Polysemy is a high-performance, zero-boilerplate effect system for Haskell, designed to simplify the handling of side effects in functional programs. Unlike traditional monad transformer stacks, Polysemy uses a modern approach based on freer monads and interpreters, allowing developers to define, compose, and interpret effects in a more modular and testable way. It aims to offer both flexibility and performance without sacrificing type safety or expressiveness.

Features

  • Defines effects as pure Haskell data types
  • Enables modular, composable effect handlers
  • Avoids monad transformer boilerplate
  • Supports runtime and compile-time interpreters
  • Promotes testability by mocking effects
  • Designed for high performance and clarity

Project Samples

Project Activity

See All Activity >

Categories

Libraries

License

BSD License

Follow Polysemy

Polysemy Web Site

Other Useful Business Software
Build Agents and Models on One Platform Icon
Build Agents and Models on One Platform

Everything you need to build production-ready agents and models. Access 200+ Google and third-party AI models and tools.

Gemini Enterprise Agent Platform is Google Cloud's comprehensive platform for developers to build, scale, govern, and optimize agents and models. Choose from Google's most advanced models and third-party models like Anthropic's Claude Model Family.
Try It Free
Rate This Project
Login To Rate This Project

User Reviews

Be the first to post a review of Polysemy!

Additional Project Details

Programming Language

Haskell

Related Categories

Haskell Libraries

Registered

2025-07-17