Interactive programs without callbacks or side-effects. Functional Reactive Programming (FRP) uses composable events and time-varying values to describe interactive systems as pure functions. Just like other pure functional code, functional reactive code is easier to get right on the first try, maintain, and reuse.
1,116
stars
891
commits
Haskell
primary language
Aug 29, 2026
updated
Interactive programs without callbacks or side-effects. Functional Reactive Programming (FRP) uses composable events and time-varying values to describe interactive systems as pure functions. Just like other pure functional code, functional reactive code is easier to get right on the first try, maintain, and reuse.
Reflex is a fully-deterministic, higher-order Functional Reactive Programming interface and an engine that efficiently implements that interface.
Visit https://reflex-frp.org for more information, tutorials, documentation and examples.
From the root of a Reflex Platform checkout, run ./scripts/hack-on haskell-overlays/reflex-packages/dep/reflex. This will check out the reflex source code into the haskell-overlays/reflex-packages/dep/reflex directory. You can then point that checkout at your fork, make changes, etc. Use the ./try-reflex or ./scripts/work-on scripts to start a shell in which you can test your changes.
(top 30 of 70)
Haskell
97.5%
C
1.3%
Nix
1.2%
Interactive programs without callbacks or side-effects. Functional Reactive Programming (FRP) uses composable events and time-varying values to describe interactive systems as pure functions. Just like other pure functional code, functional reactive code is easier to get right on the first try, maintain, and reuse.
1,116
stars
891
commits
Haskell
primary language
Aug 29, 2026
updated
Interactive programs without callbacks or side-effects. Functional Reactive Programming (FRP) uses composable events and time-varying values to describe interactive systems as pure functions. Just like other pure functional code, functional reactive code is easier to get right on the first try, maintain, and reuse.
Reflex is a fully-deterministic, higher-order Functional Reactive Programming interface and an engine that efficiently implements that interface.
Visit https://reflex-frp.org for more information, tutorials, documentation and examples.
From the root of a Reflex Platform checkout, run ./scripts/hack-on haskell-overlays/reflex-packages/dep/reflex. This will check out the reflex source code into the haskell-overlays/reflex-packages/dep/reflex directory. You can then point that checkout at your fork, make changes, etc. Use the ./try-reflex or ./scripts/work-on scripts to start a shell in which you can test your changes.
(top 30 of 70)
Haskell
97.5%
C
1.3%
Nix
1.2%