Marlowe is a platform for financial products as smart contracts. Marlowe Playground is a development tool that helps build and simulate Marlowe Contracts.
Related projects:
-
Marlowe: Marlowe language specification
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Marlowe Cardano: Implementation of the Marlowe Language for the Cardano Blockchain. Also haskell lib.
-
PureScript Marlowe: PureScript implementation of the Marlowe language for the Cardano Blockchain.
Important
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The rest of this README is focussed on people who want to develop or contribute to Marlowe. |
Important
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DO NOT IGNORE THIS If you want to use Nix with this project, make sure to set up the IOHK binary cache. If you do not do this, you will end up building GHC, which takes several hours. If you find yourself building GHC, STOP and fix the cache. |
Issues can be filed in the GitHub Issue tracker.
See CONTRIBUTING, which describes our processes in more detail including development environments.
This section contains information about how to build the project’s artifacts for independent usage. For development work see How to develop and contribute to the project for more information.
The Haskell libraries in the Marlowe project are built with cabal
and Nix.
The other artifacts (docs etc.) are also most easily built with Nix.
Install Nix (recommended). following the instructions on the Nix website.
Make sure you have read and understood the cache warning. DO NOT IGNORE THIS.
See Nix for further advice on using Nix.
You can build some of the Haskell packages without Nix, but this is not recommended and we don’t guarantee that these prerequisites are sufficient.
If you use Nix, these tools are provided for you via shell.nix
, and you do not need to install them yourself.
Run nix develop
to enter the shell.
From there, you can type info
to get a list of available commands.
The Haskell packages can be built directly with cabal
.
We do this during development (see How to develop and contribute to the project).
The best way is to do this is inside a nix-shell
.
Note
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For fresh development setups, you also need to run |
Run cabal build all
from the root to build all artifacts.
The Marlowe Playground is automatically deployed upon certain pushes to GitHub
-
Marlowe Playground staging and Marlowe Run staging are deployed from every commit pushed to
main
(these URLs subject to change)
For more details, including instructions for setting up ad hoc testing deployments, see the plutus-ops repo.
Adding the IOHK binary cache to your Nix configuration will speed up builds a lot, since many things will have been built already by our CI.
If you find you are building packages that are not defined in this repository, or if the build seems to take a very long time then you may not have this set up properly.
To set up the cache:
-
On non-NixOS, edit
/etc/nix/nix.conf
and add the following lines:experimental-features = nix-command flakes substituters = "https://cache.nixos.org" "https://cache.iog.io "https://marlowe-playground.cachix.org" trusted-public-keys = "hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ= marlowe-playground.cachix.org-1:8TmdbVgcB4QzTmuzLxNdaCxdc8ZVI9S8eeeXsY9stxo="
NoteIf you don’t have an
/etc/nix/nix.conf
or don’t want to edit it, you may add thenix.conf
lines to~/.config/nix/nix.conf
instead. You must be a trusted user to do this. -
On NixOS, set the following NixOS options:
nix.settings = { experimental-features = [ "nix-command" "flakes" ]; substituters = [ "https://cache.nixos.org" "https://cache.iog.io" ]; trusted-public-keys = [ "hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ=" ]; };
Nix on macOS can be a bit tricky. In particular, sandboxing is disabled by default, which can lead to strange failures.
These days it should be safe to turn on sandboxing on macOS with a few exceptions. Consider setting the following Nix settings, in the same way as in previous section:
sandbox = true extra-sandbox-paths = /System/Library/Frameworks /System/Library/PrivateFrameworks /usr/lib /private/tmp /private/var/tmp /usr/bin/env
Changes to /etc/nix/nix.conf
may require a restart of the nix daemon in order to take affect. Restart the nix daemon by running the following commands:
sudo launchctl stop org.nixos.nix-daemon sudo launchctl start org.nixos.nix-daemon