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

bash

# 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:

ruby

# 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:

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

)

ruby

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

ruby

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

ruby

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

bash

SENTRY_DSN=https://xxx@oYYY.ingest.sentry.io/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:

bash

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:

ruby

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

bash

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

sentry-ruby-sdk

NPX Install

SKILL.md Content

Sentry Ruby SDK

Invoke This Skill When

Phase 1: Detect

Phase 2: Recommend

Phase 3: Guide

Install

Framework Integration

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

Init — Rack / Sinatra

Init — Sidekiq standalone

Environment variables

Feature reference files

Configuration Reference

Key
`Sentry.init`
Options

Environment Variables

Verification

Phase 4: Cross-Link

Troubleshooting

sentry-ruby-sdk

NPX Install

SKILL.md Content

Sentry Ruby SDK

Invoke This Skill When

Phase 1: Detect

Phase 2: Recommend

Phase 3: Guide

Install

Framework Integration

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

Init — Rack / Sinatra

Init — Sidekiq standalone

Environment variables

Feature reference files

Configuration Reference

Key Sentry.init Options

Environment Variables

Verification

Phase 4: Cross-Link

Troubleshooting

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

Key
`Sentry.init`
Options