sentry-ruby-sdk

name	sentry-ruby-sdk
description	Full Sentry SDK setup for Ruby. Use when asked to add Sentry to Ruby, install sentry-ruby, setup Sentry in Rails/Sinatra/Rack, or configure error monitoring, tracing, logging, metrics, profiling, or crons for Ruby applications. Also handles migration from AppSignal, Honeybadger, Bugsnag, Rollbar, or Airbrake. Supports Rails, Sinatra, Rack, Sidekiq, and Resque.
license	Apache-2.0

Sentry Ruby SDK

Opinionated wizard that scans the project and guides through complete Sentry setup.

Invoke This Skill When

• User asks to "add Sentry to Ruby" or "set up Sentry" in a Ruby app
• User wants error monitoring, tracing, logging, metrics, profiling, or crons in Ruby
• User mentions sentry-ruby, sentry-rails, or the Ruby Sentry SDK
• User is migrating from AppSignal, Honeybadger, Bugsnag, Rollbar, or Airbrake to Sentry
• User wants to monitor exceptions, HTTP requests, or background jobs in Rails/Sinatra

Note: SDK APIs below reflect sentry-ruby v6.4.0. Always verify against docs.sentry.io/platforms/ruby/ before implementing.

---

Phase 1: Detect

# Existing Sentry gems
grep -i sentry Gemfile 2>/dev/null

# Framework
grep -iE '\brails\b|\bsinatra\b' Gemfile 2>/dev/null

# Web server — Puma triggers queue time guidance
grep -iE '\bpuma\b' Gemfile 2>/dev/null

# Background jobs
grep -iE '\bsidekiq\b|\bresque\b|\bdelayed_job\b' Gemfile 2>/dev/null

# Competitor monitoring tools — triggers migration path if found
grep -iE '\bappsignal\b|\bhoneybadger\b|\bbugsnag\b|\brollbar\b|\bairbrake\b' Gemfile 2>/dev/null

# Scheduled jobs — triggers Crons recommendation
grep -iE '\bsidekiq-cron\b|\bclockwork\b|\bwhenever\b|\brufus-scheduler\b' Gemfile 2>/dev/null
grep -rn "Sidekiq::Cron\|Clockwork\|every.*do" config/ lib/ --include="*.rb" 2>/dev/null | head -10

# OpenTelemetry tracing — check for SDK + instrumentations
grep -iE '\bopentelemetry-sdk\b|\bopentelemetry-instrumentation\b' Gemfile 2>/dev/null
grep -rn "OpenTelemetry::SDK\.configure\|\.use_all\|\.in_span" config/ lib/ app/ --include="*.rb" 2>/dev/null | head -5

# OpenTelemetry logging — check for logs SDK (much less common in Ruby)
grep -iE '\bopentelemetry-logs-sdk\b|\bopentelemetry-logs-api\b' Gemfile 2>/dev/null
grep -rn "OpenTelemetry::Logs" config/ lib/ app/ --include="*.rb" 2>/dev/null | head -5

# Existing metric patterns (StatsD, Datadog, Prometheus)
grep -rE "(statsd|dogstatsd|prometheus|\.gauge|\.histogram|\.increment|\.timing)" \
  app/ lib/ --include="*.rb" 2>/dev/null | grep -v "_spec\|_test" | head -20

# Companion frontend
cat package.json frontend/package.json web/package.json 2>/dev/null | grep -E '"@sentry|"sentry-'

Route from what you find:

• Competitor detected (appsignal, honeybadger, bugsnag, rollbar, airbrake) → load ${SKILL_ROOT}/references/migration.md first; delete the competitor initializer as part of migration
• Sentry already present → skip to Phase 2 to configure features
• Rails → use sentry-rails + config/initializers/sentry.rb
• Rack/Sinatra → sentry-ruby + Sentry::Rack::CaptureExceptions middleware
• Sidekiq → add sentry-sidekiq; recommend Metrics if existing metric patterns found
• Puma detected → queue time capture is automatic (v6.4.0+), but the reverse proxy must set X-Request-Start header; see ${SKILL_ROOT}/references/tracing.md → "Request Queue Time"
• OTel tracing detected (opentelemetry-sdk + instrumentations in Gemfile, or OpenTelemetry::SDK.configure in source) → use OTLP path: config.otlp.enabled = true; do not set traces_sample_rate; Sentry links errors to OTel traces automatically
• OTel logging detected (opentelemetry-logs-sdk in Gemfile, or OpenTelemetry::Logs in source) → skip enable_logs; OTel handles log export
• OTel tracing present but NOT logging (the common case) → use OTLP for tracing and Sentry native enable_logs: true for logging

---

Phase 2: Recommend

Lead with a concrete proposal — don't ask open-ended questions:

Feature	Recommend when...
Error Monitoring	Always
OTLP Integration	OTel tracing detected — replaces native Tracing
Tracing	Rails / Sinatra / Rack / any HTTP framework; skip if OTel tracing detected
Logging	Always — enable_logs: true costs nothing; skip only if OTel logging detected
Metrics	Sidekiq present; existing metric lib (StatsD, Prometheus) detected
Profiling	⚠️ Beta — performance profiling requested; requires stackprof or vernier gem
Crons	Scheduled jobs detected (ActiveJob, Sidekiq-Cron, Clockwork, Whenever)

OTel tracing + no OTel logging (the common case): "I see OpenTelemetry tracing in the project. I recommend Sentry's OTLP integration for tracing (via your existing OTel setup) + Error Monitoring + Sentry Logging [+ Metrics/Crons if applicable]. Shall I proceed?"

OTel tracing + OTel logging: "I see OpenTelemetry handling both tracing and logging. I recommend Sentry's OTLP integration + Error Monitoring [+ Metrics/Crons if applicable]. Shall I proceed?"

No OTel: "I recommend Error Monitoring + Tracing + Logging [+ Metrics if applicable]. Shall I proceed?"

---

Phase 3: Guide

Install

Rails:

# Gemfile
gem "sentry-ruby"
gem "sentry-rails"
gem "sentry-sidekiq"      # if using Sidekiq
gem "sentry-resque"       # if using Resque
gem "sentry-delayed_job"  # if using DelayedJob

Rack / Sinatra / plain Ruby:

gem "sentry-ruby"

Run bundle install.

Framework Integration

Framework / Runtime	Gem	Init location	Auto-instruments
Rails	sentry-rails	config/initializers/sentry.rb	Controllers, ActiveRecord, ActiveJob, ActionMailer
Rack / Sinatra	sentry-ruby	Top of config.ru	Requests (via Sentry::Rack::CaptureExceptions middleware)
Sidekiq	sentry-sidekiq	Sentry initializer or Sidekiq config	Worker execution → transactions
Resque	sentry-resque	Sentry initializer	Worker execution → transactions
DelayedJob	sentry-delayed_job	Sentry initializer	Job execution → transactions

Init — Rails (config/initializers/sentry.rb)

Sentry.init do |config|
  config.dsn = ENV["SENTRY_DSN"]
  config.spotlight = Rails.env.development?  # local Spotlight UI; no DSN needed in dev
  config.breadcrumbs_logger = [:active_support_logger, :http_logger]
  config.send_default_pii = true
  config.traces_sample_rate = 1.0  # lower to 0.05–0.2 in production
  config.enable_logs = true
  # Metrics on by default; disable with: config.enable_metrics = false
end

sentry-rails auto-instruments ActionController, ActiveRecord, ActiveJob, ActionMailer.

Init — Rack / Sinatra

require "sentry-ruby"

Sentry.init do |config|
  config.dsn = ENV["SENTRY_DSN"]
  config.spotlight = ENV["RACK_ENV"] == "development"
  config.breadcrumbs_logger = [:sentry_logger, :http_logger]
  config.send_default_pii = true
  config.traces_sample_rate = 1.0
  config.enable_logs = true
end

use Sentry::Rack::CaptureExceptions  # in config.ru, before app middleware

Init — Sidekiq standalone

require "sentry-ruby"
require "sentry-sidekiq"

Sentry.init do |config|
  config.dsn = ENV["SENTRY_DSN"]
  config.spotlight = ENV.fetch("RAILS_ENV", "development") == "development"
  config.breadcrumbs_logger = [:sentry_logger]
  config.traces_sample_rate = 1.0
  config.enable_logs = true
end

Environment variables

SENTRY_DSN=https://[e-mail]/ZZZ
SENTRY_ENVIRONMENT=production   # overrides RAILS_ENV / RACK_ENV
SENTRY_RELEASE=my-app@1.0.0

Feature reference files

Walk through features one at a time. Load the reference file for each, follow its steps, and verify before moving to the next:

Feature	Reference file	Load when...
Migration	${SKILL_ROOT}/references/migration.md	Competitor gem found — load before installing Sentry
Error Monitoring	${SKILL_ROOT}/references/error-monitoring.md	Always
Tracing	${SKILL_ROOT}/references/tracing.md	HTTP handlers / distributed tracing
Logging	${SKILL_ROOT}/references/logging.md	Structured log capture
Metrics	${SKILL_ROOT}/references/metrics.md	Sidekiq present; existing metric patterns
Profiling	${SKILL_ROOT}/references/profiling.md	Performance profiling requested (beta)
Crons	${SKILL_ROOT}/references/crons.md	Scheduled jobs detected or requested

For each feature: Read ${SKILL_ROOT}/references/<feature>.md, follow steps exactly, verify it works.

---

Configuration Reference

Key Sentry.init Options

Option	Type	Default	Purpose
dsn	String	nil	SDK disabled if empty; env: SENTRY_DSN
environment	String	nil	e.g., "production"; env: SENTRY_ENVIRONMENT
release	String	nil	e.g., "myapp@1.0.0"; env: SENTRY_RELEASE
spotlight	Boolean	false	Send events to Spotlight sidecar (local dev, no DSN needed)
send_default_pii	Boolean	false	Include IP addresses and request headers
sample_rate	Float	1.0	Error event sample rate (0.0–1.0)
traces_sample_rate	Float	nil	Transaction sample rate; nil disables tracing
profiles_sample_rate	Float	nil	Profiling rate relative to traces_sample_rate; requires stackprof or vernier
enable_logs	Boolean	false	Enable Sentry structured Logs
enable_metrics	Boolean	true	Enable custom metrics (on by default)
breadcrumbs_logger	Array	[]	Loggers for automatic breadcrumbs (see logging reference)
max_breadcrumbs	Integer	100	Max breadcrumbs per event
debug	Boolean	false	Verbose SDK output to stdout
capture_queue_time	Boolean	true	Record request queue time from X-Request-Start header (v6.4.0+)
otlp.enabled	Boolean	false	Route OTel spans to Sentry via OTLP; do not combine with traces_sample_rate
before_send	Lambda	nil	Mutate or drop error events before sending
before_send_transaction	Lambda	nil	Mutate or drop transaction events before sending
before_send_log	Lambda	nil	Mutate or drop log events before sending

Environment Variables

Variable	Maps to	Purpose
SENTRY_DSN	dsn	Data Source Name
SENTRY_RELEASE	release	App version (e.g., my-app@1.0.0)
SENTRY_ENVIRONMENT	environment	Deployment environment

Options set in Sentry.init override environment variables.

---

Verification

Local dev (no DSN needed) — Spotlight:

npx @spotlightjs/spotlight          # browser UI at http://localhost:8969
# or stream events to terminal:
npx @spotlightjs/spotlight tail traces --format json

config.spotlight = Rails.env.development? (already in the init block above) routes events to the local sidecar automatically.

With a real DSN:

Sentry.capture_message("Sentry Ruby SDK test")

Nothing appears? Set config.debug = true and check stdout. Verify DSN format: https://<key>@o<org>.ingest.sentry.io/<project>.

---

Phase 4: Cross-Link

cat package.json frontend/package.json web/package.json 2>/dev/null | grep -E '"@sentry|"sentry-'

Frontend detected	Suggest
React / Next.js	sentry-react-sdk
Svelte / SvelteKit	sentry-svelte-sdk
Vue	@sentry/vue — docs.sentry.io/platforms/javascript/guides/vue/

For trace stitching between Ruby backend and JS frontend, see references/tracing.md → "Frontend trace stitching".

---

Troubleshooting

Issue	Solution
Events not appearing	config.debug = true; verify DSN; ensure Sentry.init before first request
Rails exceptions missing	Must use sentry-rails — sentry-ruby alone doesn't hook Rails error handlers
No traces (native)	Set traces_sample_rate > 0; ensure sentry-rails or Sentry::Rack::CaptureExceptions
No traces (OTLP)	Verify opentelemetry-exporter-otlp gem is installed; do not set traces_sample_rate when using otlp.enabled = true
Sidekiq jobs not traced	Add sentry-sidekiq gem
Missing request context	Set config.send_default_pii = true
Logs not appearing	Set config.enable_logs = true; sentry-ruby ≥ 5.27.0 required
Metrics not appearing	Check enable_metrics is not false; verify DSN
Events lost on shutdown	Process.exit! skips at_exit hooks — call Sentry.flush explicitly before forced exits
Forking server loses events	Puma/Unicorn fork workers — re-initialize in on_worker_boot or after_fork; without this, the background worker thread dies in child processes
DSN rejected / events not delivered	Verify DSN format: https://<key>@o<org>.ingest.sentry.io/<project>; set config.debug = true to see transport errors