourceName, adds MongoDB instrumentation, and exports spans with AddSentryOtlp(...), while avoiding duplicate spans from overlapping hooks. Query context appears in Sentry traces, span samples, and the Queries experience, with Relay generating parameterized values for aggregation but retaining raw db.query.text per span. The post also demonstrates client-side redaction and describes server-side scrubbing, while exporter propagation bridges preserve correlation with errors and replays.
Your agent should understand what you see
Sentry's Seer Agent initially parsed user screens using DOM-scraped character-by-character ASCII grids, leading to severe token consumption, model context rot, and an inability to support interactive actions. To resolve these bottlenecks, Sentry replaced visual text scraping with a composable semantic context system where React UI components directly declare their state, metadata, and interactive affordances. A root React context provider maintains a registry of component nodes organized hierarchically through higher-order wrappers, serializing the resulting structure to JSON and backend-generated Markdown within the system prompt. Across twenty-four live pages, this approach reduced dashboard context tokens from roughly 5,500 to 1,300 while maintaining identical satisfaction rates and tool-call volumes across more than 14,000 evaluated conversations.
When and what should I be logging?
Targeted structured logging provides a fast way to capture operational behavior in production without requiring new deployments for debugging. Developers benefit most from logging key runtime decisions, multi-step algorithm outcomes, mutating audit operations, and context around non-critical or retried errors. Rather than outputting plain text, applications should record structured key-value pairs that capture who performed an action, what occurred, and associated trace identifiers. Sensitive information such as secrets and personally identifiable data must be excluded or scrubbed, and large unparsed payloads should be avoided to prevent excessive costs. Managing log levels appropriately and treating logs as potentially temporary instrumentation helps maintain actionable telemetry without generating unnecessary noise.
Any Apple update can break our app. Here's how we find out first.
Usage is an Apple ecosystem resource monitor that relies on undocumented APIs vulnerable to silent data structure changes across OS updates. To maintain stability across iPhone, iPad, and Mac without degrading device performance, the development team uses Sentry across separate component projects in a unified workspace. Beyond capturing standard crashes, the team wraps Swift errors with unexpected raw data payloads to quickly diagnose undocumented API structure drift while scrubbing sensitive user values. They also employ Sentry Size Analysis as a regression gate to monitor release payload deltas, preventing unintended asset omissions or bloat from slipping through code reviews. This multi-layered monitoring setup enables the team to detect and resolve platform-induced breakages before most end users encounter them.
Reading the agent traces is how you make the call your eval can't
Automated evaluations often miss unknown failure modes in AI agents because developers only write tests for anticipated errors. While building an itinerary agent for AI Engineer World's Fair, an open-weight model routed a speaker query to a tool returning only tracks, leading the model to hallucinate famous speakers and falsely claim the tool provided that data. Because a tool was executed, the trace appeared grounded until inspectable tool outputs revealed the discrepancy. To resolve this, the author retained the inexpensive model, corrected query routing, tightened system prompts against ungrounded entities, and added a custom entity-diffing eval in CI. Ultimately, directly reading agent telemetry traces alongside errors and logs is essential for diagnosing root causes and deciding trade-offs between model costs, prompt adjustments, and routing fixes.
Next.js already traces your requests. Here's how to export them with OpenTelemetry.
Next.js provides out-of-the-box tracing for incoming requests, fetch calls, middleware, and server-side rendering, but traces remain invisible without a configured exporter. Developers can use the @vercel/otel package inside an instrumentation file to initialize the OpenTelemetry SDK and transmit traces to any OTLP-compatible destination. While Next.js automatically creates spans for standard request lifecycles, developers can define custom active spans in the Node runtime to capture specific domain operations and contextual attributes. Exporting traces to backends like Sentry requires configuring standard OTLP endpoint and authentication environment variables. Choosing between direct OTLP export via @vercel/otel and the dedicated Sentry SDK depends on requirements, as direct export lacks browser tracing, error monitoring, and Edge custom spans.
Better, faster, less wrong: Enhancing issue grouping
Sentry upgraded its AI-driven issue grouping system to better prevent duplicate issues without merging distinct application errors. The team trained lightonai/modernbert-embed-large using Matryoshka Representation Learning on hundreds of thousands of stacktrace pairs labeled by Claude Sonnet 4.5. To optimize the high-throughput ingestion pipeline, embeddings were truncated from 768 to 64 dimensions, combined with bfloat16 precision, PyTorch SDPA, and CUDA graph compilation. A phased live rollout used threshold-gated index backfilling and automatic fallback to prevent issue spikes during migration. In production, the v2 model cuts the overgrouping rate from 8% to 4%, increases prevented duplicate issues to 70%, and delivers 6x faster inference.
Catch visual regressions with Snapshots, now in beta
Sentry has released the beta version of Sentry Snapshots to catch visual regressions on pull requests across any platform with a frontend. The tool captures screenshots of an application across various viewports, themes, and languages, compares them against a baseline, and blocks pull requests when diffs are detected. Teams can attach custom context metadata, including test file paths, to help developers and AI agents locate test sources and generate additional test cases. By leveraging the sentry-mcp integration, REST API, and sentry-cli, workflows can retrieve base images, diff masks, and run local diff verification before pushing commits. Originally created at Emerge Tools for mobile applications, this iteration expands automated visual testing capabilities to broader frontend codebases.
Works on my machine: how we use AI to reproduce reported bugs
Sentry maintains 159 open-source SDK packages across multiple languages, leading to high triage volume and significant boilerplate setup overhead when reproducing reported bugs. To streamline this workflow, the team developed a Claude skill that parses GitHub issue URLs to extract language, framework, and SDK versions. The skill generates a reproduction branch, sets up minimal boilerplate using ecosystem package managers like uv or npm, attempts execution, and opens a pull request with explicit run instructions. By allowing the model to exit early when encountering overly complex environments, the tool reliably prepares reproducible playgrounds without stumbling on edge cases. This workflow saved several hours in testing scenarios like Django HTTPS proxy bugs while avoiding excessive bot noise through scoped human interaction.
Errors, traces, logs, metrics: when to reach for what
Modern application telemetry relies on four overlapping signals: errors, traces, logs, and metrics. Each telemetry type addresses distinct engineering questions and powers specific debugging workflows. Errors track grouped, actionable application crashes, whereas traces map timing and execution paths across dependency waterfalls. Metrics aggregate numerical measurements across historical deployments, and logs preserve complete state and decision-making context at specific moments in execution. Emitting telemetry directly into the format needed for a given workflow proves superior to relying on a single wide event, as tools like AI coding agents require structured spans to optimize execution paths while human debuggers rely on unsampled logs and metrics to pinpoint silent failures.
How we cut build times by two-thirds by deleting our CMS
Sentry rebuilt its marketing site and blog of roughly 2,500 pages, replacing a legacy Gatsby setup and traditional headless CMS with Astro, Markdown, Frontmatter, and AI-driven automation. The previous architecture suffered from 14-minute build times, restrictive CMS schema limits, and frequent build failures caused by external API dependencies. A team of 2.5 developers executed the migration in two months using Claude Code agents for data extraction, template translation, and testing. To manage content without a CMS dashboard, Sentry built Claude Skills to guide updates, run local previews, and draft GitHub pull requests. The migration reduced average build times to under 4 minutes, cut broken staging builds by 95 percent, and improved Web Vitals scores from 89 to 97.
You don’t need to pick one: how Sentry and OpenTelemetry work together
Integrating Sentry into systems already instrumented with OpenTelemetry does not require replacing existing backend SDKs or rewriting service instrumentation. A hybrid architecture pairs the Sentry SDK on the frontend for browser tracing, Session Replay, and logs with existing OpenTelemetry configurations across backend services. Frontend requests propagate W3C traceparent headers to backend endpoints, which then export traces and logs over OTLP directly to Sentry endpoints or through an intermediate OpenTelemetry Collector. Ingested telemetry attaches backend spans and standard Python logs to the initial frontend user actions, establishing a unified distributed trace across the entire request path. Although Sentry's OTLP ingest currently supports logs and traces rather than metrics, dedicated backend Sentry SDKs remain an optional addition later for backend exception tracking and profiling.
Your agent can't fix what it can't see
Coding agents frequently fail to resolve production bugs when restricted to source code alone, as they lack critical runtime context such as stack traces, breadcrumbs, and environment data. To bridge this gap, Sentry introduces Sentry MCP and the Sentry CLI to supply agents and developers with structured production telemetry. The Model Context Protocol integration supports clients like Claude Code, Cursor, and VS Code, while the CLI enables scripted workflows. When an alert triggers, an agent uses trace and commit metadata to diagnose root causes across service boundaries, generate regression tests, and open draft pull requests. Over six months, the Autofix pull request merge rate increased from 41% to 46%.
The product analytics you already have
Software engineers frequently rely on separate product analytics tools and teams to answer user behavior questions, creating disjointed data models and delayed insights. Existing debugging telemetry within tools like Sentry—specifically spans, structured logs, and application metrics—can serve as the primary source for product metrics. Developers enrich request spans with business-level attributes, record discrete business events through wide structured logs, and track KPIs with metric counters and distributions. This unified telemetry links business outcomes directly to underlying traces, errors, releases, and source code lines, enabling immediate root-cause analysis and automated alerts. While multi-session cohort and funnel aggregation remains a current tooling gap, standard telemetry solves day-to-day adoption, performance, and revenue questions.
New ways to agentically build and edit dashboards
Pre-configured monitoring templates often fail to meet organization-specific needs, forcing developers to manually build dashboards widget by widget. Sentry introduced AI-agent-powered dashboard creation and editing in open beta, alongside CLI management tooling and template revisions. Users can prompt an AI chat interface to build or adjust dashboards, duplicate and customize uneditable Sentry-built templates, or execute dashboard commands directly in their terminal. Dashboards leverage issue, tracing, and application metric data across frontend, backend, mobile, and framework-specific views like Next.js and Laravel. Edits made through the UI, CLI, or AI agent are automatically tracked in a revision history that supports one-click rollbacks.
From vibe code to production-ready: observability for Next.js and Supabase apps
AI-assisted software development often generates functional code that lacks proper instrumentation, leading to unindexed database queries, N+1 patterns, and fragmented connection strategies. While Supabase provides built-in query analytics, security advisors, and subsystem logs, it cannot trace distributed requests across the entire application stack. Integrating Sentry bridges this visibility gap by establishing distributed traces across Next.js frontends, Deno-based Supabase Edge Functions, and Postgres databases. Teams can forward Supabase logs into dedicated Sentry projects and configure runtime integrations to automatically detect performance bottlenecks such as slow spans and Web Vitals regressions. Furthermore, integrating Model Context Protocol servers allows Sentry's Seer debugger to identify root causes and generate automated fixes for emerging issues.
Monitor Unreal Engine Game Performance with Application Metrics
Unreal Engine games frequently experience performance issues such as frame-rate drops, hitches, and network degradation that do not register as application crashes. To address the lack of live production telemetry, the Sentry Unreal SDK introduces automatic performance metrics. The integration periodically samples frame times, network health, active UObject counts, physical memory usage, and garbage collection pause durations across desktop, console, and Android platforms. Telemetry entries attach contextual hardware and environment attributes alongside trace IDs to connect aggregate latency spikes directly to underlying traces and spans. Enabled by default in Unreal SDK version 1.11.0, this telemetry provides developers with fleet-wide visibility into hardware-specific bottlenecks across game releases.
Fixing JavaScript observability, one library at a time
JavaScript application performance monitoring tools rely on monkey-patching via require-in-the-middle and import-in-the-middle, which breaks with ECMAScript Modules, bundlers, and non-Node runtimes. To solve this, an initiative is replacing monkey-patching with Node's built-in diagnostics_channel TracingChannel API across server-side JavaScript libraries. Under this pattern, libraries publish structured events while monitoring vendors subscribe to them with zero overhead when unlistened. The author leveraged Claude Code workflows alongside direct maintainer communication to draft proposals, implement code, and manage reviews across 44 target packages. Ten libraries including mysql2, node-redis, ioredis, and unjs modules have merged support, while active efforts continue on shared OpenTelemetry mapper registries and remaining ecosystem packages.
Improved debugging for Expo apps with the React Native SDK
Expo applications generate approximately 75% of the total event volume received from React Native applications in Sentry. In response, Sentry updated its React Native SDK starting in version 8.10 to improve Expo debugging and performance monitoring workflows. The update automatically enriches events with Expo constants and over-the-air update context, including channels, runtime versions, and emergency launch warnings when an OTA update fails. Developers can track remote EAS Build lifecycle failures and successes using dedicated hooks configured in package.json. Performance instrumentation now supports span generation for Expo Router route prefetching as well as asset and image loading through wrapper functions around expo-image and expo-asset.
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