version: "1.0.1" name: sentry-elixir-sdk description: Full Sentry SDK setup for Elixir. Use when asked to "add Sentry to Elixir", "install sentry for Elixir", or configure error monitoring, tracing, logging, or crons for Elixir, Phoenix, or Plug applications. Supports Phoenix, Plug, LiveView, Oban, and Quantum. license: Apache-2.0 category: sdk-setup parent: sentry-sdk-setup disable-model-invocation: true

All Skills > SDK Setup > Elixir SDK

Sentry Elixir SDK

Opinionated wizard that scans your Elixir project and guides you through complete Sentry setup.

Invoke This Skill When

• User asks to "add Sentry to Elixir" or "set up Sentry" in an Elixir or Phoenix app
• User wants error monitoring, tracing, logging, or crons in Elixir or Phoenix
• User mentions sentry hex package, getsentry/sentry-elixir, or Elixir Sentry SDK
• User wants to monitor exceptions, Plug errors, LiveView errors, or scheduled jobs

Note: SDK versions and APIs below reflect Sentry docs at time of writing (sentry v13.2.0, requires Elixir ~> 1.13).

Always verify against docs.sentry.io/platforms/elixir/ before implementing.

Phase 1: Detect

Run these commands to understand the project before making any recommendations:

# Check existing Sentry dependency
grep -i sentry mix.exs 2>/dev/null
 
# Detect Elixir version
cat .tool-versions 2>/dev/null | grep elixir
grep "elixir:" mix.exs 2>/dev/null
 
# Detect Phoenix or Plug
grep -E '"phoenix"|"plug"' mix.exs 2>/dev/null
 
# Detect Phoenix LiveView
grep "phoenix_live_view" mix.exs 2>/dev/null
 
# Detect Oban (job queue / crons)
grep "oban" mix.exs 2>/dev/null
 
# Detect Quantum (cron scheduler)
grep "quantum" mix.exs 2>/dev/null
 
# Detect OpenTelemetry usage
grep "opentelemetry" mix.exs 2>/dev/null
 
# Check for companion frontend
ls assets/ frontend/ web/ client/ 2>/dev/null

What to note:

Phase 2: Recommend

Based on what you found, present a concrete recommendation. Don't ask open-ended questions — lead with a proposal:

Recommended (core coverage):

• ✅ Error Monitoring — always; captures exceptions and crash reports
• ✅ Logging — Sentry.LoggerHandler forwards crash reports and error logs to Sentry
• ✅ Tracing — if Phoenix, Plug, or Ecto detected (via OpenTelemetry)

Optional (enhanced observability):

• ⚡ Crons — detect silent failures in scheduled jobs (Oban, Quantum, or manual GenServer)
• ⚡ Sentry Logs — forward structured logs to Sentry Logs Protocol (sentry v12.0.0+)

Recommendation logic:

Propose: "I recommend setting up Error Monitoring + Logging [+ Tracing if Phoenix/Ecto detected]. Want me to also add Crons or Sentry Logs?"

Phase 3: Guide

Option 1: Igniter Installer (Recommended)

You need to run this yourself — the Igniter installer requires interactive terminal input that the agent can't handle. Copy-paste into your terminal:

```bash

mix igniter.install sentry

```

Available since sentry v11.0.0. It auto-configures config/config.exs, config/prod.exs, config/runtime.exs, and lib/my_app/application.ex.

Once it finishes, come back and skip to [Verification](#verification).

If the user skips the Igniter installer, proceed with Option 2 (Manual Setup) below.

Option 2: Manual Setup

Install

Add to mix.exs dependencies:

# mix.exs
defp deps do
  [
    {:sentry, "~> 13.0"},
    {:finch, "~> 0.21"}
    # Add jason if using Elixir < 1.18:
    # {:jason, "~> 1.4"},
  ]
end

mix deps.get

Configure

# config/config.exs
config :sentry,
  dsn: System.get_env("SENTRY_DSN"),
  environment_name: config_env(),
  enable_source_code_context: true,
  root_source_code_paths: [File.cwd!()],
  in_app_otp_apps: [:my_app]

For runtime configuration (recommended for DSN and release):

# config/runtime.exs
import Config
 
config :sentry,
  dsn: System.fetch_env!("SENTRY_DSN"),
  release: System.get_env("SENTRY_RELEASE", "my-app@#{Application.spec(:my_app, :vsn)}")

Quick Start — Recommended Init Config

This config enables the most features with sensible defaults:

# config/config.exs
config :sentry,
  dsn: System.get_env("SENTRY_DSN"),
  environment_name: config_env(),
  enable_source_code_context: true,
  root_source_code_paths: [File.cwd!()],
  in_app_otp_apps: [:my_app],
  # Logger handler config — captures crash reports
  logger: [
    {:handler, :sentry_handler, Sentry.LoggerHandler, %{
      config: %{
        metadata: [:request_id],
        capture_log_messages: true,
        level: :error
      }
    }}
  ]

Activate Logger Handler

Add Logger.add_handlers/1 in Application.start/2:

# lib/my_app/application.ex
def start(_type, _args) do
  Logger.add_handlers(:my_app)   # activates the :sentry_handler configured above
 
  children = [
    MyAppWeb.Endpoint
    # ... other children
  ]
 
  Supervisor.start_link(children, strategy: :one_for_one)
end

Phoenix Integration

`lib/my_app_web/endpoint.ex`

defmodule MyAppWeb.Endpoint do
  use Sentry.PlugCapture          # Add ABOVE use Phoenix.Endpoint (Cowboy adapter only)
  use Phoenix.Endpoint, otp_app: :my_app
 
  # ...
 
  plug Plug.Parsers,
    parsers: [:urlencoded, :multipart, :json],
    pass: ["*/*"],
    json_decoder: Phoenix.json_library()
 
  plug Sentry.PlugContext          # Add BELOW Plug.Parsers
  # ...
end

Note: Sentry.PlugCapture is only needed for the Cowboy adapter. Phoenix 1.7+ defaults to Bandit, where PlugCapture is harmless but unnecessary. Sentry.PlugContext is always recommended — it enriches events with HTTP request data.

LiveView errors — `lib/my_app_web.ex`

def live_view do
  quote do
    use Phoenix.LiveView
 
    on_mount Sentry.LiveViewHook   # captures errors in mount/handle_event/handle_info
  end
end

Plain Plug Application

defmodule MyApp.Router do
  use Plug.Router
  use Sentry.PlugCapture          # Cowboy only
 
  plug Plug.Parsers, parsers: [:urlencoded, :multipart]
  plug Sentry.PlugContext
  # ...
end

For Each Agreed Feature

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

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

Configuration Reference

Key Config Options

Default PII Guidance

Most Sentry SDKs expose a send-default-PII option. As of sentry v12, the Elixir SDK does not expose a send_default_pii config option in its documented option list or current config schema, so do not add a non-existent option. For richer user context, use Sentry.PlugContext and explicitly set allowed fields with Sentry.Context.set_user_context/1, then scrub with :before_send if needed. If a future Elixir SDK release adds send_default_pii, recommend setting it.

Automatic PII Scrubbing: As of v13.1.0, stacktrace frame variables and FunctionClauseError/Phoenix.ActionClauseError arguments are automatically scrubbed for sensitive data using the same scrubber rules as HTTP request data. Use :scrubber config to customize which Plug.Conn.private keys are retained.

Environment Variables

Verification

Test that Sentry is receiving events:

# Send a test event from your project
MIX_ENV=dev mix sentry.send_test_event

Or add a temporary call in a controller action:

# Temporary test — remove after confirming
def index(conn, _params) do
  Sentry.capture_message("Sentry Elixir SDK test event")
  text(conn, "sent")
end

Check the Sentry dashboard within a few seconds. If nothing appears:

1. Set config :sentry, log_level: :debug for verbose SDK output
2. Verify SENTRY_DSN is set and the project exists
3. Confirm :environment_name is not set to a value Sentry filters in your alert rules

Phase 4: Cross-Link

After completing Elixir setup, check for a companion frontend missing Sentry coverage:

ls assets/ frontend/ web/ client/ ui/ 2>/dev/null
cat assets/package.json frontend/package.json 2>/dev/null | grep -E '"react"|"svelte"|"vue"|"next"'

If a frontend directory exists without Sentry configured, suggest the matching skill:

Connecting Phoenix backend and JavaScript frontend with linked Sentry projects enables distributed tracing — stack traces that span the browser, Phoenix HTTP server, and downstream services in a single trace view.

Troubleshooting