sentry-cost-tuning

Optimize Sentry costs, reduce event volume, and manage quota spend. Use when analyzing Sentry billing, reducing error/transaction volume, configuring sampling rates, or preventing overage charges. Trigger: "reduce sentry costs", "sentry billing optimization", "sentry quota management", "optimize sentry spend", "sentry sampling".

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Repository: jeremylongshore/tons-of-skills-marketplace
Last source activity: August 19, 2026 at 12:13
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name	sentry-cost-tuning
description	Optimize Sentry costs, reduce event volume, and manage quota spend. Use when analyzing Sentry billing, reducing error/transaction volume, configuring sampling rates, or preventing overage charges. Trigger: "reduce sentry costs", "sentry billing optimization", "sentry quota management", "optimize sentry spend", "sentry sampling".
allowed-tools	Read, Write, Edit, Grep, Glob, Bash(curl:), Bash(node:), Bash(npx:*)
version	1.51.0
license	MIT
author	Jeremy Longshore <jeremy@intentsolutions.io>
tags	["saas","sentry","cost-optimization","billing","quotas","sampling"]
compatibility	Designed for Claude Code

Sentry Cost Tuning

Overview

Reduce Sentry spend by 60-95% through SDK-level sampling, server-side inbound filters, beforeSend event dropping, and quota management — without losing visibility into production errors that matter.

Prerequisites

Active Sentry account with org:read and project:read scopes on an auth token
Access to the project's Sentry.init() configuration (typically sentry.client.config.ts or instrument.ts)
Current plan tier identified: Developer (free, 5K errors/mo), Team ($26/mo, 50K errors + 100K transactions), or Business ($80/mo, 100K errors + 500K transactions)
SENTRY_AUTH_TOKEN and SENTRY_ORG environment variables set for API calls
@sentry/node >= 8.0 or @sentry/browser >= 8.0 installed

Instructions

Step 1 — Audit Current Usage via the Stats API

Query the Sentry Usage Stats API to understand where volume comes from before making changes. This endpoint returns event counts grouped by category over any time period.

# Pull 30-day usage breakdown by category
curl -s -H "Authorization: Bearer $SENTRY_AUTH_TOKEN" \
  "https://sentry.io/api/0/organizations/$SENTRY_ORG/stats/usage/?statsPeriod=30d&groupBy=category&field=sum(quantity)&interval=1d" \
  | python3 -c "
import json, sys
data = json.load(sys.stdin)
print('=== 30-Day Usage by Category ===')
for group in data.get('groups', []):
    cat = group['by']['category']
    total = sum(interval[1] for interval in group.get('series', {}).get('sum(quantity)', []))
    print(f'  {cat}: {total:,} events')
"

# Identify top error-producing projects
curl -s -H "Authorization: Bearer $SENTRY_AUTH_TOKEN" \
  "https://sentry.io/api/0/organizations/$SENTRY_ORG/stats/usage/?statsPeriod=30d&groupBy=project&category=error&field=sum(quantity)" \
  | python3 -c "
import json, sys
data = json.load(sys.stdin)
projects = []
for group in data.get('groups', []):
    proj = group['by']['project']
    total = sum(interval[1] for interval in group.get('series', {}).get('sum(quantity)', []))
    projects.append((proj, total))
projects.sort(key=lambda x: -x[1])
print('=== Top Error-Producing Projects ===')
for name, count in projects[:10]:
    print(f'  {name}: {count:,}')
"

import * as Sentry from '@sentry/node';

Sentry.init({
  dsn: process.env.SENTRY_DSN,

  // 10% of errors sent = 90% cost reduction
  // Sentry extrapolates counts in the Issues dashboard
  sampleRate: 0.1,
});

import * as Sentry from '@sentry/node';

Sentry.init({
  dsn: process.env.SENTRY_DSN,

  // Static: 5% of all traces (95% cost reduction)
  tracesSampleRate: 0.05,

  // Dynamic: per-endpoint sampling for fine-grained control
  // When tracesSampler is defined, it overrides tracesSampleRate
  tracesSampler: (samplingContext) => {
    const { name, attributes } = samplingContext;

    // Never trace health checks, readiness probes, static assets
    if (name?.match(/\/(health|healthz|ready|livez|ping|robots\.txt|favicon)/)) {
      return 0;
    }
    if (name?.match(/\.(js|css|png|jpg|svg|woff2?|ico)$/)) {
      return 0;
    }

    // High-value: payment and auth flows get 50% sampling
    if (name?.includes('/checkout') || name?.includes('/payment')) {
      return 0.5;
    }
    if (name?.includes('/auth') || name?.includes('/login')) {
      return 0.25;
    }

    // API routes: 5%
    if (name?.includes('/api/')) {
      return 0.05;
    }

    // Everything else: 1%
    return 0.01;
  },
});

import * as Sentry from '@sentry/node';

Sentry.init({
  dsn: process.env.SENTRY_DSN,

  beforeSend(event, hint) {
    const error = hint?.originalException;
    const message = typeof error === 'string' ? error : error?.message || '';

    // Drop ResizeObserver noise (Chrome fires this constantly, never actionable)
    if (message.includes('ResizeObserver loop')) return null;

    // Drop network errors from flaky client connections
    if (/^(Failed to fetch|NetworkError|Load failed|AbortError)$/i.test(message)) {
      return null;
    }

    // Drop cancelled navigation (user clicked away)
    if (message.includes('cancelled') || message.includes('AbortError')) {
      return null;
    }

    // Drop browser extension errors by checking stack frames
    const frames = event.exception?.values?.[0]?.stacktrace?.frames || [];
    if (frames.some(f => f.filename?.match(/extensions?\//i) || f.filename?.match(/^(chrome|moz)-extension:\/\//))) {
      return null;
    }

    // Always send critical errors regardless of sampleRate
    // Re-enable any that were sampled out
    if (event.level === 'fatal' || event.tags?.critical === 'true') {
      return event;
    }

    return event;
  },

  // Complementary: block errors from known noisy patterns
  ignoreErrors: [
    'ResizeObserver loop completed with undelivered notifications',
    'ResizeObserver loop limit exceeded',
    'Non-Error promise rejection captured',
    /Loading chunk \d+ failed/,
    /Unexpected token '<'/,       // HTML returned instead of JS (CDN issue)
    /^Script error\.?$/,          // Cross-origin script with no details
  ],

  // Block events from third-party scripts
  denyUrls: [
    /extensions\//i,
    /^chrome:\/\//i,
    /^chrome-extension:\/\//i,
    /^moz-extension:\/\//i,
    /hotjar\.com/,
    /intercom\.io/,
    /google-analytics\.com/,
    /googletagmanager\.com/,
    /cdn\.segment\.com/,
  ],
});

Filter	What it drops	Impact
Browser Extensions	Errors from Chrome/Firefox extensions	5-15% of frontend errors
Legacy Browsers	IE 11, old Safari/Chrome versions	2-10% depending on audience
Localhost Events	Errors from `localhost` and `127.0.0.1`	Dev noise (variable)
Web Crawlers	Bot-triggered errors (Googlebot, Bingbot)	1-5% of frontend errors
Filtered Transactions	Health checks, static asset requests	10-40% of transactions

# Enable inbound filters via API
for filter in browser-extensions legacy-browsers localhost-events web-crawlers; do
  curl -s -X PUT \
    -H "Authorization: Bearer $SENTRY_AUTH_TOKEN" \
    -H "Content-Type: application/json" \
    -d '{"active": true}' \
    "https://sentry.io/api/0/projects/$SENTRY_ORG/$SENTRY_PROJECT/filters/$filter/"
  echo " -> Enabled: $filter"
done

# Add custom inbound filter for error messages
curl -s -X PUT \
  -H "Authorization: Bearer $SENTRY_AUTH_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"active": true, "subfilters": ["ResizeObserver", "ChunkLoadError", "Script error"]}' \
  "https://sentry.io/api/0/projects/$SENTRY_ORG/$SENTRY_PROJECT/filters/custom-error-messages/"

# Set rate limit: 1000 errors per hour per DSN key
curl -s -X PUT \
  -H "Authorization: Bearer $SENTRY_AUTH_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"rateLimit": {"window": 3600, "count": 1000}}' \
  "https://sentry.io/api/0/projects/$SENTRY_ORG/$SENTRY_PROJECT/keys/$KEY_ID/"

Example calculation:
  Average monthly errors:  120,000
  Plan included:            50,000  (Team plan)
  Overage:                  70,000

  On-demand cost:  70,000 x $0.000290 = $20.30/month
  Reserved cost:   70,000 x $0.000180 = $12.60/month
  Monthly savings: $7.70 ($92.40/year)

import * as Sentry from '@sentry/node';

Sentry.init({
  dsn: process.env.SENTRY_DSN,

  // Reduce breadcrumbs from default 100 to 20
  maxBreadcrumbs: 20,

  // Truncate long string values (default 250)
  maxValueLength: 500,

  // Disable features you are not actively using
  replaysSessionSampleRate: 0,    // Session replays off
  replaysOnErrorSampleRate: 0,    // Error replays off
  profilesSampleRate: 0,          // Profiling off

  beforeSend(event) {
    // Truncate large request bodies
    if (event.request?.data && typeof event.request.data === 'string') {
      if (event.request.data.length > 2000) {
        event.request.data = event.request.data.substring(0, 2000) + '...[truncated]';
      }
    }

    // Strip unnecessary headers
    if (event.request?.headers) {
      const keep = ['content-type', 'user-agent', 'referer', 'accept-language'];
      event.request.headers = Object.fromEntries(
        Object.entries(event.request.headers)
          .filter(([k]) => keep.includes(k.toLowerCase()))
      );
    }

    return event;
  },
});

# Compare current period vs previous period
curl -s -H "Authorization: Bearer $SENTRY_AUTH_TOKEN" \
  "https://sentry.io/api/0/organizations/$SENTRY_ORG/stats/usage/?statsPeriod=7d&groupBy=category&field=sum(quantity)&interval=1d" \
  | python3 -c "
import json, sys
data = json.load(sys.stdin)
print('=== Post-Optimization 7-Day Usage ===')
for group in data.get('groups', []):
    cat = group['by']['category']
    total = sum(interval[1] for interval in group.get('series', {}).get('sum(quantity)', []))
    print(f'  {cat}: {total:,} events')
print()
print('Compare against your Step 1 baseline to calculate % reduction.')
"

Problem	Cause	Fix
Critical errors missing from Sentry	`sampleRate` too low	Add `beforeSend` logic that always sends `level: 'fatal'` events regardless of sampling
Zero performance data	`tracesSampleRate: 0` or `tracesSampler` returning `0` for all routes	Set minimum `0.01` baseline in the `tracesSampler` default return
Unexpected overage charges	No rate limits or spend allocations	Set per-key rate limits (Step 6) and spend allocations in billing settings
Spike consuming entire monthly quota	Spike protection disabled or infinite error loop	Verify spike protection is active; add circuit breaker in `beforeSend`
Usage API returns 403	Auth token missing `org:read` scope	Generate new token at sentry.io/settings/auth-tokens with `org:read` + `project:read`
`beforeSend` drops too aggressively	Overly broad regex patterns	Test patterns against recent events in Sentry's Discover tab before deploying
Inbound filters not reducing volume	Filters enabled after events ingested	Filters are prospective only; wait for new events to see impact

Before: 45K errors + 800K transactions
  Included: 50K errors + 100K transactions
  Overage: 700K transactions x $0.000025 = $17.50/month

After optimization:
  tracesSampler → 800K reduced to 40K (95% drop)
  ignoreErrors + beforeSend → 45K reduced to 28K (38% drop)
  Inbound filters → additional 5% reduction

  New monthly overage: $0
  Annual savings: $210

Before: 450K errors + 200K transactions + 5K replays
  Included: 100K errors + 500K transactions + 5K replays
  Overage: 350K errors x $0.000290 = $101.50/month

After optimization:
  sampleRate 0.25 → 450K reduced to 112K
  beforeSend filtering → 112K reduced to 85K
  Inbound filters → 85K reduced to 72K

  New monthly overage: $0 (72K < 100K included)
  Annual savings: $1,218

Sentry.init({
  dsn: process.env.SENTRY_DSN,
  tracesSampler: (samplingContext) => {
    const { name } = samplingContext;

    // Internal services: minimal sampling
    if (name?.startsWith('internal.')) return 0.001;

    // Customer-facing API: moderate sampling
    if (name?.startsWith('api.')) return 0.05;

    // Background jobs: low sampling
    if (name?.includes('worker') || name?.includes('cron')) return 0.01;

    return 0.01;
  },
});