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Scowl Language

Scowl is a declarative feature-engineering language for automatic decisioning and real-time ML. It's available exclusively on the Sumatra decisioning platform.

Simple, declarative syntax. Powerful, stateful features.

emails_per_ip := CountUnique(email by ip last 2 hours)
login_device := Latest<login>(device_hash by acct_id)


Check out the tutorial for help getting started with Scowl.

Why Scowl?

  • Approachable - Designed for analysts and data scientists, not just engineers
  • Explainable - Easy to interpret data and logic behind every decision
  • Safe & Agile - Validate logic on historical data then deploy straight to production
  • Fast - Built on Go to be blazingly fast


Scowl's design was highly influenced by SQRL, created by Josh Yudaken, Pete Hunt, Julian Tempelsman, Paul Mou, Yunjing Xu, and David Newman. We are grateful to TwitterOSS and the project creators for releasing it publicly.

Special thanks to Josh and Pete for making themselves available for conversation to improve this project.