Rbspy

rbspy Plugin

Sampling CPU profiler for Ruby. Attaches to running Ruby processes (MRI, JRuby, TruffleRuby) and records stack samples with minimal overhead — ideal for production flamegraphs and call-graph analysis.

Installation

curl -L https://raw.githubusercontent.com/rbspy/rbspy/main/install.sh | sh
# or
cargo install rbspy

Basic Usage

# Profile a Ruby script by PID
rbspy record --pid 12345 --duration 30

# Profile a command directly
rbspy record -- ruby my_app.rb

# Live top-like view of hot methods
rbspy top --pid 12345

# Generate a flamegraph SVG
rbspy record --format flamegraph --output profile.svg -- ruby server.rb

Common Patterns

# Sample for 60 seconds, write raw data
rbspy record --duration 60 --file profile.gz --pid $(pgrep -f puma)

# Subprocess profiling with rate control
rbspy record --rate 100 -- bundle exec rails server

# Show version and supported Ruby versions
rbspy --version

Usage Examples

• "Profile my Rails server and find slow methods"
• "Generate a flamegraph for this Ruby worker"
• "See which methods use the most CPU in PID 9999"

SuperCLI

sc rbspy _ _ record --pid 12345 --duration 30
sc rbspy _ _ top --pid 12345
sc plugins learn rbspy