monitoring

A rule set for tracking errors and measuring application performance with Sentry, a service that collects error reports and monitoring data.

In plain words
What is it for?
Use it when configuring Sentry, structured logs, browser and server error handling, performance traces, database monitoring, and filtering unwanted network errors.
Why use it?
It defines how customer and administrator errors should be recorded, filtered, and monitored across the browser and server.

Cursor rule for Cursor

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add rules/smeubank/cursor-template/monitoring
Clone the repo
git clone --depth 1 https://github.com/smeubank/cursor-template

Made for: Cursor.

Per session 2,555 This file is loaded in full into every session.
When invoked 2,555 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.02555 $0.02555
Opus 5 $0.01277 $0.01277
Sonnet 5 $0.00511 $0.00511
Haiku 4.5 $0.00255 $0.00255

Measured 2d ago against content hash 9e46175cb459, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

monitoring scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.cursor/rules/monitoring.mdc · 451 lines

How it starts

The opening of the file, as written. The whole thing — 451 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Monitoring & Observability

🎯 Monitoring Strategy

Comprehensive error tracking and performance monitoring using Sentry with structured logging for both customer and admin experiences.

🔧 Sentry Configuration

Setup

// sentry.client.config.ts
import * as Sentry from '@sentry/nextjs'

Sentry.init({
  dsn: process.env.SENTRY_DSN,
  environment: process.env.NODE_ENV,
  tracesSampleRate: 1.0,
  debug: false,
  integrations: [
    Sentry.browserTracingIntegration(),
  ],
  beforeSend(event, hint) {
    // Filter out non-critical errors
    if (event.exception) {
      const error = hint.originalException
      if (error && error.message?.includes('Network Error')) {
        return null // Don't send network errors
      }
    }
    return event
  },
})

Server Configuration

// sentry.server.config.ts
import * as Sentry from '@sentry/nextjs'

Sentry.init({
  dsn: process.env.SENTRY_DSN,
  environment: process.env.NODE_ENV,
  tracesSampleRate: 1.0,
  debug: false,
  integrations: [
    Sentry.prismaIntegration(),
  ],
})

📊 Structured Logging Patterns

Core Logging Utility

// lib/logging.ts
import * as Sentry from '@sentry/nextjs'

export interface LogContext {
  component: string
  action: string
  userId?: string
  businessId?: string
  bookingId?: string
  [key: string]: any
}

export function logError(error: Error, context: LogContext) {
  Sentry.captureException(error, {
    tags: {
      component: context.component,
      action: context.action,
      severity: 'error',
    },
    extra: {
      ...context,
      timestamp: new Date().toISOString(),
      userAgent: typeof window !== 'undefined' ? window.navigator.userAgent : 'server',
    },
  })
}

export function logInfo(message: string, context: LogContext) {
  Sentry.addBreadcrumb({
    message,
    level: 'info',
    category: context.component,
    data: context,
  })
}

export function logWarning(message: string, context: LogContext) {
  Sentry.captureMessage(message, {
    level: 'warning',
    tags: {
      component: context.component,
      action: context.action,
    },
    extra: context,
  })
}

Read the full file on GitHub · 451 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 451 lines · 2,555 tokens per session scan A 9e46175cb459

Subscribe to this mod's changes

monitoring is a cursor rule published in the GitHub repository smeubank/cursor-template (6 stars, last pushed 1y ago), licensed MIT. It adds 2,555 tokens to every session, about $0.0128 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.