Grew installation

Grew is implemented with the Ocaml language. It can be installed on Linux or Mac OS X (installation on Windows should be possible, but this is untested). A Python binding is also available, see here.

You have to install:

  1. opam which is the standard package manager for Ocaml
  2. ocaml which can be installed by opam
  3. grew an related libraries which are available as opam packages

If you just need to upgrade your installation, please consult the Upgrade section.

⚠️ If you run into trouble using the instructions of this page, feel free to open an issue on GitHub.

Step 1: Install opam

Grew requires opam version 2.0.0 or higher. In case of trouble installing opam, please consult opam installation page.


In most Linux recent distribution, version 2 can be installed from default packages.

apt-get install opam

The following commands installs a few other needed packages:

apt-get install wget m4 unzip librsvg2-bin curl bubblewrap

Mac OS X

Step 2: Setup opam


Check that ocaml is installed with ocamlc -v. This gives you the version of Ocaml installed. This should be 4.13 or higher.

Note: There are more recent version of Ocaml (5.0 and 5.1). These versions are experimental and they are not supported (some Grew web service don’t work with ocaml 5).

Run the following command to add the grew specific opam repository:

opam remote add grew ""

Step 3: Install the Grew software

opam install grew

To verify your installation:

NB: If you want to install the Python library, see here.

Grew upgrade

To upgrade to a new version of Grew, run the commands:

opam update
opam upgrade

The latest version is 1.13. You can check your version with

opam list | grep grew

you should obtain (the third line may not appear if you haven’t installed the Python library backend):

grew                          1.13.0      Grew system
grewlib                       1.13.1      The main library for the Grew system
grewpy_backend                0.5.1       The Ocaml backend for the `grewpy` Python lib