For more background information on the project, please read this overview.
- Using Flow
- Building Flow from source
- Join the Flow community
Flow works with:
- macOS (x86_64)
- Linux (x86_64 and arm64)
- Windows (x86_64, Windows 10 recommended)
There are binary distributions for each of these platforms and you can also build it from source on any of them as well.
Building Flow from source
Flow is written in OCaml (OCaml 4.10.2 is required).
Install system dependencies:
brew install opam
sudo apt-get install opam
Other Linux: see opam docs
Windows: cygwin and a number of dependencies like
One way to install everything is to install Chocolatey and then run
.\scripts\windows\install_opam.ps1. Otherwise, see the "Manual Installation" section of OCaml for Windows docs and install all of the packages listed in our
The remainder of these instructions should be run inside the Cygwin shell:
The following instructions expect
2.x.x. Should your package manager have installed a
1.x.xversion, please refer to the opam docs to install a newer version manually.
# on Mac and Linux: opam init # on Windows: scripts/windows/init_opam.sh
Install Flow's OCaml dependencies:
# from within this git checkout make deps
note: If you find that you get an error looking for
ocaml-base-compilerversion, your local dependency repo may be out of date and you need to run
eval $(opam env) make
This produces the
opam install -y js_of_ocaml.3.9.0 make js
Running the tests
To run the tests, first compile flow using
make. Then run
bash ./runtests.sh bin/flow
There is a
make test target that compiles and runs tests.
To run a subset of the tests you can pass a second argument to the
bash runtests.sh bin/flow class | grep -v 'SKIP'
Join the Flow community
- Website: https://flow.org
- Discord: https://discord.gg/8ezwRUK
- irc: #flowtype on Freenode
- Twitter: follow @flowtype and #flowtype to keep up with the latest Flow news.
- Stack Overflow: Ask a question with the flowtype tag