The Plutus Application Framework

Table of Contents

• Maintenance mode
  • Introduction
  • Development
    • How to develop and contribute to the project
  • Documentation
    • User documentation
    • Talks
    • Specifications and design
  • Branching, Versioning and Releases
    • Dependency update
    • Version ranges
  • Working with the project
    • How to submit an issue
    • How to develop and contribute to the project
    • How to depend on the project from another Haskell project
  • Licensing

Maintenance mode

As our team is focused on other projects and the monorepo approach of this repository made it hard to maintain, we have decided to stop upgrading the content of this directory and to pass it in maintenance mode.

Note that this decision doesn’t impact at all Plutus the core language of Cardano, nor Plutus-tx the Haskell dialect to write Plutus contract. Both are still actively developed.

Parts of this repository will probably been spinned-out into their own project, as we have done with the Cardano-node-emulator, which gives you access to an emulated node that follows the same validation rule as a real node, or Marconi, a library to define and run custom indexers.

What is maintenance mode? In maintenance mode, no new feature will be actively developed by the team and we won’t upgrade the existing dependencies. We’ll welcome PR and we will review them though and we will do minor bug fixes.

Introduction

The Plutus Application Framework, part of the Plutus Platform, is a framework for developing distributed applications using the Cardano blockchain. For more information about the projects, see the User documentation.

This repository contains:

• Plutus Platform

  • Libraries which implement the Plutus Application Framework, a framework for writing applications that work with Cardano.

  • A selection of end-to-end usecases written with the Plutus Application Framework

Important

The rest of this README is focussed on people who want to develop or contribute to the Framework. For people who want to use the Framework, please consult the User documentation.

Development

How to develop and contribute to the project

Run nix develop to enter the development shell and you will be presented with a list of available commands.

*Please see CONTRIBUTING for comprehensive documentation on how to contribute to the project, including development and submitting changes

Documentation

User documentation

The main documentation is located here.

The generated Haskell API documentation (haddocks) are here: https://input-output-hk.github.io/plutus-apps/main/.

Talks

• Functional Smart Contracts on Cardano

• The Plutus Platform

Specifications and design

• Plutus Technical Report (draft)

Branching, Versioning and Releases

There are two protected development branches in plutus-apps: main and next-node. We adopt the PVP versioning scheme. Check out Branching Policy and Release Process to learn more.

Dependency update

The dependency update policy is dependent on the protected branch.

For cardano-node, we define major-version-bound the range of versions which are compatible with a specific era. For example, for the Alonzo era, that would be >= 1.29 && < 1.35. For the Vasil era, that would be >= 1.35 && < 1.36.

Independently of the protected branch:

• It should always use the same first-major-version of plutus as the one used by the plutus dependency of cardano-node

• It should always be safe to upgrade to a new second-major-version of plutus: at worst this will lead to some code breakage.

• It should, unless specified otherwise, use the same version for transitive dependencies (cardano-ledger, ouroboros-network, etc.) with cardano-node

• It should pin the major version of cardano-node for all packages

• It should pin the first and second-major version of plutus for all packages

main branch:

• It should not update cardano-node to a new major-version. In other words, it should use a cardano-node version which is compatible with the current Cardano mainnet

• It should use a cardano-wallet version which is compatible with the current cardano-node version

next-node branch:

• It may update the cardano-node to a new major-version. In other words, it may use a cardano-node version which is incompatible with the current Cardano mainnet

• It may use a cardano-wallet version which is incompatible with the current cardano-node version

Version ranges

Packages which depend on plutus-apps packages should use version ranges to control which version of those packages they build against.

• Packages in plutus-apps which are used downstream should pin the major-version of each other (e.g. plutus-pab-1.0.1 should depend on plutus-contract ^>= 1.0).

• Downstream packages should pin at least the first-major-version of plutus-apps packages.

  • Upgrading to a new second-major-version should always be safe for working on the current mainnet, with at most code breakage (following the PVP). Users may of course want to pin this version as well to avoid such breakage.

• Downstream packages pulling in plutus-apps packages via source-repository-package stanzas should always take tagged commits.

Working with the project

How to submit an issue

Issues can be filed in the GitHub Issue tracker.

However, note that this is pre-release software, so we will not usually be providing support.

How to develop and contribute to the project

See CONTRIBUTING, which describes our processes in more detail including development environments; and ARCHITECTURE, which describes the structure of the repository.

How to depend on the project from another Haskell project

None of our libraries are on Hackage, unfortunately (many of our dependencies aren’t either). So for the time being, you need to:

1. Add plutus-apps as a source-repository-package to your cabal.project.

2. Copy the source-repository-package stanzas from our cabal.project to yours.

3. Copy additional stanzas from our cabal.project as you need, e.g. you may need some of the allow-newer stanzas.

The plutus-starter project (deprecated) provides an example.

Licensing

You are free to copy, modify, and distribute the Plutus Platform with under the terms of the Apache 2.0 license. See the LICENSE and NOTICE files for details.