---
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/](https://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/](https://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 |